## Non-Chromate Aluminum Pretreatments



FINAL REPORT

Project WP-200025

MARCH 2012

June 2008

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28

- 03

- 2012 2. REP ORT TYPE

FINAL 3. DATES COVERED (From

- To) April 2000

– March 2012

4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER

Non

- Chromate Aluminum Pretreatments 5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S) 5d. PROJECT NUMBER

WP

- 200025
William Nickerson* and Craig Matzdorf 5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

AND ADDRESS(ES) 8. PERFORMING ORGANIZATION
REPORT
NUMBER Naval Aviation Systems Command (NAVAIR)
48066 Shaw Road, Building 2188
Patuxent River, MD 20670

9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) ESTCP Environmental Security Technology Certification Program

4800 Mark Center Drive, Suite 17D08 11. SPONSOR/MONITOR’S REPORT
Alexandria, VA 22350 NUMBER(S)

12. DISTRIBUTION / AVAILABILITY STATEMENT

Distribution Statement A

– Approved for public release; distribution is unlimited

13. SUPPLEMENTARY NOTES
*Cu rrent Address: Office of Naval Research, Code 35, 875 N. Randolph St., Room 1143B
Arlington, VA 22203

14. ABSTRACT Aluminum finishing in Department of Defense applications utilizes chromate chemistries for
anodizing, anodic sealing, and pretreatment (both for conversion coating aluminum substrates
and for treating aluminum

- based coatings deposited on steel). The most ubiquitous use of
chromate coatings is in the conversion coating of aluminum alloys for use as

- deposited or
prior to organic coating ap plication. These coatings are very thin, inexpensive to produced,
and can be applied by immersion, spray and wipe techniques. However, chromate conversion
coatings contain hexavalent chromium, a known carcinogen. National and international
regulations a re restricting the use of this material. This report presents the results of
laboratory and field tests to demonstrate and validate several non

- chromate aluminum

pretreatments. All of the alternatives were aqueous solutions designed to deposit a

conversi on coating on aluminum alloy substrates to enhance paint adhesion and painted
corrosion performance. Some of these alternatives are currently being implemented on several

weapons systems. 15. SUBJECT TERMS Chromate, hexavalent chromium, pretreatment, alu minum alloys

16. SECURITY CLASSIFICATION OF: 17. LIMITATION
OF ABSTRACT 18. NUMBER

OF PAGES 19a. NAME OF RESPONSIBLE PERSON

William Nickerson

a. REPORT

U b. ABSTRACT

U c. THIS PAGE

U SAR 275 19b. TELEPHONE NUMBER (include area code ) 703

- 501

- 6226

Standard Form 298 (Rev. 8

- 98)
Prescribed by ANSI Std. Z39.18ii THIS PAGE LEFT BLANK INTENTIONALLYiii 

## TABLE OF CONTENTS

DISCLAIMER

................................ ................................ ................................ ................................ v ACRONYMS AND ABBREVIATIONS

................................ ................................ ...................... vi

ACKNOWLEDGEMENTS

................................ ................................ ................................ ........... ix

SUMMARY

................................ ................................ ................................ ................................ .... x 1.0

– INTRODUCTION

................................ ................................ ................................ ................. 1
1.1

– PROJECT BACKGROUND

................................ ................................ ............................. 1
1.2

– OBJECTIVE AND SCOPE OF WORK

................................ ................................ ............ 1
2.0

– SELECTED DEMOSTRATION / VALIDATION

................................ ............................... 3
2.1

– PHASE II EFFORTS SUM MARY

................................ ................................ ................... 3
3.0

– ONGOING MAR INE ATMOSPHERE EXPOSURE TESTING

................................ ......... 5
3.1

– BACKGROUND

................................ ................................ ................................ ............... 5
3.2

– RESULTS

................................ ................................ ................................ .......................... 5
4.0

– LEVERAGED EFFORTS

................................ ................................ ................................ ..... 7
4.1

– AF F

- 16/C

- 130

................................ ................................ ................................ ................... 7
4.1.1

– BACKGROUND

................................ ................................ ................................ ........ 7
4.1.2

– STATUS

................................ ................................ ................................ ..................... 7
4.2

– NAVAIR S

- 3

................................ ................................ ................................ ..................... 8
4.2.1

– BACKGROUND

................................ ................................ ................................ ........ 8
4.2.2

– STATUS

................................ ................................ ................................ ..................... 8
4.3

– NAVAIR F/A

- 18 C/D

................................ ................................ ................................ ........ 8
4.3.1

– BACKGROUND

................................ ................................ ................................ ........ 8
4.3.4

– STATUS

................................ ................................ ................................ ..................... 8
4.4

– NAVAIR CH

- 46

................................ ................................ ................................ ................ 9
4.4.1

– BACKGROUND

................................ ................................ ................................ ........ 9
4. 4.2

– STATUS

................................ ................................ ................................ ..................... 9
4.5

– NASA SOLID ROCKET BO OSTERS

................................ ................................ ............. 9
4.5.1

– BACKGROUND

................................ ................................ ................................ ........ 9
4.5.2

– STATUS

................................ ................................ ................................ ................... 10
4.6

– BOEING/AIR FORCE/NAV Y

................................ ................................ ........................ 10
4.6.1

– BACKGROUND

................................ ................................ ................................ ...... 10
4.6.2

– STATUS

................................ ................................ ................................ ................... 10
5.0

– ESTCP NCAP EFFORTS

................................ ................................ ................................ .... 11
5.1

– US NAVY LANDING CRAF T, AIR CUSHIONED

................................ ...................... 11
5.1.1

– BACKGROUND

................................ ................................ ................................ ...... 11
5.1.2

– STATUS

................................ ................................ ................................ ................... 11
5.2

– USMC EXPEDITIONARY F IGHTING VEHICLE

................................ ....................... 12
5.2.1

– BACKGROUND

................................ ................................ ................................ ...... 12
5.2.2

– CURRENT PROCESS

– LRIP

................................ ................................ ................. 12
5.2.3

– STATUS

................................ ................................ ................................ ................... 13
5.3

– US ARMY BRADLEY FIGH TING VEHICLE

................................ ............................... 13iv 5.3.1 – INTRODUCTION .................................................................................................... 13
Direct

- to

- Metal ......................................................................................................................... 14 Chemical Processing ................................................................................................................. 14

5.3.2 – STATUS ................................................................................................................... 14
5.4 – US ARMY AVIATION ................................................................................................... 14
5.4.1 – BACKGROUND ...................................................................................................... 14 5.4.2 – GENERAL GUIDELINES – AIRCRAFT CLEANING, SURFACE TREATMENT
AND COA TING ................................................................................................................... 15
5.4.3 – STATUS ................................................................................................................... 16
6.0 – IMPLEMENTATION OF ALTERNATIVES IN DoD AND NASA ................................. 19
6.1 – MILITARY AND INDUSTRIAL PRETREATMENT SPE CIFICATIONS .................. 19
6.2 – ALODINE TM 5700 ........................................................................................................... 19
6.2.1 – NASA ........................................................................................................................ 19 6.2.2 – US Army TACOM .................................................................................................... 19
6.3 – PREKOTE TM

................................ ................................ .................................................... 20
6.3.1 – USAF ........................................................................................................................ 20
6.4 – TCP .................................................................................................................................. 20
6.4.1 – NAVSEA .................................................................................................................. 20
6.4.2 – USMC ....................................................................................................................... 20
6.4.3 – NAVAIR ................................................................................................................... 21
6.4.4 – AMCOM ................................................................................................................... 21
6.5 – AC -130/131...................................................................................................................... 21

6.5.1 – BOEING/AF ............................................................................................................. 21
7.0 – CONCLUSIONS AND RECOMMENDATIONS .............................................................. 23
REFERENCES ............................................................................................................................. 24
APPENDIX A
APPENDIX B

APP ENDIX Cv 

### DISCLAIMER

Due to the critical nature of DoD weapons systems coating performance and because of NAVAIR’s interest and involvement in the trivalent chromium process (TCP) the reports and results from this project were reviewed for technical content , accuracy, and fairness by the following: the Air Force Corrosion Prevention and Control Office (AFCPCO), the Army Research Laboratory (ARL) Coatings and Corrosion Branch, the Naval Air Systems Command (NAVAIR) Materials Division, the Naval Sea Systems Co mmand (NAVSEA) Materials Division, the Office of the Program Manager Combat Systems (PMCS), the Office of the Direct Reporting Program Manager Advanced Amphibious Assault (DRPM AAA), the US Army Aviation and Missile Command (AMCOM) Environmental, Engineeri ng, and Logistics Office (EELO), United Defense, General Dynamics Amphibious Systems, and Boeing Commercial Airplanes.vi 

### ACRONYMS AND ABBREVIATIONS

AA

– Aluminum Alloy

AAA

– Advanced Amphibious Assault

AACP

– Advanced Aircraf t Corrosion Protection

AAV

– Amphibious Assault Vehicle

ACU

– Assault Craft Unit

AETC

– Air Education and Training Command

AFB

– Air Force Base

AFRL

– Air Force Research Laboratory

AFCPCO

– Air Force Corrosion Prevention and Control Office

AMCOM

– A viation and Missile Command

APG

– Aberdeen Proving Grounds

ARL

– Army Research Laboratory

ASTM

– American Society for Testing and Materials

AVCRAD

– Aviation Classification Repair Activity Depot

AVTB

– Amphibious Vehicle Test Branch

BASC

– Boeing Air craft Support Center

BFIST

– Bradley Fire Support Team

BFV

– Bradley Fighting Vehicle

BUNO

– Bureau Number

CARC

– Chemical Agent Resistant Coating

CCAD

– Corpus Christi Army Depot

CCC

– Chromate Conversion Coating

COMNAVSEASYSCOM

– NAVSEA Commander

CONSTRKFIGHTWINGLANT

– Commander Atlantic Strike Fighter Wing

CPC

– Corrosion Preventative Compounds

CTC

– Coatings Technology Center

CY

– Calendar Year

DEM/VAL

– Demonstration/Validation

DFT

– Dry Film Thickness

DI

– Deionized

DoD

– Department of Defense

DRPM

– Direct Reporting Program Manager

DTM

– Direct to Metal

DUSD

- ES

– Deputy Undersecretary of Defense for Environmental Security

E1

– First Experimental Vehicle

– USMC EFV

EELO

– Environmental, Engineering, & Logistics Oversight

EFV

– Expe ditionary Fighting Vehicle

EMI

– Electromagnetic Interferencevii EMT

– Environmental Management Team

EPA

– Environmental Protection Agency

ESOH

– Environmental, Safety and Occupational Health

ESTCP

– Environmental Security Technology Certification Progra m
FSE

– Floor Support Engineering

GDAMS

– General Dynamics Amphibious Systems

GDLS

– General Dynamics Land Systems

HazMat

– Hazardous Material

HSTNA

– Henkel Surface Technologies North America

HSU

– Hydraulic Suspension Unit

IARC

– International Age ncy for Research on Cancer

ICT

– Inorganic Coatings Team

IETM

– Integrated Electronic Technical Manual

JG

- PP

– Joint Group on Pollution Prevention

JLC

– Joint Logistics Commander

JTP

– Joint Test Protocol

KM

– kilometers

KSC

– Kennedy Space Center

ksi

– kilopounds per Square Inch

LATP

– Lima Army Tank Plant

LCAC

– Landing Craft Air Cushion

LEX

– Leading Edge Extension

LRIP

– Low Rate Initial Production

MCB

– Marine Corps Base

MCAS

– Marine Corps Air Station

MEK

– Methyl Ethyl Ketone

MIL

- C

– Military Control Specification

MIL

- DTL

– Military Detail Specification

MIL

- H

– Military Hydraulic Fluid Specification

MIL

- P

– Military Paint Specification

MIL

- PRF

– Military Performance Specification

MIL

- SPEC

– Military Specification

MSDS

– Material Safety Data Sheet

NADEP

– Naval Aviation Depot

NAS

– Naval Air Station

NASA

– National Aeronautics and Space Administration

NAVAIR

– Naval Air Systems Command

NAVMSG

– Navy Messageviii NAVSEA

– Naval Sea Systems Command

NAWCAD

– Naval Air Warfare Center Aircraft Division

NCAP

– Non

- Chromated Aluminum Pretreatment

NORIS

– North Island Naval Depot

NSF

– Neutral Salt Fog

NSWC

– Naval Surface Warfare Center

OEM

– Original Equipment Manufacturer

OOALC

– Ogden Air Logistics Center

OSHA

– Occupational Sa fety and Health Administration

P1

– First Prototype Vehicle

– USMC EFV

PAX

– Patuxent River Naval Air Station

PEO

– Program Executive Office

PEL

– Permissible Exposure Limit

PM

– Program Manager

PMA

– Program Management Activity

PMB

– Plastic Media Blasting

PM CS

– Program Manager Army Ground Combat Systems

PMI

– Planned Maintenance Interval

POC

– Point of Contact psi

– pounds per square inch
QA

– Quality Analysis QC

– Quality Control QOT&E

– Qualification Operational Test and Evaluation
QPL

– Qualified Products List

RRAD

– Red River Army Depot

RH

– Relative Humidity

SAE

- AMS

– Society of Automotive Engineers

- Aerospace Material Specification

SCC

– Stress Corrosion Cracking

SDLM

– Standard Depot Level Maintenance

SDD

– System Design and Development

SPO

– Systems Program Office

SPT

– Self Priming Topcoat

SRB

– Solid Rocket Booster

TCP

– Trivalent Chromium Pretreatment

TO

– Technical Order

UDLP

– United Defense

USMC

– United States Marine Corps

WESTPAC

– Western Pacific

YPG

– Yuma Proving Groundsix 

### ACKNOWLEDGEMENTS

This project has been executed under the generous support of the Environmental Security Technology Certification Program (ESTCP) and the Office of the Deputy Undersecretary of Defense for Environmental Security (DUSD

- ES). The effort was led by the Naval Aviation Systems Command (NAVAIR) Materials Division Patuxent River and coordinated with Joint Group on Pollution Prevention (JG

- PP). This project was initiated by Craig Matzdorf, Code 4.3.4, NAVAIR Materials Engineering Division, Patuxent River, MD. The principal investigator for this project is Bill Nickerson, Code 4.3.4, NAVAIR Materials Engineering Division, Patuxent River, MD. Leveraged efforts were supported by their respective services.

The authors of the report wi sh to acknowledge the leadership and support of the many managers, engineers, and Fleet support personnel who contributed to this effort. Additionally, this project could not have been completed without the support and numerous contributions from

contract or engineers and managers.

A special thanks to NAVAIR Patuxent River, Army Research Laboratory (ARL), National Aeronautics and Space Administration (NASA) and contractor personnel at Kennedy Space Center (KSC), the Air Force Corrosion Prevention and Contr ol Office (AFCPCO), General Dynamics, Boeing, Lockheed Martin, United Defense, and US Army Tank Command (TACOM).

Assault Craft Unit Four (ACU

- 4), Naval Amphibious Base, Little Creek, Virginia for their support in the evaluation of test patches on Landing C raft, Air Cushioned (LCACs); S

- 3B,
F/A

- 18, and H

- 46 support personnel for their help in material flight

- tests; principal investigators from the Navy, Army, Air Force, and Marine Corp for providing project summaries and testing
results.

Special thanks to the USMC Direct Reporting Program Manager Advanced Amphibious Assault (DRPM AAA) program office for the Expeditionary Fighting Vehicle (EFV), General Dynamics Amphibious Systems engineering, and General Dynamics Land Systems Lima Army Tank Plant (LATP) for their partnership in the processing and field testing of the USMC EFV’s.

PM Ground Combat Systems (PM CS), PM CS Environmental Management Team (EMT), and United Defense CTC and United Defense York personnel for their generous assistance in the US Army B radley Fighting Vehicle (BFV) demonstration.

PEO Army Aviation, and US Army Aviation and Missile Command (AMCOM), and ARL for continued support of the ongoing rotary wing demonstration.x 

### SUMMARY

Current light metal finishing procedures for industri al, automotive, aerospace, and Department of Defense (DoD) applications center around the use of hexavalent

- chromium based chemistries for the enhancing corrosion resistance and paint adhesion. Aluminum finishing, in particular, utilizes chromate chemistri es for anodizing, anodic sealing, and pretreatment (both for conversion coating aluminum substrates and for treating aluminum

- based coatings deposited on steel). The most ubiquitous use of chromate coatings is in the conversion coating of aluminum alloys f or use as

- deposited or prior to organic coating application. These coatings are very thin, inexpensive to produce, extremely process flexible, and can be applied by immersion, spray and wipe techniques.

Chromate conversion coatings offer many advantages; however, the downside is that they contain hexavalent chromium, or chromate, species that are known to be carcinogenic. The occupational safety and health issues arising from risk of worker exposure to these chemicals, as well as the costs and the potenti al liabilities resulting from an accidental leak to the environment and waste disposal issues from normal finishing operations are making the use of chromate

based conversion coatings unattractive to the metal finishing industry.

Additionally, new Occupat ional Safety and Health Administration Permissible Exposure Limit (OSHA PEL) changes for hexavalent chromium have made the regulatory cost of using chromate very expensive. The final ruling, delivered in 2006, dropped the PEL from 100 μg/m 3 (for hexavalent chromium in the form of chromic acid) to 5 μg/m 3 with an action level of half that. An aerospace special rule was also delivered at this time, reducing the PEL to 25 1 μg/m 3 (however, this does not cover all of DoD operations, only the aircraft). As well as US OSHA regulations, new and stricter rules within the international community, especially the EU Restriction of Hazardous Substances (RoSH), End of Vehicle Life (ELV), and WEEE initiatives have placed additional hardship on the continued use of chromated chemistries.1 

### 1.0

– INTRODUCTION

1.1

– PROJECT BACKGROUND

The Environmental Security Technology Certification Program (ESTCP), established in December 1993, is managed by the Office of the Deputy Undersecret ary of Defense for Environmental Security (DUSD

- ES). The ESTCP demonstrates and validates laboratory

- proven technologies that target the DoD’s most urgent environmental needs. These technologies provide a return on investment through reduced environmental , safety, and occupational health (ESOH) risks; cost savings; and improved efficiency. The new technologies typically have broad application to both the DoD community and industry.

ESTCP selected the Non

- Chromate Aluminum Pretreatment (NCAP) project, led by the Naval Air Systems Command (NAVAIR) and coordinated with JG

- PP, to assist in the mitigation of the significant ESOH risks that are associated with the use of chromate conversion coatings. Chromate conversion coatings contain hexavalent chromium, a k nown human carcinogen that is strictly regulated. The project’s stated objective was to achieve the goal of reducing or eliminating the use of hexavalent chromium in aluminum finishing by demonstrating and validating the performance of alternatives in acc ordance with the technical requirements and tests identified in the Joint Test Protocol (JTP).

The key benefit of the non

- chromated pretreatment alternatives reported on here is the elimination or absence of hexavalent chromium from the process chemical s and as

- deposited coating. Eliminating chromates from the conversion coating or pretreatment operations will drastically reduce user liability and risk in the life cycle of the platform or parts being coated. The key challenge for the alternatives was, and remains today, to match the technical performance of chromate conversion coatings in a cost

- effective manner.

1.2

– OBJECTIVE AND SCOPE OF WORK

The Phase I Report, dated July 2003, presents an evaluation of laboratory coupon testing
of non

- chromate alu minum pretreatment alternatives through accelerated tests on flat coupons. Phase I of this effort focused on the laboratory evaluation of several possible non

- chromate alternative technologies. The results of the analysis were used to support field testin g in Phase II on components and in

- service platforms where technical performance is highly dependant on service environment and overall platform design and use. The NCAP Phase I Report from 2003 details the adhesion and accelerated corrosion performance o f these alternatives. Phase I examined the behavior of several alloy, coating, and paint system combinations. The data was generated in accordance with the NCAP JTP, dated 13 December 2000, to determine the potential effectiveness of the alternatives as re placements for chromate conversion coatings.2 In the Phase I Report, Matzdorf, et al., reported that, “Each alternative tested shows acceptable performance in some selected cases that may be satisfactory for a given user, depending on operating environment and business cases involved. The only compositions that come close to matching the technical, process, cost, and flexibility of chromates are based on trivalent chromium. Although trivalent chromium is present in the solution and coating, toxicity
studie s, International Agency for Research on Cancer (IARC) regulations, and OSHA PELs suggest that the use of Trivalent Chromium Product (TCP) is acceptable, especially given its
well

- rounded performance. The next best product in testing was Alodine TM 5200/570 0.
Alodine TM 5200/5700 contains no chromium, is process flexible and can be applied like chromate conversion coatings. The remaining alternatives performed variably in the evaluation.”

Out of the Phase I Laboratory testing, the potential alternative tech nologies were down

selected for field demonstration and validation testing by the respective services and program offices based upon their unique performance and operational environment requirements. The main advantage of any alternative is the eliminatio n of hexavalent chromium. In most cases, the alternatives are trying to match the process and technical performance of the chromate solutions and coatings.

The Phase II Interim Report, details the field testing efforts at that time to validate the
feasi bility of applying and maintaining, i.e. utilizing and repairing, these conversion coatings in
lieu of conventional chromate

- based technologies. Testing was conducted with various organic coatings systems, according to the particular service and platform requirements. This variety in field testing helps assure that potential candidates to hexavalent chromium are applicable as alternatives in their own right, without the necessity of specifying the use of only one or two possible primers/paint systems. Th e field test phase of this project was constructed to cover the broadest range of aluminum alloys, processing methods and conditions, and the operational environments experienced by fielded platforms across DoD.

This Final Report provides a detailed description of the laboratory and field testing conducted during the project as well as a summary of the transition and implementation status of the
alternatives as of the date of proj ect completion . Appendix A presents the results of the 8-year

. beach exposure corrosion testing, Appendix B presents the Phase II Interim Report in its entirety, and Appendix C presents the P hase I Laboratory Report in its entirety.3 

### 2.0

– SELECTED DEMOSTRATION / VALIDATION

Pretreatment DoD Service Platform(s) Facilities

Alodine 5700

TCP

- Color US Army Ground
Combat Bradley Fighting
Vehicle Red River Army Depot

United D efense

- York

Alodine 5700

TCP US Army Aviation CH

- 47, H

- 60 Corpus Christi

Ct AVCRAD

Alodine 5700

TCP USMC Amphibious
Assault Expeditionary Fighting Vehicle General Dynamics

– Lima

AVTB

– Camp
Pendleton

PreKote US Air Force F

- 16, C

- 130 Hill AFB

TCP NAV AIR CH

- 46, S

- 3, F

- 18 NADEP’s CP, NI

TCP NAVSEA Landing Craft, Air
Cushioned NSWC

– Little Creek,
VA

Table 2.0

– Selected Pretreatments for Dem/Val efforts

2.1

– PHASE II EFFORTS SUM MARY

Field testing of the TCP was underway with NAVAIR when the ESTCP pro ject began and the two efforts were leveraged together. In addition, Navy Sea Systems Command (NAVSEA) had begun an independent evaluation of the TCP for the Landing Craft, Air Cushioned (LCAC). As a result, the Navy supported its aircraft and LCAC demonst rations, and the Air Force (AF) took the lead on the PreKote TM demonstration with the F

- 16 and C

- 130 platforms. As a result of these initial, leveraged efforts, field testing opportunities outside the Navy were selected for the NCAP project to more broadl y cover the potential applications and operational environments. ESTCP funded the Phase II efforts for the USMC Expeditionary Fighting Vehicle (EFV), the US Army Bradley Fighting Vehicle (BFV), and the US Army Aviation and Missile Command (AMCOM) platforms . NAVAIR, Boeing, and NASA have been demonstrating the AC

- 131 TM for pre

- paint and bonding applications. The EFV demonstration/validation effort was conducted with General Dynamics Amphibious Systems (GDAMS), General Dynamics Land Systems (GDLS), and the D irect Reporting Program Manager (DRPM AAA) personnel. The BFV demonstration/validation was conducted with BAE Ground Systems (BAE) and the office of the Program Manager Combat Systems (PMCS), using

TCP

- C, a modified TCP chemistry that imparts a dark purple

- blue to brown color to the as

deposited conversion coating. The selection of TCP

- C over the baseline TCP was made at the request of BAE and PMCS engineering because of the desire for visual quality control assurance from a practical color change. Based on panel testing data generated at ARL, Aberdeen Proving Ground (APG), MD; the Red River Army Depot (RRAD) installed and currently maintains an4 Alodine TM 5700 immersion bath for conversion coating of aluminum road wheels for US Army ground combat vehicle p latforms. RRAD obtained an approval letter for use of Alodine TM 5700 on aluminum road wheels, and is currently applying the coating on re

- work vehicles via an immersion process. US Army Aviation efforts selected the Connecticut Aviation Classification

Re pair Activity Depot (AVCRAD) and Corpus Christi Army Depot (CCAD), TX as the demonstration and implementation sites. The Program Executive Office (PEO) Aviation, along with the individual Program Management Activities (PMA’s) from Army Aviation has impleme ntation authority for these efforts.5 

### 3.0

– ONGOING MARINE ATMOSPHERE EXPOSURE TESTING

3.1

– BACKGROUND

Phase I testing included outdoor, beachside exposure testing at the Corrosion Technology Testbed, Kennedy Space Center, FL. The t esting is being completed by NASA and contractor personnel at the Kennedy Space Center (KSC), FL. 3”x5” aluminum coupons were pretreated with the alternative conversion coatings being examined, primed, top

- coated, and shipped to KSC for testing in 2001. The rankings presented here are from the 5 year evaluations, completed in December 2006. High performing systems have remained in testing to further the long

- term performance data.

As stated in the Phase I report, performance ratings are measured by A STM D 1654 Procedure A; and any rating below “3” is considered failed and the panel removed from testing. NASA’s test facility is located 1.5 miles south of Launch Complex 39A. Test stands are located 30 meters (100 feet) from the mean high

- tide line an d face the water. Test coupons are installed on yellow, painted steel test stands using porcelain insulator stand

- offs. The rack angle of the coupons is 30 degrees from horizontal. An “X” incision was scribed through the coating so that the smaller angl e of the “X” was 30 to 45

- degrees, making sure that the coating was scribed all the way to the substrate. The scribe had a 45

- degree bevel, and each line of the “X” was approximately 4

- inches long. The back and edges of the coupon were primed to prevent undercutting and corrosion products from contaminating the test stands.

The coupons were evaluated for surface corrosion and creepage from the scribe at 6

- month intervals. Remaining coatings are still being evaluated, now at greater than 9 years of
beach exposure. NAVAIR is conducting correlation and statistical analysis on the coatings’
stack

- ups, and will publish those results in conference proceedings as appropriate.

9.0-10 BEST

8.0-8.9 GOOD

7.0-7.9 FAIR

5.0-6.9 OK

3.0-4.9 POOR

0.0-2.9 FAIL Figure 1: 8

- year beach exposure average rating categories.

3.2

– RESULTS

The bea ch panel testing is still ongoing, and as of the time of this report, the results from a full eight years of exposure at the Kennedy Space Center (KSC) corrosion facility were available. Many coating combinations of pretreatment and primer systems had fai led ratings long before the eight year exposure contained here; please see earlier reports for the one and three year beach exposure results.6 The results are averaged across the 5 panel set for each pretreatment and primer
combination (APPENDIX A) . The results are presented as averages across all four test alloys for each pretreatment: by primer system, by aviation or ground coating system average, and finally as a total average for all coating systems and alloys.

An overall assessment shows that acros s the different aluminum alloys and with both
chromated and non

- chromated primers, only the Trivalent Chromium Process (TCP) and
Alodine TM 5200/5700 alternatives perform comparably to the Alodine TM 1200S control

, none of
the other alternatives fared as wel l. The use of Class C chromated primer clearly reduces the impact of the pretreatment choice, allowing for comparable performance from two of the better organic

- based pretreatments, the Bi

- K Aklimate TM and the AC Technologies AC

- 131. The superior performa nce of TCP and 5200/5700 is strongly evident in the non

- chromate primer systems where no other alternative consistently approaches the level of performance.

Another general trend is the superior corrosion protection of th e inorganic

- based pretreatments ( 1200S, TCP, and 5700 )

. This is hypothesized to be due to their passivation of the active aluminum surface by a covalently bonded oxide layer which improves both adhesion and corrosion resistance. In contrast, the organic

- based pretreatments, while offerin g excellent adhesion promotion in some instances, do not reduce the activity of the aluminum surface, and
this creates a situation where the primer inhibitor is protecting not just the small areas where the oxide layer has degraded, but the entire coated s urface. More recent results with next generation Class N primers not available at the time of this project have continued to validate this
observation.

Other trends of interest include the slight advantage of the high

- solids epoxy primer

– MIL

- PRF

- 23377 C lass C2 over the water

- reducible epoxy primer

– MIL

- PRF

- 85582 Class C1. This is potentially from the difference in barrier properties and moisture perm eability between the two resin systems. This resin property effect has been clearly shown in more recen tly reported ESTCP Class N primer efforts as well. Both the difference in leach rate of the Class C2
strontium chromate inhibitor vs. the Class C1 barium chromate inhibitor and the relative amounts of inhibitor incorporated into high

- solids vs. water

- redu cible resin systems may also play a role. Like the previous corrosion tests, the chromate

- based primer systems offer superior performance

to non

- chromated systems, especially the Army CARC primers which were formulated for the protection of ferrous alloys (this effect is masked in some evaluations that have been presented, by improperly comparing aviation primers at aircraft thickness requirements, 0.6

- 0.9 mils, with CARC primers at ground vehicle thickness, 2.0

- 3.5 mils)

. Regardless of alloy, from this da ta set, the conclusion may be drawn that the CARC primers be the primary choice for ferrous substrates, but that applications on aluminum surfaces, even such as AA5083 used for ground vehicles and support equipment, are replaced with aviation Class N prime rs. The non

- chromate systems, on average, rank lower than the chromate systems especially with the poorer performing surface preparation alternatives. There are two notable exceptions in this test.

The performance of the 85582 Class N primer with Alodine TM 1200S, TCP and
Alodine TM 5200/5700 differs little from their performance with the sister chromate primers. The performance of the TCP and Alodine TM 5200/5700 with the non

- chromate epoxy primers, 530227 and 53030 is equivalent or better than Alodine TM 120 0S with the same primers. The aluminum alloy trend is that AA5083 is easier to protect than the others, and that AA2219 is the most difficult to protect across the coating systems ; at least in this data set, which only compares
stand

- alone aluminum substra tes, uncoupled from any galvanic/dissimilar material corrosion
drivers

.



### 4.0

– LEVERAGED EFFORTS

4.1

– AF F

- 16/C

- 130

4.1.1

– BACKGROUND

A multi

- year effort at Hill Air Force Base (AFB) was under taken in 2000, with the oversight of the Air Force Corrosio n Prevention and Control Office (AFCPCO), to reduce or eliminate the use of chromate compounds in the paint preparation process for aircraft. Pantheon Chemicals PreKote conversion coating was selected for transition through the T.O. 1

- 1

- 8. The applicatio n process used in the Qualification Operational Test and Evaluation (QOT&E) process
is called the “three

- step” process. Step 1: the surface of the aircraft is scrubbed with PreKote and rinsed after scrubbing. Step 2: PreKote is applied to the surface again and agitated, and allowed to completely dry on the aircraft surface. Step 3, PreKote is applied to the surface again and agitated to remove the residue from Step 2.

4.1.2

– STATUS

As of February 2004, AFCPCO has approved PreKote as a surface treatment al ternative to chromate conversion coating prior to exterior painting of USAF aircraft. The process was
added to T.O. 1

- 1

- 8, “Application and Removal of Organic Coatings, Aerospace and Non

Aerospace Equipment,” and includes specific process steps. The use of PreKote on AF aircraft requires System Program Office (SPO) approval, and the use of a chromated primer. The F

- 16,

T

- 37, T

- 38 and T

- 1 SPO’s have now approved the use of PreKote, and Headquarters Air Education and Training Command (HQ AETC) has mandated i ts use on all AETC aircraft for which it’s approved. If a base, MAJCOM, or ALC decides to pursue using PreKote in their paint processes on other systems, it must obtain approval from the appropriate SPO’s. AFCPCO will provide existing test results upon re quest to assist SPO’s with the engineering decision whether to approve PreKote.

However, the AFCPCO has noted some areas of consideration in the use of PreKote. Since application of PreKote is largely a manual process, the consistency of the process may be important to an overall satisfactory result. To achieve results equal to other weapon systems, they recommend adhering closely to application practices that have already been established. Note that all test results to date, current SPO approvals, and the assessment of low risk, are contingent on the use of a qualified chromated primer. When PreKote is used, corrosion inhibition comes only from the chromated primer. The AFCPCO strongly recommends against
the use of PreKote with non

- chromated primers.8 4.2

– NAVAIR S

- 3

4.2.1

– BACKGROUND

The US Navy’s S

- 3 support aircraft are currently sprayed with a chromate conversion coating during de

- paint/re

- paint operations while undergoing Standard Depot Level Maintenance (SDLM) at the Fleet Readiness Center (FRC) Sou thwest, North Island facility. Four aircraft were sprayed with TCP for the S

- 3 demonstration; the first two were treated with TCP on the aft (tail) section only. The 3rd and 4th aircraft were completely treated with TCP. The aircraft were then painted wi th the TT

- P

- 2756 Self

- Priming Topcoat (SPT), a non

- chromated, polyurethane topcoat that is used without an underlying primer.

4.2.2

– STATUS

The US Navy’s S

- 3 platform has been phased out of service, and no additional rework efforts are being conducted at the depots. Additionally, due to documented poor laboratory and field performance, the TT

- P

- 2756 product is no longer authorized for use on US Navy aircraft, regardless of pretreatment.

4.3

– NAVAIR F/A

- 18 C/D

4.3.1

– BACKGROUND

Naval Aviation expe riences the harshest possible environment for aluminum corrosion, in that most fielded strike and support aircraft are deployed shipboard on aircraft carriers. Current protection schemes are focused around the use of chromate materials, both for inorganic conversion coatings and secondary primer applications. Even with the current hexavalent chromium coating system, corrosion is a very large driver for operations and maintenance costs and severely impacts operational readiness. As the US Navy’s premier a ttack strike fighter aircraft, anything affecting the flight hours to maintenance down

- time is a critical issue. For this reason, any possible alternatives must at the very least meet the performance of current, less environmentally friendly systems, even while we continue to strive for better than the current corrosion protection.

4.3.4

– STATUS

Overall, the TCP technology performed at least as well as the standard chromate conversion coating in this demonstration. These aircraft had at least three carr ier deployments and may have had a fourth. Maintenance personnel were enthusiastic about new technologies due to their environmental and health benefits. The TCP aircraft are performing on par with the that are discussed in Section 4.4, NAVAIR Materials h as authorized the use of TCP (MIL

- DTL

81706 Type II qualified products) under chromated primers

.9 4.4

– NAVAIR CH

- 46

4.4.1

– BACKGROUND

NAVAIR’s fleet of H

- 46 helicopters undergoes depot

- level rework at Fleet Readiness Center (FRC) East, Cherry Point, NC. Due to severe environmental restrictions placed on the conventional spray

- on/rinse

- off chemical processing methods, the FRC had utilized a hand application wipe

- on/wipe

- off method for chromate conversion coating their aircraft. This procedure was used f or all pre

- paint surface preparation of aluminum skins. In 2000, the Environmental Affairs Office in Cherry Point determined that the NAVAIR TCP process does not fall under the environmental and health and safety regulations that govern the hexavalent
chr omium processes. This is due to trivalent chromium being non

- carcinogenic, unlike
hexavalent chromium.

Cherry Point decided to field test the TCP on the H

- 46 platform, on the basis of being able to spray apply TCP. A conventional spray application conv ersion coating process allows for faster turn around time for aircraft undergoing Standard Depot Level Maintenance (SDLM). The old hand application method required between 4 and 6 man

- hours of labor to conversion

coat one CH

- 46 airframe. The spray proces s reduced this process time by half, affording a
noticeable reduction in labor

- hour costs.

4.4.2

– STATUS

The inspection results for the CH

- 46’s indicate that TCP performed at least as well as the chromated pretreatment materials for aluminum alloys in these tests. In January 2006, FRC East, Cherry Point implemented MIL

- DTL

- 81706 Type II materials for interior and exterior spray processing operations. All rotary wing repaint operations being conducted at FRC East now use
the non

- chromated TCP material.

4.5

– NASA SOLID ROCKET BO OSTERS

4.5.1

– BACKGROUND

The Space Shuttle Solid Rocket Booster (SRB) had only one set of coatings and one type of pretreatment qualified for protection of aluminum hardware. All of the materials contained chromate compounds. A NASA project was conducted to identify and qualify alternatives for the currently qualified coating system and pretreatment. The coatings were evaluated for corrosion protection, bond strength, compatibility with other SRB materials, batch

- to

- batch

cons istency, and thermal environments stability. Two pretreatments and two coating systems met the SRB program criteria. The selected products were the Henkel Alodine 5700 and the MacDermid Chemidize 727 ND. These pretreatments were used in conjunction with non

chromate epoxy primers provided by Hentzen and by Lord Coatings. The coating systems were tested in both a primer only and a primer/topcoat configuration. Both were found to be acceptable for flight. The Alodine 5700 had very robust processing para meters and was down

selected for the first implementation as a pretreatment alternate.10 4.5.2

– STATUS

NASA implemented the Hentzen / Alodine 5700 system in June 2002. This change affected all structural aluminum (AA2219, AA6061, and AA7075) parts of the s olid rocket boosters. No issues have been reported with this system. The SRB is a one

- time use application; additional work is still ongoing to identify pretreatments with inherent corrosion protection for use on longer service life components.

4.6

– B OEING/AIR FORCE/NAVY

4.6.1

– BACKGROUND

The US Air Force and Boeing conducted evaluations using the surface treatment system,

AC

- 131 from Advanced Chemistry and Technology in Garden Grove, CA. AC

- 131 is based on technology developed at Boeing as “Boe

- gel” sol

- gel chemistry

- based conversion coating. AC

131 is intended for use as an adhesion promoter for pre

- paint applications on a variety of metallic
substrates. This effort began in September 2002.

The project focused on two main evaluations to determine validity for field demonstration. The first significant milestone of the project was to investigate ways to make Boegel/AC

- 131 visibly inspectable. Several colored dyes were successfully added to the conversion coating promoting color definition. The se cond milestone was to validate the adhesion promoting characteristics of AC

- 131 on a variety of aluminum substrates and surface conditions. Similar adhesion performance was observed for both the AC

- 131 and the Alodine 1200S chromate control in wet tape an d pull

- off adhesion testing. The performance of coating systems with AC

- 131/Boegel in laboratory adhesion testing has been reported to be equivalent or sometimes better than the performance of coating systems with conventional chromate conversion coatings

.

4.6.2

– STATUS

Boeing

- Seattle has implemented the AC

- 131 product for use in pre

- paint operations on the commercial aircraft line, under chromated primer. The AFCPCO has added the AC

- 131 to
the T.O. 1

- 1

- 8 as an acceptable surface preparation for paint ad hesion.11 

### 5.0

– ESTCP NCAP EFFORTS

5.1

– US NAVY LANDING CRAF T, AIR CUSHIONED

5.1.1

– BACKGROUND

The pre

- paint procedure for the Landing Craft, Air Cushioned (LCAC) amphibious vehicle hulls, which are composed primarily of AA5456

- H116, involved abra sive blasting with garnet to achieve a surface profile of 3 mils. Painting is then conducted with a solvent

- reducible,

non

- chromated epoxy primer, MIL

- DTL

- 24441B Type III, Formula 150, to a dry film thickness (DFT) of 3

- 4 mils and then over

- coated with MI L

- DTL

- 24441B Type III, Formula 151 for a
final DFT of 6

- 8 mils. Hexavalent chromium chemistry was suspended by NAVSEA in August 1991 and an alternative to abrasive blasting for surface preparation is desired.

Several issues have arisen with the current direct

- to

- metal process, one of which is adhesion loss due to undercutting and undercutting exacerbated by crevice corrosion between substrate and coating, and another being coating cracking due to craft flex and vibration.

Surface preparation is a key concern, as MIL

- DTL

- 24441B exhibits poor adhesion when the nominal surface profile is less then 3

- mils. This can be achieved by grit

- blasting, but not by other mechanical surface preparation methods, such as shot

- peening or grit

- impregnated sanders.

AA545 6

- H116 has a tendency to polish after approximately 2 mils of profile have been achieved by mechanical methods. Additionally, both Assault Craft Unit Four (ACU

- 4) and ACU

- 5 are prohibited by NAVSEA from sailors performing abrasive blasting due to dust gen eration. This adversely affects the coatings performance of any maintenance and repair efforts conducted at the unit level. With respect to CRAFTALT installation as performed by contractors, production schedule analysis has indicated that implementation o f TCP in place of the current abrasive blast process could reduce production time by 23 man

- days and hangar time by 8 days.

These tests were initiated and overseen by Mr. Paul Dobias, NSWC Carderock Division, Materials Process and Engineering Branch. Th e LCAC program began testing TCP as a potential surface preparation method, allowing a substitution for abrasive blasting as a pre

- paint process. The TCP was chosen for demonstration because of the potential for realizing a time/cost savings, as well as im proved adhesion and corrosion performance when compared to a direct

- to

metal process.

5.1.2

– STATUS

In December 2002, the test coupons were evaluated for surface pitting and general corrosion. Both the garnet blasted coupons and the coupons treated wi th TCP performed better than those with no surface preparation, which were now bare due to all of the coating having lost adhesion. The overall evaluation was that TCP reduced the incidence of pitting corrosion comparative to other surface preparation met hods. The two painted TCP components were evaluated after 4 years of service on LCAC #26: no corrosion, undercutting, or adhesion failures were noted. This demonstrated the adhesion performance when subjected to both corrosive and vibration/flexing envir onments. NAVSEA PEO SHIPS, PMS 377 has indicated that they will12 authorize TCP for pretreatment of aluminum alloys of LCAC pending concurrence from the Technical Warrant Holder (TWH).

5.2

– USMC EXPEDITIONARY F IGHTING VEHICLE

5.2.1

– BACKGROUND

The Exp editionary Fighting Vehicle (EFV) program was originally designated the AAAV

– Armored Amphibious Assault Vehicle. A new armor alloy, AA2519, was chosen for improvements in the strength/weight ratio and ballistic properties compared to legacy 5000 series alloys. The AA2519 is a high copper alloy very susceptible to pitting and exfoliation corrosion. Due to the extremely harsh operating environment experienced by the EFV; the corrosion control coatings and materials must be as robust at possible. At the o utset of this new acquisition program, the PM made the executive decision to comply with the strictures of an environmentally “green” program. Included in this is the full prohibition of the use of hexavalent chromium containing coatings.

Originally, the EFV prototype vehicles were prepared and coated using a grit

- blast/wash primer process that had shown good performance characteristics on high

- strength and armor steel alloys. During initial field testing with the first prototype vehicle, serious problem s arose with the coating system and its corrosion performance. These corrosion and adhesion issues needed to be addressed for the unique performance and operational requirements of AA2519

- T87. The initial coating procedure was wash with a standard alkaline steel cleaner, abrasive blast with
alumina to a 1.5

- 2.0 mil surface profile, wash prime with a water

- reducible non

- chrome primer, prime with a solvent

- reducible, epoxy CARC, and finally topcoat with a water

- reducible, polyurethane CARC. It was suggested that the program look into a chemical process and conversion coat surface preparation in lieu of the mechanical surface preparation/wash primer

process.

5.2.2

– CURRENT PROCESS

– LRIP

The chemical process for the production phase will be as finalized in the SDD prototype phase.

Alkaline Cleaner Aerowash 10% vol. 100 F

Deoxidizer Ridoline 4450 10

- 15 minute dwell

Pretreatment TCP 30

- 50% vol. 10

- 15 minute dwell

Primer MIL

- PRF

- 23377 Type I, Class N

Topcoat (Interior) MIL

- C

- 22750 seafoam green

Topcoat (Exterior) MIL

- DTL

- 64159 TyII CARC 383 Green or Tan

Table 5.1: Target coating system for EFV LRIP13 5.2.3

– STATUS

The EFV program has not yet begun the scheduled LRIP phase due to some mechanical reliability concerns still being addressed. The LRIP and FR P coating systems have been finalized, and the finishing specification revised to reflect the fully non

- chromated coating system. Henkel Alodine T5900 (TCP) has been selected as the pretreatment for the processing of
the hulls and turrets. Both TCP and Alo dine 5200/5700 have been approved for use on components by GDAMS and their vendors. The USMC AVTB is currently using Alodine 5700

pre

- saturated wipes for coating system maintenance and repair touch

- up applications on the SDD
vehicles fielded there.

5 .3

– US ARMY BRADLEY FIGH TING VEHICLE

5.3.1

– INTRODUCTION

The US Army’s M2 Bradley Fighting Vehicle entered production by United Defense (now BAE Ground Systems) in 1980. Originally, this program utilized a chromate conversion coating applied by immersion process to enhance corrosion resistance and paint adhesion on aluminum hull, turret, and armor components.

The BAE facility possessed an automated hoist and immersion system, whereby an entire hull could be lifted and dipped through the 32,000

- gallon pr ocess tank line in 2.5

– 3 hours. The process line utilized Chemetall

- Oakite TM brand chemicals, and consisted of a mildly alkaline

non

- silicated cleaner, a hot phosphoric acid etch, a ferric sulfate/nitric acid based de

- smut, and finally the chromate conv ersion coating. Each step in the process was followed by a halo

- spray, clear water rinse.

BAE

- York, PA, the OEM, is still upgrading and retrofitting BFV’s to the new M2A3, M3A3 variations. In depot maintenance and rework efforts, it was noticed that the aluminum armor alloy, AA7039, evidenced severe intrametallic delamination probably caused by environmentally assisted stress corrosion cracking (SCC). The decision was made to move to a manual surface prep method, as it was thought that the immersion pro cess trapped moisture in small cracks and tight areas on the vehicles, thereby accelerating the delamination. The PM Heavy Brigade Combat Team (PMHBCT) Environmental Management Team (EMT) had suggested an SCC evaluation of AA7039 with the current process versus an immersion process using both chromate control and TCP to ascertain the differences, if any, between the chemical immersion and manual surface preparation methods. The SCC evaluation studies were conducted simultaneously with the component field testing.

The technical challenge was to determine the effect, if any, of chemical processing (specifically the TCP) on stress

- corrosion cracking (SCC). Samples were prepared at NAVAIR Patuxent River, MD and evaluated by BAE Systems, San Jose, CA. The asse ssment was that there was no difference in SCC if the samples were or were not force dried. As a result of this testing, the York facility was able to eliminate the oven drying of Bradley structures which saved at least 4 hours cycle time per unit.14 Direc t

- to

- Metal Chemical Processing

Abrasive blast

– Paint removal Abrasive blast

Weld repair cracks Weld repair cracks

Perform weld and machining modifications Perform weld and machining modifications

X Steam clean/pressure wash

X Bake hulls prior to p aint at 180

- 200F

X Abrasive blast

– Surface Prep → Immersion application of MIL

- C

- 5541
TCP

Prime Prime

Topcoat Topcoat

TABLE 5.2

– Process parameters for SCC evaluation.

5.3.2

– STATUS

PM Heavy Brigade Combat Team (Formerly PM Abrams and PM Bradley) has approved the use of TCP for any vendor that would like to use it, including both General Dynamics Land Systems (GDLS) and BAE Ground Systems and their sub vendors. TCP has been promulgated in all new programs except where not technically practical. M any Sub Vendors are in the process of updating lines in order to accommodate TCP. For some, there are only minor adjustments and
additions that need to be made to their current lines. For others, there are much larger changes that need to be incorporated or new lines that need to be built. One Vendor in particular will purchase Tanks (2), chemicals, put in the plumbing and decking, perform the necessary engineering and pull the necessary permits in order to begin the TCP process for all small parts they supply to BAE Systems.

An additional benefit to note is that the TCP coating does not have thermal stability
concerns that have to be taken into account with chromate films. This has led to the implementation of powder

- coat paints for use on TCP treated components, since the bake cure would have detrimentally affected a chromate coating but is fully compatible with the TCP coating. The additional benefit comes from being able to reduce VOC’s and HAP’s associated with traditional liquid primers and paint s by switching to powder coating.

5.4

– US ARMY AVIATION

5.4.1

– BACKGROUND

In August of 2003, the Environmental, Engineering, and Logistics Oversight (EELO) office at AMCOM in Huntsville, AL put together a comprehensive panel test matrix to identify a

non

- chromate system for demonstration as a potential replacement coating system for their
current chromate

- based pretreatment and primer process. At that time, the current system was to15 spray chromate conversion coating, and paint with MIL

- PRF

- 23377 Clas s C2 primer and MIL

C

- 46168 Type IV CARC, a 2

- component, polyurethane topcoat. All testing and evaluation was conducted under the oversight of PEO Aviation, AMCOM Materials, EELO, ARL, and

NAVAIR.

The three alternative pretreatments selected for aluminum alloy testing were Alodine 5700, NAVAIR TCP, and PreKote. These pretreatments were evaluated over AA2024

- T351 and

AA7075

- T651 alloys. The non

- chrome primer alternative evaluated was MIL

- PRF

- 85582 Class N since no qualified version of MIL

- PRF

- 23377 Class N was available at the start of testing. All three pretreatments were evaluated under chromated primers (MIL

- PRF

- 23377 Class C2 and

MIL

- PRF

- 85582 Class C1) and the non

- chromate MIL

- PRF

- 85582 Class N. The potential replacement primers, MIL

- PRF

- 85582 Class C1 and Class N were coated with the latest generation CARC topcoats, MIL

- C

- 53039A Low VOC and MIL

- DTL

- 64159 Type II to evaluate the coating “system” performance. Testing was conducted by ARL at APG, MD by the Coatings
and Corrosion Branch. Corrosion testi ng was conducted according to ASTM B117 neutral salt fog and GM9540P cyclic corrosion. All corrosion tests were run out to 3,000 hours, with regular evaluations by ARL and AMCOM. Adhesion testing was conducted according to ASTM

D4541

- 95 pull

- off and ASTM D3359 wet tape testing. Adhesion Testing was completed in early 2004 and corrosion testing was completed in July 2004.

The initial field testing was conducted at the Connecticut Aviation Classification Repair Depot (AVCRAD) in October 2005. The CH

- 47 served as the demonstration platform for the initial processing and painting validation. The test system consisted of Henkel product line, since those were the legacy products already in use at the CT AVCRAD. The aircraft was stripped of old paint by Pla stic Media Blasting (PMB) in preparation for recoating. The chemical spray process consisted of the following: Aerowash Cleaner at 25

- 50% dilution for general surfaces, and at full strength for specific areas with high levels of fuel or oil contamination, then deoxidized with Ridoline 4450, and pretreated with Alodine T5900 (TCP). Two epoxy primers were used for this platform. The upper portion of the aircraft was primed
with MIL

- PRF

- 85582 Class C1 product from Deft, Inc. (44GN072) and the lower portion was primed with MIL

- PRF

- 23377 Class N product from Hentzen Coatings, Inc. (16708TEP). The entire aircraft was then topcoated with MIL

- DTL

- 64159 Type II CARC polyurethane paint.

5.4.2

– GENERAL GUIDELINES

– AIRCRAFT CLEANING, SURFACE TREATMENT
AND COATIN G

Aircraft will be inspected to identify coating problems and recorded in the aircraft coating test log (provided). Obvious corrosion, missing rivets, loose/flaking paint, etc. should all be noted. Aircraft shall be cleaned per normal operations at the fac ility and required maintenance accomplished prior to preparation for de

- painting/painting operations.

Components normally removed prior to de

- painting shall be removed and de

- painted in accordance with normal procedures. Any aluminum substrate components removed for hand de

painting and processing shall follow the guidelines below for surface preparation and conversion coating of the aluminum substrate. Other non

- aluminum components shall be prepared per normal procedures.16 Once stripped, the aircraft shall be inspected for corrosion, and localized corrosion removed by hand abrasion (bristle disk, sander or hand sanding) no steel or iron abrasive should be used for removing corrosion on aluminum substrates, products like steel wool, stainless steel shot or g rinding/abrading wheels, etc. should be avoided. Other identified flaws shall be repaired per normal procedures.

Cleaning of the aircraft is one of the most critical aspects of the TCP application and each step shall be closely followed to ensure a properl y prepared surface prior to TCP application. All
surfaces to be treated with TCP shall be cleaned to a water

- break

- free surface with a mild alkaline (pH 8

- 9, nothing over 9.5) cleaner conforming to MIL

- PRF

- 85570 Type II or MIL

- PRF

87937 Type II. Cleaners s hall be diluted to the proper strength using deionized (DI) water to eliminate potential ion deposition on the cleaned substrate. If obvious signs of surface contamination remain, the cleaning process shall be repeated until a water

- break

- free surface is

o btained. If there are signs of “acrylic smear” from Type V PMB an appropriate cleaner shall be substituted that will remove the contamination or the contaminants should be removed using medium grit Scotchbrite pads and an aqueous cleaner. Any alternate cle aner selection must be coordinated with the Research, Development Engineering Center, Materials Branch prior to use. Personnel shall avoid the use of high pH, strong alkaline cleaners to prevent damage to the
aluminum substrates. Rinse water shall be deion ized to eliminate conductive ions being trapped on the bare substrate creating potential corrosion initiation sites or sites where the TCP will not properly adhere. A deoxidation step may follow substrate cleaning for final surface preparation prior to TCP application. If a deoxidation process is used, the final rinse will also use DI water.

Following cleaning (and deoxidation, if used) the surface shall be treated with TCP. TCP shall be applied by hand sprayer ensuring the entire surface to be treated is completely coated with the TCP solution. The nominal dwell time prior to rinsing the TCP from the surface shall be

10

- 15 minutes. (Note: There is no obvious color change to the treated surface like Alodine 1200 series chromate conversion coatings. However, experienced personnel will be able to tell when the rinse should be performed. Properly applied, TCP leaves the treated surface with a subtle,
iridescent blue

- lavender color.) DI water shall be used for the TCP rinse step.

Following TCP treatment, the sub strate shall be allowed to dehydrate for 16

- 24 hours. This is the proper “cure” time for the pretreatment. If scheduling is tight, a 4

- hour dry time after processing can be implemented. Following dehydration, the aircraft shall be masked and coated
with th e proper primer and top

- coating as required.

5.4.3

– STATUS

The Aviation and Missile Life Cycle Management Command’s (AMCOM LCMC) G

- 4 Environmental Office has replaced the EELO in February 2006. G

- 4 personnel have continued to provide regular update brie fings to potential users of the new coating systems. In October 2005
the initial test aircraft was selected and the 1109 th Aviation Classification Repair Activity Depot (AVCRAD) in Groton CT was identified as the facility to apply the test coating. Based on Aviation Engineering Directorate (AED) recommendations, the test coating was to be standardized as TCP (MIL

- DTL

- 81706 Type II), MIL

- PFR

- 23377 Class N and either of the two new CARC coatings. The test coating was applied in October 2005 and AVCRAD person nel17 have periodically inspected this aircraft and reported no significant detectable coating issues. The use of the new, low mar chemical agent resistant coatings (CARC), the Class N primer and the

MIL

- DTL

- 81706 Type II pretreatments have resulted in a sig nificantly improved coating system. Following this initial successful demonstration, 1109 th AVCRAD personnel have continued to apply this coating system since mid

- 2006 to all aircraft coated at their facility with excellent
results. The 1109 th AVCRAD has h ad minimal problems transitioning to the new coating system and all personnel have enthusiastically reported their happiness with the new coatings.

The AMCOM AED has closely followed this test program since its inception and in the summer of 2007 provided final approval to begin implementation of the new coating system on Army Aviation assets. Since receiving this approval, AMCOM G

- 4 has worked closely with the General Services Agency (GSA) to obtain National Stock Numbers (NSN) for the Class N epoxy primer s and the new non

- hexavalent chromium conversion coatings. AMCOM LCMC will be issuing a new Maintenance Information Message (MIM) as soon as it has been approved that will initiate the transition for all subordinate organizations to either the MIL

- PRF

- 2337 7 Class N (preferred) or MIL

- PRF

- 85582 Class N primers. When NSNs have been assigned and notification from GSA has been received for the new conversion coatings, a second MIM will be drafted and distributed to appropriate AMCOM subordinate organizations to initiate the
transition to the new MIL

- DTL

- 81706 Type II conversion coatings.

The transition to the new pretreatment and primer coatings will be phased in as existing stocks are depleted. It is anticipated that as the new materials are implemented for th e first time,

AMCOM G

- 4 and technical representatives will be on

- site to ensure minimal transition difficulties. Initial processing will be done under the oversight of AMCOM G

- 4 (at a minimum). NAVAIR will be requested as needed to aid in this transition f or technical processing support. Mr. Kerry Blankenship, AMCOM G

- 4 Engineering Services Team Lead, Mr. Paul Robinson, Mr. Tim Helton, and/or Mr. Chuck Younger G

- 4 support contractors will continue to evaluate
the in

- service performance of the new coating s ystem and provide feedback and technical guidance based on observed results. As new or improved pretreatments and primer coatings are developed, AMCOM G

- 4 personnel will evaluate the test data in coordination with AMCOM AED to ascertain their applicability to Army Aviation assets.

The 1109 th Aviation Classification Repair Activity Depot in Groton CT has continued to apply the non

- hexavalent chromium coating system to rotary wing aircraft since 2006 as the Army’s “Lead the Fleet” activity. In 2008 the 1109 th AVCRAD was selected as the Secretary of the Army’s winner for their Pollution Prevention

- Facility Environmental Award for their efforts. The Army’s phase in of the MIL

- DTL

- 81706 Type II (TCP) conversion coating is proceeding.
National Stock Numbers have been obtained for the new products and the AMCOM G

- 4 has prepared and submitted for final staffing a Maintenance Information Message (MIM) for distribution to all affected commands and activities. Once distributed by the AMCOM Integrated Material Manageme nt Center, other AMCOM aviation maintenance and repair activities will begin the transition to the new conversion coating and Class N primers.

AMCOM G

- 4 also continues to work with aviation system Original Equipment Manufacturers (OEMs) to assist them in implementing the Type II conversion coatings and Class N primers. To date nearly all OEMs have selected and are performing final testing or have18 implemented the Class N primers as part of their standard coating systems. The use of the Type
II conversion co atings is also being evaluated in detail and a final decision should be reached in
the near future.

As new technologies mature and are identified for testing AMCOM G

- 4 will support and provide whatever assistance as can be made available. The need to ensur e to best performing coating system on Army Aviation assets is crucial to minimize the affects of corrosion and the associated maintenance requirements to mitigate corrosion problems. Additional applications for the Type II conversion coatings for use on m issile system ground vehicles are currently being evaluated. Potential systems where the TCP may be used include the Avenger, Patriot, Medium Extended Air Defense (MEADs), etc. and the expanded potential for the Type II conversion coatings for use over “mi xed metal” substrates is also being assessed.19 

### 6.0

– IMPLEMENTATION OF ALTERNATIVES IN DoD AND NASA

6.1

– MILITARY AND INDUSTR IAL PRETREATMENT SPE CIFICATIONS

MIL

- DTL

- 81706B was released in October 2004. MIL

- DTL

- 5541F was released in April 2006. These documents govern aluminum conversion coatings for military use. The DoD conversion coating specifications were revised and published to include a Type II designation for

non

- chromate chemistries. The proposed revisions were circulate d through DoD and government contractors for comments and review, the inputs collated and organized, and a final revision written. Both revisions allow the qualification and use of any non

- chromate aluminum pretreatment that can pass the performance requi rements for qualification. No changes have been made to the corrosion and adhesion testing requirements for aluminum conversion coatings. Additional restrictions on the chemistries were not included in the Type II designation, simply
that no hexavalent chr omium may be present. Currently all four TCP licensees have qualified commercial products to QPD

- 81706. Additionally, the SAE

- AMS Committee B has release

AMS 3175

– Non

- chromated Surface Pretreatment Prior to Painting, to test and qualify leading
adhesio n promoters such as AC

- 131, PreKote and Alodine 5200/5700. Note that this specification only covers the use of conversion coatings when used prior to paint application. Qualification testing will be underway for commercial products.

6.2

– ALODINE TM 5700

6.2.1

– NASA

NASA has implemented a non

- chromate coating system for use on their aluminum alloy Solid Rocket Boosters (SRB). The Space Shuttle SRB conducted a project to identify and qualify alternatives for the traditional, qualified chromate coating syst em and pretreatment. Testing gathered information on corrosion protection, bond strength, compatibility with other SRB materials, batch

- to

- batch consistency, and thermal environments data. Two pretreatments and two coating systems met the SRB program crite ria. The recommended pretreatments were Henkel Alodine 5200/5700 and MacDermid Chemidize 727 ND. Alodine 5700 had very robust processing parameters and was recommended for first implementation as a pretreatment
alternate.

NASA implemented a Hentzen non

- ch romate primer / Alodine 5700 pretreatment system in June 2002. This change affected all structural aluminum (2219, 6061, and 7075) parts of the
solid rocket boosters. The first hardware flew in the fall of 2002.

6.2.2

– US Army TACOM

The US Army TACOM h as implemented Alodine 5200/5700 conversion coating on

AA2024

- T4 and AA2014

- T6 road wheels for the Bradley Fighting Vehicle, the M113, and the MLRS. TACOM has also implemented Alodine 5200/5700 on Aluminum tracks for the M1A120 Abrams Tank. This technology has been implemented in the US Army Red River Army Depot's (RRAD) Rubber Products Operations since early 2003.

6.3

– PREKOTE TM

6.3.1

– USAF

As of Feb. 2004, t he F

- 16, T

- 37, T

- 38 and T

- 1 SPOs have approved the use of PreKote, and HQ Air Educatio n and Training Command (AETC) has mandated its use on all AETC aircraft for which it’s approved. If a base, MAJCOM, or ALC decides to pursue using PreKote in their paint processes on other systems, it must obtain approval from the appropriate SPOs.

AFCPCO will provide existing test results upon request to assist SPOs with the engineering decision whether to approve PreKote.

AFCPCO continues to recommend chromated conversion coatings for optimum corrosion protection. Multiple laboratory tests, by various organizations, indicate PreKote is one of the best performing non

- chromated surface treatments, but its corrosion protection is still less than that of chromated Alodine 1200S. Several other candidate materials are also being tested as possible alternativ es to Alodine. It is likely that more than one material will meet AF needs. In cases where chromate cannot be used due to environmental restrictions, PreKote provides a low risk alternative. Note that all test results to date, current SPO approvals, and th e assessment of low risk, are contingent on the use of a qualified chromated primer. When PreKote is used, corrosion inhibition comes only from the chromated primer. Past performance of non

- chrome paint systems in AF use has been poor; and AFCPCO strongly recommends against the use of
PreKote with non

- chromated primers. Since application of PreKote is largely a manual process, the consistency of the process may be important to an overall satisfactory result. To achieve results equal to other weapon systems , we recommend adhering closely to application practices that have already been established.

6.4

– TCP

6.4.1

– NAVSEA

Based on the results of the outdoor exposure panel testing and the multi

- year field
demonstration at ACU

- 4, NSWCCD Materials has indicat ed that they are in progress to implement the TCP for pretreatment of aluminum alloys on the LCAC using commercially qualified product to MIL

- DTL

- 81706B. NAVSEA Materials has been provided a copy of the NAVAIR TCP approval letter.

6.4.2

– USMC

The Expedit ionary Fighting Vehicle is approaching the end of the SDD phase. Environmental, safety and health restrictions have led the program office to mandate the use of21 chromate and cadmium free coating systems. The program is scheduled to begin LRIP in FY09.

T CP has been selected as the pretreatment for the processing of the AA2519 hull and turret structures. Both the TCP and Alodine 5200/5700 have been approved by the PM for use on aluminum components by GDAMS and their vendors. The Marines’ AVTB is currently using Alodine 5700 pre

- saturated wipes for coating system maintenance and repair touch

- up applications on the SDD vehicles fielded there.

6.4.3

– NAVAIR

NAVAIR has approved the use of MIL

- DTL

- 81706 Type II technology for aluminum conversion coating. The Fleet Readiness Center

- East, Cherry Point, NC implemented TCP in January 2006. All spray processing operations since have been conducted with qualified commercial TCP. NAVAIR does not currently have a qualification for Class N primers direct to metal, r egardless of pretreatment type. Additional field testing is underway to assess leading Class N primers, including usage over MIL

- DTL

- 81706 Type II pretreatment.

6.4.4

– AMCOM

AMCOM Materials has authorized the use of Type II conversion coatings under q ualified Class N aviation primers. The Connecticut AVCRAD has implemented TCP with Class N primer as of 2006. The Corpus Christi Army Depot has implemented Class N primers as of 2007, and is in progress to transition to the TCP pretreatment in conjunctio n with the Class N primers. This transition is planned for late FY08.

6.5

– AC

- 130/131

6.5.1

– BOEING/AF

Boeing Commercial Airplanes is using AC

- 131 on chromated aluminum rivets for B737 aircraft to improve paint adhesion to the rivets. The chromate plu s AC

- 131 coating is applied to the rivets at the rivet manufacturer. Boeing Commercial Airplanes traditionally utilized Alodine

1000 TM clear, chromate conversion coating for pretreatment of aluminum rivets on commercial aircraft. They were experiencing pai nt loss due to adhesion failure at the rivets. B737 aircraft produced since the spring of 2004 have had the chromate/AC

- 131 coated rivets used in the fuselage. The incidence of paint adhesion failures to the rivets has been significantly decreased
with t he new coating system. Boeing Commercial Airplanes has also performed scale

- up trials of

AC

- 131 and transitioned this product for pretreatment prior to Class C primer application.22 THIS PAGE LEFT BLANK INTENTIONALLY23 

### 7.0

– CONCLUSIONS AN D RECOMMENDATIONS

All the alternatives being demonstrated are aqueous solutions designed to deposit a conversion coating on aluminum alloy substrates to enhance paint adhesion and painted corrosion performance. Alternatives face the challenge of the low c ost and ease of application of the chromate conversion coatings while providing a coating that provides acceptable technical performance. Along with technical performance, processing and toxicity issues are important to consider in capturing the overall im pact of an alternative. The general trend is that no one test methodology is sufficient to predict good field performance, but that good correlation can be found to identify the top performing systems. The key to the accelerated testing is that multiple methods, such as ASTM B117 and G85 Annex 4, and GM9540P must be used in conjunction to determine top performers. While individual coating systems may do well in one or two test or particular stack

- ups, early analysis suggests very high correlation between the ordinal rankings across the laboratory testing when compared with the beach exposure (our closest test condition to mimic on platform field use). That is, the coatings that consistently performed the best on average across the alloy, primer and accel erated test methods are the same coatings that consistently performed the best in extended beach exposure testing.

There are currently four non

- chromate alternatives in various stages of validation or implementation. Alodine 5200/5700, PreKote, and AC

- 130 /131 provide paint adhesion and painted corrosion protection, and are all non

- chromium chemistries. The TCP provides both painted and unpainted corrosion protection as well as electrical conductivity in corrosive environments. However, TCP does contain tr ivalent chromium, and users will need to balance
total chromium waste

- water requirements with technical performance requirements when deciding on implementation of TCP. TCP and Alodine 5200/5700 provide the most process flexibility, as they can be applied like a chromate conversion coating, by immersion, spray, or wipe

- on methods. AC

- 130/131 can be used in spray applications. PreKote must be manually applied for proper coating performance.

All of the demonstration coatings have shown good paint adhesion and corrosion performance when used under chromated primers and in moderate environments . The PreKote
and the AC

- 130/131 have not demonstrated acceptable performance when combined with non

chromate primers in high corrosion environments. The TCP and Alo dine 5200/5700 have shown good paint adhesion and painted corrosion performance when used under both chromated and

non

- chromated primers. TCP and Alodine 5200/5700 have performed well in high corrosion environment testing.

It is therefore critical with any new non

- chromate material that it be tested to failure against the chromated control. Additionally, a ny new coating application should be demonstrated and validated by field

- testing for each operational environment where implementation is being consid ered. Only then can the complete technical performance of a coating or coating system be determined. Implementation of any alternative must take into consideration the costs, process, health and safety, laboratory and field testing performance, and
the s pecific coating system application and operational environment.24 

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## APPENDIX A

– 8

- YEAR BEACH EXPOSURE RESULTSY1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S10.0 10.0 9.6 8.8 10.0 10.0 10.0 9.9 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.0 10.0 10.0 9.9 9.4Alodine5200/5700 10.0 10.0 10.0 10.0 9.2 8.2 8.0 8.0 10.0 10.0 10.0 10.0 10.0 10.0 9.8 9.8 9.8 9.6 9.5 9.5Bi‐KAklimate 10.0 10.0 9.8 9.4 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.8 9.8 9.8 9.8 10.0 10.0 9.9 9.8AC‐13110.0 10.0 9.0 9.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.3 9.3 8.0 3.3 9.8 9.8 9.3 8.1Chemidize727ND 10.0 9.8 9.0 8.0 10.0 10.0 10.0 9.6 10.0 10.0 10.0 10.0 7.6 6.4 4.8 3.4 9.4 9.1 8.5 7.8OxsilanAl‐0500 9.6 9.6 9.6 9.6 10.0 10.0 9.8 9.5 10.0 10.0 10.0 10.0 9.8 9.8 9.8 9.4 9.9 9.9 9.8 9.6Sanchem7000 9.6 8.20.0 0.010.0 9.8 9.8 9.4 10.0 10.0 10.0 10.0 4.20.6 0.0 0.08.5 7.2 5.0 4.9TCP10.0 10.0 10.0 9.4 8.0 8.0 8.0 8.0 10.0 10.0 10.0 10.0 10.0 9.0 7.2 6.4 9.5 9.3 8.8 8.5PreKote10.0 10.0 9.6 9.2 10.0 10.0 9.6 9.4 10.0 10.0 10.0 10.0 10.0 7.20.0 0.010.0 9.3 7.3 7.2AverageCorrosionCreep(ASTMD1654‐5panel)forAluminumAlloysCoatedwithMIL‐PRF‐23377TypeI,ClassC2Primer/MIL‐PRF‐85285TypeITopcoatAllAlloyAverageOK:Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S 10.0 10.0 10.0 9.8 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0Alodine5200/570010.010.09.4 9.4 8.8 8.8 8.0 8.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.7 9.7 9.4 9.4Bi‐KAklimate 10.0 10.0 9.6 8.2 10.0 10.0 8.4 6.8 10.0 10.0 10.0 10.0 9.8 9.4 9.0 9.0 10.0 9.9 9.3 8.5AC‐13110.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.7 10.0 10.0 10.0 9.9Chemidize 727ND9.89.85.84.27.67.60.00.010.010.010.010.09.09.06.86.69.19.15.75.2AA2219AllAlloysAverageAllAlloysAverageAA5083AA2219PretreatmentPretreatmentAA2024 AA7075AA2024 AA7075AA5083BEST:Bi‐K,Al‐500,A5700,A1200S GOOD:TCP,AC‐131 FAIR:727ND,PreKotePOOR:S7000FAIL:Chemidize727ND9.89.85.84.27.67.60.00.010.010.010.010.09.09.06.86.69.19.15.75.2OxsilanAl‐0500 9.6 9.6 9.2 9.0 7.6 6.6 5.80.010.0 10.0 10.0 10.0 9.4 9.2 9.2 9.0 9.2 8.9 8.6 7.0Sanchem70000.0 0.0 0.0 0.03.22.4 0.0 0.010.0 9.4 9.4 9.4 6.4 6.40.0 0.04.9 4.62.4 2.4TCP 10.0 10.0 10.0 9.6 10.0 10.0 9.8 9.6 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.9 10.0 10.0 10.0 9.8PreKote 10.0 10.0 9.6 6.2 10.0 10.0 9.8 9.4 10.0 10.0 9.8 9.8 9.8 9.6 3.40.010.0 9.9 8.2 6.4AverageCorrosionCreep(ASTMD1654‐5panel)forAluminumAlloysCoatedwithMIL‐PRF‐85582TypeI,ClassC1Primer/MIL‐PRF‐85285TypeITopcoatAllAlloyAverageY1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S10.0 10.0 9.8 9.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.2 10.0 10.0 10.0 9.6Alodine5200/5700 10.0 9.8 9.4 8.2 8.8 8.0 8.0 8.0 10.0 10.0 10.0 10.0 9.4 9.4 9.4 8.8 9.6 9.3 9.2 8.8Bi‐KAklimate0.8 0.0 0.0 0.0 1.0 0.0 0.0 0.010.0 9.4 7.02.8 0.0 0.0 0.0 0.03.02.4 1.8 0.7AC‐1315.35.00.00.07.3 4.70.0 0.010.0 10.0 10.0 9.00.0 0.0 0.0 0.05.7 4.92.5 2.3Chemidize727ND0.8 0.0 0.0 0.0 1.2 0.0 0.0 0.010.0 9.4 5.22.8 0.0 0.0 0.0 0.03.02.4 1.3 0.7OxsilanAl‐0500 7.6 7.2 5.00.09.2 9.0 9.0 6.6 10.0 9.8 9.8 9.42.8 0.0 0.0 0.07.4 6.5 6.0 4.0Sanchem70000.0 0.0 0.0 0.05.40.0 0.0 0.09.2 8.8 5.8 4.20.0 0.0 0.0 0.03.72.2 1.5 1.1TCP10.0 10.0 9.6 9.0 9.6 9.2 8.6 8.6 10.0 10.0 10.0 10.0 9.6 9.6 9.6 8.2 9.8 9.7 9.5 9.0PreKote3.80.0 0.0 0.0 1.4 0.0 0.0 0.09.0 8.62.0 0.0 0.0 0.0 0.0 0.03.62.2 0.5 0.0AverageCorrosionCreep(ASTMD1654‐5panel)forAluminumAlloysCoatedwithMIL‐PRF‐85582TypeI,ClassNPrimer/MIL‐PRF‐85285TypeITopcoatAllAlloyAverageAllAlloysAverageFAIL:S7000PretreatmentAA2024AA7075AA2219AA5083FAIL:AC‐131,S7000,Bi‐K,727ND,PreKoteFAIR:POOR:BEST:A1200S,AC‐131,TCP,A5700 GOOD:Bi‐K FAIR:Al‐500 OK:PreKote,727NDGOOD:A5700BEST:A1200S,TCPOK:POOR:Al‐500Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S 10.0 10.0 6.62.89.8 9.8 9.4 9.0 10.0 10.0 10.0 10.02.4 0.0 0.0 0.08.1 7.5 6.5 5.5Alodine5200/5700 10.0 7.8 6.4 3.4 8.6 8.6 7.4 6.2 10.0 10.0 10.0 10.0 3.4 4.00.0 0.08.0 7.6 6.0 4.9Bi‐KAklimate0.8 0.0 0.0 0.09.40.0 0.0 0.09.8 9.4 6.4 4.70.0 0.0 0.0 0.05.02.4 1.6 1.2AC‐1315.7 3.00.0 0.04.70.0 0.0 0.010.0 10.0 10.0 10.00.0 0.0 0.0 0.05.1 3.32.5 2.5Chemidize727ND 4.80.0 0.0 0.05.80.0 0.0 0.010.0 10.0 9.8 9.40.0 0.0 0.0 0.05.22.5 2.5 2.4OxsilanAl‐0500 5.82.0 0.0 0.09.21.8 0.0 0.010.0 9.8 7.6 5.80.0 0.0 0.0 0.06.3 3.41.9 1.5Sanchem7000 9.80.0 0.0 0.0 0.2 0.0 0.0 0.010.0 9.8 9.0 6.80.0 0.0 0.0 0.05.02.5 2.3 1.7TCP10.0 10.0 9.2 6.6 10.0 10.0 9.02.210.0 10.0 10.0 10.0 3.61.4 0.0 0.08.4 7.9 7.1 4.7PreKote4.20.0 0.0 0.06.00.0 0.0 0.010.0 10.0 8.8 8.40.0 0.0 0.0 0.05.12.5 2.2 2.1AverageCorrosionCreep(ASTMD1654‐5panel)forAluminumAlloysCoatedwithMIL‐DTL‐53030Primer/MIL‐DTL‐53039TypeITopcoatAllAlloyAverageOK:Y1Y2 Y5Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S 10.0 10.0 7.20.09.8 9.6 4.00.010.0 9.8 9.8 9.60.4 0.0 0.0 0.07.6 7.4 5.32.4Alodine5200/5700 10.0 10.0 9.2 7.8 8.8 8.8 8.8 7.6 10.0 9.8 9.8 9.82.4 0.0 0.0 0.07.8 7.2 7.0 6.3Bi‐KAklimate 3.20.0 0.0 0.06.40.0 0.0 0.010.0 9.6 7.6 7.40.0 0.0 0.0 0.04.92.4 1.9 1.9AC‐1319.5 9.0 6.70.0 1.3 0.0 0.0 0.010.0 10.0 10.0 10.01.0 0.0 0.0 0.05.5 4.8 4.22.5Chemidize 727ND6.00.00.00.02.20.00.00.09.28.47.05.40.00.00.00.04.42.11.81.4AllAlloysAverageAllAlloysAverageFAIL:AC‐131,727ND,PreKote,S7000,Al‐500,Bi‐KAA5083 AA2219PretreatmentAA2024 AA7075 AA5083 AA2219PretreatmentAA2024 AA7075POOR:A1200S,A5700,TCPGOOD:FAIR:BEST:Chemidize727ND6.00.00.00.02.20.00.00.09.28.47.05.40.00.00.00.04.42.11.81.4OxsilanAl‐0500 9.42.8 0.0 0.07.61.8 0.0 0.010.0 10.0 9.8 9.80.8 0.0 0.0 0.07.0 3.72.5 2.5Sanchem7000 7.82.0 0.0 0.06.60.0 0.0 0.010.0 9.6 9.0 5.00.0 0.0 0.0 0.06.12.9 2.3 1.3TCP 10.0 9.8 6.0 4.4 10.0 10.0 9.40.010.0 10.0 10.0 10.01.4 0.0 0.0 0.07.9 7.5 6.4 3.6PreKote 3.40.0 0.0 0.0 2.6 0.0 0.0 0.010.0 9.6 5.2 3.20.0 0.0 0.0 0.04.02.4 1.3 0.8AverageCorrosionCreep(ASTMD1654‐5panel)forAluminumAlloysCoatedwithMIL‐DTL‐53022Primer/MIL‐DTL‐53039TypeITopcoatAllAlloyAverageOK:FAIL:Al‐500,AC‐131,A1200S,Bi‐K,727ND,S7000,PreKotePOOR:A5700,TCPFAIR:GOOD:BEST:Yr1 Yr2 Yr5 Yr8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S(Control) 10.0 10.0 9.9 9.4 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.6 10.0 10.0 10.0 9.6Alodine5200/5700 9.8 9.6 9.5 9.5 9.7 9.7 9.4 9.4 9.6 9.3 9.2 8.8 9.7 9.5 9.3 9.2Bi‐KAklimate10.0 10.0 9.9 9.8 10.0 9.9 9.3 8.53.0 2.4 1.8 0.77.6 7.4 7.0 6.3AC‐1319.8 9.8 9.3 8.1 10.0 10.0 10.0 9.9 5.7 4.92.5 2.38.5 8.3 7.3 6.8Chemidize727ND 9.4 9.1 8.5 7.8 9.1 9.1 5.7 5.23.0 2.4 1.3 0.77.2 6.8 5.1 4.6OxsilanAl‐05009.9 9.9 9.8 9.6 9.2 8.9 8.6 7.0 7.4 6.5 6.0 4.0 8.8 8.4 8.1 6.9Sanchem70008.5 7.2 5.0 4.9 4.9 4.62.4 2.43.72.2 1.5 1.15.7 4.62.9 2.8TCP9.5 9.3 8.8 8.5 10.0 10.0 10.0 9.8 9.8 9.7 9.5 9.0 9.8 9.7 9.4 9.1PreKote10.0 9.3 7.3 7.2 10.0 9.9 8.2 6.4 3.62.2 0.5 0.07.8 7.1 5.3 4.5AVERAGE9.6 9.3 8.6 8.3 9.2 9.1 8.1 7.6 6.2 5.5 4.7 4.0 8.3 8.0 7.2 6.6MIL‐PRF‐85285AircraftPolyurethaneTopcoatAllAlloyAverageY1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S(Control) 8.1 7.5 6.5 5.5 7.6 7.4 5.32.47.8 7.4 5.9 3.9AllAviationCoatingsPretreatment23377C2 85582C185582NCPretreatmentAllGroundCoatingsBEST:A1200S,A5700,TCP GOOD:FAIR:OK:Al‐500,AC‐131,Bi‐KPOOR:727ND,PreKoteFAIL:S70005303053022( )Alodine5200/5700 8.0 7.6 6.0 4.9 7.8 7.2 7.0 6.3 7.9 7.4 6.5 5.6Bi‐KAklimate5.02.4 1.6 1.24.92.4 1.9 1.95.02.4 1.8 1.5AC‐1315.1 3.32.5 2.55.5 4.8 4.22.55.3 4.03.3 2.5Chemidize727ND 5.22.5 2.5 2.44.42.1 1.8 1.44.82.3 2.1 1.9OxsilanAl‐05006.3 3.41.9 1.57.0 3.72.5 2.56.63.5 2.2 2.0Sanchem70005.02.5 2.3 1.76.12.9 2.3 1.35.62.7 2.3 1.5TCP 8.4 7.9 7.1 4.7 7.9 7.5 6.4 3.6 8.1 7.7 6.7 4.2PreKote 5.12.5 2.2 2.14.02.4 1.3 0.84.52.5 1.8 1.5AVERAGE 6.2 4.4 3.62.96.1 4.5 3.62.56.2 4.4 3.62.7MIL‐DTL‐53039CARCPolyureaTopcoatAllAlloyAverageFAIL:AC‐131,Al‐500,727ND,Bi‐K,S7000,PreKoteBEST:GOOD:FAIR:OK:POOR:A5700,TCP,A1200SYr1 Yr2 Yr5 Yr8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8 Y1 Y2 Y5 Y8Alodine1200S(Control) 10.0 10.0 9.9 9.4 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.6 8.1 7.5 6.5 5.5 7.6 7.4 5.32.49.1 9.0 8.3 7.4Alodine5200/5700 9.8 9.6 9.5 9.5 9.7 9.7 9.4 9.4 9.6 9.3 9.2 8.8 8.0 7.6 6.0 4.9 7.8 7.2 7.0 6.3 9.0 8.7 8.2 7.8Bi‐KAklimate10.0 10.0 9.9 9.8 10.0 9.9 9.3 8.53.0 2.4 1.8 0.75.02.4 1.6 1.24.92.4 1.9 1.96.6 5.4 4.9 4.4AC‐1319.8 9.8 9.3 8.1 10.0 10.0 10.0 9.9 5.7 4.92.5 2.35.1 3.32.5 2.55.5 4.8 4.22.57.2 6.6 5.7 5.1Chemidize727ND 9.4 9.1 8.5 7.8 9.1 9.1 5.7 5.23.0 2.4 1.3 0.75.22.5 2.5 2.44.42.1 1.8 1.46.2 5.0 3.9 3.5OxsilanAl‐05009.9 9.9 9.8 9.6 9.2 8.9 8.6 7.0 7.4 6.5 6.0 4.0 6.3 3.41.9 1.57.0 3.72.5 2.57.9 6.5 5.7 4.9Sanchem70008.5 7.2 5.0 4.9 4.9 4.62.4 2.43.72.2 1.5 1.15.02.5 2.3 1.76.12.9 2.3 1.35.6 3.92.7 2.2TCP9.5 9.3 8.8 8.5 10.0 10.0 10.0 9.8 9.8 9.7 9.5 9.0 8.4 7.9 7.1 4.7 7.9 7.5 6.4 3.6 9.1 8.9 8.3 7.1PreKote10.0 9.3 7.3 7.2 10.0 9.9 8.2 6.4 3.62.2 0.5 0.05.12.5 2.2 2.14.02.4 1.3 0.86.5 5.3 3.9 3.3AVERAGE9.6 9.3 8.6 8.3 9.2 9.1 8.1 7.6 6.2 5.5 4.7 4.0 6.2 4.4 3.62.96.1 4.5 3.62.57.5 6.6 5.7 5.1MIL‐PRF‐85285AircraftPolyurethaneTopcoat+MIL‐DTL‐64159CARCPolyureaTopcoatAllAlloyAveragePretreatment23377C285582C185582NCBEST:GOOD:FAIR:A5700,A1200S,TCP OK:AC‐131 POOR:Al‐0500,Bi‐K,7272ND,PreKoteFAIL:S70005303053022AllCoatings30 

## APPENDIX B

– PHASE II INTERIM REPORT

### Non-Chromate Aluminum Pretreatments Phase II Interim Report Project #PP0025

September 2004NCAP Phase II Interim Report September 2004

THIS PAGE LEFT BLANK INTENTIONALLY.

iiNCAP Phase II Interim Report September 2004



### TABLE OF CONTENTS

DISCLAIMER

ACRONYMS AND ABBREVIA TIONS

LIST OF FIGURES

LIST OF TABLES

ACKNOWLEDGEMENTS

SUMMARY

1.0 – INTRODUCTION

1.1 – PROJECT BACKGROUND
1.2 – PHASE I OBJECTIVE/SCOPE OF WORK
1.3 – PHASE II OBJECTIVE/SCOPE OF WORK



### 2.0 – DEMONSTRATION/VALIDATION SELECTIONS

2.1 – TCP

2.2 – ALODINE TM 5200/5700

2.3 – PRE-KOTE TM

2.4 – AC-130/131 TM

2.5 – PHASE II EFFORTS SUMMARY



### 3.0 – ONGOING ATMOSHPHER E EXPOSURE TESTING

3.1 – BACKGROUND

3.2 – COATINGS PERFORMANCE – 2 YEARS



### 4.0 – LEVERAGE D EFFORTS
4.1 – USAF F-16, C-130

4.1.1 – BACKGROUND

4.1.2 – FIELD TESTING

4.1.3 – FIELD TEST RESULTS

4.1.4 – STATUS

4.2 – NAVAIR S-3

4.2.1 – BACKGROUND

4.2.2 – PROCESSING

4.2.3 – FIELD TEST RESULTS

4.2.4 – STATUS

iiiNCAP Phase II Interim Report September 2004

4.3 – NAVAIR F/A-18 C/D

4.3.1 – BACKGROUND

4.3.2 – PROCESSING

4.3.3 – FIELD TEST RESULTS

4.3.4 – STATUS

4.4 – NAVAIR CH-46

4.4.1 – BACKGROUND

4.4.2 – PROCESSING

4.4.3 – FIELD TEST RESULTS

4.4.4 – STATUS

4.5 – NASA SOLID ROCKET BOOSTERS

4.5.1 – BACKGROUND

4.5.2 – FIELD TESTING

4.5.3 – STATUS

4.6 – BOEING/AF

4.6.1 – BACKGROUND

4.6.2 – STATUS



### 5.0 – ESTCP NCAP EFFORTS 5.1 – US NAVY LANDING CRAFT, AIR CUSHIONED (LCAC)

5.1.1 – BACKGROUND

5.1.2 – FIELD TESTING

5.1.3 – FIELD TEST RESULTS

5.1.4 – STATUS

5.2 – USMC EXPEDITIONARY FIGHTING VEHICLE

5.2.1 – BACKGROUND

5.2.2 – PROTOTYPE VEHICLE TC P PERFORMANCE VALIDATION

5.2.3 – LABORATORY TESTING

5.2.4 – P1 & LAB TEST RESULTS

5.2.4.1 – LABORATORY TESTING

5.2.4.2 – INITIAL TCP PERFORMANCE ON EFV P1

COMPONENTS

5.2.5 – SDD VEHICLE HULLS AND TURRETS PROCESSING

5.2.5.1 – BACKGROUND

5.2.5.2 – INITIAL PROCESSING

5.2.5.3 – PROCESSING

5.2.5.4 – SDD VEHICLE E7 PAINT ADHESION RESULTS

5.2.6 – PROCESSING – CURRENT PROCESS

5.2.6.1 – E8 PROCESSING

5.2.6.2 – E9 PROCESSING

5.2.7 – CURRENT PROCESS – LRIP

5.2.8 – PROTOTYPE AND SDD VEHICLES FIELD TESTING

ivNCAP Phase II Interim Report September 2004

5.2.8.1 – PERFORMANCE OF CHROMATED VS. NON-

CHROMATED SYSTEMS ON USMC EFV P1
5.2.8.2 – E2 AND E7 – IN-WATER/AMPHIBIOUS TESTING

5.2.8.3 – STATUS

5.3 – US ARMY BRADLEY FIGHTING VEHICLE

5.3.1 – INTRODUCTION

5.3.2 – COMPONENT SELECTION

5.3.3 – PROCESSING

5.3.3.1 – COMPONENTS

5.3.3.2 – PANEL TESTING – UNITED DEFENSE

5.3.4 – FIELD TESTING

5.3.5 – FIELD TEST RESULTS

5.3.6 – STATUS

5.3.6.1 – STRESS CORROSION CRACKING EVALUATION

5.4 – US ARMY AVIATION

5.4.1 – BACKGROUND

5.4.2 – LABORATORY TESTING

5.4.2.1 – PULL-OFF ADHESION TEST RESULTS

5.4.2.2 – WET TAPE ADHESION RESULTS

5.4.3 – FIELD TEST SYSTEMS SELECTION

5.4.3.1 – GENERAL GUIDELINES

5.4.4 – STATUS



### 6.0 – IMPLEMENTATION STATUS

6.1 – MILITARY AND INDUSTRIAL PRETREATMENT SPECIFICATIONS

6.2 – ALODINE TM 5200/5700

6.2.1 – NASA

6.2.2 – US ARMY TACOM

6.3 – PREKOTE TM

6.4 – TCP

6.4.1 – NAVSEA

6.4.2 – USMC

6.4.3 – NAVAIR
6.5 – AC-130/131

6.5.1 – NAVAIR

6.5.2 – BOEING



### 7.0 – CONCLUSIONS AN D RECOMMENDATIONS

REFERENCES

vNCAP Phase II Interim Report September 2004



### DISCLAIMER

Due to the critical nature of DoD weapons systems coating performance and
because of NAVAIR’s interest and involvement in the trivalent chromium process (TCP) this report has been reviewed for techni cal content, accuracy, and fairness by the following: the Air Force Corrosion Preventi on and Control Office (AFCPCO), the Army Research Laboratory (ARL) Coatings and Corrosion Branch, the Naval Air Systems Command (NAVAIR) Material s Division, the Naval Sea Systems Command (NAVSEA) Materials Division, the Offi ce of the Program Manager Combat Systems (PMCS), the Office of the Direct Reporting Program Ma nager Advanced Amphibious Assault (DRPM AAA), the US Army Aviation and Missil e Command (AMCOM) Environmental, Engineering, and Logistics Office (EELO ), United Defense, General Dynamics Amphibious Systems, and Boeing Commercial Airplanes.

viNCAP Phase II Interim Report September 2004



### ACRONYMS AND ABBREVIATIONS
AA – Aluminum Alloy AAA – Advanced Amphibious Assault

AACP – Advanced Aircra ft Corrosion Protection AAV – Amphibious Assault Vehicle

ACU – Assault Craft Unit

AETC – Air Education and Training Command

AFB – Air Force Base AFRL – Air Force Research Laboratory

AFCPCO – Air Force Corrosion Prevention and Control Office

AMCOM – Aviation and Missile Command APG – Aberdeen Proving Grounds ARL – Army Research Laboratory ASTM – American Society for Testing and Materials

AVCRAD – Aviation Classifica tion Repair Activity Depot AVTB – Amphibious Vehi cle Test Branch BASC – Boeing Aircra ft Support Center BFIST – Bradley Fire Support Team BFV – Bradley Fighting Vehicle

BUNO – Bureau Number CARC – Chemical Agent Resistant Coating CCAD – Corpus Christi Army Depot CCC – Chromate Conversion Coating

COMNAVSEASYSCOM – NAVSEA Commander

CONSTRKFIGHTWINGLANT – Commande r Atlantic Strike Fighter Wing CPC – Corrosion Preventative Compounds CTC – Coatings Technology Center

CY – Calendar Year

DEM/VAL – Demonstration/Validation DFT – Dry Film Thickness

DI – Deionized DoD – Department of Defense DRPM – Direct Reporting Program Manager

DTM – Direct to Metal DUSD-ES – Deputy Undersecretary of Defense for Environmental Security E1 – First Experimental Vehicle – USMC EFV EELO – Environmental, Engin eering, & Logistics Oversight EFV – Expeditionary Fighting Vehicle EMI – Electromagnetic Interference EMT – Environmental Management Team EPA – Environmental Protection Agency

viiNCAP Phase II Interim Report September 2004

ESOH – Environmental, Safety and Occupational Health ESTCP – Environmental Security Technology Certification Program FSE – Floor Support Engineering GDAMS – General Dynamics Amphibious Systems GDLS – General Dynamics Land Systems

HazMat – Hazardous Material HSTNA – Henkel Surface Technologies North America HSU – Hydraulic Suspension Unit IARC – International Agency for Research on Cancer ICT – Inorganic Coatings Team IETM – Integrated Electronic Technical Manual JG-PP – Joint Group on Pollution Prevention JLC – Joint Logistics Commander

JTP – Joint Test Protocol

KM – kilometers KSC – Kennedy Space Center ksi – kilopounds per Square Inch LATP – Lima Army Tank Plant LCAC – Landing Craft Air Cushion LEX – Leading Edge Extension

LRIP – Low Rate Initial Production MCB – Marine Corps Base MCAS – Marine Corps Air Station MEK – Methyl Ethyl Ketone MIL-C – Military Control Specification MIL-DTL – Military Detail Specification MIL-H – Military Hydraulic Fluid Specification MIL-P – Military Paint Specification MIL-PRF – Military Performance Specification MIL-SPEC – Military Specification MSDS – Material Safety Data Sheet NADEP – Naval Aviation Depot

NAS – Naval Air Station NASA – National Aeronautics and Space Administration NAVAIR – Naval Air Systems Command NAVMSG – Navy Message NAVSEA – Naval Sea Systems Command

NAWCAD – Naval Air Warfare Center Aircraft Division

NCAP – Non-Chromated Aluminum Pretreatment NORIS – North Island Naval Depot NSF – Neutral Salt Fog

viiiNCAP Phase II Interim Report September 2004

NSWC – Naval Surf ace Warfare Center OEM – Original Equipment Manufacturer OOALC – Ogden Air Logistics Center OSHA – Occupational Safety and Health Administration P1 – First Prototype Vehicle – USMC EFV

PAX – Patuxent River Naval Air Station PEO – Program Executive Office PEL – Permissible Exposure Limit
PM – Program Manager PMA – Program Management Activity PMB – Plastic Media Blasting PM CS – Program Manager Army Ground Combat Systems

PMI – Planned Maintenance Interval

POC – Point of Contact psi – pounds per square inch QA – Quality Analysis QC – Quality Control QOT&E – Qualification Operational Test and Evaluation QPL – Qualified Products List RRAD – Red River Army Depot RH – Relative Humidity SAE-AMS – Society of Auto motive Engineers - Aerospace Material Specification SCC – Stress Corrosion Cracking SDLM – Standard Depot Level Maintenance SDD – System Design and Development SPO – Systems Program Office SPT – Self Priming Topcoat

SRB – Solid Rocket Booster

TCP – Trivalent Chromium Pretreatment

TO – Technical Order

UDLP – United Defense USMC – United States Marine Corps

WESTPAC – Western Pacific YPG – Yuma Proving Grounds

ixNCAP Phase II Interim Report September 2004



### LIST OF FIGURES

2.1 – US Marine Corps Expeditionary Fighting Vehicle (Formerly Advanced Amphibious Assault Vehicle) 2.2 – US Army Bradley Fighting Vehicle 2.3 – US Army H-60 Blackhawk
3.1 – KSC Corrosion Testbed Beachside Aerial View 4.1 – Application of Pre-KoteTM at Hill AFB 4.2 – Fuselage Station 496 – Transition Area 4.3 – Close-up of TCP Treatment, Dry 4.4 – Finished BUNO 160144, North Island, July 1999 4.5 – Open area Corrosion 4.6 – S-3A Viking – TCP on Aft Section – August 1999 4.7 – TCP Application on BUNO 163757, North Island, November 2000 4.8 – Iridescent Blue Color of As-Deposited TCP
4.9 – F/A-18C with TCP after Primer Application – November 2000, NORIS 4.10 – Chromate and TCP F/A-18 C’s – May 2004, MCAS Beaufort 4.11 – BUNO 163757 F/A-18C w/ TCP – NAS Lemoore, May 2004 4.12 – H-46 Components with TCP – NADEP CP, October 2000 5.1 – LCAC-26 Oily Waste Tank with TCP Test Patch 5.2 – Beachside Exposure Racks, Little Creek, VA 5.3 – Bare AA5456-H116 Coupons – 1.5+ Years Beach-Side Exposure 5.4 – TCP Applied to Air Intake Plenum Deck, LCAC-26 5.5 – Cleaning Steering Bucket 5.6 – Application of TCP 5.7 – TCP Coating after Drying 5.8 – Steering Bucket after Priming with MIL-PRF-85582NC 5.9 – Steering Bucket after Topc oat Application with MIL-C-53039 5.10 – Seal Plate after Topcoat Application with MIL-C-53039 5.11 – Seal Plate Mating Surface after Corrosion Removal 5.12 – Application of TCP Coating on Seal Plate Mating Surface 5.13 – Starboard Steering Bucket and S eal Plate after 2 Weeks in Service 5.14 – Inside of Starboard Steering Bucket after 2 Weeks in Service 5.15 – EFV E3 Spray Processing – LATP 5.16 – Minimal TCP Color Change Observed Near Inserts 5.17 – P1 – 4 Months In-Water Testing
5.18 – E7 Lower Anterior Hull
5.19 – E7 Crosshatch Scribe
5.20 – E2 Driver’s Hatch 5.21 – Delaminations on BFV Hull Components – AA7039 5.22 – Headlight Guards 5.23 – Stowage Box Doors 5.24 – Floor Plate, Bilge Pump 5.25 – Driver’s Steering Yoke
5.26 – Turret Left Floor Plate 5.27 – Flagstaff Holder and GPS Antenna Bracket

xNCAP Phase II Interim Report September 2004

5.28 – Pretreated BFV Components Awaiting Primer Application – August 2003 5.29 – Primer Application – Left Headlight Guard – August 2003 5.30 – Interior Components after Applicati on of Single-Coat, Sea-Foam Green Epoxy CARC – August 2003 5.31 – Re-Man Components as Received and after Grinding/Preparation of Selected Re-
Work Areas
5.32 – Re-Man Parts after Pretreatment of Se lected Test Areas and after Primer and Topcoat Application 5.33 – QC Panels after Primer Application 5.34 – BFV M2A3 258 – APG, MD August 2003 5.35 – BFV M2A3 031 – Ft. Benning, GA May 2004 5.36 – BFV M3A3 086Y – APG, MD 5.37 – SCC Test Specimen Schematic

xiNCAP Phase II Interim Report September 2004



### LIST OF TABLES

1.1 – Summary of Non-Chromate C onversion Coating Alternatives
2.1 – Selected Pretreatments for Dem/Val Efforts 3.1 – Average Surface Corrosion and Creepage from the Scribe (5 panels) for Aluminum Alloys Coated with MIL-PRF-23377 Primer and MIL-C-85285 Topcoat 3.2 – Average Surface Corrosion and Creepage from the Scribe (5 panels) for Aluminum Alloys Coated with MIL-PRF-85582C2 Primer and MIL-C-85285 Topcoat 3.3 – Average Surface Corrosion and Creepage from the Scribe (5 panels) for Aluminum Alloys Coated with MIL-PRF-85582NC Primer and MIL-C-85285 Topcoat 3.4 – Average Surface Corrosion and Creepage from the Scribe (5 panels) for Aluminum Alloys Coated with MIL-P-53030 Primer and MIL-C-53039 Topcoat 3.5 – Average Surface Corrosion and Creepage from the Scribe (5 panels) for Aluminum Alloys Coated with MIL-P-53022 Primer and MIL-C-53039 Topcoat 3.6 – Summary Ratings for Pretreatments and Primer Systems Exposed to 12 Months of Outdoor Exposure at KSC Beachfront Corrosion Test Site 5.1 – Beachside Exposure Testing – Be gun March 2001, ACU-4 Little Creek, VA 5.2 – Coating System Test Variables 5.3 – Outline of E8 Processing 5.4 – Outline of E-9 Processing
5.5 – SDD Paint Plan 5.6 – Target Coating System for EFV LRIP 5.7 – DTM vs. Chemical Processing 5.8 – BFV Paint Systems
5.9 – Selected BFV Non-Chromate Pr etreatment Field Test Components
5.10 – Selected Re-Man BFV Non-Chromate Pretreatment Field Test Components 5.11 – BFV Components Process Parameters
5.12 – Accelerated Corrosion Testin g of QC Panels Treated a nd Painted with Field Test Components
5.13 – AMCOM – NAVAIR Panel Test Matrix October 2003
5.14 – Pull-off Adhesion Test Results AA2024-T3
5.15 – Pull-off Adhesion Test Results AA7075-T6 5.16 – Wet Tape Adhesion Test Results AA2024-T3 5.17 – Wet Tape Adhesion Test Results AA7075-T6 5.18 – Neutral Salt Fog Corrosion Results AA2024-T3 5.19 – Neutral Salt Fog Corrosion Results AA7075-T6 5.20 – Cyclic Salt Fog Corrosion Results AA2024-T3 5.21 – Cyclic Salt Fog Corrosion Results AA7075-T6 5.22 – AMCOM Coating System Demonstrations

xiiNCAP Phase II Interim Report September 2004



### ACKNOWLEDGEMENTS

This project has been executed under th e generous support of the Environmental Security Technology Certification Program (ESTCP) and the Office of the Deputy Undersecretary of Defense for Environmental Security (DUSD-ES). The effort was led by the Naval Aviation Systems Command (NAVAI R) Materials Division Patuxent River and coordinated with Joint Group on Pollution Prevention (JG-PP). This project was initiated by Craig Matzdorf, Code 4.9.7, NA VAIR Materials Engineering Division, Patuxent River, MD. The principal investigat or for this project is Bill Nickerson, Code 4.9.7, NAVAIR Materials Engineeri ng Division, Patuxent Rive r, MD. Leveraged efforts were supported by their respective services.

The authors of the report wish to acknow ledge the leadership and support of the many managers, engineers, and Fleet support personnel who contributed to this effort. Additionally, this project co uld not have been comple ted without the support and
numerous contributions from cont ractor engineers and managers. A special thanks to NAVAIR Pa tuxent River, Army Research Laboratory (ARL), National Aeronautics and Space Administratio n (NASA) and contractor personnel at Kennedy Space Center (KSC), the Air Force Corrosion Prevention and Control Office (AFCPCO), General Dynamics, Boeing, Loc kheed Martin, United Defense, and US Army Tank Command (TACOM). Assault Craft Unit Four (ACU-4), Naval Amphibious Base, Little Creek, Virginia for their support in the eval uation of test patches on La nding Craft, Air Cushioned (LCACs); S-3B, F/A-18, and H- 46 support personnel for their help in material flighttests; principal investigators from the Na vy, Army, Air Force, and Marine Corp for providing project summaries and testing results. Special thanks to the USMC Direct Reporting Program Manager Advanced Amphibious Assault (DRPM AAA) program office for the Expeditionary Fighting Vehicle (EFV), General Dynamics Amphibious Systems engineering, and General Dynamics Land Systems Lima Army Tank Plan t (LATP) for their partnership in the processing and field testing of the USMC EFV’s. PM Ground Combat Systems (PM CS), PM CS Environmental Management Team (EMT), and United Defense CTC and United Defense York personnel for their generous assistance in the US Army Bradle y Fighting Vehicle (BFV) demonstration. PEO Army Aviation, and US Army Avia tion and Missile Command (AMCOM), and ARL for continued support of th e ongoing rotary wing demonstration.

xiiiNCAP Phase II Interim Report September 2004

xiv 

### SUMMARY

Current light metal finishing procedures for industrial, auto motive, aerospace, and Department of Defense (DoD) applicati ons center around the use of hexavalentchromium based chemistries for the enhanc ing corrosion resistance and paint adhesion. Aluminum finishing, in part icular, utilizes chromate ch emistries for anodizing, anodic sealing, and pretreatment (both for convers ion coating aluminum substrates and for treating aluminum-based coatings deposited on steel). The most ubiquitous use of chromate coatings is in the conversion coati ng of aluminum alloys for use as-deposited or prior to organic coating application. These coatings are ve ry thin, inexpensive to produce, extremely process flexible, and can be applie d by immersion, spray and wipe techniques.

Chromate conversion coatings offer many advantages, however, the downside is that they contain hexavalent chromi um, or chrom ate, sp ecies that are known to be carcinogenic. The occupational safety and health issues arising from risk of worker exposure to these chemicals, as well as the costs and the potential liabilities resulting
from an accidental leak to the environmen t and waste disposal issues from normal finishing operations are making the use of chromate-based conversion coatings unattractive to the metal finishing industry.

Additionally, proposed O ccupational Safety and Health Admi ni stration Permissible Exposure Limit (OSHA PEL) cha nges for hexavalent chromium would make the use of chromate very costly. A final ruling on the PEL is scheduled for the beginning of 2006, and under the current proposal , would drop the PEL from 100 μg/m 3 (for hexavalent chromium in the form of chromic acid) to 10 μg/m 3 at the highest; or possibly as low as 0.5 or 1 μg/m 3 . This change would be especi ally hard for medium to small sized plating and coating contractors to comply with in a cost-effective manner.NCAP Phase II Interim Report September 2004



### 1.0 – INTRODUCTION

1.1 – PROJECT BACKGROUND
The Environmental Security Technol ogy Certification Program (ESTCP), established in December 1993, is managed by th e Office of the Deputy Undersecretary of Defense for Environmental Security (DUSD-ES ). The ESTCP demonstrates and validates laboratory-proven technologies that target th e DoD’s most urgent environmental needs. These technologies provide a return on in vestment through reduced environmental, safety, and occupational health (ESOH) risk s; cost savings; and improved efficiency. The new technologies typically have broad application to both the DoD community and industry.

The Joint Logistics Commanders (JLC) a nd Headquarters National Aeronautics and Space Administration (NASA) co-chartered the Joint Group on Pollution Prevention (JGPP) to coordinate joint service/agency activities affecting pollution prevention issues identified during system and component acq uisition and sustainment processes. The primary objectives of the JG-PP are to:

• Reduce or eliminate the use of Hazardous Materials (HazMats)

• Avoid duplication of effort in actions required to reduce or eliminate HazMats through joint service cooper ation and technology sharing.

JG-PP projects typically involve an or iginal equipment manufacturer (OEM) producing multiple defense systems for more than one of the Services, as well as at least one DoD depot maintaining one or more of the defense systems. JG-PP technical representatives for each project begin by identif ying a target HazMat, related process, and affected substrates or parts that may cause e nvironmental and/or work er health concerns. Project participants then identify alternat ive technologies or mate rials for evaluation.

ESTCP selected the Non-Chromate Aluminum Pretreatment (NCA P) project, led by the Naval Air Systems Command (NAVAIR) and c oordinated with JG-PP, to assist in the mitigation of the significant ESOH risks that are associated with the use of chromate conversion coatings. Chromate conversion coatings contain hexavalent chromium, a known human carcinogen that is strictly regul ated. The U. S. Environmental Protection Agency (EPA) limits air emissions and regulat es solid waste disposal from operations using hexavalent chromium. The U. S. Occ upational Safety and Health Administration (OSHA) regulates the amount of hexavalent chromium to which workers can be exposed, and has proposed reducing the Permissibl e Exposure Limit (PEL) for hexavalent
chromium to a value in the range of 10μg/m 3 to possibly less than 1 μg/m 3 . Such limits, planned for implementation within the next two years, could increase costs of the pretreatment of aluminum and aluminum a lloys; therefore, alternatives are being identified and evaluated. The project will achieve the goal of reduc ing or eliminating the
use of hexavalent chromium in aluminum finishing by dem onstrating and validating the performance of alternatives in accordance with the technical requirements and tests identified in the Joint Test Protocol (JTP).

The key benefit of the non-chromate d pretreatment alternatives being demonstrated in this report is the elimina tion or absence of hexavalent chromium from

1NCAP Phase II Interim Report September 2004

the process chemicals and as-deposited co ating. Eliminating chromates from the conversion coating or pretreatment operations will drastically redu ce user liability and risk in the life cycle of the platform or parts being coated. The key challenge for the alternatives will be matching the technical performance of chromate conversion coatings
in a cost-effective manner.

1.2 – PHASE I OBJECTIVE AND SCOPE OF WORK
The overall objective is to validate and implement multiple chromate-free aluminum pretreatment alternat ives at a broad range of us er facilities. The Phase I Report, dated 24 July 2003, presents an ev aluation of laboratory coupon testing of nonchromate aluminum pretreatment alternatives through accelerated te sts on flat coupons.
Phase I of this effort focused on the laboratory evaluation of several possible nonchromate alternative technologies. The results of the analysis were used to support field testing in Phase II on components and in-service platforms where te chnical performance is highly dependant on service environmen t and overall platform design and use. The NCAP Phase I Report from 2003 de tails the adhesion and accelerated corrosion performance of these alternatives. Phase I examined the behavior of several alloy, coating, and paint system combinati ons. The data was gene rated in accordance with the NCAP JTP, dated 13 December 2000, to determine the potential effectiveness of the alternatives as replacements for chroma te conversion coatings. Both documents are available on the JG-PP website, at the following link: http://www.jgpp.com/projects/projects_index.html , under the project titled NonChromate Aluminum Pretreatments.

Table 1.1 – taken from the NCAP Phase I report – identifies the alternative nonchromated pretreatments that were evaluated in Phase I, and provides a summary of their chemistry, applications, adva ntages and disadvantages.

Product Chemistry (from MSDSs) Processing Application

Methods Classification* Advantages Disadvantages

Alodine TM

1200S Chromic acid, complex fluorides, ferric compounds One solution,

room temperature Immersion, spray, wipe E, B, C Easy to use,
standard Contains
hexavalent
chromium

Alodine TM

5200 and
Alodine TM

5700 Organometallic
zirconate complex One solution,

room temperature Immersion, spray, wipe C Easy to use,

room temperature, drop-in replacement for
chromates Minimal corrosion inhibition, impractical color change

Bi-K
Aklimate TM Proprietary Single solution, room
temperature Immersion, spray, wipe C Easy to use,

room temperature solution replacement for
chromates Minimal bare
corrosion resistance, clear and colorless (no color change)

2NCAP Phase II Interim Report September 2004

AC-130/

131 TM Organosiloxane s, zirconates One solution,

room temperature Immersion, spray, wipe C Easy to use,

room temperature, drop-in replacement for chromates, dry in place Minimal corrosion inhibition, dry in place, kitting and solution life, clear and colorless (no color change)

Brent
Oxsilan TM

AL-0500 Organosilane, ethanol,
fluorotitanic
acid One solution,

room temperature Immersion, spray, wipe C Easy to use,

room temperature solution replacement for chromates, dry in place Minimal corrosion inhibition, dry in place, clear and colorless (no color change)

MacDermid
Chemidize TM

727ND Butyl cellosolve,
other proprietary One solution,

room temperature Spray, wipe C One solution,

room temperature Minimal corrosion inhibition, clear and colorless (no color change)

NAVAIR TCP Chromium III sulfate basic, potassium
hexafluorozirconate One solution,

room temperature, one to five
minute dwell Immersion, spray, wipe E, B, C Easy to use, drop-in replacement for chromates;
corrosion
inhibition
present; toxicology study completed Contains chromium, impractical color change

Sanchem Safegard TM 7000 (with Seal #2) Potassium
permanganate, seal: polyacrylic acid, poly propylene glycol, fatty
acid esters Two solution (coating and seal), elevated temp (200 ° F) cure on sealer;

p retreatment is
ambient Immersion, spray, wipe C Pleasing bronze-gold
color to coating, easy to

use Minimal corrosion
inhibition without
sealer. Sealer requires
elevated
temperature cure and has poor
adhesion
characteristics.

Pantheon

PreKote TM Diethylene glycol monobutyl ether, n-methyl pyrrolidone One solution, wipe on by
mechanical
abrasion of substrate,

room temperature Wipe C Non-toxic coating left as a
result of

process Minimal bare
corrosion resistance,
laborious manual application required, minimal color change * E=electrical, B=bare, C=coated Table 1.1: Summary of Non-Chromate Conversion Coati ng Alternatives

In the Phase I Report, Matzdorf, et al., reported that, “Each alternative tested shows acceptable performance in some selected cases that may be satisfactory for a given user, depending on operating environment and business cases involved. The only compositions that come close to matching the te chnical, process, cost , and flexibility of
chromates are based on trivalent chromium. Although trivalent chromium is present in

3NCAP Phase II Interim Report September 2004

the solution and coating, toxicity studies, International Agency for Research on Cancer (IARC) regulations, and OSHA PELs suggest that the use of Tr ivalent Chromium Product (TCP) is acceptable, especially give n its well-rounded performance. The next best product in testing was Alodine TM 5200/5700. Alodine TM 5200/5700 contains no chromium, is process flexible and can be ap plied like chromate conversion coatings. The remaining alternatives performe d variably in the evaluation.”

1.3 – PHASE II OBJECTIVE AND SCOPE

Out of the Phase I Laboratory testing, the potential alternativ e technologies were
down-selected for field demonstration and va lidation testing by the respective services and program offices based upon their unique performance and operational environment requirements. The main advantage of any a lternative is the elimination of hexavalent chromium. In most cases, the alternatives are trying to match the process and technical performance of the chromate solutions and coatings.

In Phase II of the ESTCP NCAP project, along with JG-PP and other leveraged funding, the focus was on validating the feasib ility of applying a nd maintaining, i.e. utilizing and repairing, these conversion coa tings in lieu of conventional chromate-based technologies. Testing was conducted with vari ous organic coatings systems, according to the particular service and platform requirements. This variety in fiel d testing helps assure that potential candidates to he xavalent chromium are applicab le as alternatives in their own right, without the necess ity of specifying the use of only one or two possible primers/paint systems. The field test phase of this project was c onstructed to cover the broadest range of aluminum alloys, pr ocessing methods and conditions, and the operational environments experienced by fielded platforms across DoD.

4NCAP Phase II Interim Report September 2004



### 2.0 – SELECTED DEMOSTRATION / VALIDATION

The pretreatments being tested in Phase II are shown in Table 1.2.

Pretreatment DoD Service Platform(s) Facilities

Alodine 5700

TCP - Color US Army Ground
Combat Bradley Fighting
Vehicle Red River Army Depot

United Defense - York

Alodine 5700

TCP US Army Aviation CH-47, H-60 Corpus Christi

Ct AVCRAD

Alodine 5700

TCP USMC Amphibious
Assault Expeditionary Fighting
Vehicle General Dynamics –
Lima

AVTB – Camp
Pendleton

PreKote US Air Force F-16, C-130 Hill AFB

TCP NAVAIR CH-46, S-3, F-18 NADEP’s CP, NI

TCP NAVSEA Landing Craft, Air
Cushioned NSWC – Little Creek,

VA

Table 1.2: Selected Pretreatments for Dem/Val efforts

2.1 – NAVAIR TRIVALENT CHROMI UM PRETREATMENT (TCP)
TCP solutions generate pretreatment film s on aluminum and aluminum alloys that improve corrosion inhibiti on and paint adhesion while maintaining electrical conductivity. The solution is used in a fa shion similar to conventional chromate pretreatments. It can be applied by immersion, spray, and wi pe application methods with a few minutes dwell time. Since the pro cess chemistry is based on a surface reaction, rinsing stops the reaction and yields the final coating. TCP films have a very light color ranging from purple to blue to tan, depending on the alloy.

2.2 – HENKEL SURFACE TEC HNOLOGIES ALODINE TM 5200  AND

ALODINE TM 5700 

Alodine TM 5700 is the ready-to-use, or pre-mixed, version of Alodine TM 5200.
The solution is used in a si milar fashion to conventional ch romate pretreatments. A major benefit is that it can be applied by immersi on, spray, and wipe application methods with a
few minutes dwell time similar to chromate c onversion coatings. Coating can be applied using rinse or dried in place. Deposited coatings have a light color ranging from blue to tan depending on the alloy.

2.3 – PANTHEON CHEMICAL COMPANY PREKOTE TM

PreKote TM is a non-chromated conversion coating used for metal surface pretreatment and pre-coating prior to painti ng. It is designed to promote paint bonding

5NCAP Phase II Interim Report September 2004

on aluminum, stainless steel, titanium, magnesium, and carbon st eel. It is biodegradable, non-toxic, non-flammable, non-hazardous, non-corrosive, and free of phosphates and heavy metals. The solution is applied by a manual or automated scrubbing process, requiring multiple material application, scrubbin g, drying, and rinsing steps. As a result, the product is not amenab le to immersion or spra y processing. PreKote TM has a slightly gray tint as applied.

2.4 – ADVANCED CHEMISTRY & TECHNOLOGY INC. AC-130/131 TM

AC-130/131 TM conversion coating is a non-chroma ted solution that is designed to increase adhesion of organic coatings to aluminum, titanium, and corrosion resistant steel. The final coating solution is a produc t of mixing four components packaged in a “kit” that can be sized appropriately for a given application. The mixed solution has a “pot life” of 12-hours and is applied by spray, wipe, brush or dipping to leave a thin wet film on the parts. The coating is dried in pl ace without rinsing and care must be taken to remove puddles and excess coati ng solution that may be retained in pockets or crevices that do not freely drain. These sol-gel coatings are clear and colorless and yield a slightly wet or glossy appearance.

2.5 – PHASE II EFFORTS SUMMARY

Field testing of the TCP was underway with NAVAIR when the ESTCP project began and the two efforts were leverage d together. In add ition, Navy Sea Systems Command (NAVSEA) had begun an independent evaluation of the TCP for the Landing Craft, Air Cushioned (LCAC). As a result , the Navy supported its aircraft and LCAC demonstrations, and the Air Force (AF) took the lead on the PreKote TM demonstration with the F-16 and C-130 platforms. As a resu lt of these initial, leveraged efforts, field testing opportunities outside the Navy were selected for the NCAP project to more broadly cover the potential a pplications and operational en vironments. ESTCP funded the Phase II efforts for the USMC Expeditionary Fighting Vehicle (EFV), the US Army Bradley Fighting Vehicle (BFV), and the US Army Aviation and Missile Command (AMCOM) platforms. NAVAIR, Boeing, and NASA have been demonstrating the AC131 TM for pre-paint and bonding applications.

Figure 2.1: US Marine Corps Expeditionary Fighting Vehicle (formerly Advanced Amphibious Assault Vehicle)

6NCAP Phase II Interim Report September 2004

USMC Expeditionary Fighting Vehicle

The EFV demonstration/validation effort was conducted with General Dynamics Amphibious Systems (GDAMS), General D ynamics Land Systems (GDLS), and the Direct Reporting Program Manager (DRPM AA A) personnel. The prototype and System Design and Development Phase (SDD) vehicle hull and turret space frame structures are
constructed from machined and welded al uminum alloys, and subsequently spray processed at the Lima Army Tank Plant (L ATP), GDLS facility. The processing and painting were performed by LATP, GDLS contra ctor personnel, with on-site technical and chemical support provided by NAVAIR an d GDAMS engineers. Additionally, since the aluminum alloy (AA) used to manufacture the hu ll and turret structures for the EFV was a new, untested alloy, AA2519-T87; NAVAIR and Army Re search Laboratory (ARL) conducted numerous laboratory panel te sts to optimize the process chemicals, time constraints, and subsequent primer/pai nt coating systems for use with the EFV. Prototype and SDD vehicles have been in field evaluation fo r over 2 years, and are still undergoing rigorous evaluations as part of the Test & Evalua tion phase of SDD, from inwater amphibious testing at the Amphibi ous Vehicle Test Br anch (AVTB), Camp Pendleton, CA and NAVAIR, Patuxe nt River, MD to desert/la nd testing at Marine Corps Base (MCB) 29 Palms, CA. On-site vehicl e inspections were c onducted periodically during testing, by GDAMS, NAVAIR, and USMC personnel.

US Army Bradley Fighting Vehicle

The BFV demo with United Defense (UDLP) and the office of the Program Manager Combat Systems (PMCS) used TCP-C, a modified TCP chemistry that imparts a dark purple-blue to brown color to the as -deposited conversion co ating. The selection
of TCP-C over the baseline TCP was made at the request of UDLP and PMCS engineering because UDLP desire d the visual quality control assurance from a practical color change. The BFV demonstrations we re component-only test s, as the OEM hull processing facilities did not have a spray- processing apparatus. A list of several components was compiled by NAVAIR, PMCS , and UDLP personnel, and then three sets of components, two new sets and one re-manufactured set, were procured. The components were immersion process conversio n coated, primed, and top-coated at the NAVAIR Patuxent River, MD facility. The components were then transported to the
field demonstration facilities to be installe d on three M2A3 or M3A3 BFV variants as
either test track or fielded tr aining vehicles at various US Army sites. ARL is tracking and evaluating the 3 BFV vehicles in field testing; and reported on the performance of the vehicles at 6-months and 1-year.

Based on panel testing data generated at ARL, Aberdeen Proving Ground (APG), MD; the Red River Army Depot (RRAD) installed and currently maintains an Alodine TM
5700 immersion bath for conversion coating of aluminum road wheels for US Army ground combat vehicle platforms. RRAD obtained an approval letter for use of
Alodine TM 5700 on aluminum road wheels, and is currently applying the coating on rework vehicles via an immersion process.

7NCAP Phase II Interim Report September 2004

Figure 2.2: US Army Br adley Fighting Vehicle

US Army Aviation Command

AMCOM engineers generated a large labo ratory test matrix in October 2003 to down-select the best conversion coatings a nd non-chrome primers to examine in field testing. The test panels were processed and painted at NAVAIR Patuxent River (PAX),
MD. Corrosion and adhesion evaluations we re conducted by ARL. The panel matrix
evaluated the several combina tions of non-chromate coating systems, consisting of TCP,
Alodine TM 5700, and PreKote TM on aluminum, with both water and solvent-reducible non-chrome primers. Alodine TM 1200S with high-solids, chro mated epoxy primer was the control system. All coating systems were top-coated with Chemical Agent Resistant Coating (CARC) paint. Two non-chrome co ating systems were identified for field testing, one with Alodine TM 5700 and the other using TCP as the conversion coating, based upon the results and r ecommendations of the labora tory evaluations at ARL. AMCOM personnel selected the Connecticut Aviation Classification Repair Activity Depot (AVCRAD) and Corpus Christi Army Depot (CCAD), TX as the two processing sites for this demo. Currently, six aircraft are planned for demonstration and validation efforts, with actual coating/pa inting operations to begin in FY05. Three aircraft will be coated at each demo site, with one airframe from each site being co ated with a chromated conversion coating and MIL-PRF-23377 C2 chro mated primer, as the control coating system. The platform for this demonstratio n will be either the CH-60 Blackhawk, the CH-47 Chinook, or some combination of th e two. The Program Executive Office (PEO)

8NCAP Phase II Interim Report September 2004

Aviation, along with the indivi dual Program Management Activities (PMA’s) from Army
Aviation will determine if more aircraft or more various platforms are required for a full
field test.

Figure 2.3: US Army H-60 Blackhawk

9NCAP Phase II Interim Report September 2004



### 3.0 – ONGOING MARINE ATMO SPHERE EXPOSURE TESTING

3.1 – BACKGROUND

Phase I testing included outdoor, beachsi de exposure testing at the Corrosion Technology Testbed, Kennedy Space Center, FL . The testing is being completed by NASA and contractor personnel at the Ke nnedy Space Center (KSC), FL. 3”x5” aluminum coupons were pretreated with th e alternative conversion coatings being examined, primed, top-coated, and shipped to KSC for testing in 2001.

The Phase I Report tabulated the performance data for the different pretreatment and primer combinations according to alumi num alloy. The rankings were from 1-year exposure data. The exposure testing was c ontinued beyond 1 year, and 2-year ratings
were taken in December 2003. As stated in the Phase I report, pe rformance ratings are measured by ASTM D 1654 Procedure A; and any rating below “3” is considered failed and the panel removed from testing.

NASA’s test facility is located 1.5 m iles south of Launch Complex 39A. Figure
3.1 shows an aerial view of the site.

Figure 3.1: KSC Corrosion Test bed Beach-side Aerial View

Test stands are located 30 meters (100 feet ) from the mean high-tide line and face the water. Test coupons are in stalled on yellow, painted steel test stands using porcelain insulator stand-offs. The rack angle of the coupons is 30 degrees from horizontal. An “X” incision was scribed through the coating so that the smaller angle of the “X” was 30 to 45-degrees, making sure that the coating was scribed all the way to the substrate. The scribe had a 45-degree beve l, and each line of the “X” was approximately 4-inches long. The back and edges of the coupon were primed to prevent undercutting and corrosion products from cont aminating the test stands.

10NCAP Phase II Interim Report September 2004

The coupons were evaluated for surface corrosion and creepage from the scribe at 6-month intervals. Two-year ratings base d on creepage from the scribe (ASTM D 1654A) are detailed here. Remaining coatings are being evaluated until failure, and will be rated on creepage from the sc ribe performance at yearly in tervals, until completion of the 5 year test in December 2006.

3.2 – COATING PERFORMANCE AT TWO YEARS

Tables 3.1-3.5 detail corrosion perform ance for coating systems on each alloy after two years. An average rating “0.0” de signation means that the coating system has failed and has been removed. However, if only some of the coatings from each set of 5 failed, the average rating is calculated fr om the remaining coupons, and the number of failed panels is given. The 1- year ratings are given first (l eft) for each coating/alloy combinations, to show any degradation re lative to the other conversion coatings.

Pretreatment AA2024 AA7075 AA5083 AA2219
Alodine 1200S (control) 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0

Alodine 5200/5700 10.0 10.0 9.2 8.2 10.0 10.0 10.0 10.0

Bi-K Aklimate 10.0 10.0 10.0 10.0 10.0 10.0 9.8 9.8

AC-131 10.0 10.0 10.0 10.0 10.0 10.0 9.3 9.3

Chemidize 727ND 10.0 9.8 10.0 10.0 10.0 10.0 7.6 6.4

Oxsilan Al-0500 9.6 9.6 10.0 10.0 10.0 10.0 9.8 9.8

Sanchem 7000 9.6 8.2 10.0 9.8 10.0 10.0 4.2 0.6 -4F

TCP 10.0 10.0 8.0 8.0 10.0 10.0 10.0 9.0

PreKote 10.0 10.0 10.0 10.0 10.0 10.0 10.0 7.2 Table 3.1: Average Surface Corrosion and Cr eepage from the scribe (5 panels) for Aluminum Alloys Coated with Mil-PRF-23377C Primer and Mil-C-85285 Topcoat

Pretreatment AA2024 AA7075 AA5083 AA2219
Alodine 1200S (control) 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0

Alodine 5200/5700 10.0 10.0 8.8 8.8 10.0 10.0 10.0 10.0

Bi-K Aklimate 10.0 10.0 10.0 10.0 10.0 10.0 9.8 9.4

AC-131 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0

Chemidize 727ND 9.8 9.8 7.6 7.6 10.0 10.0 9.0 9.0

Oxsilan Al-0500 9.6 9.6 7.6 6.6 10.0 10.0 9.4 9.2

Sanchem 7000 0.0 0.0 3.2 2.4 -2F 10.0 9.4 6.4 6.4

TCP 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0

PreKote 10.0 10.0 10.0 10.0 10.0 10.0 9.8 9.6

Table 3.2: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated with Mil-PRF-85582 C2 Primer and Mil-C-85285 Topcoat

11NCAP Phase II Interim Report September 2004

Pretreatment AA2024 AA7075 AA5083 AA2219
Alodine 1200S (control) 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0

Alodine 5200/5700 10.0 9.8 8.8 8.0 10.0 10.0 9.4 9.4

Bi-K Aklimate 0.8 0.0 1.0 0.0 10.0 9.4 0.0 0.0

AC-131 5.3 5.0 7.3 4.7 10.0 10.0 0.0 0.0

Chemidize 727ND 0.8 0.0 1.2 0.0 10.0 9.4 0.0 0.0

Oxsilan Al-0500 7.6 7.2 9.2 9.0 10.0 9.8 2.8 0.0

Sanchem 7000 0.0 0.0 5.4 0.0 9.2 8.8 0.0 0.0

TCP 10.0 10.0 9.6 9.2 10.0 10.0 9.6 9.6

PreKote 3.8 0.0 1.4 0.0 9.0 8.6 0.0 0.0 Table 3.3: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated with Mil-PRF-85582 NC Primer and Mil-C-85285 Topcoat

Pretreatment AA2024 AA7075 AA5083 AA2219
Alodine 1200S (control) 10.0 10.0 9.8 9.8 10.0 10.0 2.4 0.0

Alodine 5200/5700 10.0 7.8 8.6 8.6 10.0 10.0 3.4 4.0-4F

Bi-K Aklimate 0.8 0.0 9.4 0.0 9.8 9.4 0.0 0.0

AC-131 5.7 3.0 4.7 0.0 10.0 10.0 0.0 0.0

Chemidize 727ND 4.8 0.0 5.8 0.0 10.0 10.0 0.0 0.0

Oxsilan Al-0500 5.8 2.0-3F 9.2 1.8-4F 10.0 9.8 0.0 0.0

Sanchem 7000 9.8 0.0 0.2 0.0 10.0 9.8 0.0 0.0

TCP 10.0 10.0 10.0 10.0 10.0 10.0 3.6 1.4-4F

PreKote 4.2 0.0 6.0 0.0 10.0 10.0 0.0 0.0 Table 3.4: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated with Mi l-P-53030 Primer and Mil-C-53039 Topcoat

Pretreatment AA2024 AA7075 AA5083 AA2219
Alodine 1200S (control) 10.0 10.0 9.8 9.6 10.0 9.8 0.4 0.0

Alodine 5200/5700 10.0 10.0 8.8 8.8 10.0 9.8 2.4 0.0

Bi-K Aklimate 3.2 0.0 6.4 0.0 10.0 9.6 0.0 0.0

AC-131 9.5 9.0 1.3 0.0 10.0 10.0 1.0 0.0

Chemidize 727ND 6.0 0.0 2.2 0.0 9.2 8.4 0.0 0.0

Oxsilan Al-0500 9.4 2.8-2F 7.6 1.8-4F 10.0 10.0 0.8 0.0

Sanchem 7000 7.8 2.0-4F 6.6 0.0 10.0 9.6 0.0 0.0

TCP 10.0 9.8 10.0 10.0 10.0 10.0 1.4 0.0

PreKote 3.4 0.0 2.6 0.0 10.0 9.6 0.0 0.0 Table 3.5: Average Surface Corrosion and Cr eepage from the scribe (5 panels) for Aluminum Alloys Coated with Mi l-P-53022 Primer and Mil-C-53039 Topcoat

Summary of Alternative Performance Table 3.6 details the summary performan ce of each alternativ e pretreatment by primer system. It also shows an average ra ting for each primer across all pretreatments. These ratings provide a gauge of pretreatment robustness, showing how they perform across different alloys and primers, compared to the excellent all-around performance of
the hexavalent chromium control.

12NCAP Phase II Interim Report September 2004

13 Primer

Pretreatment 23377 85582 C2 85582 N 53022 53030 All Coatings

Alodine 1200S (control) 10.0 10.0 10.0 10.0 10.0 10.0 7.6 7.4 8.1 7.5 9.1 8.9

Alodine 5200 9.8 9.6 9.7 9.7 9.6 9.3 7.8 7.2 8.0 6.8 9.0 8.5

Bi-K Aklimate 10.0 9.9 10.0 9.9 3.0 2.4 4.9 2.5 5.0 2.4 6.6 5.4
Boegel 9.8 9.8 10.0 10.0 5.7 4.9 5.5 4.8 5.1 3.2 7.2 6.5

Chemidize 727ND 9.4 9.1 9.1 8.7 3.0 2.5 4.4 2.1 5.2 2.6 6.2 5.0

Oxsilan Al-0500 9.9 9.8 9.2 8.6 7.4 6.9 7.0 3.9 6.3 3.4 7.9 6.5

Sanchem 7000 8.5 7.2 4.9 4.3 3.7 3.8 6.1 2.9 5.0 2.5 5.6 4.1

TCP 9.5 9.3 10.0 10.0 9.8 9.7 7.9 7.5 8.4 7.9 9.1 8.9

X-It PreKote 10.0 9.3 10.0 9.9 3.6 2.4 4.8 2.5 5.1 3.1 6.5 5.4
Overall Alternative Average 9.7 9.3 9.2 9.0 6.2 5.8 6.1 4.5 6.2 4.4 7.5 6.6

Table 3.6: Summary Ratings for Pretreatme nts and Primer Systems – 24-Months of Outdoor Exposure at Kennedy Space Center Beachfront Corrosion Test Site

The Alodine TM 5200/5700 and TCP alternatives perform comparably to the
Alodine TM 1200S control regardless of the primer coating. Their superior performance is strongly evident in the non-chromate primer systems where no othe r alternative comes close. For the chromated primers, most of the alternatives s how good performance, especially PreKote TM , Bi-K Aklimate TM , and AC-131 TM , all of which rate similar to the
Alodine TM 5200 and TCP in the high 9’s. Only the TCP and AC-130 TM matched the perfect rating of the Alodine TM 1200S, and only when used in combination with the 85582C2 primer.

Like the previous corrosi on tests, the chromate-based p rimer systems perform equally well and are the basis of the best coati ng systems. The non-chromate systems, on average, rank lower than the chromate sy stems especially with the poorer performing
alternatives. There are two notab le exceptions in this test.

The performance of the 85582 N primer with Alodine TM 1200S, TCP and
Alodine TM 5200/5700 differs little from their perf ormance with the sister chromate primers. The performance of the TCP and Alodine TM 5200/5700 with the non-chromate epoxy primers, 53022 and 53030 is equivalent or better than Alodine TM 1200S with the same primers. These non-chromate systems match the performance of the sister systems with chromate primers. No other non- chromate system competes as well.NCAP Phase II Interim Report September 2004



### 4.0 – LEVERAGED EFFORTS

4.1 – AF F-16/C-130

4.1.1 – BACKGROUND A multi-year effort at Hill Air Force Base (AFB) was under taken in 2000, with the oversight of the Air Force Corrosion Pr evention and Control Office (AFCPCO), to reduce or eliminate the use of chromate comp ounds in the paint preparation process for
aircraft.

Of the four products tested, three we re eliminated early through laboratory testing. The fourth candidate, PreKote, wa s tested extensively against the current process. PreKote performed better th an chromate conversion coating in adhesion/flexibility tests and performed equally well in other testing. In addition, it was
found that PreKote could eliminate the solven t wipe down as well as the acid brightener used in conventional paint preparation proce dures. The use of PreK ote also reduced the
need to sand anodized surfaces before re painting, but the limitations are that the application process is labor intensive. The application process used in the Qualification Operational Test and Evaluation (QOT&E) process is called the “three-step” proc ess. Step 1: the surface of the aircraft is
scrubbed with PreKote and rinsed after scrubbing. Step 2: PreKote is applied to the surface again and agitated, and allowed to comp letely dry on the airc raft surface. Step 3, PreKote is applied to the surface again and ag itated to remove the residue from Step 2.

4.1.2 – FIELD TESTING

Operational tests have been conducted on several aircraft and are ongoing. Air Education & Training Command (AETC) used PreKote on two aircraft in 1996. In March 1997, an F-16 was scuff sanded and repain ted using PreKote in the prep for paint process. In November 1997, two fully stripped F-16 aircraft had their right wings treated
with PreKote while the rest of the aircraft was treated with chromate conversion coating. These aircraft are in service at Eglin and at Homestead. Test ai rcraft, T-38, F-16, A-10, and C-130’s, were prepared half with Alodine and half with PreKote. AFCPCO is the responsible engineering authority for T.O. 1-1-8, “Application and Removal of Organic Coatings, Aerosp ace and Non-Aerospace Equipment.” In 2000, they began evaluating PreKote for possible add ition to T.O. 1-1-8 as an Air Force-wide approved alternative for ch romated conversion coatings (as specified in MIL-C5541/SAE AMS-C-5541 and MIL- DTL-81706). Based on extensive laboratory testing and limited field use (on F-16s, T-37s, and T- 38s), AFCPCO determined there was not enough data on PreKote’s operational performan ce on various AF aircraft substrates in severely corrosive environments. For example, F-16s have anodized skin panels which increases their corrosion resistance, but many AF aircraft do not have anodized skins. Trainer aircraft typically do not experience extremely corrosive environments. Therefore, the AF corrosion control o ffice initiated a QOT&E of PreKote in conjunction with Ogden Air Logistics Ce nter (OOALC), the Air Force Research Laboratory (AFRL) and the applicable ope rational Major Commands. The QOT&E is a

14NCAP Phase II Interim Report September 2004

six-year, full depot maintenance cycle evaluati on in actual use, as part of a full coating system, that began in 2001 on four operati onal aircraft – two A-10s and 2 C-130s.

4.1.3 – FIELD TEST RESULTS

Hill AFB and the owning units have examined each of the test aircraft in 2002
and 2004. The results so far are very positive and no detrimental effects from the PreKote
have been discovered. The half -and-half test aircraft prepared at Hill exhibited equal or better paint adhesion on the Pr eKote side when compared to the Alodine side. The AFCPCO has completed a 24-month operational evalua tion of PreKote on
USAF aircraft. Results at th e 24-month point of the QOT&E indicated paint adhesion performance is comparable between PreKote an d Alodine 1200S chromated conversion coating. There was no evidence of decreased corrosion protection on the PreKote treated areas of the test aircraft, but corrosion perf ormance cannot be fully evaluated until the coatings are stripped at the end of the testing. The 24-month results are sufficient to allow AFCPCO to incorporate PreKote into T.O. 1-1-8, though they will continue the QOT&E for the full six years and evaluate the test aircraft when the paint is stripped in depot. Additionall y, AFCPCO is also participating in other on-going PreKote operational evaluations.

Figure 4.1: Application of PreKote at Hill AFB

4.1.4 – STATUS As of February 2004, AFCPCO has appr oved PreKote as a surface treatment alternative to chromate conversion coating pr ior to exterior painting of USAF aircraft. The approved process is being added to T.O. 1-1-8, “Application and Removal of Organic Coatings, Aerospace and Non-Aerospace Equipment,” and includes specific process steps. The use of PreKote on AF aircraft requires System Program Office (SPO) approval, and the use of a chromated primer.

The F-16, T-37, T-38 and T-1 SPO’s have now approved the use of PreKote, and Headquarters Air Education and Training Co mmand (HQ AETC) has ma ndated its use on all AETC aircraft for which it’s approved. If a base, MAJCOM, or ALC decides to

15NCAP Phase II Interim Report September 2004

pursue using PreKote in their paint processe s on other systems, it must obtain approval from the appropriate SPOs. AFCPCO will prov ide existing test results upon request to assist SPOs with the engineering de cision whether to approve PreKote. However, the AFCPCO has noted some ar eas of consideration in the use of PreKote. Since application of PreKote is largely a manual proc ess, the consistency of the process may be important to an overall satisfactory result. To achieve results equal to other weapon systems, they recommend adhe ring closely to application practices that have already been established. Also, they recommend the use of the current three-step application process, because it was used fo r the QOT&E. Variations of the process are being developed, but AFCPCO cannot recommend them until more testing is completed. Note that all test results to date, current SPO approvals, and the assessment of low risk, are contingent on the us e of a qualified chromated prim er. When PreKote is used, corrosion inhibition comes only from the ch romated primer. Past performance of nonchrome paint systems in AF use has b een poor; the AFCPCO strongly recommends against the use of PreKote with non-chromated primers.

16NCAP Phase II Interim Report September 2004

4.2 – NAVAIR S-3

4.2.1 – BACKGROUND The US Navy’s S-3 support aircraft are currently sprayed with a chromate conversion coating during de-paint/re-paint operations while undergoing Standard Depot Level Maintenance (SDLM) at the NADEP NORIS facility. Four aircraft were sprayed with TCP for the S-3 demonstration; the first two were treated with TCP on the aft (tai l) section only. The 3rd and 4th aircraft were completely
treated with TCP.

4.2.2 – PROCESSING Two tail sections of S-3A support aircraft were spray processed with TCP, in July and August of 1999. They were then fini shed with TT-P-2756, a non-chromated, selfpriming polyurethane topcoat. BUNO 160144 (AV-61) was processe d on July 24, 1999 at NADEP NORIS.
This aircraft was attached to VS-31, Jacksonville, FL . This was the first aircraft field application of the TCP. BUNO 160589 (AO-62) was processed on August 2, 1999 at NADEP NORIS. This aircraft was attached to VS-41, North Island, CA. Two full S-3B support aircraft were spray processed with TCP in April and June of 2000. They were then finished with TT-P-2756, a non-chromated, self-priming polyurethane topcoat. BUNO 159770 (AO-75) was processed on April 30, 2000 at NADEP NORIS.
This aircraft was attached to the Force S upport Test Squadron, Pa tuxent River NAS, MD. BUNO 106158 (AO-76) was processed on June 7, 2000 at NADEP NORIS. This aircraft was attached to VS-35 North Island, CA and then to VS-38 for a Western Pacific (WESTPAC) carrier deployment. The spray processing for these aircraft was overseen by Mr. Tim Woods, 4.9.7,
NORIS Materials Division.

The tail section of the S-3 was selected for the initial field testing because all of
the common aluminum surfaces used on this ai rcraft, along with the various finishes (i.e. bare, clad, anodized, etc.), are represented ove r the aft section. The control coating for the
chromated areas of the tw o tail-only demonstrations was Turco Accelagold TM . All aircraft were deoxidized using Turco 3003 TWA TM . All test aircraft were processed and painted in the same manner, with the same application procedures used for chromate processing at North Island. TCP was spray applied over the horizontal and vertical tail surfaces, and aft fuselage. North Island’s normal spray pr ocedures were followed, whereby, the conversion coating materials were sprayed on wetted surfaces beginning at the bottom and working upward. The aircraft was rinsed with tap water at 50-70 psi following each process chemical application. A bluish irid escence was evidenced in the TCP application areas, but there was little color change relative to the chromated areas.

17NCAP Phase II Interim Report September 2004

Figure 4.2: Fuselage Sta tion 496-transition area

Figure 4.3: Close-up of TCP Treatment, Dry

The aircraft was then painted with the TT-P-2756 Self-Priming Topcoat (SPT), a non-chromated, polyurethane topcoat that is used without an underlying primer.

18NCAP Phase II Interim Report September 2004

Figure 4.4. Finished BUNO 160144, North Island, July 1999

4.2.3 – FIELD TESTING RESULTS BUNO 160589 was inspected at NORI S by Tim Woods on May 17, 2001. He reported that the corrosion control actions perfor med on the tail area of that aircraft were consistent to those performed in other areas of the aircraft.

BUNO 160144 was inspected at NAS Jacksonville by Jack Benfer, NADEP JAX Materials, on January 4, 2002. This airc raft, A/C S-3B, BUNO 160144 (700) is attached to VS-31. He reported that an interview with Maintenance Control indicated that this aircraft appeared to be performing equivalent to other S-3 aircraft within the squadron. Man-hour and flight time data sin ce February 2001 was presented to the inspection team. Additional data encompa ssing man-hours and flight time since receipt from depot would require a more thorough revi ew of maintenance control log files and was not provided at the time of the insp ection. Data presented is as follows:

S-3B AC 160144 (700) [Feb 2001 to Jan 2002]
Prevention 3299.3 man-hours
Treatment 1632.2 man-hours Flight Time 419.2 hours

No differentiation of corrosion was discernable between port and starboard sides. In addition, no differentiation was discernable between forward and aft sections of the fuselage areas inspected.

BUNO 160158 was inspected at NORIS by Tim Woods and Ed Mullin on December 17, 2001, after returning from a 6+ m onth carrier deployment. It was reported

19NCAP Phase II Interim Report September 2004

by the maintenance personnel that this airc raft exhibited more corrosion than was normally observed. The aircraft showed signs of corrosion along some of the fastener rows, and in some surface areas away from fasteners or joints. The average thickness of the paint adjacent to an observed filiform corro sion area was 2 mils. This hits mid-range of the recommended thickness (1.7-2.3 mils) for SPT. Corrosion not necessarily adjacent
to fasteners could be found in areas around th e outer mold-line of the aircraft.

Figure 4.5. Open Area Corrosion

No control aircraft was available for th is evaluation, as VS-38 did not have a chromated aircraft with a pa int date close enough to 16015 8 for any correlation to be made. VS-35 had in its inventory S-3 BUNO 160567. SDLM was completed on this aircraft the week prior to 160158 being completed. BUNO 160567 (side #704) at VS-35 served as an operational control during the validation period of TCP on aircraft 160158. The fundamental difference in the finish sy stems of these aircraft is limited to the aluminum pretreatment; while 160158 had TCP applied, 160567 received chromate conversion coating (CCC). Both of thes e aircraft returned from a WESTPAC deployment within the same time period, SPT was applied to both, and both logged similar flight hours. Less active corrosi on was evident on 160567, and, relative to 160158, fewer corrosion maintenance areas were evident. The pain t thickness of 160567
measured closer to 3.0 mils in most areas inspected over the outer mold-line. One important difference to note is that 160158 was deployed on-board the USS Constellation, which is an oil-burning car rier, while 160567 was deployed on-board a nuclear-powered carrier. Of the tail only aircraft, bot h have shown equivalent perf ormance to the rest of the airframe over 2 years of service. Of the fu lly coated airframes, one has shown normal corrosion compared to similar controls. BUNO 160158 S-3B saw a full deployment in
the South Pacific on the USS Constellation. Th is airframe showed more corrosion than comparable planes in the squadron. A specific cause for the extra corrosion was not identified but two potential
causes were identified: insufficient corrosi on protection by the TCP/SPT coating system or inadequate rinsing during processing. Ex cessive TCP residue left during processing may cause corrosion in non-chromate coating systems. Since neither can be proven independently or acting together no conclusi on can be reached other than more testing with this coating system is re quired before use in the field.

20NCAP Phase II Interim Report September 2004

Figure 4.6: S-3A Viking – TC P on aft section – August 1999

4.2.4 – STATUS As a result of the mixed field perfo rmance of the TCP with SPT, additional laboratory testing was conducted with pane l specimens according to ASTM G-85 SO 2 acidified salt fog exposur e. The initial 500-hour SO 2 salt fog test performed at NAVAIR on the TCP/SPT coating did not show a diffe rence in performance between the TCP/SPT and Accelagold/SPT system that is curren tly used on the S-3. When the test was extended to 1000 hours, corrosion in the unscr ibed areas did appear on non-chromated systems but not on systems that had chromate in the pretreatment or primer. This discrepancy highlights the risk in evaluating new technologies by the minimum performance standards of the control coati ngs. NAVAIR does not recommend the use of TCP with the SPT, and will not pursue implementation of a non-chromate conversion coating on the S-3 platform at this time.

21NCAP Phase II Interim Report September 2004

4.3 – NAVAIR F/A-18 C/D

4.3.1 – BACKGROUND Naval Aviation experiences the harshe st possible environment for aluminum corrosion, in that most fielded strike and support aircraft are deployed shipboard on
aircraft carriers. Aluminum is the main metallic substrate used in production of military
airframes and aircraft skins. Current protection schemes are focused around the use of chromate materials, both for inorganic conversion coatings and sec ondary primer applications. Even with the current hexavalent chromium coating syst em, corrosion is a very large driver for operations and maintenance costs and se verely impacts operational readiness. As the US Navy’s premier attack strike fighter aircraft, a nything affecting the flight hours to maintenance down- time is a critical issue. For this reason, any possible alternatives must at the very least meet the performance of current, less environmentally friendly systems, even while we continue to strive for better than the current corrosion protection.

4.3.2 – PROCESSING Two full F/A-18C fighter aircraft we re spray processed with TCP10M2, a thickened version of the TCP, in November of 2000. They were th en primed with MILPRF-85582 C1 and topcoated with MIL-P-85285 Gray. BUNO 163757 (RF94) was processed on November 18, 2000 at NADEP NORIS. This aircraft, was assigned to COMSTR KFIGHTWINGPAC, VFA-146, at NAS Lemore,

CA. BUNO 163459 (RF96) was processed on November 21, 2000 at NADEP NORIS. This aircraft, was assigned to COMSTRKFIGHTWINGLANT, VFA-81, NAS Oceana,

VA. The spray processing for these aircraft was overseen by Mr. Tim Woods, 4.9.7, NORIS Materials Engineering Division. A synopsys of his initial evaluation of BUNO 163757 pro cessing is included below. Both aircraft were stripped, processed, and painted in the same manner, consistent
with the chromate convers ion coating processing. The paint was removed using plastic medi a blasting (PMB). Subsequently, glass bead blasting was used to remove any corrosion products.
The aircraft was washed with Turco 5948R TM mildly alkaline cleaner, and then deoxidized with Turco 3003 TWA. During bot h of these cycles, white Scotch Bright TM
pads were used to scrub the bare aluminum su rfaces. The deoxidizer was left to dwell on
the aircraft for 15 minutes.

22NCAP Phase II Interim Report September 2004

Figure 4.7: TCP Application on BUNO 163757, North Island, November 2000

Following a thorough rinse after each of th ese steps the TCP was spray applied. Ten gallons was enough to suffici ently coat the metal surfaces of the aircraft twice. For both applications, the TCP was applied from the bottom of the aircraft and working upward. The TCP dwelled for 20+ minutes befo re rinsing at approximately 60 psi. While the surface was still wet, black streaking was evident in some areas that were glass bead blasted the day before. Presumab ly aluminum clad or anodize was removed leaving a bare aluminum substrate (likely AA 7075). These bare areas took on more color than areas not treated with glass bead blasti ng. The dark streaks pe rsisted after the TCP was rinsed off and the surface had dried (Dry ing conditions: 75.3 degrees @ 25% RH).

Figure 4.8: Iridescent Blue Co loration of As-deposited TCP

The pretreatment was allowed to dry ove rnight. The airplane was then primed with Mil-PRF-85582, Type I, Class 1 at 0.8- 1.8 mils, and top-coated with Mil-PRF85285 polyurethane.

23NCAP Phase II Interim Report September 2004

Figure 4.9: F/A-18C with TCP after Prim er Application – November 2000, NORIS

4.3.3 – FIELD TESTING RESULTS Both aircraft were subject to “pre-d eployment” inspections by Tim Woods in 2001. These were done after only a few months at the squadron, where the aircraft had undergone at most a month or two shipboard. No issues or differences were noticed
between the TCP aircraft and normal coating system aircraft . It was reported that the TCP aircraft were “invisible” to the squadrons , i.e. no one noticed that the TCP aircraft were in fact processed differently than the control system. Following this, the two F-18’s were depl oyed with their respective squadrons for full carrier deployments, i.e. several months. Th ese aircraft are still in service with the TCP, and have each currently undergone th ree or more full carrier deployments. BUNO 163459 was inspected at Marine Co rps Air Station (MCAS) Beaufort, SC by Tim Woods and Craig Matzdorf in May 2002, af ter returning from a 6+ month carrier deployment. This aircraft ha d been in service for 13-months with TCP on all aluminum surfaces, including touch-up before final painting with MIL-PRF-85582 C and MIL-PRF85285 Gray polyurethane topcoat. They repor ted that the coating system performance looked excellent, with no visible differences when compared to another squadron aircraft painted around the same time with the chro mated control coating. The TCP F-18 wasslightly better than average when compared to other aircraft being evaluated for the nonchromate primer demonstration. Craig Matzdorf and Dr. Kevin Kovale ski, Materials Engineering Division, NAWCAD, Pax River, MD inspected BUNO 1 63459 after 3+ years in service with TCP, in May 2004 at MCAS Beaufort, SC. Two other squadron jets were select ed for comparison: BUNO 163487 (tail number 406) and BUNO 163433 (tail number 403). Both were finished with the standard
MIL-C-5541 chromate conversion coati ng, MIL-PRF-85582 C primer, and MIL-PRF85285 topcoat.

24NCAP Phase II Interim Report September 2004

Figure 4.10: Chromate and TCP F/A- 18 C’s – May 2004, MCAS Beaufort

Maintenance personnel noted that 163459 was “one of the best je ts with respect to corrosion”. When asked about time or effort sp ent when repairing test aircraft, personnel did not feel they were paying any more or less a ttention to these aircraft than to others in the squadron. Repaint occurred over scuff-sanded finish system and did not result in the removal of the pretreatment.

BUNO 163757 was inspected at NAS Le moore, CA by Tim Woods in May 2004, after at least three full lengt h carrier deployments. He reports that VFA-146 does an excellent job of inspecting and maintaining their planes. The inspection showed the aircraft to be in great shape; with the overall condition with respect to corrosion being very good. The average paint thic kness on this test aircraft was 5-mils, with nothing over 9-m ils DFT. The squadron did not report any issues or concerns with the TCP aircraft; no ting, “other jets require more diligence in maintaining the coating system.”

Figure 4.11: BUNO 163757 F/A-18C w/TCP – NAS Lemoore, May 2004

4.3.4 – STATUS

25NCAP Phase II Interim Report September 2004

Overall, the TCP technology is performi ng at least as well as the standard chromate conversion coating in this demons tration. These aircraft had at least three carrier deployments and may have had a fourth. Maintenance personnel were enthusiastic about new technologies due to th eir environmental and health benefits. The TCP aircraft are performing on par with th e best corrosion performance of the fully chromated system. The Planned Maintenance Interval (PMI) cycle for the F/A-18 is 60- months, meaning that these aircraft will be returning to the depot for re-work in approximately two years. This will mean the TCP aircraft will have been in service for 5

years or more. As a result of these positive field test results, and combined with the H-46
demonstrations that are discussed in Sec tion 4.4, NAVAIR Material s is planning to authorize the use of TCP under chromated prim ers, with the approval letter planned to
issue in FY05. Additional FY05 efforts will focus on an extensive evaluation of new, non-chromate primer systems under qualifi cation testing to MIL-PRF-23377 Class N; with field testing over TCP planned if applicable based on laboratory testing.

26NCAP Phase II Interim Report September 2004

4.4 – NAVAIR CH-46

4.4.1 – BACKGROUND NAVAIR’s fleet of H-46 helicopters undergo depot-level rework at NADEP Cherry Point, NC. Due to severe environm ental restrictions placed on the conventional spray-on/rinse-off chemical pr ocessing methods, NADEP CP, fo r the past several years, has utilized a hand application wipe-on/wipe -off method for chromate conversion coating their aircraft. This procedure is used for all pre-paint surface prep aration of aluminum skins for the H-46 program. The hand applicat ion method generates ve ry little waste, thereby significantly minimizing environmenta l wastewater issues experienced in spray operations with hexavalent chromium. In 2000, the Environmental Affairs Office in Cherry Point determined that the NAVAIR TCP process does not fall under the environmental and health and safety regulations that govern the hexa valent chromium processes. This is due to trivalent chromium being non-carcinogenic, unlike hexavalent chromium. Cherry Point decided to field test the TCP on the H-46 platform, on the basis of being able to spray apply TCP. A conven tional spray applicati on conversion coating process allows for faster tu rn around time for aircraft unde rgoing Standard Depot Level Maintenance (SDLM). The current hand a pplication method requires between 4 and 6
man-hours of labor to conversion coat one CH -46 airframe. A spray application could reduce this process time by half , which affords a significant cost savings. At FY00 labor rates, it was estimated that annual cost s savings by switching to a non-hazardous spray application would be approximately $30K for the sixty aircraft processed annually on

average.

4.4.2 – PROCESSING On October 23, 2000, NADEP Cherry Point completed its first trivalent chromium conversion coating (TCP) demons tration on specific areas of an H-46 helicopter, BUNO 165454. This helicopter was scheduled to go to HMM 774 in Norfolk, VA in November, 2000.
The three areas treated were the drive shaft tunnel, forward pylon, and aft pylon and cargo door.

Figure 4.12: H-46 Components with TCP – NADEP CP, October 2000

27NCAP Phase II Interim Report September 2004

Following a thorough cleaning, the bare me tal surfaces were deoxidized using MIL-C-10578 phosphoric acid. While the surface wa s still wet, a total of fifteen gallons of TCP was applied using a reciprocating drum pump. Artisans sprayed the material through a fan shaped nozzle, evenly sprayi ng the drive shaft tunnel, forward and aft pylons, and the cargo door with one coat of TCP. The TC P remained on the surface for one minute, and then a second application wa s sprayed onto all su rfaces again. After another minute this process was repeated for a third and final time. A very faint green tint began to show following the second application. After approximately 7 minutes the aircraft was rinsed thoroughly, evaluated fo r any remaining residue, and rinsed once again. The pretreatment was allowed to cure overnight, and the aircraft was painted the next morning.

On October 26, 2001, BUNO 154819 CH-46E was spray processed with TCP at NADEP Cherry Point. The aircraft was near ing completion of SDLM. The surface skin of the H-46 is primarily composed of clad AA2024-T3. James Whitfield, AIR 4.9.7 Materials Engineering, NADEP Che rry Point, NC oversaw the processing with TCP. His observations and comments on the processing are included below.
The exterior surfaces of the aircraft were stripped of old paint coatings by plastic media blasting. Landing gear and other surfaces sensitive to chemical processing were masked off prior to the start of spray operations. Cleaning was accomplished using a combination of steam cleaning and by scr ubbing with MIL-PRF-85570 Type II Aircraft Cleaning Compound at 20% by volume. After cleaning, the aircraft was thoroughly rinsed with clean tap water. The clea ning step required approximately 2 hours. While still wet from cleaning, the he licopter was deoxidized using MIL-C-10578 Type II Metal Cleaner and Conditioner at 20% by volume. The deoxidizer was allowed to dwell on the surface for 5-minutes before thorough rinsing with clean tap water. Surfaces were visually inspected to ensure a water-break free surface was obtained. The deoxidizing step took approximately 15 minut es and required 25 gallons of solution. While still wet, surfaces were coated using TCP solution. The TCP was spray applied from the bottom working upward to ensure complete coverage. TCP was reapplied after 5-minutes to prevent drying. Total TCP dwell time was 10 minutes. Surfaces where then thoroughly rinsed with cl ean tap water and allowed to dry. Ambient temperature during application was 65 0 F with 50% RH. The TC P application step took approximately 15 minutes and required 35 gallons of TCP. Shop artisans indicated that the proce ss went well and was less labor intensive than the hand application coating process used for the chromate conversion coatings. The entire cleaning, deoxidizing, and conversio n coating pretreatment process took approximately 2.5 hours. They estimated that as much as 1 hour was saved on process throughput. After a 12-hour pretreatment dry time, the helicopter was primed and painted with MIL-PRF-85582 C1 water-reducible, epoxy primer and MIL-PRF-85285 Type I polyurethane topcoat. The shop artisans did note that the surface treatment color change is one of the
few downsides to TCP. Conventional chromate conversion coatings provide a distinct color change on treated surf aces. TCP, however, does not provide a noticeable color change. For process consistency and quality control, a color change or other simple

28NCAP Phase II Interim Report September 2004

means of determining surface treatment is desired. For tracking and follow-up purposes, an aircraft logbook entry was made indicating TCP surface treatment.

4.4.3 – FIELD TESTING RESULTS
BUNO 154819 was fielded with HMM-264 squadron at MCAS New River, NC following final paint at Cherry Point. This aircraft was inspected by James Whitfield, NADEP CP, at HMM-264 on November 6, 2003, after 13-months in service. This aircraft had recently returned from an 8-month deployment, most of which was shipboard on the USS Iwo Jima. This depl oyment included tours in Iraq, the horn of Africa, Albania, and Liberia. While deployed, aircraft in this squa dron were subjected to the harsh corrosive environment typi cal for Navy and Marine operations. The aircraft was examined to assess corrosion and coating system issues, and to compare finish system performance with other aircraft in th e squadron (standard chromated coating system). Particular attenti on was given to fastener patterns, lap joints, butt joints, and other corrosion prone areas. The paint system was found to be in good condition with only minor touch-up indications typical of aircraft in service for 2-years. No corrosion was noted during the inspection. Squadron mainte nance records indicated th at there were no notable
differences between corrosion or paint repairs on this aircraft and other aircraft in the squadron that were finished with standard pretreatment materi als. This was confirmed by inspection of other squadron aircraft that were refinished within a few months, before or after, of the date this aircraft was painted.

4.4.4 – STATUS The inspection results for the CH-46’s indi cate that TCP is performing at least as well as standard pretreatment materials for aluminum alloys. NADEP Cherry Point has expressed the intention to implement spra y processing of TCP upon issuance of the NAVAIR approval letter. As a result of these positive field results, and combined with the F/A-18C demonstrations discussed in Section 4.3, NAVAIR Materials is planni ng to authorize the use of TCP under chromated primers, with the approval letter planned to issue in FY05.
Additional FY05 efforts will focus on an ex tensive evaluation of new, non-chromate primer systems under qualification testing to MIL-PRF-23377 Class N; with field testing over TCP planned if applicable based on laboratory testing.

29NCAP Phase II Interim Report September 2004

4.5 – NASA SOLID ROCKET BOOSTERS

4.5.1 – BACKGROUND The Space Shuttle Solid Rocket Booster (S RB) had only one set of coatings and one type of pretreatment qualified for prot ection of aluminum hardware. All of the materials contained chromate compounds. A project was conducte d to identify and qualify alternatives for the currently qualif ied coating system and pretreatment.

The coatings were evaluated for corrosion protection, bond strength, compatibility with other SRB materials, batch-to-batch cons istency, and thermal environments stability. Two pretreatments and two coating system s met the SRB program criteria. The recommended products are Henkel Alodine 5700, MacDermid Chemidize 727 ND, and the coating systems submitted by Hentzen and by Lord Coatings. The coating systems were tested in both a primer only and a prim er/topcoat configuration. Both were found to be acceptable for flight. There are significant processing advantages for each of the materials depending on how they are used. Th e Hentzen coatings are chromate free and have very good processing characteristics along with good overall properties and are recommended for first implementation as an alternate. Likewise , Alodine 5700 had very robust processing parameters and is r ecommended for first implementation as a pretreatment alternate.

4.5.2 – FIELD TESTING NASA began treating SRB’s with the non-chromate Alodine 5700/Hentzen primer system in 2002. The first hardware flew in the fall of 2002.

4.5.3 – STATUS NASA implemented the Hentzen / Alodine 5700 system in June 2002. This change affected all structural aluminum (AA2219, AA6061, and AA7075) parts of the
solid rocket boosters. No issues have been reported with this system.

30NCAP Phase II Interim Report September 2004

31 4.6 – BOEING/AIR FORCE/NAVY

4.6.1 – BACKGROUND The US Air Force and Boeing have been evaluating a Sol-gel-based conversion coating pro cess for paint adhesion applications where chromate pretreatments are traditionally used. The surface treatment system being used is AC-131 from Advanced Chemistry and Technology in Garden Gr ove, CA. AC-131 is based on technology developed at Boeing as “Boe-gel” sol-gel ch emistry-based conversion coating. AC-131 is intended for use as an adhesion promoter fo r pre-paint applications on a variety of
metallic substrates. The objective of the Advanced Aircraft Corrosion Protection (AACP) program, sponsored by the Aging Aircraft Division of the Aeronautical Enterp rise Program Office,
is to dem onstrate and validate a coating syst em evolved from the AC-131/Boegel and to apply the coating system to aircraft for operational flight testing. Th is effort began in September 2002. The project focused on two main evalua tions to determine valid ity for field demonstration. The first significant milestone of the project was to investigate ways to make Boegel/AC-131 visibly inspectable. Se veral colored dyes were successfully added to the conversion coating promoting color definition. The second milestone was to validate the adhesion promoting characteristics of AC-131 on a variety of aluminum substrates and surface conditions. To accomplish th is goal, the team worked to define the cleaning and deoxidizing requirements fo r aluminum surfaces required for good
adhesion. Good adhesion was exhibited to al uminum alloys when either AC-131 or Alodine 1200S was applied, however, wet adhesion failures were observed when no conversion coating was applie d. Similar adhesion perf ormance was observed for both
the AC-131 and the Alodine 1200S chromate c ontrol in wet tape and pull-off adhesion testing. The performance of coating system s with AC-131/Boegel in laboratory testing has been reported to be equiva lent or sometimes better than the performance of coating systems with conventional chromate conversion coatings.

4.6.2 – STATUS Advanced Chemistry and Technology, Inc. is currently eval uating a blue-dyed version of the AC-131 developed during the B oeing efforts to determ ine the adhesion performance of the colored coa tings and to evaluate the effect of the dye on long term coating system performance. The AF/Boeing plan is to field test the AC-131 versus a chromate conversion coating for prepaint operations beginning in FY05. An F-15, to be stationed at Eglin AFB, FL, and a KC-135 support aircraft, to be stationed at Hickam AFB, HI, will be painted at Warner Robbins ALC and The Boeing Aircraft Suppo rt Center (BASC), respectively, both in San Antonio, TX. Half of each aircraft will receive the conventional chromated coating, with the other half being processed with the AC-131 non-chromate sol-gel coating. The aircraft will then be primed with MIL-PRF-23377 C chromated, epoxy primer and top-coated with Advanced Performance Topcoat (APC).NCAP Phase II Interim Report September 2004



### 5.0 – ESTCP NCAP EFFORTS

5.1 – US NAVY LANDING CRAFT, AIR CUSHIONED

5.1.1 – BACKGROUND The current pre-paint procedure for th e Landing Craft, Air Cushioned (LCAC) amphibious vehicle hulls, which are composed primarily of AA5456-H116, involves abrasive blasting with garnet until a surface profile of 3 mils is achieved. Selected compartments and
voids are then coated with a solvent-reducible, non-chromated epoxy primer, MIL-DTL-24441BType III, Formula 150, to a dry film thickness (DFT) of 3-4 mils and then coated with MILDTL-24441B Type III, Formula 151 for a final DFT of 6-8 mils. This is done for the recently
created Craft Alterations CA-369K and CA-445K, which appl y coatings to selected corrosion prone voids. Hexavalent chromium chemistr y was suspended by NAVSEA in August 1991 and an alternative to abrasive blasting for surface preparation is desired.
Several issues have arisen with the curren t direct-to-metal process, one of which is adhesion loss due to undercutting and undercutting exacerbated by crevice corrosion between substrate and coating, and anothe r being coating cracking due to craft flex and vibration. Surface preparation is a key concern, as MIL-DTL-24441B exhibits poor adhesion when the nominal surface profile is less then 3-mils. Th is can be achieved by grit-blasting, but not by other mechanical surface preparation methods, su ch as shot-peening or grit-impregnated sanders. AA5456-H116 has a tendency to polish after approximate ly 2 mils of profile have been achieved by mechanical methods. Additionally, both As sault Craft Unit Four (ACU-4) and ACU-5 are prohibited by NAVSEA from sailors performing abrasive blasting due to dust generation. This adversely affects the coatings performance of any maintenance and repair efforts conducted at the unit level. With respect to CRAFTALT installation as perf ormed by contractors, production schedule analysis has indicated that implementati on of TCP in place of the current abrasive blast process could reduce production time by 23 man-days and hangar time by 8 days.
These tests were initiated and overseen by Mr. Paul Dobias , NSWC Carderock Division, Materials Process and Engineer ing Branch. The LCAC progr am began testing TCP as a potential surface preparation met hod, allowing a substitution for abra sive blasting as a pre-paint process. The TCP was chosen for demonstrati on because of the potential for realizing both a time/cost savings, as well as improved adhesion a nd corrosion performance when compared to a direct-to-metal process.

5.1.2 – FIELD TESTING The US Navy LCAC program has been field-te sting TCP for the last 3-4 years, in both beach-side outdoor exposure testing and vehicle applications. This work was conducted at ACU4 in Little Creek, VA. The LCAC is a NAVSEA program, and initiated this field test using ARCOVA-supplied TCP. The exposure testing was conducted on panels composed from AA5083-H111, AA5086- H116, and AA5456-H116 (AA5456-H116 is the primar y alloy used for construction of LCAC hull structures).

Al alloy Surface Prep Primer/Topcoat Test

5456H116

5086H116

5083H111 None, Garnet-blast to 3 mil, 120-grit abrade w/ TCP None Bare,
Beachside Outdoor Exposure

5456H116

5086H116

5083H111 None, Garnet-blast to 3 mil, 120-grit abrade w/ TCP MIL-DTL-24441B TyIII
F150/151
DFT – 8-10 mil Scribed, Painted
Beachside Outdoor Exposure

32 Table 5.1: Beach-side Exposure Testing – begun March 2001, ACU-4 Little Creek, VANCAP Phase II Interim Report September 2004

Two test components were tr eated on LCAC-26 in August 2000, to examine the TCP as an adhesion promoter for surface preparation, and to evaluate TCP for surface corrosion protection. The components were pa inted with MIL-DTL-24441B TyIII. The first test area was the deck of the oily waste tank, which can contain MIL-H-23699 hydraulic fluid, seawater, and engine cleaning detergents. This is an area where adhesion loss is
observed due to breakdown of the organic coating.

Figure 5.1: LCAC-26 Oily Wast e Tank with TCP Test Patch

The second test area was on the deck where there is a void observed to suffer periodic seawater penetration. The TCP for this effo rt was obtained from the American Research Corporation of Virginia (ARCOVA).

5.1.3 – RESULTS Beach-side testing coupons were exposed on 30 degree racks at the Little Creek, VA site for 4 years. Within 6 months of exposure, the scribed painted coupons with no surface preparation exhibited undercut ting from the scribe. The ga rnet-blasted coupons developed undercutting around 3.5 years, the TCP coupons are st ill in testing, no unde rcutting is evident.

Figure 5.2: Beach-side Exposure Racks, Little Creek, VA

33NCAP Phase II Interim Report September 2004

Untreated Blasted TCP

Figure 5.3: AA5456-H116 Coupons (B are, Blasted, or TCP) co ated with MIL-DTL-24441B F150/151 – 1.5+ years Beach-side Exposure

In December 2002, the test coupons were evaluated for surface pitting and general corrosion. Both the garnet blasted coupons and the coupons treated with TCP performed better than those with no surface prepar ation, which were now bare due to all of the coating having lost
adhesion. The overall evaluation was that TCP reduced the incidence of pitting corrosion comparative to other surface preparation methods.

The two painted TCP components were evalua ted after 4 years of service on LCAC #26: no corrosion, undercutting, or adhesion failures we re noted. This demonstrated the adhesion performance when subjected to both corrosi ve and vibrational/flexing environments. The field test for bare corrosion resistance was deemed inconclusive due to prior pitting damage that was not fully removed.

Figure 5.4: TCP Applied
to Air Intake Plenum Deck, LCAC-26

5.1.4 – STATUS NAVSEA PEO SHIPS, PMS 37 7 has indicated that they will authorize TCP for pretreatment of aluminum alloys of LCAC as soon as commercia l products are qualified to MILDTL-81706B and concurrence from the Techni cal Warrant Holder (TWH) are obtained.

34NCAP Phase II Interim Report September 2004

5.2 – USMC EXPEDITIONARY FIGHTING VEHICLE

5.2.1 – BACKGROUND The Marine Corps’ current Amphibious Assau lt capability currently relies on the use of the legacy platform USMC Amphibious Assau lt Vehicle (AAV); a lightly armored aluminum troop carrier capable of transporting a full squad of Marines from an o ff-shore transport ship onto dry land. This platform is from a 20+ old design, and the USMC realized the need to update their capability in th is critical area. The Expeditionary Fighting Vehicle (EFV) pr ogram was originally designated the AAAV – Armored Amphibious Assault Vehicle. The contractor and designer, GDAMS, has been manufacturing and testing prototype and SDD vehicl es for the past few years. The SDD phase is still underway, with all ten of the planned vehicles either in testing or in the final stages of manufacture; with the planned production of one more training vehicle. For reasons of weight limit concerns, and because of im proved ballistics properties; the EFV program decided to move away from the AA5083-H131 alloy used for th e AAV, and chose a new alloy AA2519-T87. While the ballistics and strength/weight rati o improved with the use of this alloy, the problem of corrosion was greatly magnified. AA 2519 is a high copper alloy very susceptible to pitting and exfoliation corrosion. Due to the use of a corrosion-pr one alloy, in conjunction with the extremely harsh operating environment e xperienced by the EFV; the corrosion control coatings and materials must be as robust at possible. At the outset of this new acquisition progr am, the PM made the executive decision to comply with the strictures of an environmentally “green” program. Included in this is the full prohibition of the use of hexavale nt chromium containing coatings. The OEM is GDLS; and the EFV’s are bei ng produced at the Lima Army Tank Plant (LATP) facility, in Lima, OH. The LATP site is where the US Army’s M1A2 Abrams battle tank
is manufactured. Originally, the EFV prototype vehicles were prepared and coated using a grit-blast/wash primer process that had shown good performance ch aracteristics on high-strength and armor steel alloys (like the Abrams). During initial field an d in-water testing with P1, the first prototype vehicle, serious problems arose with the coating system and its corrosion performance. These
corrosion and adhesion issues needed to be addressed for the unique performance and operational requirements of AA2519-T87. The corrosion coating system issues that needed to be addressed were serious coating/substrate adhesion loss on the P1 hull, turret, and other components, as well as rapid
exfoliation corrosion of the aluminum substrate. The initial coating procedure was wash with a standard alkaline steel cleaner, abrasiveblast with alumina to a 1.5-2.0 mil surface profile, wash prime with a water-reducible nonchrome primer, prime with a so lvent-reducible, epoxy CARC, and finally topcoat with a waterreducible, polyurethane CARC. It was suggested that the program look in to a chemical process and conversion coat surface preparation in lieu of the mechanical surface preparation/wash primer process.

5.2.2 – P1 - TCP PERFORMANCE VALIDATION General Dynamics and the EFV Program re quested that the Inorganic Coatings Team (ICT) refurbish deflectors, part number AV 1060625, commonly called “ste ering buckets” and two seal plates, numbers AV106015-1P (port si de) and AV106015-1A (starboard side) from

EFV P1.

35NCAP Phase II Interim Report September 2004

Two deflectors were refurbished and an eval uation was done to validate the performance of NAVAIR’s TCP using a standard “wet” surface preparation process. These parts were grit blasted with alumina on August 14, 2001 to remove the paint system and corrosion products. Later that morning the four components were pr ocessed in the Inorganic Coatings Lab, Patuxent River, MD using the following process: 1. Cleaned using a warm mildly-alkaline, non-silicated, non-etchi ng aluminum cleaner. (Turco 4215 NC LT TM – 120 F) Solution was scrubbe d lightly onto the components with Scotch-Brite pads. Figure 5.5 s hows the cleaning of a steering bucket. 2. Rinsed thoroughly with warm tap wate r followed by deionized (DI) water. 3. While still wet, Turco 3003 TWA cleaner/deoxi dizer was hand-applied with Scotch-Brite pads, scrubbing gently to ensure contact of the chemical with all surfaces.
4. Allowed 3003 TWA to dwell on the substrate for 15 minutes. 5. Rinsed thoroughly with cold ta p water followed by DI water. 6. While still wet, spray-applied TCP10P solu tion using a two-liter, hand-pumped solution sprayer. Figure 5.6 shows the application of TCP.
7. Allowed TCP to dwell on the surface for 5 minutes, keeping the surface wet. This required the additional misting of the surface twice due to the low humidity and high
airflow in the lab. 8. Rinsed thoroughly with cold ta p water followed by DI water. 9. Allowed components to air-dry for one hour. Figure 5.7 shows a component with a dried
TCP film.

Figure 5.5: Cleaning Steering Bucket

36NCAP Phase II Interim Report September 2004

Figure 5.6: Application of TCP

Figure 5.7: TCP Coating after Drying

37NCAP Phase II Interim Report September 2004

Later in the afternoon of August 14, 2001, the components were pain ted using MIL-PRF85582-NC Type II primer from PRC-DeSoto. This prim er is flat black in co lor. On the morning of August 15, 2001, the components were painted with a MIL-C- 53039 gray CARC topcoat from Hentzen. Components were allowed to cure until la te in the afternoon when they were picked up by a member of the GDAMS team and taken back to the test building. It is important to note that the tight schedule for reworking the components le d to only a 6-hour cure for the topcoat. Ideally, the topcoat would be a llowed to cure for 24 hours before handling and exposure to a corrosive environment. Painted components are detailed in Figures 5.8, 5.9, and 5.10. All four components were reinstalled on th e P1 that evening and painted black for aesthetic purposes.

Figure 5.8: Steering Bucket afte r Priming with MIL-PRF-85582 NC

Figure 5.9: Steering Bucket after T opcoat Application with MIL-C-53039

38NCAP Phase II Interim Report September 2004

Figure 5.10: Seal Plate after T opcoat Applicatio n with MIL-C-53039

While the components were bei ng painted on the afternoon of August 14, members of the Inorganic Coatings Team (ICT) applied a TCP coa ting to the mating surfaces of the seal plates on the port and starboard sides where corrosion a nd adhesion damage had occurred. In addition, the P1 team requested that TCP coating be app lied to the port and starboard water jet thrust plates. These areas were cleaned and mechanica lly prepped by the P1 team. Immediately after being wiped clean with an alcohol wipe, the surfaces were treated with TCP. The TCP was wiped onto the surfaces using a clean cotton rag a nd allowed to dwell for 10 minutes. Repeat applications of TCP were made after approximate ly three to seven minutes. No TCP solution ran onto adjoining surfaces. After the dwell, un-reacte d solution was wiped from the treated surfaces using a second clean rag saturated with clean DI water. The surfaces were then allowed to airdry with help from a large fan. That evening, the P1 crew primed these surfaces using MILPRF-85582 NC material applied from Sem-pen TM touch-up paint applicators. Figures 5.11 and 5.12 depict the TCP touch-up process.

39NCAP Phase II Interim Report September 2004

Figure 5.10: Seal Plate Mating Surface after Corrosion Removal

Figure 5.11: Application of TCP Co ating on Seal Plate Mating Surface

5.2.3 – LABORATORY TESTING Concurrently with the limited initial field testing on the P1, a large laboratory panel test
matrix was started at NAVAIR Pax River to dete rmine the optimum surface preparation and prepaint coating system for processing of late r prototype and SDD vehicles at LATP. This matrix looked at the possible process co mbinations resulting from using grit-blasted and as-machined surfaces, with and without an alkaline chemi cal cleaner, and wi th and without a chemical deoxidation step. Two wash primers at specified thicknesses were evaluated by dry/wet tape adhesion and neutral salt fog (ASTM B117) compared to two non-chromate chemical conversion coating alternatives and a chromate control. All coating permutations were subsequen tly coated with either MIL-PRF-85582 N or MIL-P-53022, with MIL-PRF-85582C1 as the chromated control primer.

40NCAP Phase II Interim Report September 2004

Mechanical

Surface Prep Dwell Alkaline Clean Chemical

Deoxidize Pretreatment or
Wash Primer Primer Test

Grit Blast 2 hours or
24 hours None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Aqua Zen (1.0, 2.5, & 4.0 mils) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

Grit Blast 2 hours or
24 hours None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Kem Aqua (1.0, 2.5, & 4.0 mils) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

Grit Blast 2 hours or
24 hours None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Slikote (1.0, 2.5, & 4.0 mils) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

As-Machined N/A None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Aqua Zen (1.0, 2.5, & 4.0 mils) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

As-Machined N/A None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Kem Aqua (1.0, 2.5, & 4.0 mils) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

As-Machined N/A None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Slikote (1.0, 2.5, & 4.0 mils) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

Grit Blast 2 hours or
24 hours None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Alodine 5200 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

As-Machined N/A None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Alodine 5200 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

Grit Blast 2 hours or
24 hours None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo TCP 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

As-Machined N/A None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo TCP 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

Grit Blast 2 hours or
24 hours None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Turco Accelagold (chromate control) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

As-Machined N/A None, Turco 4215,
or MEK solvent wipe none or Turco
3003/SmutGo Turco Accelagold (chromate control) 85582 NC

or 53022 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF

Grit Blast N/A Turco 4215 Turco
3003/SmutGo Accelagold, TCP, Alodine

5200 85582 C1 Dry, 1,4,7 Day Wet
Adhesion or ASTM

B117 NSF Table 5.2: Coating System Test Variables

41NCAP Phase II Interim Report September 2004

The last coating system variable was the control, a fully chromated coating system – using a chromate control primer, MIL-PRF-85582C1 evaluated over the chromate control, as well as a chromated primer control over non- chromate pretreatments Alodine 5200 and TCP. The process protocols are outlined below. 1. Alkaline Cleaner – Turco 4215 NC LT, 15-minute immersion at 120 0 F 2. Deoxidizer – Turco 3003 TWA 25% by volume, 15- minute contact by spray application at ambient temperature with a Scotch-Brite scrub 3. Desmutter – Turco Smut-Go NC, 30 to 60-sec ond contact by spray application at ambient
temperature 4. Primer – Mil-PRF-85582 C and N & Mil-P-53 022 were applied at a DFT of 0.9-1.5 mils 5. Topcoat – MIL-DTL-64159 Type II CARC 383 Green for ASTM B117 Neutral Salt Fog 6. Process – Coupons were rinsed thoroughly between each step with ambient DI water 7. Coupons were not allowed to dr y out between process steps. This mitigates re-oxidation or
contamination of the surface 8. Pretreated surfaces were allowed to dry overnight before primer applications or per technical process instruction for th e wash primer products 9. Coupons were top-coated 24 to 48-hours after primer application 10. Grit-Blast with alumina (aluminum oxide) to a 1.0-1.5-mil surface profile 11. Wash Primers were applied at wet film thic knesses of 1.0, 2.5, and 4 .0-mils – corresponds to a DFT of 1.0, 1.5, and 2.0-mils

5.2.4 – P1 AND LABORATORY TESTING RESULTS

5.2.4.1 – LABORATORY TESTING The chemical conversion coatings, Alodine 1200S, TCP, and Alodine 5700 outperformed the wash primers in corrosion and adhesion testi ng, regardless of prim er. Both of the nonchromate conversion coatings aver aged better than a “4A” rating in dry and wet adhesion testing by ASTM D 3359, regardless of surface preparation method or subsequent primer coating. Based on the delamination and blistering issu es noticed with the wash primer coating system on the P1, NAVAIR made the recommenda tion that for this aluminum alloy and operational environment, the EFV program shoul d use a chemical conversion coating as the preferred surface preparation process. In the laboratory testing, no difference wa s observed in the corrosion and adhesion performance of the conversion coatings when applied over an as-machined surface compared to a grit-blasted surface. The EFV program decide d to pursue a chemical clean and deoxidation process, which is less costly and less time/labor in tensive than an abrasive blast process. The performance of the wet processed TCP/MIL-PR F-85582 NC coating system merited additional investigation and valida tion of the process and coating syst em for potential implementation by GD for the EFV program. Early performance feedb ack led to discussions of potentially using a wet process for new hulls as well as evaluatin g TCP in other EFV applications including the track cover door, sprocket carriers, idler wheels and hull touch-up.

5.2.4.2 – PERFORMANCE OF INITIAL CO MPONENTS WITH TCP ON EFV P1 NAVAIR personnel visually inspected the perf ormance of the new coatings after one, two, four and six week intervals. Feedback wa s also garnered from the P1 crew. At each interval there was no evidence of corrosion, paint blistering or other coa ting problems. Figures
5.13 and 5.14 show the star board steering bucket and seal pl ate on EFV P1 after 2 weeks in service on the platform. The performance of the pretreated components on the P1 was

42NCAP Phase II Interim Report September 2004

significantly better than the original coating sy stem, and the vehicle was re-worked with a full conversion coating system. Sin ce the re-coat chemicals were hand applied, one half of the
vehicle was coated with a chroma te control system and the othe r half was a non-chromate test
system.

Figure 5.13: Starboard Steering Bucket a nd Seal Plate after 2 Weeks in Service

Figure 5.14: Inside of Starboard Stee ring Bucket after 2 Weeks in Service

43NCAP Phase II Interim Report September 2004

5.2.5 – SDD VEHICLE HULL AND TURRET PROCESSING

5.2.5.1 – BACKGROUND The SDD phase of this new acquisition program began in 2000, with the production and processing of E1 at LATP. Ten vehicles were planned for the SDD phase, nine “E” variants – standard model squad amphibious vehicle, and 1 “C” variant – a commander’s vehicle, lacking the 25mm gun on the turret but w ith an upgraded communications and electron ics package. Based on the outcome of the early laboratory test ing and the initial field test data on the P1 components, Alodine 5700 and TCP were select ed as the non-chromate conversion coating alternatives. One SDD vehicle was planne d for a fully chromated coating system.

5.2.5.2 – INITIAL PROCESSING A representative from NAVAIR was present at LATP for the processing of the first SDD
EFV – E1. GDAMS and Henkel Surface Technol ogies (HSTNA) – maker of the Alodine TM
product line and main chemical supplier for LATP – were also present for on-site technical support. The E1 process used an alkaline clea ner already stocked at LATP for cleaning of painted steel surfaces, and an aerospace standard phosphoric acid deoxidizer with a mild, nitricacid desmutter for surface preparation. The E1 vehicle was sprayed with Alodine 5700 using 2- gallon plastic garden sprayers. Several spra y processing recommendations were made by NAVAIR and HSTNA, and these changes were in corporated into the process for the next
vehicle.

5.2.5.3 – PROCESSING When initial prototype and SDD manufacture be gan for this program, LATP did not have any experience with aluminum finishing. The orig inal prototype vehicles were mechanically prepared and wash primed with the same pr ocess as that employed for steel substrates. Additionally, the use of a newl y designed aluminum alloy, AA2519-T87, meant that there was a large learning curve to overcome in the pretreatme nt of these vehicles. The first few vehicles in
SDD exhibited cohesive adhesion fa ilures occurring at the primer metal interface. This indicated a possible problem with the conve rsion coating process. The orig inal chemical process needed improvements in chemical selection, application temperatures, and greater attention to detail in chemical dwell times and rinsing parameters. The first issue, resolved after the pro cessing of E1, was the use of the 2-step deoxidation/de-smutting process originally sugg ested by NAVAIR. While this process worked well in the laboratory tests, it was found to be too time and labor intensive for a manual spray process application. By the time the chemicals we re finished being appl ied, the first area would be dry, allowing for the deposition of chemical contaminants and/or re-oxidation of the aluminum substrate. Laboratory testing was conducted at NAVAIR to look at milder, slower acting single-step deoxidizers that would not ca use extensive smutting of the surface, even at longer dwell times. Ridoline TM 4450, a citric/dilute hydro-acetic acid mix was selected as the giving the best clean, oxide free surface without smutting. E2 was processed using the Ridoline

4450.
The next issue was the use of the K-56 TM cleaner, where it was observed that even after several cleanings, the aluminum did not exhibit a uniformly wate r-break free surface. A waterbreak free surface indicates the high-surface tens ion of the metal when it is free of organic contaminants such as machining oils, dirt, a nd fingerprints. HSTNA suggested the use of a cleaner, Aerowash TM , specifically designed for cleaning al uminum alloys. The transition was

44NCAP Phase II Interim Report September 2004

made to the use of Aerowash before E4; howev er, it was noted that the Aerowash’s cleaning capability was greatly diminished when not used at an elevated temperature.

Figure 5.15: EFV E3 Spray Processsing – LATP

For quality control, several adhesion tests were conducted for each vehicle, in accordance with ASTM D 3359 Procedure B, to ascertain th e consistency of the pr ocessing and the quality of the conversion coating. Adhesion issues were seen up to SDD vehicle E4, as the process parameters were gradually optimized. It was noted that the third SDD vehicle, C1, had the best overall adhesion (though still not in keeping with performance levels suggested by laboratory testing). This vehicle experienced the shortest dwell times and mo st consistent rinsing of the early demonstrations. This suggested that wi th proper process contro l and optimization, high performance could be achieved with the selected non-chromate pretreatments. Between E4 and E7, several significant changes we re made to the process chemi cals and controls. E6 was the chromate control vehicle, and no adhesion or pr ocessing issues were experienced. E7 was processed with the non-chromate system, TCP and MIL-P-53022.

5.2.5.4 – E7 PAINT ADHESION RESULTS
There were no adhesion issues observed w ith E7. The processing dwell times were exactly within the optimum range and the TCP so lution was diluted to 30% by volume instead of the usual 50% by volume. This may have lowe red the solution activity, making the conversion coating reaction less restrictive on dwell time.

45NCAP Phase II Interim Report September 2004

5.2.6 – PROCESSING – CURRENT PROCESS

5.2.6.1 – E8 Processing for the E-08 began on 15 March 2004. Table 5.3 outlines the pretreatment steps for the EFV E8 including alkaline cleaning, deoxidizing and application of TCP. A fourman crew was used. All adhesion test re sults were ratings of 4A or better.

Time Notes

0845 Rinsed pumps, hoses and vacuum tubes. Fi lled rinse barrel. Retrieved a degrease can on top of the vehicle. K-56 wash only at de- b urr station. Very little filings. Spray cleaned with hot AerowashTM.

0853 Begin AerowashTM.

0909 Finish AerowashTM. Good foamy coverage.

0930 Finish rinse. Stress high volume, low pressure for rinsing vehicles.

0935 Vacuum out water. Three new drain holes on this vehicle resulted in less water being trapped after rinsing. Will do a doubl e rinse after deoxidizing – first quick rinse to dilute the chemical and a second longer rinse to focus better on coverage and
inserts.

0945 Break.

0950 Chips and shavings appear to have collect ed at the two rear ce ntral floor panels. Vacuumed prior to deoxidizing.

1015 Begin deoxidization using Ridoline 4450TM. St art from bottom of vehicle and work

up. 1029 Begin first rinse.

1032 Begin second rinse focusing on inserts.

1050 Vacuum out all water.

1102 Begin TCP application. Start from the bo ttom and work up the vehicle. Apply on outside of vehicle, then inside of vehi cle and finally a quick second coat on the
outside.

1125 Begin Rinse.

1145 Final DI water rinse. Table 5.3: Outline of E8 Processing

46NCAP Phase II Interim Report September 2004

5.2.6.2 – E9



### Time Notes

0834 Started Aerowash. Began in front, then be low hull, up the sides to the top and then
inside.

1005 Completed Aerowash. Total Aerowash time – 45 minutes

1010 Rinsing started.

1035 Rinsing finished. Nice water break-free surface.

1040 Excess water vacuumed out of hull from areas where it had collected. Set-up Ridoline 4450 spray wands and pump hoses. Two 2.5 gal/min. pumps were to be
used.

1048 Vacuuming complete.

1216 Began spraying Ridoline 4450. 4450 app lication approximately 25 minutes.

1241 Began rinse. Rinse overlapped approxim ately one minute more of 4450 application.

1302 Finished rinsing. Tota l rinse time ~ 20 minutes.

1309 Begin TCP-cc2 spray.

1331 Completed TCP-cc2 application.

1332 Began fire hose rinse.

1347 Finished fire hose rinse.

1349 Began DI water rinse.

1404 Finished DI water rinse. Table 5.4: Outline of E9 Processing

This was the first vehicle to receive a spray a pplication of TCP-color. TCP-color is a pHstabilized formulation of the TCP used on the pr evious vehicles. TCP-color also incorporates additional chemistry that enables a color change upon the treated areas for an easier visual confirmation of the application. Previous laboratory studies s howed a dark purple/brown color on treated areas when using an im mersion application process. High-pressure spray application could not be suitably tested with in the laboratory environment pr ior to use on the vehicle. After TCP-color application, a visible co lor change was not observed. A darker brown/gray coloring was visible in areas where TCP streaked/ran off from inserts. See Figure 5.16. This same coloring could also be seen wher e TCP pooled in pocketed areas of the vehicle. An overall very slight smoky appearance could be seen on the vehicle. The iridescent appearance from the non-color change TCP was mo re evident than the observed color change from the TCP-C application. The dark colore d streaking and well areas were examined the following morning and a powdery coating was not present in those areas. Regardless of film coloration, no adhesion failures we re seen with this vehicle.

47NCAP Phase II Interim Report September 2004

Figure 5.16: Minimal TCP Color Change Observed Near Inserts

No adhesion performance differences were noted between the chromate control vehicle, E6, and the latter SDD vehicles. Several process ite rations were used in this demonstration with various results, until the optimum chemicals and parameters were found. This indicates the importance of repeatability a nd quality control in the vali dation of these non-chromate alternatives. Table 5.5 outlines the chemicals, pr etreatments, and paint systems used in the SDD phase of the EFV program and shows the gr adual optimization of the coating system.

48NCAP Phase II Interim ReportSeptember 2004Paint Plan as of 02/03/03SDD VehicleCleanerDeoxPretreatmentPrimerExterior Top CoatInterior Top CoatBuild OrderE1K-56Turco 3000/TurcoSmut-goAlodine 5700MIL-PRF-85582 - NCMIL-PRF- 64159 TyIICARCMIL-PRF-227501E2K-56Ridoline 4450Alodine 5700MIL-PRF-85582 - NCMIL-PRF- 64159 TyIICARCMIL-PRF-227502C1K-56Ridoline 4450NAVAIR - TCPMIL-P-53022MIL-PRF- 64159 TyIICARCMIL-PRF-227503E3AerowashRidoline 4450NAVAIR - TCPMIL-PRF-85582 - NCMIL-PRF- 64159 TyIICARCMIL-PRF-227504E4AerowashRidoline 4450Alodine 5700MIL-P-53022MIL-PRF- 64159 TyIICARCMIL-PRF-227505E5AerowashRidoline 4450NAVAIR - TCPMIL-P-53022MIL-PRF- 64159 TyIICARCMIL-PRF-227506E6AerowashRidoline 4450Alodine 1200S -Hex CrMIL-P-23377 - CMIL-PRF- 64159 TyIICARCMIL-PRF-227507E7AerowashRidoline 4450NAVAIR - TCPMIL-P-53022MIL-PRF- 64159 TyIICARCMIL-PRF-227508E8AerowashRidoline 4450NAVAIR - TCPMIL-P-53022MIL-PRF- 64159 TyIICARCMIL-PRF-227509E9AerowashRidoline 4450NAVAIR - TCPMIL-P-53022MIL-PRF- 64159 TyIICARCMIL-PRF-2275010Alodine 5700 and TCP are Non-hexavalent chromium conversion coatingsMIL-P-53022, and MIL-PRF-85582 N are Non-hexavalent chromium primers.E6 is a fully chromated system - this is the control vehicleTable 5.5: SDD PAINT PLAN49NCAP Phase II Interim Report September 2004

5.2.7 – CURRENT PROCESS – LRIP The chemical process will be as finalized in the SDD phase: standard aluminum process, spray clean – 100+ 0 F, mildly-alkaline, non- etching, non-silicated clea ner; spray deoxidize – ambient, non-smutting citric/acetic acid soluti on; spray conversion coating – ambient TCP or
Alodine 5700. The current manual spray process – 3-4 man team , 6 hours start to finish is planned to be replaced in Low Rate Initial Production (LRI P) with an automated, car-wash style spray processing line for clean, prep, a nd conversion coating application.

Alkaline Cleaner Aerowash 10% vol. 100 F

Deoxidizer Ridoline 4450 10-15 minute dwell

Pretreatment TCP 30-50% vol. 10-15 minute dwell

Primer MIL-P-53022 CARC white Topcoat (Interior) MIL-C-22750 seafoam green Topcoat (Exterior) MIL-DTL-64159 TyII CARC 383 Green or Tan Table 5.5: Target coating system for EFV LRIP

5.2.8 – PROTOTYPE AND SDD VEHICLES FIELD TESTS

5.2.8.1 – P1 - PERFORMANCE OF CHRO MATED AND NON-CHROMATED SYSTEMS

ON USMC-EFV P1 P1 and P3 were stripped and repainted by a third-pa rty, industrial painter using chemical conversion coating as the surface preparation befo re field testing, because of the corrosion and paint adhesion issues experienced with the prototype vehicles . Both vehicles had a fully chromated test coating on the starboard side that was compared to a non-chromated coating system, using TCP as the pretreatment, on the port side.
Before the P1 vehicle was fielded at th e USMC Amphibious Vehicle Test Branch (AVTB) at Camp Pendleton, the paint system was scribed through in an “X” pattern at several
locations on the hull. The main scribe loca tion was forward on the lower side-wall of each vehicle. This area is subject to scrapes and di ngs during land movement, and is fully submerged
when the vehicle is in the wate r. The initial inspection of P1 was conducted at 4 months, at AVTB. Preliminary results indicated that the n on-chromate system was keeping pace with the chromated products. The next inspection was conduc ted at roughly 1 year of testing, in August

2003.

50NCAP Phase II Interim ReportSeptember 2004P1 Non-chromate vs. chromate Testing ResultsNon-ChromateChromateFigure 5.17: P1 – 4 Months In-Water Testing51NCAP Phase II Interim Report September 2004

Craig Matzdorf, NAVAIR, visited the AVTB on the morning of August 6, 2003 and
observed corrosion issues on the forward scribed ar eas on each side of the P3 hull. A field observation was conducted and photos were taken of interior and ex terior examples of corrosion.
The forward scribed area on each side of the hull of the USMC-EFV P1 was observed. The chromated coating showed no corrosion whatso ever, with the scribes remaining bright and shiny. The non-chromated coating showed some white corrosion product in the scribe and one or two small corrosion pits. No undercutting or damage was noted away from the scribes. The other general areas that were visible showed no difference in performance on either side. Of note is that the vehicle was parked facing north and the por t side (with the nonchromate system) was very wet under the flaps. The starboard side (with the chromate system) was dry. This may be due to the washing schedule and how much sun the EFV gets after rinsing. If the port side is typically we t longer, the corrosion potential is far higher than for the starboard
side. This must be taken into account when co mparing the coating systems. It was suggested that AVTB personnel be questioned regarding the rinsing protocol and whether the port side does typically stay wet longer, be fore or after rinsing. It was noted that the steering buckets a nd brackets around them on both sides were different than previously and had large unpainted areas that were beginning to surface corrode and pit. It was recommended that these surfaces be cleaned of corros ion, treated with TCP, primed and top-coated as soon as pos sible to prevent further degradation.

Figure 5.18: P1 Inspection – C. Matzdor f at AVTB, Camp Pendleton – August 2003

52NCAP Phase II Interim Report September 2004

P1 was inspected by Bill Nickerson of NAVAIR and Kevin Clar k of GDAMS at the GDAMS Woodbridge, VA facility on February 19, 2004. Again, similar surface corrosion and paint adhesion performance was observed between the fully chromated and fully non-chromate coating systems. One area of concern was noted in the perfor mance difference with respect to galvanic corrosion. The non-chromate system exhibited significantly more corr osion around dissimilar metal interfaces than did the chromated coating system. It was noted that the non-chromate system was MIL-PRF-85582 N primer, a water-re ducible non-chrome epoxy primer; while the chromated side was MIL-PRF-23377 C2 primer, a solvent-reducible chromated epoxy primer. Subsequent laboratory testing c onfirmed that the large discrepancy in galvanic protection was a property of the primer system. The MIL-P-53022 solvent-reducible non-chrome epoxy primer performed very similarly to the MIL-23 377 C2 primer; leading to the conclusion that a solvent-based primer, regardless of chromate c ontent, was preferable for galvanic corrosion protection due to increased barrie r protection against moisture ingress compared to water-based primers for use on the EFV platform.

5.2.8.2 – E2 AND E7 – IN WATER TESTI NG, AVTB, CAMP PENDLETON, CA EFV SDD Vehicles E2 and E7 were insp ected by Bill Nickerson, NAVAIR, and Kevin Clark, GDAMS, along with Subra Bettadapur, DR PM AAA, at AVTB, Camp Pendleton on May 24, 2004. These vehicles have been undergoing in-water testing and evaluation at the Amphibious Vehicle Test Branch, Camp Pendleton, CA for almost 2 years. Both of these vehicles were spray processe d at the LATP facility with a non-chromate alternative conversion coating, and painted wi th a non-chromate primer and CARC topcoat.

E2 was processed as follows:
1. Clean with K-56 alkaline cleaner
2. Deoxidize with Ridoline 4450
3. Pretreat with Alodine 5700
4. Prime with MIL-PRF-85582 N 5. Topcoat with MIL-DTL-64159 TyII E7 was processed as follows:
1. Clean with Aerowash
2. Deoxidize with Ridoline 4450
3. Pretreat with TCP
4. Prime with MIL-P-53022 5. Topcoat with MIL-DTL-64159 TyII

It was observed that both vehicles had area s of paint loss due to scraping and gouging caused by rocks and debris around track areas, and on the lower anterior-hull from abrasion during water-to-land movements. Figure 5.19 shows severe sc raping damage on the lower
anterior-hull of E7 – no additional undercut ting from the damaged areas is evident.

53NCAP Phase II Interim Report September 2004

Figure 5.20: E7 Lower Anterior Hull

Figure 5.21 shows a cross-hatch scribe area on E7 from the initial QC paint adhesion inspection at LATP – no undercutting or peeling of the paint system from the scribe was observed. No corrosion product was evident in the scribed area.

Figure 5.21: E7 Cross-hatch Scribe

54NCAP Phase II Interim Report September 2004

E2 exhibited significantly more corros ion, additional undercutting, paint adhesion problems from damaged areas than did E7. Fi gure 5.22 shows paint chipping on E2’s top, port side, in front of the driver’s hatch. This area sees a high volume of traffic, but similar damage
was not evident on the E7.

Figure 5.22: E2 Driver’s Hatch

It is important to note that E2 was processed much earlier in the SDD cycle than was E7, and some paint adhesion issues in QC testing after processing were noted even before field testing. E7 had perfect paint adhesion test resu lts after processing. The biggest factor was the processing differences, as E2 wa s still cleaned using the K-56 pr oduct, which is not designed for aluminum substrates. After the processing of E 2, it was agreed by consensus that a water-breakfree surface must be achieved before c ontinuing with the chemical processing.
The field tests bear out the absolute crit icality of applying the chemical conversion coating with the proper process controls and parameters. Once the proper chemicals and process checks were in place, such as wetting the surf ace after cleaning to ensu re water-break free surface and good attention to chemical dwell times during processing, no paint adhesion issues have been reported. E7, E8, and E9 vehicles all passed the QC paint adhesion inspection at LATP and the non-chromate coating system is pe rforming very well on E7 in field testing.

5.2.8.3 – STATUS The EFV program is scheduled to begin LRIP in early FY06. TCP has been selected as the pretreatment for the processing of the hul ls and turrets. Both TCP and Alodine 5200/5700 have been approved for use on components by GDAMS and their vendors. The USMC AVTB is currently using Alodine 5700 pre- saturated wipes for coating system maintenance and repair touch-up applications on the SDD vehicles fielded there.

55NCAP Phase II Interim Report September 2004

5.3 –US ARMY BRADLEY FIGHTING VEHICLE

5.3.1 – INTRODUCTION

The US Army’s M2 Bradley Fighting Vehicle entered production by United Defense in 1980. Originally, this program utilized a chromate conversion coating applied by immersion process to enhance corrosion resistance and paint adhesion on aluminum hull, turret, and armor components. The United Defense facility possesses an automated hoist and immersion system, whereby an entire hull can be lifted a nd dipped through the 32,000- gallon process tank line in 2.5 – 3 hours. The process line utilized Chemetall-Oakite TM brand chemicals, and consisted of a mildly alkalin e non-silicated cleaner, a hot phosphoric acid etch, a ferric sulfate/nitric acid based de-smut, and finally the chromate conversion coating. Each step in the process was followed by a halo-spray, clea r water rinse. This line is not currently in

use. UDLP-York, the OEM, is still upgradi ng and retrofitting BFV’s to the new M2A3, M3A3 variations. In depot maintenan ce and rework efforts, it was noticed that the aluminum armor alloy, AA7039, evidenced severe intrametallic delamination probably caused by environmentally assist ed stress corrosion cracking (SCC). The
decision was made to move to a manual surf ace prep method, as it was thought that the immersion process trapped moisture in sm all cracks and tight areas on the vehicles, thereby accelerating the delamination. The PM CS Environmental Management Team (EMT) has suggested an SCC evaluation of AA7039 with the current process versus an immersion process using both ch romate control and TCP to ascertain the differences, if any, between the chemical immersion or manual surface preparation methods.

Figure 5.23:
Delaminations on BFV Hull Components – AA7039

56NCAP Phase II Interim Report September 2004

The current repair procedure for SCC damaged parts on re-man BFV’s is as follows: abrasive media blast, weld repa ir visible surface cracking, leave existing delaminations as is, perform weld and mach ining modifications, st eam clean/pressure wash, bake/dry hulls at 180-200 0 F, abrasive blast, prime, and topcoat. The manual surface preparation, direct-to-me tal (DTM), involved grit-blasting the hulls and turrets to a 1.5-3.0 mil surface profile to enhance paint adhesion. The DTM process increases the corrosion performan ce through adding surface area with the roughened profile thereby increas ing adhesion of primer/paint systems to the substrate; however, the mechanical su rface modification offers no active corrosion inhibition beyond that supplied by the primer inhibitors. Mechanical bonding helps protect from undercutting at damaged areas, but offers no protection from surface corrosion where paint is removed at damaged areas. Add itionally, the same delamination SCC issues have been observed with AA7039 as were observed with the original chemically processed vehicles. The current DTM process affords re duced corrosion protection versus a chemically conversion coated surface and has not been seen to elim inate or reduce the SCC of the armor components. A chemical coa ting process also gives the extra benefit of being a faster, and much less labor-intensive process. This allows for uniform surface preparation, even in corners, bolt-holes, and other areas inac cessible to grit-blasting. The DTM process is also more costly and time-consuming than the chemical process – which cleans, etches, and prepares the surface at the same time. The chemical process could save roughly 4-hours of labor costs per vehicle.

Direct-to-Metal Chemical Processing
Abrasive blast – Paint removal Abrasive blast Weld repair cracks Weld repair cracks Perform weld and machining modifications Perform weld and machining modifications

X Steam clean/pressure wash

X Bake hulls prior to paint at 180-200F

X Abrasive blast – Surface Prep → Immersion application of MIL-C-5541

TCP

Prime Prime Topcoat Topcoat

Table 5.7: DTM vs. chemical processing

UDLP would like to re-instate the old conversion coating process, but a return to the chromate-based chemistry is now prohibi ted by environmental and health & safety regulations. The BFV program office, along with the OEM, is seeking a viable, nonchromate aluminum pretreatment for im plementation on re-manufactured Bradley Fighting Vehicles. Being able to return to a chemical surface preparation method will yield a performance increase a nd a cost savings to the prog ram. An added bonus to the OEM would be to conserve an uncommon resource in having a high volume process line capable of treating entire hull structures by immersion. As a result, the BFV was added to the NCAP project as a high-value demonstrati on platform; with a ve ry high likelihood of implementing a non-chromate pretreatment.

57NCAP Phase II Interim Report September 2004

5.3.2 – COMPONENT SELECTION

PM Combat Systems (PMCS) and NAVAIR generated a list of selection criteria for the demonstration/validation components. A gro up of ten BFV parts were selected for NCAP Phase II testing. NAVAIR’s TCP conversi on coating was selected by the PMCS Environmental Management Team (EMT) as th e demonstration technology for these field
evaluations. The test components met the following criteria:

 Common to M2A3, M3A3, and M3A3 BFIST vehicles

 Material: AA5083 or AA5086

 Pretreatment: DTM (no conversion coating) or with MIL-C-5541 Class 1a or 3

 Modular - easily removed and replaced (bolt-on)

 Not a safety critical item

 Sized to fit within a 2 cubic foot space To ensure the greatest possible range of performance evaluation, the parts were selected to expose the altern ative pretreatment to a wide stress environment; including sun/weathering, abrasion, flexing, non-skid, electrical bonding, cemented cushion/seal material, heat, water. Both interior and exterior parts were selected, allowing for evaluation of the pretreatment with both coatings systems in use on BFV’s. Table 5.8 lists the primer/paint systems for interior and exterior applications.

COMPONENT CURRENT

PRETREATMENT PRIMER TOPCOAT

Exterior None MIL-P-53022 Solvent Reducible, Epoxy CARC,
White MIL-C-53039A Solvent-based, 1K, Moisture-cured, 1.5lbs VOC, Polyurethane CARC, 686 Green
or 686 Tan*

Interior None or Class 1A
chromate MIL-P-22750 Solvent Reducible, Single-coat, Epoxy CARC, Sea-foam Green *Note: for this field evaluation, all exteri or parts were top-co ated with 686 Tan

Table 5.8: BFV Paint Systems

The ten components selected are listed in Table 5.9 by part number and description. For this demonstration, all exterior components are curren tly DTM processed.

58NCAP Phase II Interim ReportSeptember 2004* Cushion/gasket material cemented to part after paintingInteriorNoneHull interior, inside powerplantcompartmentBracket, Mounting, vehiclemotionsensor1246991710.ExteriorNoneTurret exterior - atop bustleAntenna Bracket129763549.ExteriorNoneTurret exterior - atopprimarysight“doghouse”Holder, Flagstaff123072558.InteriorClass 1A MIL-SPEC-5541Turret interior - basketfloorPlate, Floor, Left Hand **123073247.InteriorNoneHull interior - driver’sstationSteering Wheel (yoke)123073866.ExteriorNoneHull exterior - on left rearDoor Assembly, StowageBox,LeftSide*****122979155.ExteriorNoneHull exterior - on right rearDoor, Stowage Box, Right *****122976764.InteriorClass 1A MIL-SPEC-5541Hull interior - driver’sstationFloor Plate, Bilge Pump *122974233.ExteriorNoneHull exterior - front glacisGuard, headlight left123692392.ExteriorNoneHull exterior - front glacisGuard, headlight right123692371.CARCPAINTSURFACETREATMENTLOCATIONDESCRIPTIONPARTNO.NO.** Nonskid applied to part before painting.*** Requires insert p/n 12307422****Stowage box and door used for re-man parts to avoid fit-up problemsDue to time and availability constraints the re-man component set did not contain Part No.s 3, 9, or 10Table 5.9: Selected BFV Non-chromatePretreatment Field Test Components59NCAP Phase II Interim Report September 2004

Figure 5.24: Headlight Guards

Left
Guard Right
Guard

60NCAP Phase II Interim Report September 2004

Figure 5.25: Stowage Box Doors

Right

Door Left

Door

61NCAP Phase II Interim Report September 2004

Figure 5.26: Floor Plate, Bilge Pump

Driver’s Steering Yoke

Figure 5.27: Driver’s Steering Yoke

Figure 5.28: Turret Left Floor Plate

Figure 5.29: Flagstaff Holder (Top R)

and GPS Antenna Bracket (Lower R)

62NCAP Phase II Interim Report September 2004

5.3.3 – PROCESSING

5.3.3.1 – COMPONENTS

Two sets of new components were procured and shipped to Patuxent River, MD in August 2003. One of the identified components in the sets was not treated at that time, as the component was plated steel that had been ch romated by the vendor before procurement by the program office. This component, Part No. 12469917, Bracket, Mounting, Vehicle Motion Sensor, was subsequently dropped from the test matrix, and was not evaluated during field testing.

NAVAIR pretreated the components by an immersion process, using the same chemical products as used in the processing lin e at the York, PA fac ility. Heather McNabnay, Environmental Coordinator, PM Ground Combat Systems, and Tom Braswell, Floor Support Engineering, UDLP-York were on hand to observe and assist in the pretreatment. Table 5.10 outlines the pretreatment process.

PRODUCT NAME CHEMICAL

DESCRIPTION PROCESS

TEMPERATURE IMMERSION TIME

Oakite NST 10% Mild alkaline, nonetching, non-silicated
cleaner 120-130 F 6 minutes

Oakite 33 12.5% Phosphoric aci d etch 117-120 F 6-12 minutes

Oakite LNC 10% Dilute acid/ferric
based desmutter/brightener Ambient 30 seconds –2
minutes

TCP-CC Non-chromate conversion coating with color change Ambient (80 F) 5-15 minutes

TABLE 5.10: BFV Components Process Parameters

Mr. Braswell primed the components within 24-hours of conversion coating, and topcoated the exterior components within 48-hours of priming. The interior components were sprayed with a single-coat, solvent-reducible, epoxy CARC. The exterior components wereprimed with a solvent-reducible, epoxy CARC primer and top-coated with a singlecomponent, moisture-cur ed, polyurethane CARC.

At the PMCS EMT meeting October 2003, a co ncern was raised about the validity ofonly testing new components, when in fact the majority of BFV’s and BFV parts are remanufactured. Re-man parts wi ll be blasted or ground to re move old paint, corrosion, or other surface damage before re-work and pain ting operations take pl ace. This distressed surface is much rougher and less uniform than th e neat, machined surface of a new part.

63NCAP Phase II Interim Report September 2004

As a result, a third set of components was procured; these being removed from fielded vehicles recently arrived at UDLP-York fo r re-manufacturing. This set of components included a right and left storage box in lieu of the right a nd left storage box doors in the two sets of new components. The parts were ship ped to Patuxent River, MD in November 2003. Several areas on each part were ground down to bare aluminum using a typical grinder and 120-180 grit grinding wheel. The re-man parts we re then pretreated in accordance with the procedures in Table 5.10, by NAVAIR and UDLP personnel.

The re-worked components from set th ree were then primed over the newly conversion coated areas, and th e entire part was then top-coat ed; the paint system was the
same as in the first two sets.

Figure 5.30: TCP-C BFV Components Awaitin g Primer Application – August 2003

64NCAP Phase II Interim Report September 2004

Figure 5.31: Primer Application – Left Headlight Guard – August 2003

65NCAP Phase II Interim Report September 2004

Figure 5.32: Interior Components after Appli cation of Single-Coat, Sea-Foam Green Epoxy CARC – August 2003

66NCAP Phase II Interim Report September 2004

Figure 5.33: Re-Man Components – As received – November 2003 (Top)

And after Grinding/Preparation of Selected Re-Work Areas (Bottom)

67NCAP Phase II Interim Report September 2004

Figure 5.34: Re-Man Parts after Pretreat ment of Selected Test Areas (Top)

And after Primer and Top-Coat Application (Bottom)

68NCAP Phase II Interim Report September 2004

5.3.4 – QC PANEL TEST ING/LAB VALIDATION

To ensure that the coatings were not damaged or c ontaminated during the component processing, two sets of quality control panels were coated and painted at the same time. Each
set consisted of 10-each of 4”x12” aluminum panels, one set of AA5083-H131 and the other of AA6061-T6. The panels were then primed and painted at the NAVAIR Pax River, MD facility at the same time as the field test comp onents. These QC panels were then shipped to UDLP-York for accelerated corrosion testing in ASTM B117 neutral salt fog and GM9540P cyclic testing.

Another set of panels, 20-each of 4”x12” AA5083-H131 and AA6061-T6 were processed with the original TCP, two va riations of the TCP-C, and Oakite 163 TM chromate control to determine the optimum conversion coati ng formulation for this effort. These panels were then packaged and shipped to UDLP-York , for primer and topcoat application in the York small parts production paint line. These pa nels were also put into accelerated corrosion testing in accordance with ASTM B117 and GM9540P.

Figure 5.35: QC panels after MI L-P-53022 Primer Application

All panels were processed in accordance with the parameters contained in Table 5.10. Laboratory accelerated corrosion testing and evaluation was conducted by Doug Russo, CTC at the United Defense, York, PA facility. Table 5.11 outlines th e test parameters and results for the QC test matrix. All testing and eval uation was performed by CTC York, with testing oversight provided by York FSE, N AVAIR, ARL, and the BFV EMT.

All panels were given a numer ical rating by distance of undercutting from the scribed area, according to ASTM D610.

69NCAP Phase II Interim Report September 2004

ASTM B117- 3,000 HRS.

PANEL ID DFT IN MILS ASTM D610 UNDERCUTTING

TCP5083 #1 3.2 10 <0.01 IN.

TCP5083 #2 3.9 10 <0.01 IN.

TCP5083 #3 3.2 10 <0.01 IN.

TCP5083 #4 3.1 10 <0.01 IN.

TCP5083 #8 3.6 10 <0.01 IN.

TCP6061 #5 2.9 10 <0.01 IN.

TCP6061 #6 3 10 <0.01 IN.

TCP6061 #7 3.4 10 <0.01 IN.

CONTROL 6061 #9 4 10 <0.01 IN.

CONTROL 6061 #10 3.2 10 <0.01 IN.

GM9540P-120CYCLES

TCP5083 #11 3.1 10 <0.01 IN.

TCP5083 #12 3.3 10 <0.01 IN.

TCP5083 #13 3.8 10 <0.01 IN.

TCP5083 #14 3.8 10 <0.01 IN.

TCP6061 #15 3.1 10 <0.01 IN.

TCP6061 #16 3.4 10 <0.01 IN.

TCP6061 #17 3.2 10 <0.01 IN.

CONTROL 5083 #18 3.8 10 <0.01 IN.

CONTROL 5083 #19 3.1 10 <0.01 IN.

CONTROL 5083 #20 3.4 10 <0.01 IN. Table 5.11: Accelerated Corrosion Testing of QC Pa nels Pretreated and Painted at the time of the Field Test Components.

All panels passed regardless of alloy or pretreatment, and no performance difference
was identified between the chromate controls a nd the TCP panels. This validates that the TCP conversion coating applied to the BFV test components was done properly; thereby supporting the field test results as valid data.

The secondary set of corrosion panels fo r TCP process optimization were run out to 3,020-hours of ASTM B117 and 120-cycles (3000-hour s) of GM9540P with same results as the first set of coupons.

The average DFT was 4.92-mils for the TCP panels and 4.93-mils for the chromate control panels.

70NCAP Phase II Interim Report September 2004

5.3.5 – FIELD TESTS

5.3.5.1 – RESULTS

M2A3 Bradley Fighting Vehicle #258 – Part s were installed at APG, MD on August 30, 2003. This vehicle was scheduled for testing at APG Test Track facility. After testing at APG, this test vehicle was shipped to Huntsvil le, AL for modification, th en returned to APG.

Brian Placzankis, Coatings and Corrosion Branch, Army Research Lab, APG, MD and Bill Nickerson, Inorganic Coatings, Naval Air Warfare Center, Aircra ft Division, Patuxent River, MD inspected the vehicl e at 6 months in January 2004 at the APG Test Track. Heather McNabnay, PMCS, and Tom Braswell, UDLP-York were also present for the inspection. No corrosion or adhesion loss was observed on any of the components at this time. Additionally, no undercutting or propagating paint loss was observed at damaged or dinged areas. This vehicle was again inspected at 12 months of service by Brian Placzankis, when it was
returned to APG after instal lation of the Chassis Modern ization/Embedded Diagnostics upgrade at Huntsville, AL. This mod kit is an upgrade to the hull electronics for the BFV’s, and requires the removal of th e legacy steering yoke compon ent. All other TCP components
remain in service on the vehicle. While the ve hicle evidenced much use, and was quite dirty and scuffed from testing, no corrosion or adhesion problems were reported, and no undercutting or additional paint adhesion loss was noted at damaged or dinged areas.

Figure 5.36: BFV M2A3 258 – APG, MD August 2004

71NCAP Phase II Interim Report September 2004

M2A3 Bradley Fighting Vehicle #031 – Pa rts were installed at Ft. Benning, GA on October 16, 2003. This vehicle is a training vehicle for soldiers, an d is frequently in the field.
This vehicle is still fielded and used for training at Ft. Benning, GA.

Brian Placzankis, ARL, and Bill Nickers on, NAVAIR, inspected the vehicle at 9 months in May 2004 at the Ft. Benning Motor Pool. The vehicle had approximately 6500 kM put on it in training operations since fielding in October 200 3. No corrosion or adhesion loss was observed on any of the components at th is time. Additionally, no undercutting or propagating paint loss was obser ved at damaged or dinged ar eas. All TCP test components, including the legacy steering yoke, re main in service on the vehicle.

Figure 5.37: BFV M2A3 031 – Ft. Benning, GA May 2004

72NCAP Phase II Interim Report September 2004

M3A3 Bradley Fighting Vehicle #086Y – Re -man parts were installed at Yuma Proving Ground (YPG) on February 18, 2004. This ve hicle was scheduled for desert testing at the YPG vehicle test track; th is terrain is very ha rd and rocky, leading to a lot of damage from dings and scrapes. This vehicle was transferred to APG, MD for the Chassis Modernization/Embedded Diagnostics modification kit installation on July 27, 2004.

Brian Placzankis, ARL, inspected the vehicle after almost 6 months in service with the test components, in July 2004 at APG. This vehicle had more dings, scrapes, and overall dirt and damage to the coating system than the other tw o test platforms. In several areas, the paint removal was down to exposure of the underl ying TCP. See figure 5.38. This is again attributable to the extremely rocky terrai n at YPG. No corrosion or adhesion loss was observed on any of the components at this time. Additionally, no undercutting or propagating paint loss was observed at damaged or dinged areas. All TCP test components, with the exception of the legacy steering yoke, re main in service on the vehicle.

Figure 5.38: BFV M3A3 086Y – APG, MD

73NCAP Phase II Interim ReportSeptember 2004Table 5.12: Vehicle TestSchedule – 28 July 200474NCAP Phase II Interim Report September 2004

NAVAIR test parts remain on al l three vehicles except for th e steering yokes on 2AGR0258 and
3AGR00086Y at APG. Chassis Mode rnization/Embedded Diagnostics mod kits were installed and revised yokes replaced the NAVAIR st eering yokes. There are no repor ted problems with NAVAIR test
parts.

5.3.6 – STATUS No adhesion or corrosion issues have been report ed with the test compone nts. Testing will be continued for another 12 months, and possibly longer, to extract as much test data as possi ble. Currently, UDLP-York has expressed the intention to implement TCP as soon as a commercial source is qualified to MIL-DTL-81706B. PMCS has approved its use for spray app lications only at this time. Approval for full immersion processing of the hull and turret structur e is pending the results of the stress-corrosioncracking test being conducted by Un ited Defense CTC Santa Clara, CA.

5.3.6.1 – STRESS CORROSION CRACKING EVALUATION The SCC testing will be conducted by CTC Santa Clara, with testing oversight by the PMCS EMT. The purpose of this evaluation is to determine effect of hexavalent chrome, trivalent chrome, and the current steam cleaning process on SCC in AA7039 armor plating. The same 7039 plate, i.e. same heat lot, will be used to produce all samples. The sample s will be modified to create short transverse cracks. The following variables will be examined, hexavale nt chromium conversion coating, TCP conversion coating, pressure wash, and steam clean; with and without subsequent drying bake. This test will use
fasteners and Belleville washers to create a controlled stress.

The sample size will be 8 inches wide, 12 inches long, and 1 inch thick. The selected proportional fastener torque will create 5-ksi tensile stress.

Figure 5.39: SCC test specimen schematic

75NCAP Phase II Interim Report September 2004

The test plan is as follows: create cracked samp les from untreated AA7039, to rque fasteners to the predetermined value, expose the samples to a salt spray environment, examine the samples daily for cracks using ultrasonic imaging in an attempt to grow a 2-inch crack. The test samples, two replicat es each (16 total), will then be processed with the following pretreatments, and re-exposed to a salt spray environment to mon itor propagation of the crack. The pretreatments will be – none, MI L-C-5541 (chromate control), NAVAIR TC P, pressure wash, bake, and
no bake. The results from this test will be presented to the PM Combat Systems EM T at the next quarterly meeting, with final status on chemical conversion coating by immersion processing to be determined at
that time.

76NCAP Phase II Interim Report September 2004

5.4 – US ARMY AVIATION

5.4.1 – BACKGROUND

In August of 2003, the Environmental, Engineeri ng, and Logistics Oversight (EELO) office at AMCOM in Huntsville, AL put together a comprehens ive panel test matrix to identify a non-chromate system for demonstration as a potential replacement coating system for their current chromate-based pretreatment and primer process. Currently, Army Aviation Depots spray chromate conversion coating, and paint with MIL-PRF-23377 C primer and MIL-C-46168 Type IV CARC, a 2-component, polyurethane topcoat.

Panel preparation and coating was conducted by NAVAIR, Patuxent River, with AMCOM EELO, and ARL present from October 14-17, 2003. Panels were then shipped to ARL for corrosion and adhesion testing. All testing a nd evaluation was conducted under th e oversight of PEO Aviation, AMCOM Materials, EELO, ARL, and NAVAIR.

The three alternative pretreat ments selected for aluminum a lloy testing were Alodine 5700, NAVAIR TCP, and PreKote. These pretreatme nts were evaluated ove r AA2024-T351 and AA7075-T651 alloys. The non-chrome primer alternative eval uated was MIL-PRF-85582 N since no qualified version
of MIL-PRF-23377 N was available at the start of tes ting. All three pretreatments were evaluated under chromated primers (MIL-PRF-23377 C and MIL- PRF-85582 C) and the non-chromate MIL-PRF-85582 N. The potential replacement primers, MIL-PRF-85582 C and N were coated with the latest generation CARC topcoats, MIL-C-53039A Low VOC and MIL- DTL-64159 Type II to evaluate the coating “system” performance.

5.4.2 – LABORATORY TESTING

Testing was conducted by ARL at APG, MD by the Coatings and Corrosion Branch. Corrosion testing was conducted according to ASTM B117 ne utral salt fog and GM9540P cyclic corrosion. All corrosion tests were run out to 3,000 hours, with re gular evaluations by AR L and AMCOM. Adhesion testing was conducted according to ASTM D4541-95 pu ll-off and ASTM D3359 wet tape testing. Adhesion Testing was completed in early 2004 and corrosion testing wa s completed in July 2004. Table 5.13 shows the full aluminum coating system test matrix.

77NCAP Phase II Interim ReportSeptember 200478ALUMINUM AL2024-T3ALUMINUM AL7075-T6PNLID4Control5678910111213141513Control141516171819Panel Type2024T32024T32024T32024T32024T32024T32024T32024T32024T32024T32024T32024T37075T67075T67075T67075T67075T67075T67075T6Panel PreTreatmentMIL-C-5541MIL-C-5541MIL-C-5541MIL-C-5541TCPTCPTCPAlodine5200Alodine5200Alodine5200X-ITPrecoatX-ITPrecoatMIL-C-5541MIL-C-5541MIL-C-5541TCPTCPTCPMIL-C-5541Primer23377C85582N85582N85582N85582C85582N85582N85582C85582N85582N85582C85582N23377C85582N85582N85582C85582N85582N85582CTopcoat46168IV5303964159II64159IILSL64159II5303964159II64159II5303964159II64159II64159II46168IV5303964159II530395303964159II64159IIAWet Adhesion -ASTM D 33592222222222222222222BSalt Spray -ASTM B 1175555555555555555555CPull-OffASTM D 4541-952222222222222222222DGM 9540B -Method B5555555555555555555EOutdoorExposure - FL5555555555555555555FQTRAC10101010101010101010101010101010101010GElectrochemicalImpedanceSpectroscopyN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AN/AControl Set2222222222222222222TOTALPANELS RQDPER SET16161616161616161616161616161616161616ALUMINUM - AL2024-T3192ALUMINUM - AL7075-T6112Table 5.13: AMCOM –NAVAIR PANEL TEST MATRIX OCTOBER 2003NCAP Phase II Interim Report September 2004

5.4.2.1 – PULL-OFF ADHESION TE STING – ASTM D 4541-95

AA2024-T3

Pretreatment Primer Topcoat Adhesion (30 measurement Avg. – psi)

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 3205.67 + 261.15

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 2913 + 213.79

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 2609 + 246.89

TCP MIL-PRF – 85582 C MIL-DTL-64159 Ty II 2739 + 177.91

TCP MIL-PRF – 85582 N MIL-C-53039A 3064.33 + 194.35

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 2579.33 + 204.21

Alodine 5700 MIL-PRF – 85582 C MIL-DTL-64159 Ty II 2601.33 + 304.37

Alodine 5700 MIL-PRF – 85582 N MIL-C-53039A 2563.67 + 423.28

Alodine 5700 MIL-PRF – 85582 N MIL-DTL-64159 Ty II 1644 + 275.91

PreKote MIL-PRF – 85582 C MIL-DTL-64159 Ty II 2388 + 114.09

PreKote MIL-PRF – 85582 N MIL-DTL-64159 Ty II 2861 + 272.94

Table 5.14: Pull-Off Ad hesion Data – AA2024T3

AA7075-T6

Pretreatment Primer Topcoat Adhesion (30 measurement Avg. – psi)

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 3229 + 317.41

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 2993 + 233.90

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 2310 + 173.90

TCP MIL-PRF – 85582 C MIL-C-53039A 2994.33 + 427.70

TCP MIL-PRF – 85582 N MIL-C-53039A 2931 + 201.93

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 2509.67 + 149.05

Alodine 1200S MIL-PRF – 85582 C MIL-DTL-64159 Ty II 2712 + 195.95

Table 5.15: Pull-Off Ad hesion Data – AA7075T6

79NCAP Phase II Interim Report September 2004

5.4.2.2 – WET TAPE ADHESION TESTING – ASTM D 3359

AA2024-T3

Pretreatment Primer Topcoat Panel 1 – 2 meas. Avg Panel 2 – 2 meas. Avg

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 5 5

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 5 5

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 4 4

TCP MIL-PRF – 85582 C MIL-DTL-64159 Ty II 4 5

TCP MIL-PRF – 85582 N MIL-C-53039A 5 5

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 5 4.5

Alodine 5700 MIL-PRF – 85582 C MIL-DTL-64159 Ty II 4.5 4 Blisters

Alodine 5700 MIL-PRF – 85582 N MIL-C-53039A 4 4.5 Blisters

Alodine 5700 MIL-PRF – 85582 N MIL-DTL-64159 Ty II 3.5 3.5

PreKote MIL-PRF – 85582 C MIL-DTL-64159 Ty II 3.5 3 Blisters

PreKote MIL-PRF – 85582 N MIL-DTL-64159 Ty II 4.5 4

Table 5.16: Wet Tape A dhesion Data – AA2024T3

AA7075-T6

Pretreatment Primer Topcoat Panel 1 – 2 meas. Avg Panel 2 – 2 meas. Avg

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 4.5 5

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 5 5

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 4.5 4.5

TCP MIL-PRF – 85582 C MIL-C-53039A 5 5

TCP MIL-PRF – 85582 N MIL-C-53039A 5 5

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 4.5 4.5

Alodine 1200S MIL-PRF – 85582 C MIL-DTL-64159 Ty II 5 4

Table 5.17: Wet Tape A dhesion Data – AA7075T6

80NCAP Phase II Interim Report September 2004

5.4.2.3 – NEUTRAL SALT FOG TE STING – ASTM B 117

AA2024-T3 – Ratings According to ASTM D 1654 Procedure A

Pretreatment Primer Topcoat Corrosion Results (5 panel Avg.)

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 8.6 + 0.89

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 7.2 + 0.44

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 7.4 + 0.55

TCP MIL-PRF – 85582 C MIL-DTL-64159 Ty II 9.0 + 0.00

TCP MIL-PRF – 85582 N MIL-C-53039A 5.8 + 0.84

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 5.0 + 0.71

Alodine 5700 MIL-PRF – 85582 C MIL-DTL-64159 Ty II 8.6 + 0.55

Alodine 5700 MIL-PRF – 85582 N MIL-C-53039A 6.4 + 1.34

Alodine 5700 MIL-PRF – 85582 N MIL-DTL-64159 Ty II 4.4 + 0.55

PreKote MIL-PRF – 85582 C MIL-DTL-64159 Ty II 7.4 + 0.55

PreKote MIL-PRF – 85582 N MIL-DTL-64159 Ty II 2.4 + 1.52

Table 5.18: Neutral Salt Fog Corrosion Data – AA2024T3

AA7075-T6 – Ratings According to ASTM D 1654 Procedure A

Pretreatment Primer Topcoat Corrosion Results (5 panel Avg.)

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 9.0 + 0.0

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 7.4 + 0.55

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 7.8 + 0.45

TCP MIL-PRF – 85582 C MIL-C-53039A 8.8 + 0.45

TCP MIL-PRF – 85582 N MIL-C-53039A 7.2 + 0.45

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 7.2 + 0.45

Alodine 1200S MIL-PRF – 85582 C MIL-DTL-64159 Ty II 9.0 + 0.0

Table 5.19: Neutral Salt Fog Corrosion Data – AA7075T6

81NCAP Phase II Interim Report September 2004

5.4.2.3 – CYCLIC SALT FOG TESTING – GM9540P

AA2024-T3 – Ratings According to ASTM D 1654 Procedure A

Pretreatment Primer Topcoat Corrosion Results (5 panel Avg.)

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 9.0 + 0.0

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 6.2 + 0.45

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 6.4 + 0.45

TCP MIL-PRF – 85582 C MIL-DTL-64159 Ty II 8.4 + 0.89

TCP MIL-PRF – 85582 N MIL-C-53039A 5.4 + 0.55

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 5.0 + 0.0

Alodine 5700 MIL-PRF – 85582 C MIL-DTL-64159 Ty II 8.6 + 0.55

Alodine 5700 MIL-PRF – 85582 N MIL-C-53039A 5.0 + 0.0

Alodine 5700 MIL-PRF – 85582 N MIL-DTL-64159 Ty II 4.2 + 0.84

PreKote MIL-PRF – 85582 C MIL-DTL-64159 Ty II 8.6 + 0.89

PreKote MIL-PRF – 85582 N MIL-DTL-64159 Ty II 3.6 + 0.89

Table 5.20: Cyclic Salt F og Corrosion Data – AA2024T3

AA7075-T6 – Ratings According to ASTM D 1654 Procedure A

Pretreatment Primer Topcoat Corrosion Results (5 panel Avg.)

Alodine 1200S MIL-PRF – 23377 C MIL-C-46168 Ty IV 9.4 + 0.55

Alodine 1200S MIL-PRF – 85582 N MIL-C-53039A 7.6 + 0.89

Alodine 1200S MIL-PRF – 85582 N MIL-DTL-64159 Ty II 7.2 + 0.45

TCP MIL-PRF – 85582 C MIL-C-53039A 9.2 + 0.45

TCP MIL-PRF – 85582 N MIL-C-53039A 7.0 + 1.41

TCP MIL-PRF – 85582 N MIL-DTL-64159 Ty II 8.6 + 0.55

Alodine 1200S MIL-PRF – 85582 C MIL-DTL-64159 Ty II 8.8 + 0.45

Table 5.21: Cyclic Salt F og Corrosion Data – AA7075T6

82NCAP Phase II Interim Report September 2004

5.4.3 – FIELD TEST SYTEMS SELECTION

The current demonstration selection is to evaluate two non-chromate coating systems in field application on Army helicopters. Subject to approval from the PMA’s, the plan is to process six full CH-47 aircraft at two separate depots. Three aircraft will be processed at CCAD and three aircraft will be processed at the CT AVCRAD facility. Each site will process one cont rol aircraft, to be primed with MIL-PRF-23377 C1 or C2, chromated epoxy primer. Table 5.18 outlines th e planned demonstration coating systems.

Aircraft Pretreatment Primer Topcoat

CH-47 TCP MIL-PRF-23377 C MIL-C-53039A

1.5VOC

CH-47 TCP MIL-PRF-85582 N MIL-C-53039A

1.5VOC

CH-47 TCP MIL-PRF-23377 N MIL-C-53039A

1.5VOC

CH-47 Alodine 5700 MI L-PRF-23377 C MIL-DTL-64159 TyII

CH-47 Alodine 5700 MI L-PRF-85582 N MIL-DTL-64159 TyII

CH-47 Alodine 5700 MI L-PRF-23377 N MIL-DTL-64159 TyII

Table 5.22: AMCOM Coating System Demonstrations

5.4.3.1 – GENERAL GUIDELINES – AI RCRAFT CLEANING, SURFACE

TREATMENT AND COATING

Aircraft will be inspected to identify coating problems and recorded in the aircraft coating test log (provided). Obvious corrosi on, missing rivets, loose/ flaking paint, etc. should all be noted. Aircraft shall be cleaned per normal operations at the facility and required maintenance accomplished prior to preparation for de-painting/painting operations.

Components normally removed prior to de-painting shall be removed and depainted in accordance with normal procedur es. Any aluminum substrate components removed for hand de-painting and processi ng shall follow the guidelines below forsurface preparation and conversion coating of the aluminum substrate. Other nonaluminum components shall be prepared per normal procedures.

Once stripped, the aircraft shall be inspected for corrosion, and localized corrosion removed by hand abrasion (bristle di sk, sander or hand sand ing) no steel or iron abrasive should be used for removing corrosion on aluminum substrates, products like steel wool, stainless steel shot or grinding/abrading wheels, etc. should be avoided. Other identified flaws shall be repaired per normal procedures.

83NCAP Phase II Interim Report September 2004

84 Cleaning of the aircraft is one of the most critical aspec ts of the TCP application and each step shall be closely followed to ensure a properly prepared surface prior to TCP application. All surfaces to be treated w ith TCP shall be cleaned to a water-breakfree surface with a mild alkaline (pH 8-9, nothing over 9.5) cleaner conforming to MILPRF-85570 Type II or MIL-PRF-87937 Type II. Cl eaners shall be diluted to the proper strength using deioni zed (DI) water to eliminate poten tial ion deposition on the cleaned substrate. If obvious signs of surface contamin ation remain, the cleaning process shall be repeated until a water-break-free surface is obtai ned. If there are signs of “acrylic smear” from Type V PMB an appropriate cleaner sh all be substituted that will remove the
contamination or the contaminants should be removed using medium grit Scotchbrite pads and an aqueous cleaner. Any alternate cleaner selecti on must be coordinated with the Research, Development Engineering Center, Materials Branch prior to use. Personnel shall avoid the use of high pH, strong alkali ne cleaners to prevent damage to the aluminum substrates. Rinse water shall be deionized to eliminate conductive ions being trapped on the bare substrate creating potential corrosion initiation sites or sites where the TCP will not properly adhere. A deoxidation st ep may follow substrate cleaning for final surface preparation prior to TCP application. If a deoxidation process is used, the final
rinse will also use DI water.

Following cleaning (and deoxidation, if used) the surface shall be treated with TCP. TCP shall be appl ied by hand sprayer ensuring the entire surf ace to be treated is completely coated with the TCP solution. The nominal dwell time prior to rinsing the TCP from the surface shall be 10-15 minutes. (N ote: There is no obvious color change to
the treated surface like Alodine 1200 series chromate conversion coatings. However, experienced personnel will be ab le to tell when the rinse should be performed. Properly applied, TCP leaves the treated surface with a subtle, iridescent blue-lavender color.) DI water shall be used for the TCP rinse step.

Following TCP treatment, the substrate sh all be allowed to dehydrate for 16-24 hours. This is the proper “cure” time for the pr etreatm ent. If scheduling is tight, a 4-hour dry time after processing can be implemen ted. Following dehydration, the aircraft shall be masked and coated with the proper primer and top-coating as required.

5.4.4 – STATUS EELO personnel briefed the cognizant PM A’s and AMCOM Materials in Fall 2004 to obtain approval for the CH-47 as th e demonstration platform. If the PMA’s do not want to accept the results of the demo wit hout a b roader platform base, i.e. CH-60’s, AH-64E’s, etc., the planned number of aircraft w ill have to be increased. No changes to the processing sites should be necessary, regardless of the outcome of the PMA’s
decision. All processing will be done under the oversight of AMCOM Materials, and EELO. Bill Nickerson, NAVAIR will be presen t for technical processing support.

W illiam Alvarez, AMCOM EELO and Paul Robinson, (Titan Systems) EELO will evaluate the in-service performance of the test systems. Final approval for implementation must come from AMCOM Materials and Engineering. Spray processing is planned to begin in the early 2005 timeframe, with the first 6
month in-service evaluation in FY05.

### 6.0 – IMPLEMENTATION OF AL TERNATIVES IN DoD AND NASA

6.1 – MILITARY AND INDUSTRIAL PRETREATMENT SPECIFICATIONS
NAVAIR is currently in the process of revising the MIL-DTL-81706 qualification specification and the MIL-C-5541 quality c ontrol specification governing aluminum conversion coatings. The proposed revisions are circulated through DoD and government contractors for comments and review, the inputs collated and organized, and a fina l revision written. Both revisions will allow the qualificati on and use of any non-chromate aluminum pretreatment that can pass the performance requirements for qualification. No changes
have been made to the corrosion and a dhesion testing requirements for aluminum conversion coatings. Additionally, NAVAIR Materials will be working with the SAE-AMS Committee
B toward the revision of the industrial alumin um conversion coating specification, also to include provisions for non-chromate coati ngs that meet the corrosion and adhesion performance requirements.

6.2 – ALODINE TM 5700

6.2.1 – NASA NASA has implemented a non-chromate coating system for use on their aluminum alloy Solid Rocket Boosters (SRB). The Space Shuttle SRB conducted a project to identify and qualify alternatives for the traditional, qualified chromate coating system and pretreatment. Testing gather ed information on corrosion protection, bond strength, compatibility with other SRB materi als, batch-to-batch consistency, and thermal environments data. Two pretreatments and two coating systems met the SRB program criteria. The recommended pretreat ments were Henkel Alodine 5200/5700 and
MacDermid Chemidize 727 ND. Alodine 5700 had very robust processing parameters and was recommended for first implementa tion as a pretreatment alternate.

NASA implemented a Hentzen non-chromate primer / Alodine 5700 pretreatment system in June 2002. This change affect ed all structural aluminum (2219, 6061, and 7075) parts of the solid rocket boosters. The first hardware flew in the fall of 2002.

For More Information Contact: Paul W. Hayes
Phone: 321-853-5774 HayesP@usasrb.ksc.nasa.gov

856.2.2 – US Army TACOM

The US Army TACOM has implemente d Alodine 5200/5700 conversion coating
on AA2024-T4 and AA2014-T6 road wheels for th e Bradley Fighting Vehicle, the M113, and the MLRS. TACOM has also impleme nted Alodine 5200/5700 on Aluminum tracks for the M1A1 Abrams Tank. This technology ha s been implemented in the US Army Red River Army Depot's (RRAD) Rubber Produc ts Operations since early 2003.

For More Information Contact: Heather McNabnay – PM CS Environmental Coordinator
Ph: 586-753-2385 Heather.McNabnay@ngc.com

6.3 – PREKOTE TM
As of Feb. 2004, the F-16, T-37, T-38 and T-1 SPOs have approved the use of PreKote, and HQ Air Education and Traini ng Command (AETC) has mandated its use on all AETC aircraft for which it’s approved. If a base, MAJCOM, or ALC decides to pursue using PreKote in their paint processe s on other systems, it must obtain approval from the appropriate SPOs. AFCPCO will prov ide existing test results upon request to assist SPOs with the engineering de cision whether to approve PreKote.
AFCPCO continues to recommend chro mated conversion coatings for optimum corrosion protection. Multiple laboratory te sts, by various organizations, indicate PreKote is one of the best performing non- chromated surface treatments, but its corrosion protection is still less than that of chromated Alodine 1200S. Several other candidate materials are also being tested as possible alternatives to Alodine. It is likely that more
than one material will meet AF needs. In cases where chromate cannot be used due to environmental restrictions, PreK ote provides a low risk alternative. Note that all test results to date, current SPO approvals, and th e assessment of low ris k, are contingent on the use of a qualified chromated primer. Wh en PreKote is used, corrosion inhibition comes only from the chromated primer. Past performance of non-chro me paint systems in AF use has been poor; and AFCPCO strongly recommends against the use of PreKote with non-chromated primers. Since applicatio n of PreKote is largely a manual process, the consistency of the process may be importa nt to an overall satisfactory result. To achieve results equal to other weapon syst ems, we recommend adhering closely to application practices that ha ve already been established.

For More Information Contact:
Richard H. Buchi
Phone: 801-775-2993 richard.buchi@hill.af.mil

866.3 – TCP

6.3.1 – NAVSEA Based on the results of the outdoor exposure panel testing and the multi-year field demonstration at ACU-4, NSWCCD Materials has indicated that they will implement the TCP for pretreatment of aluminum alloys on the LCAC as soon as a commercial product is qualified to MIL-DTL-81706B. NAVSEA Mate rials is awaiting the issuance of the NAVAIR TCP approval letter for implementation.

For More Information Contact:
Paul Dobias
Phone: 215-897-1545 DobiasPA@nswccd.navy.mil

6.3.2 – USMC The Expeditionary Fighting Vehicle is a pproaching the end of the SDD phase. Environmental, safety and hea lth restrictions have led the program office to mandate the use of chromate and cadmium free coating syst ems. The program is scheduled to begin
LRIP in FY06. TCP has been selected as the pretreatme nt for the processing of the AA2519 hull
and turret structures. Both the TCP a nd Alodine 5200/5700 have been approved by the PM for use on aluminum components by GDAMS and their vendors. The Marines’ AVTB is currently using Alodine 5700 pre- saturated wipes for coating system maintenance and repair touch-up applicati ons on the SDD vehicles fielded there.

For More Information Contact:
Kevin Clark – GDAMS Materials
Phone: 703-490-7533 clarkk@gdls.com

876.3.3 – NAVAIR Overall, the TCP technology is performi ng at least as well as the standard chromate conversion coating in the demonstr ations with the F/A-18’s and CH-46’s. NAVAIR Materials is pla nning to authorize the use of TCP under chromated primers, with the approval letter planne d to issue FY05. Add titional FY05 efforts will focus on an extensive evaluation of new, non-chromate primer systems under qualification testing to MIL-PR F-23377 Class N; with field te sting over TCP planned if applicable based on laboratory testing. As a result of the mixed field perfor mance of the TCP with SPT, NAVAIR does
not recommend the use of TCP with the SPT , and will not pursue implementation of a non-chromate conversion coating on the S-3 platform at this time.

For More Information Contact: Craig Matzdorf – NAVAI R Materials Division
Phone: 301-342-9372 craig.matzdorf@navy.mil

6.4 – AC-130/131

6.4.1 – BOEING/AF Boeing Commercial Airplanes is using AC -131 on chromated aluminum rivets for B737 aircraft to improve paint adhesion to th e rivets. The chromate plus AC-131 coating is applied to the rivets at the rivet manufacturer. Boeing Commercial Airplanes traditionally utilized Alodine 1000 TM clear, chromate conversi on coating for pretreatment
of aluminum rivets on commercial aircraft. They were experienci ng paint loss due to
adhesion failure at the rivets . B737 aircraft produced si nce the spring of 2004 have had
the chromate/AC-131 coated rivets used in th e fuselage. The incidence of paint adhesion failures to the rivets has been significantly decreased with the new coating system. Boeing Commercial Airplanes is also pe rforming scale-up and producibility trials of AC-131 with the goal of replacing th e colorless chromated Alodine 1000 that is currently applied to new production commercial aircraft. Negotiations with customers to identify an operational evaluation are underway with application to production aircraft anticipated in mid 2005.

For More Information Contact: Joe Osborne – Boeing-Seattle
Phone: 425-237-8518 joseph.h.osborne@boeing.com

886.4.2 – NAVAIR/AF Although not part of the scope of the ESTCP Non-Chromate Aluminum Pretreatments project, which focuses on pre- paint conversion coati ng applications for increased paint adhesion, corrosion protecti on, and electrical properties of aluminum alloys, a closely related use of hexavalent chromium coatings is as a pre-adhesive treatment on aluminum alloys prior to stru ctural bonding applicatio ns. Traditionally, adhesive bonding is done with chromated aluminum surfaces. This Joint Service program (PP-0204) is also being funded by the support of the ESTCP office. This project is using repair demonstrations to validate the use of sol-gel based surface preparations for adhesive bonding that were developed under SERDP programs PP-130 and PP-1113. This work has focused on the implementation of repair practices developed for a commercial, epoxy functional sol-gel – AC -130 from AC Tech – in applications where th e sol-gel could be used to replace a hazardous surface preparation method with no reduction in e xpected adhesive bond performance. Furthermore, the use of the AC-130 system has the added benefits of simplicity and process robustness, especially when comp ared to difficult and dangerous surface preparation methods that use strong acids a nd hexavalent chromium. These two factors have been combined to guide the use of sol- gel in DoD repair applications to both replace hazardous surface preparation methods and to supplant obsolescent repair methods with inferior structural performance. The use of this sol-gel is coupled with a zero-VOC primer material in most applications to provide a surface protection scheme for steel, aluminum, or titanium that is suitable for structural bonding. In laboratory testing, this
combination has been used to demonstrat e bonded strength and dur ability performance that exceeds the best existing treatments for the alloys evaluated. Through the demonstration process, this is being translated into a robust repair process that allows repair artisans to restore components to near pristine conditi on. To this end, demonstration of process utility has occurr ed with repair development on a number of weapon systems for the tri-service partners , and off-program tran sitions have been deployed with success in the field. Current work in this program has targeted highimpact transitions that will provide the most benefit per dollar spent, and will enable the services to move sol-gel tec hnology through their logistics a nd repair systems as quickly as possible.

For More Information Contact:
Matt Tillman – NAVAIR Materials Division
Phone: 301-995-7561 matthew.tillman@navy.mil

89THIS PAGE LEFT BLANK INTENTIONALY

90

### 7.0 – CONCLUSIONS AND RECOMMENDATIONS

All the alternatives being demonstrated are aqueous solutions designed to deposit a conversion coating on aluminum alloy substr ates to enhance paint adhesion and painted corrosion performance. Alternat ives face the challenge of the low cost and ease of application of the chromate c onversion coatings while provid ing a coating that provides acceptable technical performance. Along with technical performance, processing and toxicity issues are important to consider in capturing the overall impact of an alternative.

There are currently four non-chromate altern atives in various stages of validation or implementation. Alodine 5200/5700, PreKote, and AC-130/131 provide paint adhesion and painted corrosion protection, and are a ll non-chromium chemistries. The TCP provides both painted and unpainted corrosion protection as well as electrical conductivity in corrosive envi ronments. However, TCP does contain trivalent chromium,
and users will need to balance total chromi um waste-water requirements with technical performance requirements when deciding on im plementation of TCP. TCP and Alodine 5200/5700 provide the most process flexibility, as they can be app lied like a chromate conversion coating, by immersion, spray, or wi pe-on methods. AC-130/131 can be used in spray applications. PreKote must be manua lly applied for proper coating performance.

All of the demonstration coatings have shown good paint adhesion and corrosion performance when used under chromated pr imers. The PreKot e and the AC-130/131 have not yet been demonstrated in high co rrosion environments. The TCP and Alodine 5200/5700 have shown good paint adhesion a nd painted corrosion performance when
used under both chromated and non-chromate d primers. TCP and Alodine 5200/5700 have performed well in high corrosion environment testing. The exception to this is the performance of the TCP on one of the four NAVAIR S-3 demonstrations using nonchromated Self-Priming Topcoat. A positive outcome of the S-3 testing was the finding
that 500-hour SO 2 salt-fog was not enough to discriminate between the chromated and non-chromate coating systems. By extending the test to 1000-hours, additional corrosion and blistering were observed with fully non-ch romated coating systems. This is a clear example of a test designed to evaluate the performance of chromate-based materials, which are not typically tested to failur e, but to minimum performance standards.

It is therefore critical w ith any new non-chromate materi al that it be tested to failure against the chromated control. Add itionally, any new coating application should be demonstrated and validated by field-te sting for each operational environment where implementation is being considered. Only then can the complete technical performance of a coating or coating system be determined.

Implementation of any alternative must take into consideration the costs, process, health and safety, laboratory and field te sting performance, and the specific coating system application and op erational environment.

91

### REFERENCES

Section 1.2 – ESTCP NCAP Phase I Report, C. Matzdorf, July 2003

Section 3.0 – “Protective Coatings Coupon Project – Ratings and Pictures, J. Curran, Jan.

2004

Section 4.1 – AFCPCO Position Paper, D. Kinzie , O. Jett, D. Buchi, M. Spicer, Feb. 2004

Section 4.2.2 – “TCP Application and Pro cessing Notes”, T. Woods, July 1999; T. Woods, Aug. 1999

Section 4.2.3 – “In-Service Field Inspecti on Notes”, T. Woods, May 2001; T. Woods, Dec. 2001; J. Benfer, Jan. 2002

Section 4.3.2 – “TCP Application and Processing Notes”, T. Woods, Nov. 2000

Section 4.3.3 – “In-Service Field Inspecti on Notes”, T. Woods, July 2001; T. Woods,

Oct. 2001

Section 4.3.3 – “Trip Report AM005”, K. Kovaleski, C. Matzdorf, Mar. 2004

Section 4.4.2 – “Materials Engineering Analys is Report – Processing”, J. Whitfield, Oct. 2000; J. Whitfield, Nov. 2001

Section 4.4.3 – “Materials Engineering Analys is Report – Status”, J. Whitfield, Jan. 2004

Section 4.5 – ESTCP NCAP Phase I Report, C. Matzdorf, July 2003

Section 4.6 – “Advanced Aircraft Corro sion Protection Final Report for period September 2002 through April 2003”, J. Osbor ne, Prepared by Boeing for Universal Technologies Corporation under contract #02-S470-009-C1, April 25, 2003

Section 4.6 – “Advanced Aircraft Corrosion Pr otection Update Notes”, J. Osborne, Oct.

2004

Section 5.1 – “Trivalent Chromi um Pretreatment (TCP) testi ng for the Landing Craft, Air Cushioned (LCAC) Program Update Notes”, P. Dobias, July 2004

Section 5.2.2 – “Inorganic Coatings Team Laboratory Report LR02-001”, C. Matzdorf, Aug. 2001

Section 5.2.3 – “Inorganic Coatings Team Te st Matrix M1_07”, C. Matzdorf, Jan. 2002

Section 5.2.4 – “Inorganic Coatings Team Laboratory Reports”, LR02-007, B. Nickerson, Aug. 2002; LR03-006, C. Matzdorf, Aug. 2003

92Section 5.2.5 – “EFV Hull and Turret Processing Notes”, B. Nickerson, C. Matzdorf, K. Clark, D. Gerty, S. Bettadapur , A. Hilgeman, S. Brown, 2001-2004

Table 5.5 – “EFV SDD Hull and Turret Paint Plan”, K. Clark, Feb. 2003

Section 5.2.8 – “In-Service Field Evaluations”, C. Matzdorf, Aug. 2003; B. Nickerson, K. Clark, Mar. 2004; B. Nickerson, K. Clark, S. Bettadapur, May 2004

Section 5.3 – “US Army PM Combat Syst ems Environmental Management Team Meeting Presentations”, T. Braswell, B. Ni ckerson, J. Kinchen, H. McNabnay, J. Dorsch, Oct. 2003, May 2004

Section 5.3.3 – “US Army M2A3/M3A3 Bradley Fighting Vehicle Component Processing Notes”, T. Braswell, H. McNabna y, B. Nickerson, Aug. 2003; T. Braswell, B. Nickerson; Nov. 2003

Section 5.3.4 – “CTC York Adhesion and Corrosion Testing Results”, D. Russo, T. Braswell, Sep. 2003

Section 5.3.5 – “US Army PM Combat Sy stems Environmental Management Team Meeting – ARL Update”, B. Placzankis, Aug. 2004

Section 5.3.6 – “US Army PM Combat Sy stems Environmental Management Team Meeting – UDLP CTC Update”, J. Dorsch, Aug. 2004

Section 5.4 – “US Army Aviation Non-Chrome Coating System Test Program – Master Schedule”, F. Baker, J. Escarsega, C. Matzdor f, B. Nickerson, M. Kane, W. Alzarez, T. Helton, P. Robinson, Oct. 2003

Section 5.4.2 – “Accelerated Corrosion Perf ormance for Aviation Coating Systems – ARL”, C. Miller, B. Placzankis, In-Progress 2004

Section 5.4.3 – “Field Tests/Coatings Systems Selection Meeting – NAVAIR and AMCOM”, W. Alvarez, P. Robinson, T. He lton, B. Nickerson, C. Matzdorf, July 2004

Section 5.4.3.1 – “Aircraft Cleaning, Surface Treatment, and Coating Guide”, P. Robinson, T. Helton, June 2004

Technology Demonstration Plan “Demonstr ation and Validation of Non-Chromate Aluminum Pretreatments,” Science Applicati ons International Corporation for the Naval Aviation Systems Command (NAVAIR), May 2002.

Joint Test Protocol, “Joint Test Protocol for Validation of Non-Chromate Aluminum Pretreatments,” Naval Air Systems Command Inorganic Coatings Team, December 13,

2000.

93MIL-DTL-81706A, “Chemical Conversion Ma terials for Coating Aluminum and Aluminum Alloys,” U.S. Department of Defense, Washington, DC, 1999.

MIL-PRF-85582, “Primer Coatings, Epoxy, Waterbor ne,” U.S. Department of Defense, Washington, DC, September 1997.

MIL-P-53030A, “Primer, Epoxy Coating, Wate r Reducible, Lead and Chromate Free,” Revision A, Amendment 2, U.S. Department of Defense, Washington, DC, 1992.

MIL-P-53022-10, “Primer, Epoxy Coating, Corro sion Inhibiting, Lead and Chromate Free,” U.S. Department of Defe nse, Washington DC, February 1992.

MIL-PRF-23377G, “Primer Coatings, Epoxy, High So lid,” U.S. Department of Defense, Washington, DC, September 1994.

ASTM D1654, “Standard Method for Evalua tion of Painted or Coated Specimens Subjected to Corrosive Environmen ts,” ASTM, West Conshohocken, PA, 1984.

ASTM F22-65, “Standard Test Method fo r Hydrophobic Surface Films by the WaterBreak Test, ASTM, West Conshohocken, PA, 1965.

Lab Report #LR02-004, “Coating Weights and Processing of Alternatives for ESTCP NCAP Project PP0025,” Craig Matzdorf ESTC P for the NCAP Project PP0025, July 24,

2002.

MIL-C-53039A, “Coating, Aliphatic Polyuretha ne, Single Component, Chemical Agent Resistant,” U.S. Department of Defense, Washington DC, May 1993.

MIL-PRF-85285, “Coating, Polyurethane, High So lids,” U.S. Department of Defense, Washington, DC, April 1997.

MIL-T-81772, “Thinner, Aircraft Coating,” U.S. Department of Defense, Washington, DC, Oct 25, 1991.

ASTM B117, "Standard Method of Practice fo r Operating Salt Spray (Fog) Apparatus," ASTM, West Conshohocken, PA, 1990.

Placzankis, Brian E. and Miller, Chris E ., “ASTM B 117 Screening of Non-Chromate Conversion Coatings on Aluminum A lloys 2024, 2219, 5083, and 7075 using DoD Paint Systems,” Army Research Laboratory Re port, Aberdeen Proving Ground, Maryland.

GM 9540P, “Accelerated Corrosion Test; GM 9540P,” General Motors Engineering Standards, 1997.

ASTM G85 “Standard Practice for Modifi ed Salt Spray (Fog) Testing,” ASTM International, West Conshohocken, PA, 2002.

94Matzdorf, Craig and Kane, Dr. Michael J., “Evaluation of Non-Chromate Conversion Coatings in DoD Coating Systems using ASTM G85 SO 2 Salt Fog,” NAVAIR, Patuxent River, MD.

Plazankis, Brian E., Miller, Chris E., Matz dorf, Craig, “Analysis of Non-chromate Conversion Coatings on Aluminum All oys 2024, 5083, and 7075 with DoD Coatings Using GM 9540P Cyclic Accelerated Corr osion Exposure,” Proceedings from the Triservice Conference on Corrosion, San Antonio, TX, January 2002.

ASTM D1654-92, “Standard Test Method for Ev aluation of Painted or Coated Specimens Subjected to Corrosive Environmen ts,” ASTM, West Conshohocken, PA, 1992.

FED-STD-141, “Paint, Varnish, Lacquer, and Related Materi als: Methods of Inspection, Sampling, and Testing,” 1986.

ASTM D3359, “ Standard Method for Measur ing Adhesion by Tape Test, Method A & B” ASTM International, 1997.

“Demonstration Report (Technology Impr ovement Report) for Non-Chromate Pretreatments of Non-Ferrous Metals,” Na tional Defense Center for Environmental Excellence/Concurrent Technologies Corporation for the Environmental Security Technology Certification Program, September 20, 2002.

“Acute Oral Toxicity/LD50 in Rats,” MB 02-10327.01, Cerven, Daniel R. for MB Research Laboratories, 2002.

“Acute Dermal Toxicity/LD50 in Rabbits ,” MB 02-10327.02, Cerven, Daniel R. for MB Research Laboratories, 2002.

“Justification Report (Technology Improve ment Report) for Non-Chromate Pretreatments of Non-Ferrous Metals,” Na tional Defense Center for Environmental Excellence/Concurrent Technologies Corporation for the Environmental Security Technology Certification Program, September 24, 2002.

“Non-chromated Conversion Coatings fo r Weapon Systems Rework and Repair,”
National Defense Center for Environmen tal Excellence/Concurrent Technologies Corporation for the Environmental Secu rity Technology Certification Program, September 24, 2001.

Zook L., Clayton C., and Raley R, “Alte rnate SRB Aluminum Coating System Qualification Test Report,” CPC-025- 00MP, United Space Alliance, May 1, 2000

Buchi, Richard H., Patterson, Ken, and Go wers, Clyde J. “Non-Chromate Conversion Coating,” Ogden Air Logistics Center, April 3, 1998.

9596 MIL-P-24441B Ty III F150/151, “Epoxy Polyam ide Formula 150 & Form ula 151,” U.S. Department of Defense, Washington, DC, 1994.

Osborn, Joseph H., “Advanced Aircraft Corr osion Protection Final Report for period September 2002 through April 2003”, Prepared by Boeing for Universal Technologies Corporation under contract #02- S470-009-C1, April 25, 2003.31 

## APPENDIX C

– PHASE I LABORATORY REPORT

### Non-Chromate Aluminum Pretreatments Phase I Report Project #PP0025

August 2003NCAP Phase I Report August 2003

THIS PAGE LEFT BLANK INTENTIONALLY.NCAP Phase I Report August 2003



### TABLE OF CONTENTS

ACRONYMS AND ABBR EVIATIONS ............................................................. IX

EXECUTIVE SUMMARY .................................................................................. XI

ACKNOWLEDGE MENTS ................................................................................XII

1.0 INTRODUCTION .........................................................................................1

1.1 Project Background

......................................................................................................... 1
1.2 Objective and Scope of Work

......................................................................................... 2



### 2.0 TEST PROTOCOL DE SCRIPTIO N ..........................................................3

3.0 NON-CHROMATE CONVERSION COATING ALTERNATIVES ......7

3.1 Alodine 1200S

.............................................................................................................. .. 7
3.2 Bi-K Aklimate

.............................................................................................................. ... 7
3.3 Boeing Boegel Sol-gel (Now Available Fr om Advanced Chemistry & Technology Inc. as AC-131)

..................................................................................................................... 7

3.4 Brent OXSiLAN  AL-0500

............................................................................................ 7

3.5 Fortune Chemical Company X-It PreKote 

................................................................... 8

3.6 Henkel Surface Technologies Alodine 5200  and Alodine  5700 ................................ 8

3.7 MacDermid Chemidize  727ND

.................................................................................. 8
3.8 NAVAIR Trivalent Chromium Pretreatment (TCP) ....................................................... 8
3.9 Sanchem Safegard7000

................................................................................................... 8



### 4.0 INITIAL PROCESSING INFORMATION ..............................................12

4.1 Initial Surface Preparation

............................................................................................ 12

4.1.1 Coupon Preparation, Cleaning, and Deoxidizing ................................................ 12
4.1.1.1 Application Procedure fo r Each Alternative ..................................................... 12
4.1.1.2 Coating Weight Measurement

.......................................................................... 13
4.1.1.3 Coupon Handling After Coating

....................................................................... 14
4.2 Initial Paint Application

................................................................................................ 14

4.2.1 Description of Paints ............................................................................................ 15
4.2.1.1 MIL-PRF-23377G, Type I, Class C

.................................................................. 15
4.2.1.2 MIL-PRF-85582 C, Type II, Class C2 and N ................................................... 15
4.2.1.3 MIL-P-53022

.................................................................................................... 15
4.2.1.4 MIL-P-53030

.................................................................................................... 15
4.2.1.5 MIL-PRF-85285C Topcoat

............................................................................... 15
4.2.1.6 MIL-C-53039

.................................................................................................... 15



### 5.0 TEST METHODS AND RESULTS ...........................................................18

5.1 Neutral Salt Fog on Unpainted S ubstrate with Pretreatment ........................................ 18

iNCAP Phase I Report August 2003

5.1.1 Test Description .................................................................................................... 18

5.1.2 Test Results ........................................................................................................... 18
5.2 Electrical Contact Resistance U npainted, Pretreated Substrates .................................. 24

5.2.1 Test Description .................................................................................................... 24

5.2.2 Test Results ........................................................................................................... 24
5.3 Dry Tape Adhesion of Painted Substrates

.................................................................... 27

5.3.1 Test Description .................................................................................................... 27

5.3.2 Test Results ........................................................................................................... 28
5.4 Wet Tape Adhesion and Water Resi stance of Painted Substrates ................................ 32

5.4.1 Test Description .................................................................................................... 32

5.4.2 Test Results ........................................................................................................... 33

5.5 Neutral Salt Fog on Scribed, Painted Substrate ............................................................ 39

5.5.1 Test Description .................................................................................................... 39

5.5.2 Test Results ........................................................................................................... 40
5.6 SO 2 Salt Fog on Scribed, Painted Substrates

................................................................ 57
5.6.1 Test Description .................................................................................................... 57
5.6.2 Test Results ........................................................................................................... 57

5.7 Cyclic Corrosion on Scribed, Painted Substrates ......................................................... 65

5.7.1 Test Description .................................................................................................... 65

5.7.2 Test Results ........................................................................................................... 65
5.8 Filiform Corrosion Resistance

...................................................................................... 76

5.8.1 Test Description .................................................................................................... 76

5.8.2 Test Results ........................................................................................................... 77
5.9 Marine Atmospheric Test (Beach Te st) on Scribed, Painted Substrates ...................... 82

5.9.1 Test Description .................................................................................................... 82

5.9.2 Test Results ........................................................................................................... 84
5.10 Toxicology

............................................................................................................... ..... 87

5.10.1 Demonstration Report for Non-Chromate Pretreatment for Non-ferrous Metals 88
5.11 Repairability

............................................................................................................. ..... 89



### 6.0 ISSUES IN EVALUATING NO N-CHROMATED SYSTEMS ..............91

7.0 IMPLEMENTAION STATUS OF ALTERNATIVES IN DOD AND
NASA .............................................................................................................93

7.1 NASA (Alodine 5700)

.................................................................................................. 93
7.2 US Army TACOM (Alodine 5700)

.............................................................................. 94
7.3 USAF (X-It PreKote)

.................................................................................................... 94
7.4 NAVSEA/MARINES (TCP)

........................................................................................ 95

7.5 NAVAIR TCP

............................................................................................................... 96
7.6 USMC (TCP and Alodine 5200/5700)

......................................................................... 97

7.7 Joint Boeing/Air Force/Navy (Boegel)

......................................................................... 98



### 8.0 CONCLUSIONS AND RE COMMENDATIONS ................................. 100

iiNCAP Phase I Report August 2003



### 9.0 REFERENCES ......................................................................................... 101

iiiNCAP Phase I Report August 2003



## LIST OF FIGURES
Figure 5.1.2.1: Alodine 5200 on 2024 a nd 2219 After 1 Week Exposure ............................... 20 Figure 5.1.2.2: Alodine 5200 on 5083 a nd 7075 After 1 Week Exposure ............................... 21 Figure 5.1.2.3: Sanchem 7000 With Sealer # 2 on 5083-H131 After 2 Weeks Exposure ........ 21 Figure 5.1.2.4: TCP on 5083 and 2024 After 2 Weeks Exposure ............................................ 22 Figure 5.1.2.5: TCP on 2219 and 7075 After 2 Weeks Exposure ............................................ 22 Figure 5.1.2.6: Alodine 1200S on 5083 a nd 2024 After 2 Weeks Exposure ............................ 23 Figure 5.1.2.7: Alodine 1200S on 2219 a nd 7075 After 2 Weeks Exposure ............................ 23 Figure 5.3.1.1: Example Coupon with Sc ribe Pattern After Testing ........................................ 27 Figure 5.5.2.1: Test Chamber and Panels Used for ASTM B 117 ............................................ 40 Figure 5.5.2.2: Aluminum 2024 Coated With 85582 N/85285 Coating System at 3000 Hours
Duration

....................................................................................................................... . 44 Figure 5.5.2.3: Aluminum 2024 Coated With 53030/53039 Coating System at 3000 Hours
Duration

....................................................................................................................... . 45 Figure 5.5.2.4: Aluminum 2219 Coated With 85582 N/85285 Coating System at 3000 Hours
Duration

....................................................................................................................... . 46 Figure 5.5.2.5: Aluminum 2219 Coated With 53030/53039 Coating System at 3000 Hours
Duration

....................................................................................................................... . 47 Figure 5.5.2.6: Aluminum 5083 Coated With 53030/53039 Coating System at 3000 Hours
Duration

....................................................................................................................... . 49 Figure 5.5.2.7: Aluminum 5083 Coated With 53022/53039 Coating System at 3000 Hours
Duration

....................................................................................................................... . 50 Figure 5.5.2.8: Severe Delamination of Oxsilan AL 0-500 Pretreated on Al 7075 Coated With 85582C2/25285 Coating System at 1 Week Exposure ................................................ 51 Figure 5.5.2.9: Severe Delamination of Oxsilan AL 0-500 Pretreated on Al 7075 Panels with 85582C2/25285 Coating System at 2 Weeks Exposure ............................................... 51 Figure 5.5.2.10: Aluminum 7075 Coated With 85582 N/85285 Coating System at 3000 Hours Exposure

....................................................................................................................... 52 Figure 5.5.2.11: Aluminum 7075 Coated With 53022/53039 Coating System at 3000 Hours Exposure

....................................................................................................................... 53 Figure 5.5.2.12: Coating System Pe rformance of Alum inum 2219 ......................................... 55 Figure 5.5.2.13: Coating System Pe rformance of Alum inum 5083 ......................................... 56 Figure 5.6.3.1: Pretreatments With 23377/85285 Coating System on Al 2024 after 500 Hour Exposure

....................................................................................................................... 62 Figure 5.6.3.2: Pretreatments With 23377/85285 Co ating System on Al 2219 After 500 Hour Exposure

....................................................................................................................... 62 Figure 5.6.3.3: Pretreatments With 53030/53039 Coating System on Al 2024 after 500 Hour Exposure to SO 2 Salt Fog

............................................................................................. 63 Figure 5.6.3.4: Pretreatments With 53022/53039 Coating System on Al 2024 after 500 Hour Exposure

....................................................................................................................... 63 Figure 5.6.3.5: Pretreatments With 85582 NC /85285 Coating System on Al 2219 after 500 Hour Exposure

.............................................................................................................. 64 Figure 5.6.3.6: Pretreatments With 53022/53039 Coating System on Al 5083 after 500 Hour Exposure

....................................................................................................................... 64

ivNCAP Phase I Report August 2003

Figure 5.7.2.1: Test Chamber Configuration Used for GM 9540P .......................................... 65 Figures 5.7.2.2: Aluminum 2024 Coated With 85582 N/85285 Coating System .................... 71 Figure 5.7.2.3: Aluminum 2024 Coated With 53030/53039 Coating System .......................... 72 Figure 5.7.2.4: Aluminum 2219 Coated With 85582 C2/85285 Coating System .................... 73 Figure 5.7.2.5: Aluminum 2219 Coated With 85582 C2/85285 Coating System .................... 74 Figure 5.7.2.6: Aluminum 7075 Coated With 53022/53039 Coating System .......................... 75 Figure 5.8.1.1: Filiform Corrosi on Rating Template Layout .................................................... 77 Figure 5.8.1.2: Example Coupon Prepared for Template Rating Method for Filiform Corrosion

............................................................................................................................... ....... 77 Figure 5.8.2.1: Alodine 1200S w ith 23377 Primer, Rating: 16 ................................................ 80 Figure 5.8.2.2: TCP with 23377 Primer, Rating: 82

................................................................. 80 Figure 5.8.2.3: TCP with 85582 N Primer, Rating: 94 ............................................................. 81 Figure 5.8.2.4: Alodine 5200 with 85582 N Primer, Rating: 22 .............................................. 81 Figure 5.8.2.5: Sanchem 7000 with 53030 Primer, Rating: 0 ................................................... 82 Figure 5.9.1.1: Kennedy Space Center Beachsite Aerial View ................................................ 83 Figure 5.9.1.2: Coupon Exposure Racks

.................................................................................. 83 Figure 7.1.1: Launch Photo of the SRBs

.................................................................................. 93 Figure 7.3.1: Application of X-It PreKote

................................................................................ 95 Figure 7.5.1: F/A-18 after TCP A pplication and Painting ........................................................ 96 Figure 7.6.1: Spray Applied Alodine 5700 to AAAV .............................................................. 97

vNCAP Phase I Report August 2003



## LIST OF TABLES
Table 2.1: Engineering a nd Testing Requirements

.................................................................... 3 Table 2.2: Rating Classes for Coating Systems

......................................................................... 4 Table 2.3: Substrate Descriptions

.............................................................................................. . 5 Table 3.1: Summary of Non-Chromate Conversion Coating Alternatives .............................. 10 Table 4.1.1.1.1: Processing Details

........................................................................................... 13 Table 4.1.1.2.1: Coating Weights of Alternative Coatings on 2024-T3 ................................... 14 Table 5.1.2.1: Aluminum alloy 2024-T3

.................................................................................. 19 Table 5.1.2.2: Aluminum alloy 7075-T6

.................................................................................. 19 Table 5.1.2.3: Aluminum alloy 2219-T87

................................................................................ 19 Table 5.1.2.4: Aluminum alloy 5083-H131

.............................................................................. 20
Table 5.2.2.1: Contact Resist ance of As-Coated TCP .............................................................. 25
Table 5.2.2.2: Contact Resistance of TCP af ter exposure to Salt Fog for 168 hours ............... 25
Table 5.2.2.3: Contact Resistance of Alodine 1200S As-Coated (30-Second Immersion) ...... 25
Table 5.2.2.4: Contact Resistance of Alodine120 0S After Exposure (30-Second Immersion) 26
Table 5.2.2.5: Contact Resistance of Alodine 1200S, As-Coated (60-Second Immersion) ..... 26
Table 5.2.2.6: Contact Resistance of Alodine 1200S After Exposure (60-Second Immersion) 26 Table 5.3.1.1: Rating Scale for ASTM D 3359 Method B Tape Adhesion Test ..................... 28 Table 5.3.2.1: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-PRF-23377 Primer

................................................................ 29 Table 5.3.2.2: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-PRF-85582 C2 Primer ........................................................... 29 Table 5.3.2.3: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-PRF-85582 NC Primer .......................................................... 29 Table 5.3.2.4: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-P-53030 Primer

..................................................................... 30 Table 5.3.2.5: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-P-53022 Primer

..................................................................... 30 Table 5.3.2.6: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-PRF-23377 Primer

................................................................ 30 Table 5.3.2.7: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-PRF-85582 C2 Primer ........................................................... 31 Table 5.3.2.8: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-PRF-85582 NC Primer .......................................................... 31 Table 5.3.2.9: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-P-53030 Primer

..................................................................... 31 Table 5.3.2.10: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-P-53022 Primer

..................................................................... 32 Table 5.4.1.1: Rating Scale for ASTM D 3359 Method A Tape Adhesion Test ...................... 32 Table 5.4.2.1: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-PRF-23377 Primer

............................................................................................................................... ....... 33 Table 5.4.2.2: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 C2
Primer

......................................................................................................................... .. 33

viNCAP Phase I Report August 2003

Table 5.4.2.3: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 NC
Primer

......................................................................................................................... .. 34 Table 5.4.2.4: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53030 Primer .. 34 Table 5.4.2.5: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53022 Primer .. 34 Table 5.4.2.6: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-PRF-23377 Primer

............................................................................................................................... ....... 35 Table 5.4.2.7: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 C2
Primer

......................................................................................................................... .. 35 Table 5.4.2.8: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 NC
Primer

......................................................................................................................... .. 36 Table 5.4.2.9: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53030 Primer .. 36 Table 5.4.2.10: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53022 Primer 36 Table 5.4.2.11: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-PRF-23377 Primer

............................................................................................................................... ....... 37 Table 5.4.2.12: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 C2
Primer

......................................................................................................................... .. 37 Table 5.4.2.13: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 NC
Primer

......................................................................................................................... .. 38 Table 5.4.2.14: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53030 Primer 38 Table 5.4.2.15: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53022 Primer 38 Table 5.4.2.16 Summary Ratings for Pretreatments and Primer Systems in Wet Tape Adhesion

Tests

.......................................................................................................................... .... 39 Table 5.5.2.1: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with
Mil-PRF-23377 Primer and Mil-C-85285 Topcoat Exposed to 3000 Hours ............... 41 Table 5.5.2.2: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with
Mil-PRF-85582 C2 Primer and Mil-C- 85285 Topcoat Exposed to 3000 Hours ......... 41 Table 5.5.2.3: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with
Mil-PRF-85582 N Primer and Mil-C-85285 Topcoat Exposed to 3000 Hours ........... 42 Table 5.5.2.4: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with
Mil-PRF-53030 Primer and Mil-C-53039 Topcoat Exposed to 3000 Hours ............... 42 Table 5.5.2.5: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with
Mil-PRF-53022 Primer and Mil-C-53039 Topcoat Exposed to 3000 Hours ............... 42 Table 5.5.2.6: Summary Ratings for Pretreatment s and Primer Systems exposed to 3000 hours of ASTM B117 Salt Fog (Rati ngs per ASTM D 1654A) ............................................. 54 Table 5.6.3.1: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated With
Mil-PRF-23377 Primer and Mil-C-85285 T opcoat and Exposed to 500 Hours .......... 59 Table 5.6.3.2: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated With
Mil-PRF-85582 C2 Primer and Mil-C-85285 T opcoat and Exposed to 500 Hours .... 59 Table 5.6.3.3: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated With
Mil-PRF-85582 NC Primer and Mil-C-85285 Topcoat and Exposed to 500 Hours .... 59 Table 5.6.3.4: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated With Mil-P-53030 Primer and Mil-C-53039 Topcoat 500 Hours ......................................... 60 Table 5.6.3.5: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with Mil-P-53022 primer and Mil-C-53039 t opcoat and Exposed to 500 Hours ................. 60

viiNCAP Phase I Report August 2003

Table 5.6.3.6: Summary Ratings for Pretreatment s and Primer Systems exposed to 500 Hours (Ratings per ASTM D 1654A)

..................................................................................... 61 Table 5.7.2.1: GM 9540P Cyclic Corrosion Test Details ......................................................... 66 Table 5.7.2.2: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with Mil-PRF-23377 Primer and Mil-C-85285 Topcoat ...................................................... 66 Table 5.7.2.3: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with Mil-PRF-85582 C2 Primer and Mil-C-85285 Topcoat ................................................ 67 Table 5.7.2.4: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with Mil-PRF-85582 NC Primer and Mil-C-85285 Topcoat ............................................... 67 Table 5.7.2.5: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with Mil-PRF-53030 Primer and Mil-C-53039 Topcoat ...................................................... 67 Table 5.7.2.6: Average Scribe Fa ilure Rating (5 panels) for Al uminum Alloys Coated with Mil-PRF-53022 Primer and Mil-C-53039 Topcoat ...................................................... 68 Table 5.7.2.7: Summary Ratings fo r Pretreatments and Primer Sy stems exposed to 120 Cycles of GM9540P Corrosion Test (Ratings per ASTM D1654A) ....................................... 70
Table 5.8.1.1: Filiform Corrosi on Standard Rating Method ................................................ 76 Table 5.8.2.1 Filiform Corrosion Ratings per Standard Technique .......................................... 78
Table 5.8.2.2: Filiform Corrosion Ra tings per Template Technique ....................................... 79 Table 5.9.2.1: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil-PR F-23377 Primer and Mil-C-85285 Topcoat .. 84 Table 5.9.2.2: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil-PR F-85582 C2 Primer and Mil-C-85285 Topcoat

............................................................................................................................... ....... 84 Table 5.9.2.3: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil-PR F-85582 NC Primer and Mil-C-85285 Topcoat

............................................................................................................................... ....... 85 Table 5.9.2.4: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil- P-53030 Primer and Mil-C-53039 Topcoat ....... 85 Table 5.9.2.5: Average Surface Corrosion and Creepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil- P-53022 Primer and Mil-C-53039 Topcoat ....... 85 Table 5.9.2.6: Summary Ratings for Pretreatment s and Primer Systems exposed to 12 Months of Outdoor Exposure at Kennedy Space Cent er Beachfront Corrosion Test Site ........ 87

viiiNCAP Phase I Report August 2003



### ACRONYMS AND ABBREVIATIONS

ACU-4 Assault Craft Unit Four

AAAV Advanced Amphibious Assault Vehicle

AETC Air Education & Training Command

AFB Air Force Base

ARL Army Research Laboratory

ASTM American Society for Testing and Materials

CARC Chemical Agent Resistant Coating

CCTC Cyclic Corrosion Test Chambers

CTC Concurrent Technologies Corporation

DoD Department of Defense Dpi Dots Per Inch

DUSD-ES Deputy Undersecretary of De fense for Environmental Security

ESOH Environmental, Safet y, and Occupational Health

ESTCP Environmental Security Technology Certification Program

FED Federal

FOD Foreign Object and Debris

GM General Motors

HazMats Hazardous Materials

HCl Hydrochloric Acid

JG-PP Joint Group on Pollution Prevention

JLC The Joint Logistics Commanders

JTP Joint Test Protocol

LC 50 Median Lethal Concentration

LCAC Landing Craft, Air Cushion

LD 50 Lethal Dose

MEK Methyl Ethyl Ketone

MIL Military

MSDS Material Safety Data Sheet

NASA National Aeronautics and Space Administration

NAVAIR Naval Air Systems Command

NCAP Non-Chromate Alumi num Pretreatment Project

NCMS National Center for Manufacturing Sciences

NDCEE National Defense Center for Environmental Excellence

OEM Original Equipment Manufacturer

OSHA Occupational Safety and Health Administration

PEL Permissible Exposure Limit

RH Relative Humidity

RRAD Red River Army Depot

RT Room Temperature

ixNCAP Phase I Report August 2003

SPO System Program Office

SPT Self Priming Topcoat

SRB Solid Rocket Booster

STD Standard

TCP Trivalent Chromium Pretreatment

TO Technical Order

UDRI University of Dayton Research Institute

USMC United States Marine Corps

VOC Volatile Organic Compounds

xNCAP Phase I Report August 2003



### EXECUTIVE SUMMARY

Aerospace and Department of Defense (DoD) user s presently enhance the corrosion resistance and paint adhesion perform ance of aluminum all oys with hexavalent chrom ium-based products that deposit a conversion coating on the surface of the metal. These coatings are very thin, inexpensive to produce, extremely process flexib le, and can be applied by immersion, spray and wipe techniques.

Although chrome conversion coatings offer m any a dvantages, the downside is that they contain hexavalent chromium, or chroma te, species that are know n carci nogens. The risk of worker exposure to these chem icals, the potential liabilities due to accide ntal leaks to the environm ent, and waste disposal issues ar e making the use of chrom ate -based conversion coatings
unaffordable.

This report examines accelerated corrosion exposure of aluminum alloys 2024, 2219, 5083, and 7075 specimens treated with the candidate hexava lent chromium free pretreatments as well as one hexavalent chromium based pretreatment (Alodi ne 1200S) used as a control. The data from the Nonchromated Aluminum Pretreatment Project (NCAP) Joint Te st Pr otocol (JTP) tests are considered together to form an accurate evaluati on of the potential effectiveness of the selec ted alternatives as replacem ents for chromate conversion coatings. This data is solely intended to provide support for additional product validation and f ield-testing at user f acilities. The performance requirements are docum ented in the JTP for Validation of Non-Chromate
Aluminum Pretreatments dated 13 December 2000.

Eight potential nonchromated pretre atment alternatives are identified and discussed in this Phase I Report. They are H enkel Surface Technologies Alodine  5200/5700, Fortune Chem ical Company X-It PreKote  , MacDermid Chemidize  727ND, Brent OXSiLAN  AL-0500, NAVAIR Trivalent Chromium Pretreatment (TCP), Boeing Boegel Sol-gel (now av ailable from Advanced Chemistry & Technology Inc. as AC-131), Bi-K Aklim ate, and Sanche m Safegard7000.

Each alternative tested shows acceptable performance in som e selected cases that m ay be satisfactory for a given user, depending on operating environm en t and business cases involved. The only compositions that come close to matching the technical, process, cost, and flexibility of
chromates are based on trivalent chrom ium. Although trivalent chrom ium is present in the solution and coating, toxicity studies and OSHA P ELs suggest that the use of TCP is acceptable, especially given its well-rounded performance. The next best product in testing was Alodine 5200/5700. Alodine 5200/5700 contains no chrom ium, is process flexible and can be applied like chromate conversion coatings. The rem aini ng alternatives perform ed variably in the
evaluation.

xiNCAP Phase I Report August 2003



### ACKNOWLEDGEMENTS

This report was prepared by the generous supp ort of the E nvironmental Security Technology Certification Program (ESTCP) and the Of fice of the De puty Undersecretary of Defense for Environmental Security (DUSD-ES). The e ffort was led by the Na val Aviation Systems Command (NAVAIR) Materials Di vision Patuxent River and c oordinated with Joint Group on Pollution Prevention (JG-PP). The principal i nvestigator for the NCAP project is Craig Matzdorf, Code 4.3.4, NAVAIR Materials Division Patuxent River.

The authors of the report wish to acknowledge the leadership and support of the m any Navy managers, engineers, and Fleet support personnel who contributed to this ef fort. A special thanks to NAVAIR Patuxent River, Ar my Research Laboratory (ARL), University of Dayton Research Institute (URDI), National Aeron a utics and Space Administra tion (NASA) and contractor personnel at Kennedy Space Center in Florida, National Defense Center for Environmental Excellence (NDCEE) and Concurrent Technologies Corporation (CTC) for their support in m aterial testing and dem onstratio n; Assault Craft Unit Four (ACU-4), Naval Amphibious Base, Little Creek, Virginia for their support in the evaluation of test patches on Landing Craft, Air Cushions (LCACs); S-3B, F/A-18, and H-46 support personnel for their help in material flight-tests; principal investigators from the Navy, Army, Air Force, and Marine Corp for providing project summ aries and testing r esults; and, Science Applica tions International Corporation for their support in the preparation of this report.

xiiNCAP Phase I Report August 2003



### 1.0 INTRODUCTION

1.1 Project Background
The Environmental Security Technology Certif i cation Program (ESTCP) was established as a program of the DoD in Decem ber 1993. The ES TCP is managed by the Office of the Deputy Undersecretary of Defense for Environm ental S ecurity (DUSD-ES). The ESTCP dem onstrates and validates laboratory-proven te chnologies that target the DoD’ s most urgent environmental needs. These technologies pr ovide a return on investm ent through reduced environm ental, safety, and occupational health (E SOH) risks; cost saving s; a nd improved efficiency. The new technologies typically have broad applicati on to both the DoD sustainm ent community and industry.

The Joint Logistics C ommanders (JLC) and Headquarters National Aeronautics and Space Administration (NASA) co-chartered the Jo int Group on Pollution Prevention (JG-PP) to coordinate joint service/agency activities affect ing pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of the JGPP are to:

• Reduce or eliminate the use of Hazardous Materials (HazMats)

• Avoid duplication of effort in actions requi red to reduce or elim inate HazMats through joint service cooperation and technology sharing.

JG-PP projects typically involve an original equipment manufacturer (OEM) producing multiple defense systems for more than one of the Services , as well as at least one DoD depot maintaining one or more of the defense system s. JG-PP t echnical representatives for each project begin by identifying a target HazMat, rela ted process, and affected substr ates or parts that m ay cause
environmental and/or w orker health concerns. Project participants then identify alternative technologies or materials for evaluation.

ESTCP selected the NCAP project, led by Naval Air System s Command (NAVAIR) an d coordinated with JG-PP, to assis t in the m itigation of the signif icant ESOH risks that are
associated with the use of chromate conversion coatings. Chromate conversion coatings contain hexavalent chromium, a known hum an carcinogen th at is strictly regulated. The U. S. Environmental Protection Agency (EPA) limits air emissions and regulates solid waste disposa l from operations using hexavalent chrom ium. The U. S. Occupational Safety and Health Administration (OSHA) regulates the amount of hexavalent chromium to which workers can be exposed, and has proposed redu cing the Perm issible Exposure Limit (PEL) for hexavalent chromium from the current 50 m icrograms per cubic meter (μg/m 3 ) to less than 1 μ g/m 3 . Such limits could increase co sts of the p retreatment of aluminum and aluminum alloys; therefore, alternatives are being identified and evaluated. The project will achieve the goal of reducing or eliminating the use of hexavalent chrom ium in aluminum finishing by de monstrating and validating the perf ormance of alternatives in accordance with the t echnical requirements and
tests identified in the JTP.

1NCAP Phase I Report August 2003

The key benefit of the nonchrom ated pretreatment alternatives being demonstrated in this repor t
is the elim ination or absence of hexavalent chromium from the process chem icals and as - deposited coating. Elim inating chromates fr om the conversion coating or pretreatm ent operations will drastically reduce user liability and risk in the life cycle of the platform or parts being coated. The key challenge for the alterna tives will be matching the technical performance of chromate conversion coatings in a cost-effective manner.

1.2 Objective and Scope of Work
The overall objective is to v alidate and implement multiple chromate-free aluminum pretreatment alternatives at a broa d range of user facilities. This report presents an evaluation of laboratory coupon testing of non- chromate aluminum pretreat ment alternatives through accelerated tests on flat coupons. Section 2 of this docum ent disc usses the testing requirements for alternative aluminum pretreatments, which we re prepared for tests called out in the NCAP JTP. Section 3 provides an overview of the altern ative aluminum pretreatments. In Section 4, initial surface preparation and initial pa int app lications are described. Section 5 presents the
results of the tests conducted on various alum inum alloys for nonchrom ate aluminum pretreatment alternatives. Section 6 provides an overview of uncertainty as sociated with nonchromated systems, and Section 7 presents the implementation status of alternative aluminum pretreatments in other organizations. The result s of the analysis will be used to support and justify field testing on components or in-service platforms where technical performance is highly dependant on service environment and overall platform design and use.

2NCAP Phase I Report August 2003



### 2.0 TEST PROTOCOL DESCRIPTION Eight non-chromate aluminum pretreatments were pr epared for tests called out in the NCAP JTP. Table 2.1 lists all engineering a nd testing requirements, and accepta nce criteria identified in the NCAP JTP for validating alternatives to chromate conversion coatings.

Table 2.1: Engineering and Testing Requirements

Engineering Requirement Test JTP
Section Acceptance Criteria

Corrosion Resistance Neutral Salt Fog on Unpainted Substrate with

Pretreatment 3.1 • Class E: 7 days with no visible sign of corrosion whatsoever; spots and discoloration are acceptable; lightening of coating is acceptable.

• Class B1: 7 days with no visible sign of corrosion; lightening of coating is acceptable.

• Class B2: 14 days with no visible sign of corrosion; lightening of coating is acceptable.

Corrosion Resistance Neutral Salt Fog on Scribed,
Painted Substrate 3.2 • Class C: 3,000 hours with no evidence
of corrosion (minor surface corrosion in scribe permissible).

Corrosion Resistance SO 2 Salt Fog on Scribed,
Painted Substrates 3.3 • Class C: 500 hours with no evidence of corrosion (minor surface corrosion in scribe permissible).

Corrosion Resistance Cyclic Corrosion Test on Scribed, Painted Substrates 3.4 • Class C: Equivalent or improved performance compared to controls.

Corrosion Resistance Filiform Corrosion
Resistance 3.5 All filaments < 1/4"; Majority < 1/8".

Corrosion Resistance Marine Atmospheric Test (Beach Test) Exposure on Scribed, Painted Substrates 3.6 Class C: Equivalent or improved performance compared to chromate controls.

Adhesion Wet Tape Adhesion and
Water Resistance of Painted
Substrates 3.8 Method A: Rating of < 4A.

Adhesion Dry Tape Adhesion of
Painted Substrates 3.9 Method B: Loss of two or more complete primer squares shall constitute failure ( < 4B).

Electrical Resistance Elect rical Conductivity of Unpainted, Pretreated
Substrates 3.11 • <5 milliohms/square-inch as coated.

• <10 milliohms/square-inch after 168 hours neutral salt fog exposure

Environmental, Safety and Occupational Health (ESOH) Toxicology 3.12 Less toxic than MIL-C-81706 chromate conversion coating control per EPA Toxicity Categories (40 CFR 156.10).

Reparability Reparability 3.13 Corrosion resistance, paint adhesion, and electrical contact resistance equal to or better
than controls.

3NCAP Phase I Report August 2003

Paint adhesion, bare corrosion, and electrical contact resistance test s were completed first. After achieving acceptable paint adhesion results, painted corrosion tests were then completed. For all testing, alternatives were applie d and tested by DoD or contra ctor personnel and not at vendor
sites. Alte rnatives not available f or “in-serv ice” testing were consid ered immature for this project. Alterna tives must reach m aturity before depots and OEMs will consider them for implementation.

Alternatives were also r ated on process flexibility. Parameters such as number of solutions or steps in the process, heating re quirements, and curing requirements were detailed. Processes that require elevated temperatures for pretreatm ent solutions or curing m ay be appropriate for immersion application, but m ay not be applicable for spray or wipe application to alreadyassembled platforms.

Coating usage was divided into the following three categories:

B - Unpainted (bare) substrates requ iring maximum corrosion resistance. C - Painted surfaces requiring maximum paint adhesion and corrosion resistance. E - Unpain ted (bare) su rfaces for electrical ap plications requiring corrosion resistance and low resistivity.

Test results for each coating sys tem lead to a rating based on overall performance. Table 2.2 lists the rating classes fo r these coating systems.

Table 2.2: Rating Classes for Coating Systems

Rating Class Requirement

B1 Bare corrosion resistance for 7 days.

B2 Bare corrosion resistance for 14 days.

C1 Painted corrosion resistance and paint adhesion using MIL-P-23377G primer.

C2 Painted corrosion resistance and paint adhesion using MIL-PRF-85582B Class C2 primer.

C3 Painted corrosion resistance and paint adhesion using MIL-PRF-85582B Class N primer.

C4 Painted corrosion resistance and paint adhesion using MIL-P-53022B primer.

C5 Painted corrosion resistance and paint adhesion using MIL-P-53030A primer.

E Bare corrosion resistance for 7 days and acceptable electrical conductivity.

Substrate Descriptions: Table 2.3 lists alloy name, compositi on, and typical use for each of the 5 substrates selected for testing. These substrat es represent a cross sec tion of aluminum alloys used in the joint community.

4NCAP Phase I Report August 2003

Table 2.3: Substrate Descriptions

Alloy Name Composition Typical Use/ Field Test Platforms
2024-T3 (clad used
for Filiform Corrosion Test) 4.5% Cu, 1.5% Mg, 0.6% Mn Aircraft structures, rivets , hardware, truck wheels.

2219-T87 6.3% Cu, 0.3%

Mn Structural uses at high temperatures, high strength weldments.

5083 4.5% Mg, 0.7%

Mn Applications requiring a weldable, moderate-strength alloy having good corrosion resistance. Marine and welded structural applications.

7075-T6 5.5% Zn, 2.5% Mg, 1.5% Cu,
0.3% Cr Applications where very good strength and good resistance to corrosion are required. Airc raft structural parts.

6061-T6 1.0% Mg, 0.6% Si, 0.25% Cu,
0.25% Cr Applications where good strength, formability, weldability, and very good resistance to corrosion are required.

Experimental Procedure: All coupons for the entire NCAP J TP were procured and prepared at
the same time at NAVAIR’s facilities at Pat uxent River, MD. Coupons used were nominally 3.0 inches by 5.0 inches for paint adhesion and painted corrosion testing and 3.0 inches by 10.0
inches for bare corrosion and electrical contact resistance testing. Coupons varied in thickness depending on the alloy. All nine pretreatments, including th e chromate conversion coating control Alodine 1200S, were applied over a tw o-week period for all painted coupon tests. Pretreatments were applied by m anufacturer’s recommendations using the sam e alkaline cleaning and deoxidizing chem ical s for all processes: Turco 4215 alkaline cleaner and Turco Smut-GO NC, respectively. The coatings were then allowed to stand overnight with subsequent primer and topcoat application. T he coating sy stem’s respective prim er coats were applied within 24 hours after th e pretreat ment application for each pretreatm ent for each alloy, and the topcoats were applied after 24-hou r primer cure. The full coating sy stem was then cured at ambient conditions for 14 days before testing. T h e coupons were then sorted for each JTP test, respectively, which are di scussed in Section 5.0.

5NCAP Phase I Report August 2003

THIS PAGE LEFT BLANK INTENTIONALLY.

6NCAP Phase I Report August 2003



## 3.0 NON-CHROMATE CONVERSIO N COATING ALTERNATIVES The main advantage of any alternative is the elim ination of hexavalent chromium. In most cases the alternatives are try ing to m atch the proce ss and technical perform ance of t he chromate solutions and coatings. Section 3.0 describes the alternatives being evaluated in this report.

3.1 Alodine 1200S
Alodine 1200S is the control pro cess and coating used for this ev aluation. The solution is mixed from powdered chemicals and yields a solution th at can be used by im mersion, spray, or wipe processes. This product is qualified to MI L-OTL-81706A. Final coati ngs are light tan to iridescent gold depending on alloy.

3.2 Bi-K Aklimate
Bi-K solutions are proprietary aqueous m ixtures designed to produce an adhesion-prom oting coating on aluminum alloys. The solution is used in a similar fashion to conventional chrom ate pretreatments. Rinsing yields the final coating. Although not processed by spray or wipe methods in this project, these appear feasible . Aklimate coatings are clear and colorless.

3.3 Boeing Boegel Sol-gel (Now Availabl e From Advanced Chemistry & Technology Inc. as AC-131)
Boegel EP-II convers ion coating is a non-chrom ated solution that is designed to increas e adhesion of organic coatings to aluminum, titanium, and corros i on resistant steel. The final coating solution is a product of mixing four components packaged in a “kit” that can be sized appropriately for a given application. The m ixe d solution has a “pot li fe” of 12 hours and is applied by spray, wipe, brush or dipping to leave a thin wet f ilm on the parts. The coating is dried in place without rinsing and care m ust be taken to rem ove puddles and excess coating solution that may be retained in pockets or crevices that do not freely drain. Boegel coatings are clear and colorless and yield a sli ghtly wet or glossy appearance.

3.4 Brent OXSiLAN  AL-0500
OXSiLAN® AL-0500 is a silane based multi-purpos e, two-part liquid treatment for aluminum that is designed to im prove the perform an ce of paint system s and inhibit corrosion on nonpainted surfaces. It d oes not con tain any regulated heavy m etals, phosphates, nitrites, o r molybdates. The solution is used in a sim ilar fashion to conventional chrom ate pretreatments and can be applied via immersion, spray or wipe methods. Coati ngs are not rinsed and allowed to dry in place. Chemetall Oakite purchased Brent in 2001. The OXSiLAN coating is clear and colorless and yields a surface with slightly wet or glossy appearance.

7NCAP Phase I Report August 2003

3.5 Fortune Chemical Company X-It PreKote 

X-It PreKote is a non-chromated conversion coating used for meta l surface pretreatment and precoating prior to painting. It is des igned to promote paint bonding on alum inum, stainless steel, titanium, magnesium, and carbon steel. It is biodegradable, non-toxic, non-flamm able, nonhazardous, non-corrosive, and free of phosphates and heavy metals. The solution is applied by a manual or autom ated scrubbing process, requiri ng multiple material application, scrubbing, drying, and rinsing steps. As a result, the pr oduct is not am enable to imm ersion or spray processing. PreKote has a slig htly gray tint as applied.

3.6 Henkel Surface Technologies Alodine 5200  and Alodine  5700
Alodine 5700 is the ready-to-use, or pre-mixed, version of Alodine 5200. The solutio n is used in a similar fashion to co nventional chromate pretreatments. A m ajor benefit is th at it can be applied by imm ersion, spray, and wipe applica tion methods with a few m inutes dwell tim e similar to chromate conversion coatings. Coating can be applied using rinse or dried in place. Deposited coatings have a light color ranging from blue to tan depending on the alloy.

3.7 MacDermid Chemidize  727ND
Chemidize® 727ND is a non-chromated product that is designed to clean and treat an aluminum surface in a single operation. The solution is pr e-thickened paste-like material designed to be brush applied to surface during pr ocessing. Material rinsing from coupon surface required water impingement or mechanical action to remove. Once disturbed the material was easy to rinse. As formulated, the material is not amenable to im mersion processing and difficult to spray. The 727ND leaves aluminum surfaces a bright metal lic color with no visible evidence of coating.

3.8 NAVAIR Trivalent Chromi um Pretreatment (TCP)
TCP solutions generate pretreat ment films on alum inum and alum inum alloys that im prove corrosion inhibition and paint adhesion while main taining electrical conductivity. The solution
is used in a sim ilar fashion to co nventional ch romate pretreatments. It can be applied by immersion, spray, and wipe application m ethods with a few m inute dwell tim e. Since the process chemistry is based on a surface reactio n, rinsing stops the reaction and yields the final coating. TCP films have a very light color ranging from purple to blue to tan, depending on the alloy.

3.9 Sanchem Safegard7000

The solution is used in a si milar fashion to c onventional chromate pretreatments. It is deep purple in color and was spray-applied for this pr oject. Immersion and wipe application methods appear feasible. Sanchem 7000 with the sealer ha s historically demonstrated unacceptable paint adhesion. As a result, painted system s in this testing were used with the Sanchem 7000 without sealer to maximize paint adhesion. Since prior evaluations noted unaccept able paint adhesion

8NCAP Phase I Report August 2003

with Seal #2, it was only used to evaluate bare (unpainted) corrosion resistance. Sanchem 7000 coatings were an attractive bronze-gold colo r, similar to chromate conversion coatings.

Table 3.1 provides the summary of non-chromate pretreatm ent alte rnatives being evaluated i n Phase I: Lab Validation of this p roject. Alternative chemistry, applications, advantages and disadvantages are all detailed.

9NCAP Phase I Report August 2003

Table 3.1: Summary of Non-Chromate Conversion Coating Alternatives

Product Chemistry (from MSDSs) Processing Application

Methods Classification* Advantages Disadvantages

Alodine

1200S Chromic acid, complex fluorides,
accelerators One solution,

room temperature Immersion, spray, wipe E, B, C Easy to use,
standard Contains
hexavalent
chromium

Alodine
5200 and
Alodine

5700 Organometallic
zirconate complex One solution,

room temperature Immersion, spray, wipe C Easy to use,

room temperature, drop-in replacement for
chromates Minimal corrosion inhibition, impractical color change

Bi-K
Aklimate Proprietary Single solution, room
temperature Immersion, spray, wipe C Easy to use,

room temperature solution replacement for
chromates Minimal bare
corrosion resistance, clear and colorless (no color change)

BoeingBoegel Solgel Organosiloxanes,
zirconates One solution,

room temperature Immersion, spray, wipe C Easy to use,

room temperature, drop-in replacement for chromates, dry in place Minimal corrosion inhibition, dry in place, kitting and solution life, clear and colorless (no color change)

Brent
Oxsilan AL0500 Organosilane, ethanol,
fluorotitanic acid One solution,

room temperature Immersion, spray, wipe C Easy to use,

room temperature solution replacement for chromates, dry in place Minimal corrosion inhibition, dry in place, clear and colorless (no color change)

MacDermid
Chemidize

727ND Butyl cellosolve, other proprietary One solution,

room temperature Spray, wipe C One solution,

room temperature Minimal corrosion inhibition, clear and colorless (no color change)

10NCAP Phase I Report August 2003

NAVAIR
TCP Chromium III sulfate basic, potassium
hexafluorozircona

te One solution,

room temperature, one to five
minute dwell Immersion, spray, wipe E, B, C Easy to use, drop-in replacement for chromates;
corrosion
inhibition
present; toxicology study completed Contains chromium, impractical color change

Sanchem Safegard 7000 (with Seal #2) Potassium
permanganate, seal: polyacrylic acid, poly propylene glycol, fatty acid esters Two solution (coating and seal), elevated temp (200 ° F) cure on sealer;

p retreatment is
ambient Immersion, spray, wipe C Pleasing bronze-gold
color to coating, easy to

use Minimal corrosion
inhibition without
sealer. Sealer requires
elevated
temperature cure and has poor
adhesion
characteristics.

X-It

PreKote Diethylene glycol monobutyl ether, n-methyl pyrrolidone One solution, wipe on by
mechanical
abrasion of substrate,

room temperature Wipe C Non-toxic coating left as a
result of

process Minimal bare
corrosion resistance,
laborious manual application required, minimal color change * E=electrical, B=bare, C=coated

11NCAP Phase I Report August 2003



### 4.0 INITIAL PROCESSING INFORMATION

4.1 Initial Surface Preparation
For painted corrosion tests, coupons were 3 in ches wide by 5 inches long and of thickness (0.020-0.125 inch) as supplied by vendor. Test coupons were pain ted within 24 hours of the application of the pretreatm ent. For unpainte d corrosion and electrical conductivity tests, coupons were 3 inches wide by 10 inches long and of suitable thickness.

4.1.1 Coupon Preparation, Cl eaning, and Deoxidizing
In a typical process line, aluminum substrates ar e cleaned to remove oils , dirt, residue, and then deoxidized to provide an optim um, water-break fr ee surface for reactio n w ith the pretreatment solution. The following genera l immersion processing procedures were follow ed for each
alternative:

Procurement: Test coupons of alloys 2024-T 3, 7075-T6, 6061-T6 and clad 2024-T3 were purchased from Q-Panel. Aluminum alloys 5083-H131 and 2214-T87 were purchased fr om Pierce Aluminum. Coupons were engraved on the reverse side with a unique tracking
number.

Degreasing: The 2024, 7075, clad 2024, and 6061 were degr eased and cleaned as supplied.
The 2219 and 5083 were received with mill marks and other dirt present and were degreased in methyl ethyl ketone (MEK) i mmersion fo llowed by acetone immersion. Solvent cleaned coupons were then racked for cleaning per the next step.

Cleaning: Coupons were racked in titanium fixtur es and immersed in Turco 4215 at about

120 ° F for 15 minutes. Air agitatio n was maintained in the cleaner tank during processing. Cleaning was followed by two warm tap wate r rinses for at least one minute each.

Deoxidizing: Immediately following the cleaning ri nse, coupon racks were imm ersed in Turco Smut-Go NC at ambient temperature for 1-15 minutes. There wa s no solution or rack agitation during this step. Deoxidizing was followe d by two cool tap water rinses for at least one minute each followed by a flowing deionized water rinse.

Pretreatment: Immediately following the deoxidizer ri nse, coupon racks were processed for each alternative according to vendor instructions.

4.1.1.1 Application Procedure for Each Alternative
Work instructions for the m ake up and use of each alternative were written b ased on th e technical literature supplied from alterna tive suppliers. Table 4.1.1.1.1 provides a summ ary of the general processing protocol fo r each alternative. All were applied at room temperature and straightforward to set up and apply.

12NCAP Phase I Report August 2003

Table 4.1.1.1.1: Processing Details

Alkaline
Clean Deoxidize Coating Coating Deposition

Alodine 1200S 1 minute immersion; double rinse in static a mbient temperature tap water and final rinse in flowing
deionized water

Alodine 5200 1 minute immersion; double rinse in static a mbient temperature tap water and final rinse in flowing
deionized water

B i-K Aklimate 1 minute immersion; double rinse in static a mbient temperature tap water and final rinse in flowing
deionized water Boegel Spray applied kee ping surface wet for 5 minutes, excess solution drained by inclining coupons at 20 degree angle

Chemidize 727D Brush on with 10 minute dwell; do uble rinse with flowing ambient temperature tap water and final rinse in flowing deionized water

Oxsilan AL0500 1 minute immersion; dry in place (no rinse)

Sanchem Safeguard7000 1 minute spray dwell; double rinse with flowing ambient temperature tap water and final rinse in flowing deionized water

TCP 2 minute immersion; double rinse in static ambient temperature tap water and final rinse in flowing
deionized water 15 minute
immersion

in 120 ° F Turco 4215;
double rinse
in reverse flow hot tap

water Immersion in Turco Smut Go NC; double
rinse in static ambient
temperature tap water and final rinse in flowing deionized water; 15 minute
immersion for aluminum alloys 2024 and 2219, 1
minute immersion for
6061 and 7075 and clad 2024, and 30
second immersion for

5083

X-It PreKote Solution scrubbed onto coupons surface using saturated brown Scratch-Brite pad. Coating air dried in place. Coat re-applied in similar fashion and then double rinsed in flowing ambient temperature tap water and final rinse in flowing deionized water

4.1.1.2 Coating Weight Measurement
Coating weight measurement was used to quant ify the amount of coating being deposited by a given process. Coating weights for the altern atives were evaluated using alum inum alloy 2024- T3. Three rep licates of each co ating were prepared, weighed and stripped per MIL-DTL81706A: freshly coated coupons were weighed and th en immersed in 50% nitric acid solution for five minutes. An aerospace wipe was used to gently rub coupon on both sides to help rem ove the coating. The coupons were rinsed thoroughly in tap water followed by deionized water and then blown dry with compressed air. The coupons were re-weighed at this tim e. The difference in weight before and after stripping yields the coating weight in milligrams. The unit of measure for coating weight is milligrams per squa re foot as specified in MIL-DTL-81706A.

Table 4.1.1.2.1 details coating weight data for each alternative. No alternative deposits as m uch coating weight as Alodine 1200S or meets the coating weight requirement of MIL-DTL-81706A. TCP and Boegel show the highest coating we ight among the alternatives, averaging 22

13NCAP Phase I Report August 2003

milligrams per square foot, with the remaining coatings yielding weights in the rang e of 7 to 16 milligrams per square foot. Coating weights alone are not indicative of corrosion performance or paint adhesion but once a correlation is estab lished, they are a poten tial method for quality
control.

Table 4.1.1.2.1: Coating Weights of Al ternative Coatings on 2024-T3

Coating Coupon # Total Weight after Coating (gm) Total Weight after Stripping (gm) Coating Weight (mg/ft 2 ) Average Coating Weight (mg/ft 2 )

1 21.6601 21.6522 37.92

2 21.6437 21.6350 41.76 Alodine 1200S

3 21.6192 21.6124 32.64 37.44

1 21.6395 21.6369 12.48

2 21.6228 21.6197 14.88 Alodine 5200

3 21.5997 21.5962 16.80 14.72

1 21.5549 21.5542 3.36

2 21.5389 21.5357 15.36 Bi-K Aklimate

3 21.5152 21.5133 13.92 10.88

1 16.9646 16.9592 25.92

2 16.7746 16.7703 20.64 Boegel (method B)

3 16.9477 16.9434 20.64 22.40

1 21.5235 21.5226 4.32

2 21.5056 21.5039 8.16 Chemidize 727D

3 21.4832 21.4810 10.56 7.68

1 21.6024 21.5992 15.36

2 21.5853 21.5815 18.24 Oxsilan AL-0500

3 21.5622 21.5592 14.40 16.00

1 21.5445 21.5413 15.36

2 21.5268 21.5238 14.40 Sanchem 7000

3 21.5040 21.5012 13.44 14.40

1 21.6262 21.6215 22.56

2 21.6095 21.6045 24.00 TCP

3 21.5865 21.5819 22.08 22.88

1 21.7740 21.7729 10.56

2 21.7793 21.7783 9.60 X-It PreKote

3 21.7780 21.7768 11.52 10.56

4.1.1.3 Coupon Handling After Coating
Following pretreatment, coupons were allowe d to stand 24 hours before handling.

4.2 Initial Paint Application
Each coating system’s respective primer coats we re applied following pretreatm ent application. The topcoats were applied after 24-hour primer cure. The full co ating system was then cured a t ambient conditions for 14 days before testing. Coupons were then sorted for each JTP test.

14NCAP Phase I Report August 2003

4.2.1 Description of Paints In order to closely m atch conditions found in curre ntly fielded equipment, five organic coating systems commonly used in DoD system s were selected. The following prim ers and topcoats were used in the Phase I Study. These prim ers and topcoats represent a cross-section of those used in the joint community.

4.2.1.1 MIL-PRF-23377G, Type I, Class C
MIL-PRF-23377G is a two com ponent, low volat ile organic compound ( VOC), solvent-borne, epoxy primer coating that is corrosion inhibiti ng and chem ical and s olvent resistant. The maximum VOC content of the adm ixed primer co atings is 340 gram s per liter (2.8 pounds per gallon). Type I specifies standard pigm ents. Cl ass C is for strontium chromate based corrosion
inhibitors and Class N is for non-chrom ate based corrosion inhibitors. Re vision F took effect in 1989 and was superseded by Revision G in 1994.

4.2.1.2 MIL-PRF-85582 C, Type II, Class C2 and N
MIL-PRF-85582C is a waterborne, e poxy primer coating that is co rrosion inhibiting, chemical and solvent resistant, and ha s a maximum VOC content of 340 gram s per liter (2.8 pounds per gallon). Type II specifies low infrared reflectiv e pigments. Class C2 is for strontium chromate
based corrosion inhibitors and Cl ass N is for non-chromate based corrosion inhibitors. Revision
B took effect in 1994 and was superseded by Revision C in 1997.

4.2.1.3 MIL-P-53022
MIL-P-53022 is a flash drying, co rrosion inhib iting epoxy prim er for ferrous and nonferrous metals. The prim er is lead and chrom ate free and m eets the air po llution requirements for
solvent emissions. Revision A took effect in 1983 and was superseded by Revision B in 1998.

4.2.1.4 MIL-P-53030 MIL-P-53030 is a water-reducible, air-drying, corrosion inhibiting, epoxy-type prim er for pretreated ferrous and non-ferrous m etals. The primer is lead and chrom ate-free and is compatible with chemical agent resistant aliphatic polyurethane t opcoats. The pri mer contains no more than 340 grams per liter (2.8 pounds per gall on) of VOCs, as applied. Revision A took
effect in 1992.

4.2.1.5 MIL-PRF-85285C Topcoat
MIL-PRF-85285 topcoat is a high-s olids, aliphatic po lyurethane coating with the m aximum VOC content specified by type. Type I is fo r aircraft application and has a m aximum VOC content of 420 gram s per liter. Type II is for ground support equipm ent application and has a maximum VOC content of 340 gram s per liter. Revision B took effect in 1988 and was superseded by Revision C in 1997.

4.2.1.6 MIL-C-53039
MIL-C-53039 topcoat specifies C hemical Agent Resistant Coating (CA RC) topcoats. This specification covers both cam ouflage and noncam ouflage, one com ponent chemical ag ent resistant, aliphatic polyurethane coating for use as a finish coat on m ilitary combat equipment.

15NCAP Phase I Report August 2003

The coating is lead and chromate (hexavalen t) free and has maximum of 420 gram s/liter (3.5 lbs/gallon) VOC content. Revision A took effect in 1988.

16NCAP Phase I Report August 2003

THIS PAGE LEFT BLANK INTENTIONALLY.

17NCAP Phase I Report August 2003



### 5.0 TEST METHODS AND RESULTS

5.1 Neutral Salt Fog on Unpainted Substrate with Pretreatment

5.1.1 Test Description
This test method evaluates a coating system ’s ab ility to prevent substrate corrosion. Operation of the fog cham ber for this test is in acco rdance with A STM B 117 [ Standard Practice for Operating Salt Spray (Fog) Apparatus ].

The five replicates of each coating per alloy were placed into a fog chamber at a 6-degree ang le. The coupons were not allowed to contact other surfaces in th e ch amber, and condensate from a coupon also did not contact any other coupons. The salt solutio n and the fog cham ber were prepared as specified in the Te st Methodology of the JTP. The no zzles were adjusted in the fog chamber so that sprayed salt solution did not di rectly impinge on the c oupon surfaces. The fog chamber was operated continuously for the test duration. Coupons were then evaluated per
ASTM D 1654 Method B for surface corrosion at 24-hour intervals for the first 4 days, then at 7, 10 and 14 days. This rating m ethod allows for pe rformance evaluation of coatings that do not meet MIL-OTL-81706A, which requires no evidence of corrosion after 2 weeks of ASTM B 117 exposure. The coupons were carefully rem oved at the end of the test duration and cleaned by gently flushing with running water [water temper ature less than 38 degrees °C (100°F)]. The coupons were air-dried at am bien t conditions then visually exam ined for corrosion, ignoring edges and contact points.

5.1.2 Test Results
Three of the eight alternatives were chosen for this test: TCP, Alodine 5200 and Sanchem 7000 with Seal #2. Prior testing de monstrated that the other altern atives have poor bare corrosion
resistance and would not be candidates for u npainted applications. Sanchem 7000 without sealing shows poor bare corrosion performance, so Seal #2 was used for this particular test.

Alodine 1200S and TCP coatings exposed to 1-week and 2-week Neutral Salt F og Exposure show no corrosion on 2024-T3, 7075-T6, and 5083-H131. Alodine 5200 and Sanchem 7000
with Seal #2 show surface corrosion within 48 hours on 20 24-T3 and 7075-T6. Alodine 5200
and Sanchem 7000 with Seal #2 show som e co rrosion on 5083-H131 after 2-week exposure. TCP performs best on 2219-T87 showing some m inor pitting after 2 weeks of exposure. The tables and photos below detail corrosion performance for pretreatm ents on each alloy. Each rating is an average of 5 test coupons.

18NCAP Phase I Report August 2003

Table 5.1.2.1: Aluminum alloy 2024-T3

Average Rating (5 Panels) after Exposure to ASTM B 117 Neutral Salt Fog (ASTM D 1654 Method B) Pretreatment

24 hrs 48 hrs 168 hrs 336 hrs

Alodine 1200S 10.0 10.0 10.0 10.0

Alodine 5200 9.0 8.0 3.0
-

Sanchem 7000
with Seal #2 9.0 8.0 2.0
-

TCP 10.0 10.0 10.0 10.0

Table 5.1.2.2: Aluminum alloy 7075-T6

Average Rating (5 Panels) after Exposure to ASTM B 117 Neutral Salt Fog (ASTM D 1654 Method B) Pretreatment

24 hrs 48 hrs 168 hrs 336 hrs

Alodine 1200S 10.0 10.0 10.0 10.0

Alodine 5200 10.0 9.0 6.0
- Sanchem 7000
with Seal #2 9.0 8.0 2.0
-

TCP 10.0 10.0 10.0 10.0

Table 5.1.2.3: Aluminum alloy 2219-T87

Average Rating (5 Panels) after Exposure to ASTM B 117 Neutral Salt Fog (ASTM D 1654 Method B) Pretreatment

24 hrs 48 hrs 168 hrs 336 hrs

Alodine 1200S 10.0 10.0 5.4 5.0

Alodine 5200 0.0
- - - Sanchem 7000
with Seal #2 9.0 8.0 0.0
-

TCP 10.0 10.0 9.0 9.0

19NCAP Phase I Report August 2003

Table 5.1.2.4: Aluminum alloy 5083-H131

Average Rating (5 Panels) after Exposure to ASTM B 117 Neutral Salt Fog (ASTM D 1654 Method B) Pretreatment

24 hrs 48 hrs 168 hrs 336 hrs

Alodine 1200S 10.0 10.0 10.0 10.0

Alodine 5200 10.0 10.0 9.0 7.0

Sanchem 7000
with Seal #2 10.0 10.0 9.0 8.0

TCP 10.0 10.0 10.0 10.0

Alodine 5200
2024-T3

Alodine 5200

2219-T87

Figure 5.1.2.1: Alodine 5200 on 2024 a nd 2219 After 1 Week Exposure

20NCAP Phase I Report August 2003

Alodine 5200

5083-H131

Alodine 5200
7075-T6

Figure 5.1.2.2: Alodine 5200 on 5083 a nd 7075 After 1 Week Exposure

Figure 5.1.2.3: Sanchem 7000 With Sealer # 2 on 5083-H131 After 2 Weeks Exposure

21NCAP Phase I Report August 2003

Figure 5.1.2.4: TCP on 5083 and 2024 After 2 Weeks Exposure TCP
5083-H131

TCP
7075-T6

TCP
2219-T87

TCP
2024-T3

Figure 5.1.2.5: TCP on 2219 and 7075 After 2 Weeks Exposure

22NCAP Phase I Report August 2003

Figure 5.1.2.6: Alodine 1200S on 5083 and 2024 After 2 Weeks Exposure Alodine 1200S
2024-T3

Alodine 1200S

5083-H131

Alodine 1200S
2219-T87

Alodine 1200S
7075-T6

Figure 5.1.2.7: Alodine 1200S on 2219 and 7075 After 2 Weeks Exposure

23NCAP Phase I Report August 2003

5.2 Electrical Contact Resistance Unpainted, Pretreated Substrates

5.2.1 Test Description
This test method evaluates a coating system ’s ability to provide init ial electrical contact resistance after application of pretreatm ent a nd after exposure to a corrosive environm ent. Pretreated aluminum 6061-T6 coupons were evalua ted for electrical cond uctivity using apparatus and method described in MIL-DTL-81706A. Operation of the fog chamber for this test is in accordance with ASTM B 117 [ Standard Practice for Operati ng Salt Spray (Fog) Apparatus ]. Testing was completed by NAVAI R personnel at the Patuxent River, MD test facility.

In order to expose substr ate to corrosive environment, they we re placed into a fog cham ber at a 6-degree angle for 168 hours. The coupons were not allowed to contact other surfaces in the chamber, and condensate from a coupon did not c ontact any other coupons. The salt solution and the fog cham ber were prepared as specified in the Test Methodology of the JTP. The nozzles were adjusted in the fog cham ber so th at sprayed salt solution did not directly im pinge on the coupon surfaces. The fog chamber was oper ated continuously for 168 hours. The coupons were then carefully removed at the end of the test duratio n, and cleaned with running water (water temperature less than 38 ° C (100°F)). The coupons were then air-dried at am bient conditions, and then visually examined for corrosion.

5.2.2 Test Results
All eight alternatives and th e chromate control were coated onto the 6061 test coupons and
evaluated for initial electrical contact resistance. A sister se t was exposed to salt fog and
evaluated for corrosion resistance.

All coatings passed the initial el ectrical conductivity test by measuring less than 5 milli-ohms per square inch per the JTP. Only Alodine 1200S a nd TCP completed the salt fog test with no signs of corrosion on any coupon. The seven other alternatives all be gan corroding before the end of
the test duration and therefore do not meet the test criteria. Due to the corrosion on the substrate,
electrical contact resistance measurements could not be completed for those coatings.

Data for as-coated TCP and Alodine 1200S ar e presented in Tabl es 5.2.2.1, 5.2.2.3, and 5.2.2.5.
Alodine 1200S was coated at two different immersion tim es to evaluate potential im pact on contact resistance. As the tables show, TCP and Alodine 1200S deposited by 30- and 60- second
immersion times meet the cont act resistance test criteria.

After the coupons with Alodine 1200S and TCP coatings were remove d from the salt fog chamber, rinsed and dried, they w ere subjected to electrical contact resistance measurement. Tables 5.2.2.2, 5.2.2.4, and 5.2.2.6 show the test re sults for all 15 cou pons. Although each coating showed average measurement increases over the as-coated set, all coatings m et the test criteria by measuring less th an 10 milli-ohms per square inch. Mos t measurements still fell below the more strict as-coated requirement.

24NCAP Phase I Report August 2003

The Alodine 1200S with 60-second immersion tim e did show higher measurements than the 30- second immersion set, especially after salt f og. The 60-second immersion tim e was used for all other coupons in the JTP tests showing that one immersion time can satisfy bare corrosion, paint adhesion, painted corrosion, and electr ical contact resistance requirem e nts. This is true for the TCP coating as well. A 2-m inute immersion time wa s used for the electrical con tact resistance test, the same as for all the other testing.

Table 5.2.2.1: Contact Resist ance of As-Coated TCP

As-Coated Spot Measurements on Coupon (milliohms/in 2 ) per MIL-DTL-81706

Coupon # 1 2 3 4 5 6 7 8 9 10 Average 50 Avg Standard
Deviation

1 1.52 1.66 1.79 1.46 1.80 1.26 1.67 1.59 2.01 1.16 1.59

2 1.35 1.47 1.36 1.34 1.51 1.22 1.25 1.25 1.20 1.33 1.33

3 1.42 1.72 2.15 2.14 1.55 1.34 1.72 1.54 1.05 1.58 1.62

4 1.33 1.69 1.70 1.97 1.07 1.33 1.57 1.54 1.36 1.83 1.54

5 1.33 1.82 1.81 1.92 2.18 1.54 1.85 2.21 1.09 1.86 1.76 1.57 0.30

Table 5.2.2.2: Contact Resistance of TCP a fter exposure to Salt Fog for 168 hours

After Exposure to
Salt Fo g for

168 hours Spot Measurements on Coupon (milliohms/in 2 ) per MIL-DTL-81706

Coupon # 1 2 3 4 5 6 7 8 9 10 Avg 50 Avg Std Dev

1 3.05 4.46 3.48 3.36 4.25 2.70 2.42 3.72 2.43 5.16 3.50

2 5.39 2.93 6.18 3.03 7.27 3.20 4.67 4.44 4.15 2.94 4.42

3 2.40 2.36 2.50 3.94 2.45 2.11 4.23 2.40 1.25 3.83 2.75

4 3.18 1.83 3.01 1.45 4.35 7.65 5.20 2.39 1.52 1.89 3.25

5 2.34 1.80 2.19 2.13 2.06 2.45 2.10 1.71 1.69 1.80 2.03 3.19 1.45

Table 5.2.2.3: Contact Resistance of Alodin e 1200S As-Coated (30-Second Immersion)

As-Coated Spot Measurements on Coupon (milliohms/in 2 ) per MIL-DTL-81706

Coupon # 1 2 3 4 5 6 7 8 9 10 Avg 50 Avg Std Dev

1 2.09 2.18 2.26 2.23 2.47 1.49 1.46 1.68 1.23 0.84 1.79

2 1.34 1.42 1.56 1.28 1.26 1.40 1.21 1.25 1.09 0.73 1.25

3 1.01 1.50 1.49 1.92 1.34 1.70 1.40 1.44 1.33 1.08 1.42

4 1.95 1.56 2.01 1.22 1.40 1.70 1.63 1.47 1.30 0.99 1.52

5 1.42 1.23 0.98 1.12 1.57 1.58 1.51 1.81 1.10 1.67 1.40 1.48 0.37

25NCAP Phase I Report August 2003

Table 5.2.2.4: Contact Resistance of Alodine1 200S After Exposure (30-Second Immersion)

After Exposure to
Salt Fo g for

168 hours Spot Measurements on Coupon (milliohms/in 2 ) per MIL-DTL-81706

Coupon # 1 2 3 4 5 6 7 8 9 10 Avg 50 Avg Std Dev

1 2.32 3.52 3.39 2.08 1.33 1.55 2.07 1.31 1.34 1.70 2.06

2 2.96 1.75 2.68 2.07 1.66 3.11 1.98 1.64 2.44 2.23 2.25

3 1.66 2.11 0.74 1.23 0.90 2.54 2.46 2.24 1.65 2.03 1.76

4 2.07 2.53 2.97 2.12 1.09 1.56 2.33 2.34 1.00 1.15 1.92

5 1.84 3.07 1.02 1.12 1.03 1.63 2.59 2.56 2.41 1.66 1.89 1.98 0.68

Table 5.2.2.5: Contact Resistance of Alodin e 1200S, As-Coated (60-Second Immersion)

As-Coated Spot Measurements on Coupon (milliohms/in 2 ) per MIL-DTL-81706

Coupon # 1 2 3 4 5 6 7 8 9 10 Avg 50 Avg Std Dev

1 1.25 2.23 2.20 2.14 1.90 1.19 1.22 1.10 0.93 1.08 1.52

2 1.41 2.44 1.49 1.27 1.06 0.99 1.36 1.41 1.56 1.70 1.47

3 2.08 1.42 1.46 2.25 1.76 1.91 2.27 2.80 2.25 1.77 2.00

4 1.86 1.23 1.18 1.12 0.93 1.70 2.13 2.06 2.00 2.03 1.62

5 1.88 2.30 2.26 2.13 2.17 1.54 2.66 1.78 1.32 1.40 1.94 1.71 0.48

Table 5.2.2.6: Contact Resistance of Alodine 1200S After Exposure (60-Second Immersion)

After Exposure to
Salt Fo g for

168 hours Spot Measurements on Coupon (milliohms/in 2 ) per MIL-DTL-81706

Coupon # 1 2 3 4 5 6 7 8 9 10 Avg 50 Avg Std Dev

1 4.89 4.76 4.54 2.61 2.83 5.06 4.03 4.73 3.62 2.80 3.99

2 4.06 3.22 6.92 4.62 3.36 5.28 2.63 7.47 3.05 3.04 4.37

3 4.89 7.23 6.18 8.64 6.54 1.65 1.75 5.07 9.42 6.92 5.83

4 5.03 8.31 9.20 4.66 6.49 6.80 6.82 5.66 7.28 3.15 6.34

5 3.10 1.42 0.88 1.72 2.63 2.70 3.02 3.33 2.25 2.91 2.40 4.58 2.15

26NCAP Phase I Report August 2003

5.3 Dry Tape Adhesion of Painted Substrates

5.3.1 Test Description
This test method describes a procedure for es tablishing adequacy of intercoat and surface adhesion of an organ ic coating by applying pressure sensitive tape o ver a scr ibed area of the coating. Method A testing was completed by NAVAIR personnel and Me thod B testing was completed by Arm y Research Lab oratory (ARL) personnel at the Patuxe nt River, MD test facility.

Dry tape adhesion testing was conducted in accordance with ASTM D 3359, Methods A and B (Standard Test Methods for Measuring Adhesion by Tape Test, Test Method B-Cross-Cut Tape Test).

For Method A, two par allel lines were then s cri bed approximately one in ch apart, making sure that the coating was scribed a ll the way through and into the substrate. Two angled “X” incisions were scribed through the coating across the para llel lines to create an “X” so that the smaller angle of the “X” was 30 to 45 degrees, m a king sure that the coating was scribed all the way through and into the substrate. Each line of the “X” was approxim ately 1.5 inches long. Figure 5.3.1.1 shows an exam ple coupon with Met hod A (top) and Method B (bottom ) scribe patterns. A piece of tape was im mediately placed over the incisions parallel to the parallel scribe lines, and the tape was s moothed by rolling a 3-lb roller over it once. The tape was then removed rapidly at approximately a 180-degree angl e. The incision area was then inspected for damage.

Figure 5.3.1.1: Example Coupon with Scribe Pattern After Testing

27NCAP Phase I Report August 2003

For tape adhesion testing according to ASTM D 3359, Method B; each test panel was subjected to a crosshatch tape test (minimum tape adhesion rating of 45 oz. per inch of width). The test pattern was 4 x 4 sc ribe lines to the metallic layer at 2-millimeter (mm) intervals (approximate) and was no closer than 12 mm from any edge. E ach line was cut seq uentially. Ratings wer e assigned in accordance with the ASTM D 3359, Method B rating scale shown in Ta ble 5.3.1.1. The loss of two or more complete pr imer squares constituted failure.

Table 5.3.1.1: Rating Scale for ASTM D 3359 Method B Tape Adhesion Test

Rating

Number Description of Failure

5 The edges of the cuts are completely smooth; none of the squares of the lattice are
detached.

4 Small flakes of the coating are detached at intersections; less than 5% of the area is
affected.

3 Small flakes of the coating are detached along edges and at intersections of cuts. The area
affected is 5 to 15% of the lattice.

2 The coating has flaked along the edges and on pa rts of the squares. The area affected is 15
to 35% of the lattice.

1 The coating has flaked along the edges of cuts in large ribbons and whole squares have
detached. The area affected is 35 to 65% of the lattice.

0 Flaking and detachment worse than Rating 1.

5.3.2 Test Results

An additional surface treatment was included in the adhesion test to study the effectiveness of a manually cleaned and scrubbed surface to prov ide adequate paint adh esion. To evaluate this type of process, one set of al uminum alloys was thoroughly scr ubbed with an Alconox saturated Scotch-Brite pad until a water break free surface was obtained. Coupons were then thoroughly rinsed in ta p water and final deionized water ri nse and allowed to stan d overnight with other alternative pretreatments coatings before priming.

The tables below detail the results of dry tape adhesi on per ASTM D 3359 Method A and Method B. All coating s perf ormed acceptably in both adhesion methods with m ost coatings scoring 5 out of 5 per the ASTM rating m ethod. Note: The Boegel coating for all adhesion tests was applied by an incorrect procedure where the c oating was dried in place without draining. This led to beach marks on the coupon surfaces and uneven coating thicknesses. This error was corrected in subsequent paint ed corrosion test coatings.

28NCAP Phase I Report August 2003

Table 5.3.2.1: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-PRF-23377 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 4.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 4.0 5.0 3.0

X-It PreKote 5.0 5.0 5.0 4.0

Table 5.3.2.2: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-PRF-85582 C2 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.3.2.3: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-PRF-85582 NC Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 4.0 5.0 5.0

Bi-K Aklimate 4.0 5.0 5.0 5.0 Boegel 4.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 4.0 5.0 5.0 5.0

Scrub with Alconox 4.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0 Method A

29NCAP Phase I Report August 2003

Table 5.3.2.4: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-P-53030 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

5.0 5.0 5.0

Bi-K Aklimate 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 4.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0 5.0

Table 5.3.2.5: Dry Tape Adhesion per ASTM D 3359 Method A (X scribe) for Aluminum Alloys Coated with Mil-P-53022 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 4.0 5.0 5.0 4.0 Boegel 4.0 5.0 5.0 4.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 4.0 5.0 5.0 4.0

Scrub with Alconox 4.0 5.0 5.0 4.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 4.0 5.0 4.0 5.0

Table 5.3.2.6: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-PRF-23377 Primer Method B

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

30NCAP Phase I Report August 2003

Table 5.3.2.7: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated wi th Mil-PRF-85582 C2 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.3.2.8: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-PRF-85582 NC Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 4.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.3.2.9: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-P-53030 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

31NCAP Phase I Report August 2003

Table 5.3.2.10: Dry Tape Adhesion per ASTM D 3359 Method B (Crosshatch) for Aluminum Alloys Coated with Mil-P-53022 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 4.0 5.0 5.0 5.0

5.4 Wet Tape Adhesion and Water Re sistance of Painted Substrates

5.4.1 Test Description
This test method covers a procedure for establis hing adequacy of intercoat and surface adhesion of an organic coating im mersed in water by appl ying pressure sensitive ta pe over a scribed area of the coating. The test also m easures the coa ting’s ability to res ist penetration by water . Coatings were evaluated by imm ersion at room temperature for 24 hours, 120o F for 96 hours, and 150o F for 168 hours. Coupons are imm ersed in deionized water and let stand without disturbing for duration of immersion. This te st was performed in accordance with Method 6301 of FED-STD-141 [ Paint, Varnish, Lacquer and Related Materials; Methods of Inspection Sampling and Testing ], and ASTM 3359 Method A. Te sting was com pleted by NAVAIR personnel at the Patuxent Ri ver, MD test facility.

Ratings were assigned in accordance with th e ASTM D 3359, Method A rating scale shown in
Table 5.4.1.1.

Table 5.4.1.1: Rating Scale for ASTM D 3359 Method A Tape Adhesion Test

Rating Number Description of Failure

5 No peeling or removal.

4 Trace peeling or removal along inci sions or at their intersection.

3 Jagged removal along incisions up to 1/16 inch on either side

2 Jagged removal along most of incisions up to 1/8 inch on either side.

1 Removal from most of the area of the X under the tape.

0 Removal beyond the area of the X.

32NCAP Phase I Report August 2003

5.4.2 Test Results
The tables below detail the results of wet tape adhesion.

24-Hours (1 Day Test) at room temperature

Table 5.4.2.1: Wet Tape Adhesion for Alum inum Alloys Coated with Mil-PRF-23377
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 4.0 4.0 4.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.2: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 C2
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 2.0 0 2.0 2.0 Boegel 2.0 0 2.0 2.0

Chemidize 727ND 0 0 3.0 2.0

Oxsilan Al-0500 0 0 3.0 1.0

Sanchem 7000 2.0 0 2.0 2.0

Scrub with Alconox 2.0 0 2.0 2.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

33NCAP Phase I Report August 2003

Table 5.4.2.3: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 NC
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 4.0 5.0 5.0 Boegel 5.0 4.0 5.0 5.0

Chemidize 727ND 5.0 4.0 5.0 5.0

Oxsilan Al-0500 4.0 4.0 5.0 4.0

Sanchem 7000 5.0 4.0 5.0 5.0

Scrub with Alconox 5.0 4.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.4: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53030 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 4.0 5.0 Boegel 5.0 5.0 4.0 5.0

Chemidize 727ND 4.0 5.0 5.0 5.0

Oxsilan Al-0500 3.0 3.0 5.0 4.0

Sanchem 7000 5.0 5.0 4.0 5.0

Scrub with Alconox 5.0 5.0 4.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.5: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53022 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 1.0 5.0 5.0

Oxsilan Al-0500 4.0 4.0 5.0 4.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 2.0 3.0 5.0 0

Coatings tested for adhesion af ter a 24-hour imm ersion in room temperature deionized water generally performed well. For the 2 3377 primer, all alternatives provided acceptable adhesion ratings of 4 or 5 out of 5. For the 85582 C2 primer, Alodine 1200S, TCP, Alodine 5200 and X-It

34NCAP Phase I Report August 2003

PreKote performed well. All other coating syst ems performed poorly, failing on all alloys. For the 85582 N primer, all coatings again pe rformed well, with no failures noted.

Coatings again performed well with the 53030 pr imer with only Oxsilan Al-0500 showing some marginal performance on 2024 and 7075. W ith the 53022 primer, all coatings perform ed well except for X-It PreKote with showed poor re sults on 2024 and 2219 and m arginal performance, rating of 3, on 7075. Chemidize 727D performed well on all alloys except 7075.

Interestingly, the Scrub with Alconox contro l performed well with all prim ers except the 85582 C2 where it showed equally poor perform ance with a number of alternatives.

96-Hours (4 Day Test) at 120o F

Table 5.4.2.6: Wet Tape Adhesion for Alum inum Alloys Coated with Mil-PRF-23377
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 4.0 4.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.7: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 C2
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 3.0 1.0 3.0 3.0 Boegel 3.0 1.0 3.0 3.0

Chemidize 727ND 3.0 3.0 3.0 3.0

Oxsilan Al-0500 0 0 3.0 0

Sanchem 7000 3.0 1.0 3.0 3.0

Scrub with Alconox 3.0 1.0 3.0 3.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

35NCAP Phase I Report August 2003

Table 5.4.2.8: Wet Tape Adhesion for Alumin um Alloys Coated with Mil-PRF-85582 NC
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 2.0 3.0 5.0 4.0 Boegel 2.0 3.0 5.0 4.0

Chemidize 727ND 5.0 4.0 4.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 2.0 3.0 5.0 4.0

Scrub with Alconox 2.0 3.0 5.0 4.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.9: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53030 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 4.0 4.0 4.0 4.0

Alodine 5200 4.0 4.0 4.0 4.0

Bi-K Aklimate 4.0 4.0 3.0 5.0 Boegel 4.0 4.0 3.0 5.0

Chemidize 727ND 3.0 4.0 3.0 4.0

Oxsilan Al-0500 3.0 3.0 4.0 4.0

Sanchem 7000 4.0 4.0 3.0 5.0

Scrub with Alconox 4.0 4.0 3.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 4.0 4.0 4.0 4.0

Table 5.4.2.10: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53022 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 1.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 3.0 4.0 5.0 3.0

Coatings tested for adhesion af ter a 96-hour immersion in 120 F deionized water did not perform as well as in the 24-hour test. Coatings perfor med best with the 23377 prim er with all systems achieving acceptable adhesion. The sam e four co atings that performed well with the 85582 C2

36NCAP Phase I Report August 2003

primer in the 24-hour test did well in the 96 -hour test. A lthough the rem aining coatings all showed unacceptable adhesion for all alloys, ratings were generally better than in the 24-hour

test.

For the 85582 N primer, whereas all coatings pe rformed well in the 24-hour test, Sanchem 7000, Bi-K Aklimate, Scrub with Alconox, and Boegel Method A all showed unacceptable adhesion on 2024 and 7075. The 53030 prim er systems saw similar incremental decreases in performance by Sanchem 7000, Bi-K A klimate, Scrub with Al conox and Boegel Meth od A on 5083 where all performed marginally, scoring 3. Oxsilan Al -0500 had marginal perf ormance with 2024 and 7075 for this prim er and Chemdize 727D on 5083. For 53022, only X-It PreKote and Oxsilan Al-0500 did not rate 5 for all alloys.

168-Hours (7 Day Test) at 150o F

Table 5.4.2.11: Wet Tape Adhesion for Alum inum Alloys Coated with Mil-PRF-23377
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 5.0 5.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 4.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.12: Wet Tape Adhesion for Alumi num Alloys Coated with Mil-PRF-85582 C2
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 1.0 1.0 3.0 2.0 Boegel 1.0 1.0 3.0 2.0

Chemidize 727ND 2.0 2.0 3.0 2.0

Oxsilan Al-0500 0 0 3.0 1.0

Sanchem 7000 1.0 1.0 3.0 2.0

Scrub with Alconox 1.0 1.0 3.0 2.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 4.0

37NCAP Phase I Report August 2003

Table 5.4.2.13: Wet Tape Adhesion for Alumi num Alloys Coated with Mil-PRF-85582 NC
Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 0 0 3.0 1.0 Boegel 0 0 3.0 1.0

Chemidize 727ND 3.0 0 4.0 4.0

Oxsilan Al-0500 3.0 5.0 5.0 5.0

Sanchem 7000 0 0 3.0 1.0

Scrub with Alconox 0 0 3.0 1.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Table 5.4.2.14: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53030 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 4.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 4.0 4.0 4.0 4.0 Boegel 4.0 4.0 4.0 4.0

Chemidize 727ND 3.0 4.0 4.0 4.0

Oxsilan Al-0500 3.0 3.0 4.0 4.0

Sanchem 7000 4.0 4.0 4.0 4.0

Scrub with Alconox 4.0 4.0 4.0 4.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 4.0 5.0 5.0 4.0

Table 5.4.2.15: Wet Tape Adhesion for Aluminum Alloys Coated with Mil-P-53022 Primer

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 5.0 5.0 5.0 5.0

Alodine 5200 5.0 5.0 5.0 5.0

Bi-K Aklimate 5.0 5.0 5.0 5.0 Boegel 5.0 5.0 5.0 5.0

Chemidize 727ND 5.0 5.0 5.0 5.0

Oxsilan Al-0500 4.0 4.0 5.0 5.0

Sanchem 7000 5.0 5.0 5.0 5.0

Scrub with Alconox 5.0 5.0 5.0 5.0

TCP 5.0 5.0 5.0 5.0

X-It PreKote 5.0 5.0 5.0 5.0

Coatings tested for adhesion after a 168-hour immersion in 150 ° F deionized water generally performed better than in the 96- hour test. This performance tre nd is not unusual where in m any cases the 96-hour test proves to be the m ost severe on many coatings. For this test, all coatings

38NCAP Phase I Report August 2003

again performed well with the 2337 7 primer with virtually all coatings rating 5. For the 85582 C2, the same four coatings that performed well in the 24- and 96-hour test performed well in the
168-hour test. All others showed marginal to poor perform ance on all alloys. The sam e four coatings, Alodine 1200S, TCP, Alodine 5200 and X-It PreKote performed well with the 85582 N primer. All others perform ed significantly worse than in the 96-hour test, with m any coatings failing completely and rating 0. Alum inum 2024 a nd 7075 were especially prone to com plete failures with these coatings. Perform ance of all coatings with 53030 and 53022 wa s acceptable on all alloys with the excepti on of marginal performance of Oxsilan Al-0500 on 2024 and 7075 and Chemidize 727D on 2024 using the 53030 primer.

Summary of Alternative Performance Table 5.4.2.16 details the summ ary performance of each alternative pretreatm ent by prim er system. It also shows an average rating for ea ch primer across all pretreatm ents. Only the Alodine 1200S control, TCP and Alodine 5200 rated 4 or 5 on all adhesion tests. This is a very important measure of the overall ad hesion quality of these coating s and their f lexibility to b e used on any alloy. It is comforting to re-valid ate the adhesion prom oting qualities of Alodine 1200S. These tests also point out the extrem e difficu lty in achieving robust pretreatment coating characteristics on a variety of aluminum surf aces with a variety of organic coatings.

Table 5.4.2.16 Summary Ratings for Pretreatment s and Primer Systems in Wet Tape
Adhesion Tests

Primer

Pretreatment 23377 85582 C2 85582 N 53022 53030 All Coatings

Alodine 1200S (control) 5.0 5.0 5.0 5.0 4.6 4.9

Alodine 5200 5.0 5.0 5.0 5.0 4.7 4.9

Bi-K Aklimate 5.0 1.9 3.1 5.0 4.3 3.9
Boegel 5.0 1.9 3.1 5.0 4.3 3.9

Chemidize 727ND 5.0 2.2 4.0 4.7 4.0 4.0

Oxsilan Al-0500 5.0 0.9 4.6 4.3 3.6 3.7

Sanchem 7000 5.0 1.9 3.1 5.0 4.3 3.9

Scrub with Alconox 5.0 1.9 3.1 5.0 4.3 3.9

TCP 4.5 5.0 5.0 5.0 5.0 4.9

X-It PreKote 5.0 4.9 5.0 3.8 4.5 4.6

Overall Alternative Average 5.0 3.1 4.1 4.8 4.3 4.2

5.5 Neutral Salt Fog on Scribed, Painted Substrate

5.5.1 Test Description
This test method evaluates a coating system’s abi lity to prevent substrate corrosion and the effect
that corrosion has on ad hesion of the coati ng system. Operation of the fog cham ber for this test

39NCAP Phase I Report August 2003

is in accordance with ASTM B 117. Testing wa s completed by Army Research Laboratory (ARL) personnel at the Ab erdeen, MD test facility.

Prior to exposure, an “X” incision w as manually scribed through the test coupon coating using a carbide tip scribe as per ASTM D 1654, m aking sure that the co ating was scribed all the way through and into the substrate. The sm aller angl e of the “X” was 30 to 45 degrees and each line of the “X” was approxim ately 4 inches long. The back and e dges of the test coupons were primed to prevent corrosion products from contamin ating the chamber. The salt solution and the fog chamber were prepared as specified in the Test Methodology of the JTP. The nozzles were adjusted in the fog cha mber so that sprayed sa lt solution did not directly im pinge on the coupon surfaces. The fog chamber was operated contin uously for 3,000 hours. Coupons were evaluated for surface corrosion and creepage from the scribe at weekly intervals up to 3 weeks and then at 500-hour intervals. The coupons we re carefully rem oved at the end of the test duration and cleaned by gently flushing with running water [w ater temperature less than 38 degrees °C (100°F)]. The coupons were air-dried at am bient conditions and then visually examined without magnification.

5.5.2 Test Results
This test specifically examines ASTM B 117 accelerated corrosion exposure of aluminum alloys 2024, 2219, 5083, and 7075 specim ens treated with the candidate hexavalent chrom ium free pretreatments as well as one hexavalent chromium based pretreatment (Alodine 1200S) used as a control. Twenty-five panels with each pretreat ment combination were prepared fo r each alloy for neutral salt fog exposure. E ach set of 25 panels was further subdivided to 5 groups, one for each of the 5 selected DoD coatin gs. The larg e corrosion test chamber which was used to
evaluate all of the coated aluminum test panels is depicted in Figure 5.5.2.1.

Figure 5.5.2.1: Test Chamber and Panels Used for ASTM B 117

40NCAP Phase I Report August 2003

In order to chronicle the corrosi on, specimens were numerically ra ted for damage at prescribed
intervals. Specimen group failures were defined when for 3 or more of the panels in a particular alloy/pretreatment/coating set were measured wi th a rating of 0 under method ASTM D 1654. In addition, the representative panels rated from each of the five test p anels were digitally scanned at 600 dpi resolution and saved as high quality gra phics files. W ith the exception of the early failures defined above under ASTM D 1654, the co ated panels were al l subjected to 3000 hours of ASTM B 117. The prevalent failure m ode for the most of the panels was blistering along the
scribe.

The tables below detail corrosion perform ance for pretreatments on each alloy.

Table 5.5.2.1: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with
Mil-PRF-23377 Primer and Mil-C-85285 Topcoat Exposed to 3000 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 8.3 9.0 9.4 9.2

Alodine 5200 9.0 9.0 9.2 8.8

Bi-K Aklimate 7.8 9.0 9.0 8.4 Boegel 9.0 9.0 9.0 4.2

Chemidize 727ND 7.6 8.8 9.0 4.8

Oxsilan Al-0500 9.4 9.0 9.0 8.6

Sanchem 7000 3.2 9.0 6.0 3.2

TCP 8.8 8.4 8.4 7.2

X-It PreKote 8.6 8.8 9.0 7.2

Table 5.5.2.2: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-85582 C2 Primer and Mil-C-85285 Topcoat Exposed to 3000 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 9.2 9.0 8.8 9.0

Alodine 5200 9.0 9.0 9.0 9.0

Bi-K Aklimate 8.0 5.8 9.0 6.6 Boegel 9.0 9.0 9.6 5.6

Chemidize 727ND 8.4 2.0 8.2 3.6

Oxsilan Al-0500 9.2
- 9.0 8.6

Sanchem 7000 7.4 1.4 8.0 6.2

TCP 8.8 9.0 9.0 8.4

X-It PreKote 8.8 8.6 9.0 9.0

41NCAP Phase I Report August 2003

Table 5.5.2.3: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with
Mil-PRF-85582 N Primer and Mil-C-85285 Topcoat Exposed to 3000 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 7.0 9.0 9.0 5.6

Alodine 5200 6.4 8.8 8.8 6.0

Bi-K Aklimate

- - - - Boegel 6.6 7.8 8.2 3.8

Chemidize 727ND 2.2
- - 2.2

Oxsilan Al-0500 6.6 8.8 8.2 5.4

Sanchem 7000

- 1.4 2.4
- TCP 4.2 8.0 9.0 4.4

X-It PreKote
- 1.6 0.4
-

Table 5.5.2.4: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with
Mil-PRF-53030 Primer and Mil-C-53039 Topcoat Exposed to 3000 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 7.4 7.8 5.8 6.0

Alodine 5200 7.8 6.0 7.8 4.6

Bi-K Aklimate

- - 2
- Boegel 4.4 2.8 6.4 1.4

Chemidize 727ND

- - - - Oxsilan Al-0500

- 0.8
- - Sanchem 7000

- - 2.4
- TCP 4.8 6.4 7.4 5.0

X-It PreKote
- 1.2 4.2
-

Table 5.5.2.5: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with
Mil-PRF-53022 Primer and Mil-C-53039 Topcoat Exposed to 3000 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 3.8 6.6 3.6 1.0

Alodine 5200 6.4 6.4 5.4 3.2

Bi-K Aklimate

- - - - Boegel 6.6 4.6 3.2 0.6

Chemidize 727ND

- - - 2.4

Oxsilan Al-0500

- 3.2
- - Sanchem 7000

- 4.2
- - TCP 4.2 8.6 6.8 4.6

X-It PreKote
- - - -

Aluminum 2024 For Al 2024, the top perfor ming pret reatments were clearly evident. For this particular alloy it
was the Cr +6 free coating systems that most aided in revealing the better perform ers. With the

42NCAP Phase I Report August 2003

exception of the Sanchem process, all of the pret reatments for the hexavalent chromium bearing 23377/85285 coating system performed well and co mpleted 3000 hours with the highest ratings among the coating systems.

The 85582 C2/85285 coating system containing hexa valent chromium performed similar when compared to the 23377/85285 system for the sa me pretreatments. As with 23377/85285, Sanchem showed degradation though not as severe. In addition to problems on Sanchem treated panels, the Bi-K pretreatment had blistering away from the scribed areas past 2500 hours.

The non-chromate coating systems, 85582 N/85285, 53030/53039, and 53022/53039, provided a much greater challenge for the pretreatm ents. At the conclusion of 3000 hours, all of the pretreatments, including Alodi ne 1200S, showe d significant corrosion dam age. M any of the pretreatments were unable to sustain acceptable perf ormance levels and were terminated prior to
the end of 3000 hours. The m ost consistent performance among the three chromate free coating systems was provided by the Boegel, Alod ine 5200, N AVAIR TCP, and Alodine 1200S pretreatments. Figure 5.5.2.2 shows the re sults of Al 2024 alloy coated with 85582 N/85285 coating sytem at 3000 hours exposure. Figure 5.5. 2.3 shows that in the specific case of the 53030/53039 system, Alodine 5200 even exceeded the perform ance for Alodine 1200S. The Brent Oxsilan pretreatment rende red respectable performance at or near the leaders for the 85582 N/85285 system but performed poorly on th e 53030/53039 and 53022/53039 coating systems.

Aluminum 2219 Of all of the Al alloys examined in this study, Al 2219 with its hi gh Cu content is by far the most corrosion prone and provides a difficult situatio n for even Alodine 1200S. For the chrom atebased 23377/85285 coating system, although all pretr eatments lasted the full 3000-hour duration, significant corrosion damage occurred on most of the pretreatments. The best performers for this coating system were Alodine 1200, Alodine 5200, Oxsilan, and Bi-K . It should be noted that NAVAIR TCP had m ixed results, two panel replic ates rated “4” and “5” and the rem aining 3 panels all rated at “9”. Fo r the chromate containing 85582 C2/85285 system, the best performers were Alodine 1200, Alodine 5200, NAVAIR TCP, X-It PreKote, a nd Oxsilan. T he remaining pretreatments performed in th e intermediate range with ra tings ranging from 4 to 7.

For the three-chromate free coating sy stems, 85582 N/85285, 53030/53039, and 53022/53039, there was significant corrosion damage with m a ny of the pretreatm ent s unable to endure 3000 hours without com plete failure. The m ost cons istent performers for these system s were NAVAIR TCP, Alodine 1200 and Alodi ne 5200. Figures 5.5.2.4 and 5.5.2.5 show that Boegel pretreatment produced som ewhat modest ra tings versus the leaders for the 85582 N/85285 coating system but performed much more poorly on the CARC based systems.

43NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Oxsilan AL-0500

Figure 5.5.2.2: Aluminum 2024 Coated With 85582 N/85285 Coating System at 3000 Hours
Duration

44NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.5.2.3: Aluminum 2024 Coated With 53030/53039 Coating System at 3000 Hours
Duration

45NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.5.2.4: Aluminum 2219 Coated With 85582 N/85285 Coating System at 3000 Hours
Duration

46NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.5.2.5: Aluminum 2219 Coated With 53030/53039 Coating System at 3000 Hours
Duration

47NCAP Phase I Report August 2003

Aluminum 5083 Al 5083, well known for its stable protective oxide layer, does not usually significantly corrode,
even under uncoated accelerated co nditions. Du e to its widespread use in ground system s,
accelerated corrosion methods such as ASTM B 117 ar e still necessary for this alloy to detect potential adhesion and quality control is sues. In contrast to the cyclic accelerated corros ion exposure studies under GM 9540P (Section 5.7), su rprisingly significan t amounts of creepback corrosion via blistering were measured on the chro mate-free coating systems as shown in Figures 5.5.2.6 and 5.5.2.7. As with other alloys, the 23377/85285 coating system proved superior and there was no significant creepback resulting fr om corrosion or coating system delamination for any pretreatment. For 85582 C2/85285, blistering away from the scribe appeared at 1000 hours for Sanchem 7000. The Chemidize and Bi-K pretreat ments also showed blistering away from the scribe appearing at 1500 and 2000 hours respectively. Corrosi on was m ost severe for the Oxsilan pretreatment, which rated a “7” begi nning at 2500 hours. For 3000 hours, the best performers were NAVAIR TCP, Alodine 1200, and Alodine 5200, and Boegel, which achieved these ratings free of any other defe cts such as coating delamination.

For the 85582 N/85285 and 53022/53039 coating syst ems, the superiority of Alodine 1200S, Alodine 5200, and NAVAIR TCP pretreatm e nts was obvious. For the 53030/53039 coating system, the ratings were significantly lowe r, however Alodine 1200, Alodine 5200, and NAVAIR TCP pretreatments still performed better than the other pretreatments.

Aluminum 7075 For the coating system 23377/85285, as in the other alloys, most of the pr etreatments performed well with little o r no da mage to the scribed regi on. All of the pretreatm ents rated “9” at the
conclusion of 3000 hours. One item of note was a slight lifting or delamination along the length
of the entire scribe of the NAVAIR TCP. This delamination first measured at 1 week was very slight and never progressed duri ng the remainder of the test.

For the 85582 C2/85285 coating system , the top pe rformers with little or no dam age were Alodine 1200S, Alodine 5200, TCP, X-It Pr eKote, and Boegel. As with the 23377/85285 coating system, NAVAIR TCP di splayed the sam e minor delamination issue. The other pretreatments for this system were disqualifi ed either by lower ratings due to corrosion, delamination, or both. Oxsilan Al-0500 pretre atment catastrophically failed prior to 2 weeks exposure across the m ajority of its 5 panels. Figures 5.5.2.8 and 5.5.2.9 show the m assive delamination of this particular pretreatment.

For the chrom ate-free paint system s the most consistent perform ers were Alodine 1200S, Alodine 5200, and NAVAIR TCP. Figures 5.5.2.10 and 5.5.2.11 show that unlike the chrom ate containing coating system s, NAVAIR TCP pret reatment showed none of the m inor coating delamination issue. Two notable but inconsistent performers were Oxsilan Al-0500 and Boegel, which performed extremely well on 85582 N/85285 yet performed poorly on the CARC systems.

48NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) X-It PreKote

Figure 5.5.2.6: Aluminum 5083 Coated With 53030/53039 Coating System at 3000 Hours
Duration

49NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.5.2.7: Aluminum 5083 Coated With 53022/53039 Coating System at 3000 Hours
Duration

50NCAP Phase I Report August 2003

Figure 5.5.2.8: Severe Delamination of Oxsi lan AL 0-500 Pretreated on Al 7075 Coated With 85582C2/25285 Coating System at 1 Week Exposure

Figure 5.5.2.9: Severe Delamination of Oxsilan AL 0-500 Pretreated on Al 7075 Panels with 85582C2/25285 Coating System at 2 Weeks Exposure

51NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Oxsilan AL-0500

Figure 5.5.2.10: Aluminum 7075 Coated With 85582 N/85285 Coating System at 3000 Hours Exposure

52NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.5.2.11: Aluminum 7075 Coated With 53022/53039 Coating System at 3000 Hours Exposure

53NCAP Phase I Report August 2003

Summary of Alternative Performance Table 5.5.2.6 details th e summary performance of each alternative pretreatm ent by primer system. It also shows an average rating for each primer across all pretreatm ents. Alodine 5200 slightly edges out TCP as the best overall performer and is sligh tly better than the Alodine 1200S control. TCP perform s about the sam e as the control, Boegel ranks third and the other 5
alternatives rank a distant fourth. This data highlights the strong infl uence pretreatments can have on the full coating system , with much mo re variation in perform ance noted for the nonchromate primer systems.

Table 5.5.2.6: Summary Ratings for Pretreatm ents and Primer Systems exposed to 3000 hours of ASTM B117 Salt Fog (Ratings per ASTM D 1654A)

Primer

Pretreatment 23377 85582 C2 85582 N 53022 53030 All Coatings

Alodine 1200S (control) 8.9 9.0 7.7 3.8 6.8 7.2

Alodine 5200 9.0 9.0 7.5 5.4 6.6 7.5

Bi-K Aklimate 8.6 7.4 0.0 0.0 0.5 3.3
Boegel 7.8 8.3 6.6 3.8 3.8 6.0

Chemidize 727ND 7.6 5.6 1.1 0.6 0.0 3.0

Oxsilan Al-0500 9.0 6.7 7.3 0.8 0.2 4.8

Sanchem 7000 5.4 5.8 1.0 1.1 0.6 2.7

TCP 8.2 8.8 6.4 6.1 5.9 7.1

X-It PreKote 8.4 8.9 0.5 0.0 1.4 3.8
Overall Alternative Average 8.0 7.8 3.8 2.1 2.6 4.8

In an effort to d isplay the extremes in al loy corrosion susceptibilit y, Figures 5.5.2.12 and 5.5.2.13 show the perform ance of various coating systems on Al 2219 and Al 5083 alloys over
the duration of the netural sa lt fog test. P retreatments in clude Alodine 1200S and 5700 and NAVAIR TCP, which, on average, were the best performers in this test. Prim ers are 53022 and 85582 Class N. Whereas all system s perform e qually well on 5083, dram atic differences are apprarent on 2219, the most corrosi on prone alloy in this test. As indicated, the alloys used and performance requirements for the co ating systems are critical for the selection of an acceptable chromate-free coating system.

54NCAP Phase I Report August 2003

0 1 2 3 4 5 6 7 8 9 10Corrosion Ratings

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Alodine 1200S/85582NC Alodine 1200S/53022 TCP/85582NC TCP/53022 Alodine 5200/85582NC Alodine 5200/53022

Weeks in Neutral Salt Fog

Figure 5.5.2.12: Coating System Performance of Aluminum 2219

55NCAP Phase I Report August 2003

0 1 2 3 4 5 6 7 8 9 10Corrosion Ratings

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Alodine 1200S/85582NC Alodine 1200S/53022 TCP/85582NC TCP/53022 Alodine 5200/85582NC Alodine 5200/53022

Weeks in Neutral Salt Fog

Figure 5.5.2.13: Coating System Performance of Aluminum 5083

56NCAP Phase I Report August 2003

5.6 SO 2 Salt Fog on Scribed, Painted Substrates

5.6.1 Test Description
This test method evaluates a coating system’s ability to prevent substrate corrosion and the effect
that corrosion has on adhesion of the coating s ystem while subjec ted to an a cidified, corrosive environment. Operation of the fog chamber fo r this test is in acco rdance with ASTM G 85 Annex 4 [ Standard Practice for Modified Salt Spray (Fog) Testing ]. Testing was completed by NAVAIR personnel at the Patuxent River, MD test facility.

The SO 2 salt fog test is typically required by NAVAI R for the laboratory evaluation of any new coating system. This test is used to simulate the stack gases from airc raft carriers and supporting surface ships as well exhaust gases from aircraft to which the aircraft on the deck of carriers are constantly exposed. These gases are usually pr esent in combination with chloride containing seawater and mists that constantly contact aircraft coating systems.

Prior to exposure, an “X” incision w as manually scribed through the test coupon coating using a carbide tip scribe as per ASTM D 1654, m aking sure that the coating was scribed all the way through and into the substrate. The smaller angl e of the “X” was 30 to 4 5 degrees and each line of the “X” was approxim ately 4 inches long. The back and e dges of the test coupons were primed to prevent corrosion pr oducts from contam inating the cham ber. The scribed coupons were placed into the fog cha mber at a 15-deg ree incline. The coupons were not allowed to
contact other surfaces in the cham ber and cond ensate from a coupon also did no t contact any other coupons. The salt solution and the fog cham ber were prepared as specified in the T est Methodology of the JTP. The noz zles were adju sted in the fog chamber so that sprayed salt solution did not directly im pinge on the co upon surfaces. The fog cham ber was operated continuously for 500 h ours. Coupons were eval uated for surface co rros ion and creepage from the scribe weekly. The coupons were carefully rem oved at the end of the test duration and cleaned with running water [water temperature less than 38 °C (100°F)]. The coupons were airdried at ambient conditions a nd then visually examined.

Per the JTP, a to tal of 1000 test coupons were exposed to the SO 2 salt fog environment. Due to size limitations of the t est chamber, eight racks of 20 coupons were tested in batches. This resulted in approximately 6 months of serialized testing in the same SO 2 cabinet to complete the full coupon set. Racks were rem oved at 1, 2 a nd 3-weeks (completion) and one representative coupon of each set of five duplicates scanned. Af ter testing all coupons were rated per ASTM D
1654 method A.

5.6.2 Test Results
The performance of the eight ca ndidate non-chromate aluminum pr etreatments with five organic military coating systems was evaluated on four alum inum alloys: 2024, 7075, 5083, and 2219. Significant differences in coating system performa nce were noted amongst the various alloys and coating systems. Typical high-performance chro mated coating systems showed no or very little signs of corrosion after the test when evaluated on Al 2024 and 7075 substrates.

Tables 5.6.3.1 through 5.6.3.5 present corrosion rating results for candi date coating system s. Ratings are the average of 5 test panels.

57NCAP Phase I Report August 2003

Aluminum 2024 TCP, Alodine 5200 and Boegel perform ed consiste ntly well across all prim ers. In m ost cases they performed as well as or slightly better th an the Alodine 1200S control. Perform ance of the other alternatives was highly variab le from primer to primer, in general being better with the two chromate primers than the non-chromates. X-It PreKote, for example, performed relatively well with the 23377, 85582 and 53030 system s but not w ith the 53022 system . In another exam ple,
the Chemidize 727ND rated 5 to 7 on the 23377, 85582 C2, 53030 and 53022 system s and then very poorly on the 85582 N system.

Aluminum 2219 The 2219 was the m ost difficult alloy of the group to protect and had the lowest overall ratings. For the 23377 and 85582 C2 pri mers, most coating ratings were grouped in the 4 to 6 range. Strong differences in perform ance were evid ent with the non-chrom ate primers. TCP and Alodine 5200 perform ed the sam e as the Alod ine 1200S control for all three non-chrom ates. Boegel performed next best, followed by the re maining alternatives. Interestingly, the 85582 N primer performed on a verage much better than the 53030 and 53022 prim ers for the lesser performing pretreatments.

Aluminum 5083
The SO 2 corrosion test showed unusual results f or 5083. Whereas this alloy is usually the m ost corrosion resistant, in this test the overall performance was about the same as for 2024. TCP did especially well with the chrom ate primers, equaling the perform an ce of the Alodine 1200S control. Most other coatings rated in the 6 to 7 range. For 85582 N, no coating was as good as the control, but Boegel, Oxsilan and Alodine 5200 cam e in a close second. TCP and X-It PreKote followed, with the rest of the coatings a distant fourth. For 53022, the Boegel rated far above any other coating, with TCP a nd Alodine 5200 rating the same as the control. For 53030, TCP, Alodine 5200 and Boegel rated one unit better th an the control, with all others worse than the control. Overall, Boegel pe rformed the best on this alloy, with Alodine 1200S and TCP close behind. Alodine 5200 rated fourth, the other alte rnatives were 1 to 2 rating units behind.

Aluminum 7075
Corrosion on 7075 was worse on av erage than for 2024 in the SO 2 salt fog test. On average, the Alodine 1200S control perform ed the best. TCP was second and perform ed consistently across all primers. Alodine 5200 and Boegel rated th ird, about 1 unit behi nd TCP, and perform ed consistently across all primers. The remaining co atings performed very inconsistently across the primers and all rated on average 2 to 3 units below the Alodine 5200 and Boegel.

The 23377 primer performed the best across all pretreatments. TCP performed notably well here and X-It PreKote poorly. The 85582 C2 pri mer was next best with Alodine 5200, TCP, Oxsila n and Boegel a distant second to the control. All three non-chrom a te primers performed about the same on average, with TCP, Alodine 5200 and Boeg el performing consistently about the same as
the control.

58NCAP Phase I Report August 2003

Table 5.6.3.1: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated With
Mil-PRF-23377 Primer and Mil-C-85285 To pcoat and Exposed to 500 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 8.0 7.0 8.0 6.0

Alodine 5200 8.0 5.0 6.0 5.0

Bi-K Aklimate 4.0 6.0 6.0 4.0 Boegel 7.0 6.0 8.0 5.0

Chemidize 727ND 5.0 6.0 7.0 5.0

Oxsilan Al-0500 6.0 6.0 8.0 5.0

Sanchem 7000 3.0 5.0 6.0 4.0

TCP 8.0 8.0 8.0 5.0

X-It PreKote 8.0 1.0 6.0 6.0

Table 5.6.3.2: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated With Mil-PRF-85582 C2 Primer and Mil-C-85285 Topcoat and Exposed to 500 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 7.0 9.0 9.0 6.0

Alodine 5200 6.0 6.0 8.0 6.0

Bi-K Aklimate 9.0 4.0 8.0 4.0 Boegel 9.0 6.0 7.0 6.0

Chemidize 727ND 7.0 0 7.0 5.0

Oxsilan Al-0500 7.0 6.0 6.0 4.0

Sanchem 7000 6.0 4.0 7.0 0

TCP 8.0 6.0 9.0 6.0

X-It PreKote 7.0 3.0 6.0 4.0

Table 5.6.3.3: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated With Mil-PRF-85582 NC Primer and Mil-C-85285 Topcoat and Exposed to 500 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 8.0 8.0 8.0 5.0

Alodine 5200 8.0 6.0 7.0 5.0

Bi-K Aklimate 1.0 1.0 4.0 3.0 Boegel 9.0 5.0 7.0 3.0

Chemidize 727ND 1.0 1.0 4.0 3.0

Oxsilan Al-0500 7.0 0 7.0 5.0

Sanchem 7000 0 1.0 4.0 1.0

TCP 9.0 6.0 6.0 5.0

X-It PreKote 6.0 0 5.0 3.0

59NCAP Phase I Report August 2003

Table 5.6.3.4: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated With Mil-P-53030 Primer and Mil-C-53039 Topcoat 500 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 8.0 6.0 5.0 5.0

Alodine 5200 8.0 5.0 6.0 5.0

Bi-K Aklimate 0 0 1.0 3.0 Boegel 8.0 5.0 6.0 3.0

Chemidize 727ND 7.0 0 1.0 0

Oxsilan Al-0500 0 4.0 4.0 1.0

Sanchem 7000 0 3.0 4.0 1.0

TCP 9.0 6.0 6.0 5.0

X-It PreKote 5.0 2.0 4.0 2.0

Table 5.6.3.5: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-P-53022 primer and Mil-C-53039 topcoat and Exposed to 500 Hours

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 7.0 6.0 5.0 5.0

Alodine 5200 8.0 6.0 5.0 5.0

Bi-K Aklimate 0 6.0 1.0 1.0 Boegel 8.0 5.0 9.0 5.0

Chemidize 727ND 6.0 0 1.0 0

Oxsilan Al-0500 0 0 0 1.0

Sanchem 7000 0 0 1.0 0

TCP 9.0 6.0 5.0 5.0

X-It PreKote 0 2.0 4.0 0

Summary of Alternative Performance Table 5.6.3.6 details th e summary performance of each alternative pretreatm ent by primer system. It also shows an average rating for each primer across all pretreatments. TCP performs the best, on average, and is com parable to th e Alodine 1200S control. Alodine 5200 and Boegel
rank a close second. The other 5 alte rnatives rank a distant third.

Not surprisingly, the chromate-based primers perf orm equally well and are the basis of the best coating systems. The non-chromate systems, on av erage, rank 2 units lower than the chrom ate systems. This is due to the relative poor perform a nce of most of the alte rnatives that lower the average of the better-perform i ng alternatives, which rate co mparably to the Alodine 1200S
control for all three non -chromate primers.

60NCAP Phase I Report August 2003

Table 5.6.3.6: Summary Ratings for Pretreatm ents and Primer Systems exposed to 500 Hours (Ratings per ASTM D 1654A)

Primer

Pretreatment 23377 85582 C2 85582 N 53022 53030 All Coatings

Alodine 1200S (control) 7.3 7.8 5.8 6.0 6.8

Alodine 5200 6.0 6.5 6.5 6.0 6.0 6.2

Bi-K Aklimate 5.0 6.3 2.3 2.0 1.0 3.3
Boegel 6.5 7.0 6.0 6.8 5.5 6.4

Chemidize 727ND 5.8 4.8 2.3 1.8 2.0 3.3

Oxsilan Al-0500 6.3 5.8 4.8 0.3 2.3 3.9

Sanchem 7000 4.5 4.3 1.5 0.3 2.0 2.5

TCP 7.3 7.3 6.5 6.3 6.5 6.8

X-It PreKote 5.3 5.0 3.5 1.5 3.3 3.7
Overall Alternative Average 6.0 6.1 4.5 3.4 3.8 4.8 7.3

61NCAP Phase I Report August 2003

Figures 5.6.3.1 through 5.6.3.6 show examples of performance of various pretreatments with different primers and alloys.

Alodine 1200S TCP Alodine 5200

Figure 5.6.3.1: Pretreatments With 23377/85285 C oating System on Al 2024 after 500 Hour Exposure

Alodine 1200S TCP Alodine 5200

Figure 5.6.3.2: Pretreatments With 23377/85285 Coating System on Al 2219 After 500 Hour Exposure

62NCAP Phase I Report August 2003

Alodine 1200S TCP Alodine 5200

Figure 5.6.3.3: Pretreatments With 53030/53039 C oating System on Al 2024 after 500 Hour Exposure to SO 2 Salt Fog

Alodine 1200S TCP Boegel

Figure 5.6.3.4: Pretreatments With 53022/53039 C oating System on Al 2024 after 500 Hour Exposure

63NCAP Phase I Report August 2003

Alodine 1200S TCP Alodine 5200

Figure 5.6.3.5: Pretreatments With 85582 NC/ 85285 Coating System on Al 2219 after 500 Hour Exposure

Alodine 1200S TCP Alodine 5200

Figure 5.6.3.6: Pretreatments With 53022/53039 C oating System on Al 5083 after 500 Hour Exposure

64NCAP Phase I Report August 2003

5.7 Cyclic Corrosion on Scribed, Painted Substrates

5.7.1 Test Description
This test method evaluates a coating system’s ability to prevent substrate corrosion and the effect
that corrosion has on the adhesion of coating system. Operation of the fo g chamber for this test is in accordance with GM 9540P ( Accelerated Corrosion Test ). Testing was completed by Army Research Laboratory personnel at the Aberdeen, MD test facility.

Prior to exposure, an “X” incision w as manually scribed through the test coupon coating using a carbide tip scribe as per ASTM D 1654, m aking sure that the coating was scribed all the way through and into the substrate. The smaller angl e of the “X” was 30 to 4 5 degrees and each line of the “X” was approxim ately 4 inches long. The back and e dges of the test coupons were painted to prevent corrosion products from cont aminating the cham ber. The scribed coupons were placed into a fog chamber at a 15-degree in cline. The coupons were not allowed to contact
other surfaces in the ch amber and condensate from a coupon also did not contact any other coupons. The salt solution and the fog chamber were prepared as specified in the Tes t Methodology of the JTP. The nozzles were then ad justed in the fog chambe r so that sprayed salt solution did not directly im pinge on the cou pon surfaces. The fog cham ber was operated continuously for 120 cycles. Coupons were eval uated for surface corro sion and creepage fr om the scribe at 20-cycle interval s. The coupons were carefully rem oved at the end of the test duration and cleaned with running wa ter [water temperature less than 38 ° C (100°F)]. The coupons were then air-dried at ambient c onditions, and then visually examined.

5.7.2 Test Results
Three cyclic corrosion test chambers (CCTC) were used to evaluate the coated alum inum test panels. In order to maximize uniformity of test conditions, each alloy wa s given its own specific chamber. Figure 5.7.2.1 depicts the configuration of the test chamber used for GM Standard Test 9540P, which provides more dynamic accelerat ed conditions versus conventional ASTM B 117 Salt Fog. The GM 9540P test consists of 18 se parate stages that include the following: saltwater spray, humidity, drying, ambient, and heated drying.

Figure 5.7.2.1: Test Chamber Configuration Used for GM 9540P

65NCAP Phase I Report August 2003

The environmental conditions and d uration of each stag e for one complete 9540P cycle are provided in Table 5.7.2.1. The standard 0.9% NaCl, 0.1% CaCl 2 , 0.25% NaHCO 3 test solution was used. In addition, each chamber was calibra ted with standard steel m ass loss calib ration coupons described in GM Standa rd Test 9540P and supplied by GM. In order to visibly chronicle the corrosion, one represen tative panel of each of the five test panels was chosen at 20 cycles of exposure and digitally scanned at 600 dpi resolution. Subsequent scans of the sa me representative panel were m ade at every 20 cy cles until the conclusion of 120 cycles or until specimen group failure. Specimens were numerically rated for damage at each 20 cycle interval using method ASTM D 1654. Specim en group fa ilures were defined by a rating of 0 under ASTM D 1654 for 3 or m ore of the panels in a pa rticular alloy/pretreatment/coating set. W ith the exception of premature failur es under ASTM D 1654, the coated panels were all subjected to 120 cycles of GM 9540P.

Table 5.7.2.1: GM 9540P Cyclic Corrosion Test Details

Interval Description Time (min) Temperature ( + 3 ° C)

1 Ramp to Salt Mist 15 25

2 Salt Mist Cycle 1 25

3 Dry Cycle 15 30

4 Ramp to Salt Mist 70 25

5 Salt Mist Cycle 1 25

6 Dry Cycle 15 30

7 Ramp to Salt Mist 70 25

8 Salt Mist Cycle 1 25

9 Dry Cycle 15 30

10 Ramp to Salt Mist 70 25

11 Salt Mist Cycle 1 25

12 Dry Cycle 15 30

13 Ramp to Humidity 15 49

14 Humidity Cycle 480 49

15 Ramp to Dry 15 60

16 Dry Cycle 480 60

17 Ramp to Ambient 15 25

18 Ambient Cycle 480 25

The tables below detail corrosion perform ance for pretreatments on each alloy.

Table 5.7.2.2: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-23377 Primer and Mil-C-85285 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 8.8 9.0 9.0 9.0

Alodine 5200 8.2 6.0 9.0 9.4

Bi-K Aklimate 7.8 9.0 9.0 7.0 Boegel 8.4 8.6 9.0 6.2

Chemidize 727ND 7.4 9.0 9.2 4.6

Oxsilan Al-0500 8.2 9.0 9.6 9.4

66NCAP Phase I Report August 2003

Table 5.7.2.2: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-23377 Primer and Mil-C-85285 Topcoat (Continued)

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Sanchem 7000 7.6 8.6 6.0 6.8

TCP 8.4 9.0 9.0 8.0

X-It PreKote 7.0 9.0 9.0 5.4

Table 5.7.2.3: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-85582 C2 Primer and Mil-C-85285 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 8.2 9.0 9.0 9.6

Alodine 5200 7.8 6.0 9.0 9.0

Bi-K Aklimate 7.8 9.0 9.0 5.2 Boegel 8.4 9.0 9.0 7.6

Chemidize 727ND 6.0 5.8 9.4 7.4

Oxsilan Al-0500 4.0 6.2 9.2 9.2

Sanchem 7000

- - 7.6 6.4

TCP 8.2 9.0 9.0 8.6

X-It PreKote 6.2 9.0 9.0 6.6

Table 5.7.2.4: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-85582 NC Primer and Mil-C-85285 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 6.4 8.0 9.0 6.0

Alodine 5200 6.0 5.6 9.0 6.0

Bi-K Aklimate 0.6
- 8.4
- Boegel 2.8 4.8 9.0
- Chemidize 727ND 1.8 0.6 7.0
- Oxsilan Al-0500 5.6 7.0 9.0 3.4

Sanchem 7000

- - 3.0
- TCP 5.4 6.8 9.0 5.0

X-It PreKote 4.6 2.2 8.2
-

Table 5.7.2.5: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-53030 Primer and Mil-C-53039 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 6.4 7.0 9.0 3.8

Alodine 5200 6.6 4.0 9.0 2.6

67NCAP Phase I Report August 2003

Table 5.7.2.5: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-53030 Primer and Mil-C-53039 Topcoat (Continued)

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Bi-K Aklimate 1.2
- 9.0
- Boegel 2.2 3.0 9.0
- Chemidize 727ND 1.2
- 7.8
- Oxsilan Al-0500 3.4 1.2 9.0
- Sanchem 7000 4.0
- 6.4
- TCP 7.8 6.6 9.0 2.0

X-It PreKote 4.6 1.4 9.0
-

Table 5.7.2.6: Average Scribe Failure Rating (5 panels) for Aluminum Alloys Coated with Mil-PRF-53022 Primer and Mil-C-53039 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219

Alodine 1200S 5.8 5.0 9.0 0.0

Alodine 5200 6.4 4.2 9.0 3.2

Bi-K Aklimate 2.8 0.6 7.8
- Boegel 3.0 2.4 9.0
- Chemidize 727ND 2.4
- 7.2
- Oxsilan Al-0500 4.4 3.2 9.0
- Sanchem 7000 1.8 1.2 8.4
- TCP 7.8 6.8 9.0 1.6

X-It PreKote 2.2 1.4 9.0
-

Aluminum 2024 For the hexavalent chrom ium bearing 23377/85285 coating system, all of the pretreatm ents performed fairly well and com pleted 120 cycles with the highest ratings am ong the coating systems. Although the 85582C2/85285 coating system also contains hexavalent chrom ium, overall it performed much worse when com par ed versus the 23377/85285 system for the sam e
pretreatments.

For the remaining three coating syst ems, 85582 N/85285, 53030/53039, and 53022/53039, the best performance was provided by the NAVAIR TCP and Alodine 1200S pretreatm ents (See Figures 5.7.2.2 and 5.7.2.3). In the specific cases of the 53030/53039 and 53022/53039 CARC system, the TCP pretreatment even exceeded the performance for Al odine 1200S. Alodine 5200 pretreatment rendered respectab le performance at or near th e leaders for these ch romium-free coating systems.

Aluminum 2219 Of the aluminum alloys in this test, Al 2219 with its high Cu content is by far the most corrosion prone and provides a difficult ta sk for even hexavalent-chromiu m-based Alodine 1200S. For the chromate-based 23377/85285 coating system, although all pretreatments last ed the full 120-cycle duration, significant corrosion dam age occurred on many of them. The best performers for this coating system were Alodine 1200, Alodine 5200 and Oxsilan. TCP showed mixed performance among its five respective replicates, but overall s till performed much better than the rem aining

68NCAP Phase I Report August 2003

pretreatments. For the chrom ate-containing 85582C2/85285 system, the best perform ers were Alodine 1200 and Alodine5200, NAVAIR TCP, Oxsila n and Boegel. Figures 5.7.2.4 and 5.7.2.5 show that the remaining pretreatments performed in the intermediate range with ratings ranging
from 5 to 7.

For the three chrom ate free coating sy stems, 85582 N/85285, 53030/53039, and 53022/53039, there was significant corrosion damage and m ost of the coating systems were unable to endure 120 cycles without early specimen group failure. Although the corrosion damage was severe, the most consistent performers for these systems were NAVAIR TCP, Alodine 1200 and Alodine 5200. Oxsilan rated only m arginally better than the rem aining pretreatments for the chromate free coatings but only by virtue of not completely failing as soon.

Aluminum 5083 Al 5083, an alloy known for its stable protectiv e oxide layer, does not usually significantly corrode, even under accelerated conditions. Due to its widespread use in tactical ground systems,
accelerated corrosion methods such as GM 9540P are still necessary for this alloy for quality
assurance and also for de tecting potential coating adhesion i ssues. As expected, most coatin g systems completed the full 120 cycle duration wit hout any noticeable damage. As in Al 2024 the 23377/85285 coating system proved superior and th ere was no significant creepback resu lting from corrosion or coating system delamination. For 85582 C2/85285, there were adhesion issues with the Sanchem 7000 pretreatment, which rated a 7 by 60 cycles and then stabilized for the balance of the 120 cycles. For the non-ch romium based for mulation 85582 N/85285, the problems with the Sanchem process were more pronounced with more severe creepback resulting from actual corrosion. Any dam age for Al 5083 is significant si nce even in a bare
uncoated and untreated condition this alloy will not significantly corrode. For this sam e coating system, the Chemidize 727ND pretreatment also showed blistering though to a somewhat less severe degree along the scribe. For the wate rborne 53030 primer based CARC system, Sanchem exhibited damage due to adhesion failure similarl y as noted above. For the solvent prim er based 53022/53039 CARC s ystem, the only noticeable da mage occurred on the Bi-K Aklim ate pretreated system.

Aluminum 7075 For the coating system 23377/85285 as in the othe r alloys, m ost all of the pretreatm ents performed well with little or no dam age to the scribed region. The exception for this case was Alodine 5200 with damage characterized by coat ing delamination from the scribed regions.

For the 855 82 C2/85285 system , the top perform ers with little or no damage were Alodine 1200S, TCP, X-It PreK ote, and Boegel. Other pret reatments for this system were disqualified either by lower ratings due to corrosion, dela mination, or both. Sanchem 7000 pretreatm ent failed across the majority of its 5 panels by 100 cycles.

The only top perform ers were Alodine 1200S and TCP for the chromate free 85582 N/85285 system. The next best perform ing alternatives Alodine 5200 and Boegel, which both rated a “5” through 120 cycles. Panels failing the exposure f o r this coating system were Sanchem and Bi-K Aklimate. In particula r, the f ailure for Sanchem was severe with par tial series failures at 20 cycles and specimen group failure by 40 cycles exposure.

69NCAP Phase I Report August 2003

As in previous alloys, the CARC system s were mo re susceptible to corrosion attack than their aircraft coating counterparts. For the wate rborne primer system 53030/53039, Alodine 1200S and TCP pretreatments performed best. The m o de of creepback progression on the TCP treated panel was due to delam ination of the coating. Th e next best performers for this coating system were Alodine 5200 and Boegel, however their performance at best was fair with both pretreatments only rating a “4” at the conclusion of 120 cycles. Series that failed prior to completion of 120 cycles in or der of decreasing se verity included: Chem idize 727ND, Bi-K Aklimate, and Sanchem 7000.

The 53022/53039 system perfor mance for all pretr eatments overall was better than for the waterborne primer CARC series for Al 7075. The NAVAIR TCP pret reatment was clearly superior for this group as shown in Figure 5.7.2.6. Next best finishers were Alodine 5200 and Alodine 1200S with ratings at 120 cycles of “6” and “5” respectivel y. Boegel rated a “3” with the others all rating a “2” or lower at 120 cycles . The only failure prior to 120 cycles was the Chemidize 727ND pretreatment, wh ich failed as a set by 60 cycles.

Summary of Alternative Performance Table 5.7.2.7 details th e summary performance of each alternative pretreatm ent by primer system. It also shows an average rating for each primer across all pretreatments. TCP performs the best overall, generally as good as the contro l. Alodine 5200 is a solid second. Oxsilan Al0500 and Boegel rank third and othe r 4 alternatives rank fourth.

Interestingly, TCP perform s notably better th an Alodine 1200S with 53022 prim er but not as good with the 85582 N primer. This is similar to th e trend in the painted neutral salt fog and SO 2 salt fog tests. Also of note is the consistent performance of TCP for all three no n-chromate primers. Alodine 5200 did clear ly better with the 85582 N prim er compared to the 53022 and 53030 coatings. This trend is eviden t for the neutral salt fog and SO 2 salt fog tests as well.

Table 5.7.2.7: Summary Ratings for Pretreatm ents and Primer Systems exposed to 120 Cycles of GM9540P Corrosion Test (Ratings per ASTM D1654A)

Primer

Pretreatment 23377 85582 C2 85582 N 53022 53030 All Coatings

Alodine 1200S (control) 9.0 9.0 7.4 5.0 6.6 7.4

Alodine 5200 8.2 8.0 6.7 5.7 5.6 6.8

Bi-K Aklimate 8.2 7.8 2.3 2.8 2.6 4.7
Boegel 8.1 8.5 4.2 3.6 3.6 5.6

7.6 7.2 2.4 2.4 2.3

Oxsilan Al-0500 9.1 7.2 6.3 4.2 3.4 6.0

Sanchem 7000 7.3 3.5 0.8 2.9 2.6 3.4

TCP 8.6 8.7 6.6 6.3 6.4 7.3

X-It PreKote 7.6 7.7 3.8 3.2 3.8 5.2
Overall Alternative Average 8.0 7.4 4.3 3.8 3.9 5.5 Chemidize 727ND 4.3

70NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figures 5.7.2.2: Aluminum 2024 Coated With 85582 N/85285 Coating System

71NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.7.2.3: Aluminum 2024 Coated With 53030/53039 Coating System

72NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Oxsilan AL-0500

Figure 5.7.2.4: Aluminum 2219 Coated With 85582 C2/85285 Coating System

73NCAP Phase I Report August 2003

(a) X-It PreKote (b) Chemidize

(c) Bi-K Aklimate (d) Boegel

Figure 5.7.2.5: Aluminum 2219 Coated With 85582 C2/85285 Coating System

74NCAP Phase I Report August 2003

(a) Alodine 1200S (b) TCP

(c) Alodine 5200 (d) Boegel

Figure 5.7.2.6: Aluminum 7075 Coated With 53022/53039 Coating System

75NCAP Phase I Report August 2003

5.8 Filiform Corrosion Resistance

5.8.1 Test Description
This test measures the ability of a coating system to protect the substrate against the formation of filiform corrosion. Te sting was completed by the Univ ersity of Dayton Resea rch Institute (URDI) under contract to the Air Force Re search Laboratory in Dayton, Ohio.

An “X” incision was scribed throug h the coating so that the smaller angle of the “X” was 30 to 45 degrees, making sure that the coating was scribed all the way through and into the substrate.

The scribe had a 45 ° bevel, and each line of the “X” wa s approximately 4 inches long. The scribed coupons were placed in a d esiccator containing 12 N hydrochlor ic acid (HCl) for one

hour at 24 ± 3 ° C (75 ± 5 ° F). Within five minutes of remo val from the desiccator, the coupons were placed in a hum idity cabinet maintained at 40 ± 1.7 ° C (104 ± 3 ° F) and 80 ± 5 percent relative humidity (RH) for 1, 000 hours. The length of any th read-like filaments was then
measured at the end of the test duration. The filiform corrosion test uses clad 2024-T3.

Two methods were used to rate co ating resistance to filiform corrosion. Table 5.8.1.1 details a standard method based on m easuring the length s of any filam ents a nd noting their relative density along the scribes. This method yields a two-digit rating w ith score of 0-0 being the best with no corrosion noted and 5-5 being the worst.

Table 5.8.1.1: Filiform Corrosion Standard Rating Method

Sites (% of scribe affected) Length (of filament)

0 – none 0 – none

1 - <10% 1 - <1/16”

2 – 10-50% 2 – 1/16 – 1/8”

3 – 50-75% 3 – 1/8 – 1⁄4”

4 - >75% 4 - >1/4”

5 – 100% 5 - >1/4”, solid mass For example, a specimen with no corrosion would be rated as 0-0, or total degradation as 5- 5. If sites is 0, length must also be 0. If there are spots at the scribe where it appears corrosion is initiating, but has not yet developed a filiform pattern, rate sites with a length of 0 (i.e., 1-0)

An alternative “tem plate” rating method was also used. After rating per the standard m ethod, coatings are stripped from about 50% of th e coupon exposing the filiform corrosion on the m etal surface. The rating template, detailed in Figure 5.8. 1.1, is then centered over one scribe leg with the short en d aligned with the in tersection of th e two scribe lines. The num ber of squares in which filaments do not appear are counted. The pr ocess is repeated for the other leg of the X scribe. Readings for both measurements were adde d and reported as a total. The maximum rating for no filiform corrosion is 120. Figure 5.8.1.2 shows an example coupon prepared for tem plate rating.

Note: The filiform corrosion rating template consists of a matrix of 60 1/8” squares, arrayed in a 15 x 4 square matrix.

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Figure 5.8.1.1: Filiform Corrosion Rating Template Layout

Figure 5.8.1.2: Example Coupon Prepared for Template Rating Method for Filiform
Corrosion

5.8.2 Test Results
Filiform corrosion resistance data is presented in Tables 5.8.2.1 and 5.8.2.2. The results from the standard technique do not allow for discrim inati on of pretreatment performance for any prim er except for the excellent performance of Alodi ne 1200S and TCP with the 85582 C2 primer. The template technique does provi de relative perform ance data that discriminates among the candidate pretreatments for each prim er. Based on this data, TCP is the clearly superior performer on average. For the 85582 N and 53022 system it surpasses th e performance of any other coating including the Al odine 1200S control. W ith the 53030 primer it performs poorly, like most of the other coatings. The excellent performance of TCP with the 85582 N prim er was recently reconfirmed by an in-hous e NAVAIR filiform corrosion test.

77NCAP Phase I Report August 2003

Notably, the Alodine 5200 and Boegel coatings , which perform ed fairly well with the nonchromate primers in the accelerated corrosion test s do poorly compared to TCP, especially with the two water-borne non-chrom ates. This appears to be an area where the inheren t corrosion resistance that TCP possesses helps boost perfor mance relative to the other alternatives.

Not surprisingly, the chrom ate primers performe d the best regardless of the pretreatment. One unexplained result is the relativ e poor performance of the 23377 primer with Alodine 1200S where strong perform ance was expected. No other evidence of unan ticipated or unusual performance with the 23377 primer wa s noted in all the JTP testing.

Table 5.8.2.1 Filiform Corrosion Ra tings per Standard Technique

Primer

Pretreatment 23377/85285 85582 C2/85285 85582 N/85285 53030/53039 53022/53039

4-5 1-1 3-3 4-4 4-5

Alodine 1200S 4-5 1-1 3-4 4-4 4-4

4-5 1-1 2-2 4-4 4-4

3-3 3-3 5-5 4-5 4-5

Alodine 5200 3-4 2-2 3-3 4-5 4-4

4-4 2-2 4-3 4-5 4-5

3-4 2-4 3-4 3-4 4-5

Bi-K Aklimate 4-5 2-2 2-3 3-3 4-5

4-5 3-4 3-3 3-4 4-5

3-4 2-3 4-4 4-5 5-5 Boegel 4-5 2-4 3-4 3-4 3-4

5-5 2-3 3-4 4-5 3-4

4-5 3-4 3-4 3-4 4-4

Chemidize 727D 4-5 4-4 3-3 3-4 4-5

4-5 2-2 2-3 3-4 4-5

3-4 3-2 4-5 3-4 4-5

Oxsilan AL-0500 3-5 3-4 3-4 4-4 4-5

3-5 2-4 3-4 4-4 4-5

2-3 4-3 4-5 4-5 4-5

Sanchem 7000 4-5 4-5 3-4 4-5 4-4

4-5 4-4 3-4 4-5 4-4

2-2 1-1 3-4 4-5 4-4

TCP 3-3 1-1 3-3 4-4 3-4

2-3 1-1 3-3 4-4 3-4

2-3 3-4 4-5 4-5 4-5

X-It PreKote 4-5 4-4 3-4 4-5 4-4

4-5 4-4 3-3 4-5 4-4

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Table 5.8.2.2: Filiform Corrosion Ratings per Template Technique

Primer

Pretreatment 23377/85285 85582 C2/85285 85582 N/85285 53030/53039 53022/53039 Average

16.0 84.0 58 .0 12.0 13.0

Alodine 1200S 26.0 77.0 53.0 16.0 22.0 39.2

25.0 100.0 53.0 10.0 23.0

89.0 73.0 22.0 1.0 6.0

Alodine 5200 55.0 63.0 4.0 2.0 3.0 31.5

73.0 72.0 3.0 2.0 4.0

66.0 58.0 7.0 9.0 3.0

Bi-K Aklimate 56.0 62.0 13.0 25.0 4.0 29.2

50.0 41.0 7.0 27.0 10.0

40.0 19.0 14 .0 12.0 44.0 Boegel 16.0 10.0 4.0 11.0 25.0 18.5

28.0 22.0 8.0 12.0 13.0

63.0 68.0 17.0 0.0 0.0

Chemidize 727D 58.0 73.0 5.0 0.0 3.0 26.3

46.0 60.0 0.0 0.0 2.0

63.0 65.0 8.0 17.0 7.0

Oxsilan AL-0500 42.0 58.0 0.0 10.0 17.0 29.3

50.0 72.0 0.0 17.0 13.0

75.0 76.0 11.0 0.0 2.0

Sanchem 7000 72.0 74.0 2.0 0.0 9.0 31.8

71.0 76.0 6.0 0.0 3.0

82.0 99.0 94.0 2.0 89.0

TCP 74.0 82.0 99.0 4.0 92.0 71.9

69.0 90.0 97.0 4.0 102.0

50.0 32.0 48.0 0.0 5.0

74.0 39.0 13.0 0.0 1.0

32.0 49.0 9.0 2.0 1.0

54.1 67.4 24.3 7.2 19.1 X-It PreKote 23.7

Average

Figures 5.8.2.1 through 5.8.2.5 show a selecti on of coatings and the relative differences in filiform corrosion resistance. Ratings noted in the title are based on the template technique.

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Figure 5.8.2.1: Alodine 1200S wi th 23377 Primer, Rating: 16

Figure 5.8.2.2: TCP with 23377 Primer, Rating: 82

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Figure 5.8.2.3: TCP with 85582 N Primer, Rating: 94

Figure 5.8.2.4: Alodine 5200 with 85582 N Primer, Rating: 22

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Figure 5.8.2.5: Sanchem 7000 with 53030 Primer, Rating: 0

5.9 Marine Atmospheric Test (Beach Te st) on Scribed, Painted Substrates

5.9.1 Test Description
This test method evaluates a coating system’s ability to prevent substrate corrosion and the effect
that corrosion has on the adhesi on of the coating system. Te sting was completed by NASA and contractor personnel at Kenne dy Space Center, Florida.

Outdoor exposure testing was con ducted at th e Kennedy Space Center’s Beach C orrosion Test Site. This site is located approximately 1.5 m iles south of Launch Complex 39A. Figure 5.9.1.1 shows an aerial view of the Kennedy Space Center’s Beachsite.

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Figure 5.9.1.1: Kennedy Space Center Beachsite Aerial View

Test stands are located 30 m eters (100 feet) from the mean high-tide line and face the water. Test coupons are installed on stainl ess steel test stands using porcel ain insulator stand-offs. The rack angle of the coupons is 30 degrees from horizontal. Figure 5.9.1.2 shows the coupon exposure racks.

Figure 5.9.1.2: Coupon Exposure Racks

An “X” incision was scribed throug h the coating so that the smaller angle of the “X” was 30 to 45 degrees, making sure that the co ating was scribed all the way to the substrate. The scribe had a 45-degree bevel, and each line of the “X” was approxim ately 4 inches long. The back and

83NCAP Phase I Report August 2003

edges of the coupon were primed to prev ent undercutting and corrosion p roducts from contaminating the test stands.

The coupons were then evaluated for surface co rrosion and creepage from the scribe at 3,000- hour (4, 8, and 12 m onths) interv als for 12 m onths. Rating base d on creepage from the scribe (ASTM D 1654A) are detailed here. Coupon groups rating “3A” or less on average were moved from the test stands. Remaining coatings are being evaluated until failure.

5.9.2 Test Results
The tables below detail corrosion performa nce for coatin g systems on each alloy after 12
months.

Table 5.9.2.1: Average Surface Corrosion and C reepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil- PRF-23377 Primer and Mil-C-85285 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 10.0 10.0 10.0 10.0

Alodine 5200 10.0 9.2 10.0 10.0

Bi-K Aklimate 10.0 10.0 10.0 9.8 Boegel 10.0 10.0 10.0 9.3

Chemidize 727ND 10.0 10.0 10.0 7.6

Oxsilan Al-0500 9.6 10.0 10.0 9.8

Sanchem 7000 9.6 10.0 10.0 4.2

TCP 10.0 8.0 10.0 10.0

X-It PreKote 10.0 10.0 10.0 10.0

Table 5.9.2.2: Average Surface Corrosion and C reepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil-PR F-85582 C2 Primer and Mil-C-85285 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 10.0 10.0 10.0 10.0

Alodine 5200 10.0 8.8 10.0 10.0

Bi-K Aklimate 10.0 10.0 10.0 9.8 Boegel 10.0 10.0 10.0 10.0

Chemidize 727ND 9.8 7.6 10.0 9.0

Oxsilan Al-0500 9.6 7.6 10.0 9.4

Sanchem 7000 0.0 3.2 6.4 10.0

TCP 10.0 10.0 10.0 10.0

X-It PreKote 10.0 10.0 10.0 9.8

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Table 5.9.2.3: Average Surface Corrosion and C reepage from the scribe (5 panels) for Aluminum Alloys Coated With Mil- PRF-85582 NC Primer and Mil-C-85285 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 10.0 10.0 10.0 10.0

Alodine 5200 10.0 8.8 10.0 9.4

Bi-K Aklimate 0.8 1.0 10.0 0.0 Boegel 5.3 7.3 10.0 0.0

Chemidize 727ND 0.8 1.2 10.0 0.0

Oxsilan Al-0500 7.6 9.2 10.0 2.8

Sanchem 7000 0.0 5.4 9.2 0.0

TCP 10.0 9.6 10.0 9.6

X-It PreKote 3.8 1.4 9.0 0.0

Table 5.9.2.4: Average Surface Corrosion and C reepage from the scribe (5 panels) for Aluminum Alloys Coated With Mi l-P-53030 Primer and Mil-C-53039 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 10.0 9.8 10.0 2.4

Alodine 5200 10.0 8.6 10.0 3.4

Bi-K Aklimate 0.8 9.4 9.8 0.0 Boegel 5.7 4.7 10.0 0.0

Chemidize 727ND

10.0

Sanchem 7000 9.8 0.2 10.0 0.0

TCP 10.0 10.0 10.0 3.6

X-It PreKote 4.2 6.0 10.0 0.0 4.8 5.8 10.0 0.0

Oxsilan Al-0500 5.8 9.2 0.0

Table 5.9.2.5: Average Surface Corrosion and C reepage from the scribe (5 panels) for Aluminum Alloys Coated With Mi l-P-53022 Primer and Mil-C-53039 Topcoat

Pretreatment Al 2024 Al 7075 Al 5083 Al 2219
Alodine 1200S (control) 10.0 9.8 10.0 0.4

Alodine 5200 10.0 8.8 10.0 2.4

Bi-K Aklimate 3.2 6.4 10.0 0.0 Boegel 9.5 1.3 10.0 1.0

Chemidize 727ND 6.0 2.2 9.2 0.0

Oxsilan Al-0500 9.4 7.6 10.0 0.8

Sanchem 7000 7.8 6.6 10.0 0.0

TCP 10.0 10.0 10.0 1.4

X-It PreKote 3.4 2.6 10.0 0.0

Aluminum 2024 At four m onths, only the Bi-K Aklim ate coa ting with 85582 Class N prim er showed any degradation, rating an average 9 out of 10. By eight m onths, co rrosion began to appear on a

85NCAP Phase I Report August 2003

number of coatings, all based on non-chromate primers. For the 85582 Class N system, Sanchem 7000, X-It PreKote, Chemidize 727D, Bi-K Aklimate, and Boegel coatings ra ted 7 or 8. Alodine 1200S, TCP, Alodine 5200 and Oxsilan Al-0500 re mained undamaged. For the 53022 system the coatings performed somewhat better, but the X- It PreKote and Bi-K Ak limate showed initial corrosion damage. The trend continued for th e 53030 system s, with Alodine 1200S, TCP, Alodine 5200 and Sanchem 7000 remaining undamaged. The remaining coatings rated 8 or 9 on

average.
At 12 m onths, most alternatives continued to perform well with ch romate primers. A notable exception is Sanchem 7000 which rated 0 with the 85582 C2 pri mer. System degradation continued in the non-chromate primer systems, with only Alodine 1200S , TCP and Alodine 5200 exhibiting no damage on any coupon.

Aluminum 2219 Like the other corrosion tests, alum inum 2219 represents the m ost serious challenge to the coating systems in the beach exposure test. Mi nor degradation began to occur in most nonchromate primer systems by four months. By eight months, serious degradation was underway for numerous non-chromate primer systems. Most notable was the lack of degradation in the 85582 N systems with TCP and Alodine 5200. These tw o alternatives were typically superior for the 53022 and 53030 systems, as well.

At 12 months, all alternatives with primers 23377 and 85582 C2 were performing well with little or no corrosion except f or Sanchem 7000, which ra ted in the 4 to 6 rang e. Alodine 1200S, TCP and Alodine 5200 were particularly good, show ing no evidence of corrosion on any coupon. For the non-chromate primers, Sanchem 7000, X-It PreKote, Chemidize 727ND and Bi-K Akli mate all completely failed, rating 0 for all coupons. Bo egel had one coupon rate a 3, with the rest failing completely. Oxsilan Al-0500 m aintained some protection with the 85582 N pri mer, but failed with the 53022 and 53030 systems.

Somewhat surprisingly, TCP and Alodine 5200 perform ed very well with the 85582 N pri mer, with all coupons rating 9 or 10 after 12 m onths. The coatings did not fare as well with the 53022 and 53030 system s, although perform ance was better than the other alternatives. This performance was, however, similar to the Alodi ne 1200S control which di d very well with the 85582 N system but poorly with the 53022 and 53030 systems.

Aluminum 5083 No significant corrosion appear ed on any test coupons in the 12-month period. This is not surprising given the excellent corrosion resistance of the 5083 alloy relative to the others in this

test.

Aluminum 7075 Corrosion trends in this alloy were very si milar to coating perform ance on 2024. TCP and Alodine 5200 were again the clear winners among the alternatives, showing performance as good
as the Alodine 1200S control in m ost cases. These two alternatives also m aximized the performance of the 85582 N, 53022, and 53030 primer s, yielding overall performance as good as the chromate primers. For this alloy, TCP wa s somewhat better than Alodine 5200, rating 1 unit

86NCAP Phase I Report August 2003

better for the 85582, 53022, and 53030 coating system s. Among the other alternatives, Oxsilan Al-0500 performed the best, yielding respectabl e ratings ranging from 7 to 9 on average.

Summary of Alternative Performance Table 5.9.2.6 details th e summary performance of each alternative pretreatm ent by primer system. It also shows an average rating for ea ch primer across all pretreatm ents. TCP and Alodine 5200 perform as well as the Alodine 1200S control across most coatings. Their superior performance is strongly evident in the non-chromate primer systems where no other alternative comes close. For the chrom ated primers, most of the alternatives show good perfor mance, especially X-It PreKote and Bi-K Aklimate, wh ich match the perfect performance of the Alodine
1200S controls.

Like the previous corrosion tests, the chrom ate -based primer systems perform equally well and
are the basis of the best coatin g systems. The non-chromate system s, on average, rank lower than the chromate systems especially with the poorer performing alternativ es. One notable exception is the performance of the 85582 N prim er with Alodine 1200S, TCP a nd Alodine 5200. These non-chromate systems match the perfor mance of the sister systems with chromate primers. No other non-chromate system competes as well.

Table 5.9.2.6: Summary Ratings for Pretreatm ents and Primer Systems exposed to 12 Months of Outdoor Exposure at Kennedy Spa ce Center Beachfront Corrosion Test Site

Primer

Pretreatment 23377 85582 C2 85582 N 53022 53030 All Coatings

Alodine 1200S (control) 10.0 10.0 10.0 7.6 8.1 9.1

Alodine 5200 9.8 9.7 9.6 7.8 8.0 9.0

Bi-K Aklimate 10.0 10.0 3.0 4.9 5.0 6.6
Boegel 9.8 10.0 5.7 5.5 5.1 7.2

Chemidize 727ND 9.4 9.1 3.0 4.4 5.2 6.2

Oxsilan Al-0500 9.9 9.2 7.4 7.0 6.3 7.9

Sanchem 7000 8.5 4.9 3.7 6.1 5.0 5.6

TCP 9.5 10.0 9.8 7.9 8.4 9.1

X-It PreKote 10.0 10.0 3.6 4.0 5.1 6.5
Overall Alternative Average 9.7 9.2 6.2 6.1 6.2 7.5

5.10 Toxicology
A leveraged effort ex ecuted by National Defense Center for Environmental Excellence (NDCEE)/ Concurrent Technologies Corporation (CTC) was used to complete toxicology testing requirements per the JT P. Based on technical performance and inputs from users on products they plan to field test, TCP and Alodine 5700 were chosen for toxicological evaluation. Alodine
1200S was tested as the chrom ate baseline for toxicologi cal properties. Othe r alternatives may be subjected to similar testing at the discretion of potential users. The following is a summary of the toxicology testing completed by MB Research Laboratories.

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5.10.1 Demonstration Report for Non-Chromate Pretreatment for Non-ferrous Metals
Performance testing of alternative alum inum non-chromate pretreatm ents generated two potential candidates for toxicological evalua tion, TCP and Alodine 5700 (Alodine 5700 is prepared by mixing 50mls of Alodine 5200 to 1950 mls of distilled water). TCP, Alodine 5700, Alodine 5200, and the baseline ch romate pretreatment process, Alodine 1200S, were subjected to toxicological testing. Toxico logical testing included Acute Oral T oxicity, Acute Derm al Toxicity, Acute Inhalation Toxic ity, and Skin Sensitization.

The Acute Oral Toxicity tes t obj ective was to determine the poten tial for toxicity of the test article when administered orally. Five male and five female rats were used as the subjects for the test. If any m ortality takes plac e at the initial dose le vel of 2,000 mg of th e test article/kg of animal body weight, at least two additional groups would need to be dosed to determine the LD 50 level. All anim als survived the 2000-m g/kg or al doses of Alodine 1200S, TCP, Alodine 5700,
and Alodine 5200. No abnorm al physical signs were noted a nd body weight changes/necropsy results were nor mal. Therefore, th e oral LD 50 of Alodine 1200S, TCP, Alodine 5700, and Alodine 5200 are all g reater than 2000 m g/kg si nce no mortality occurred du ring the tes ting periods. No further testing was required.

The objective of Acute Dermal Toxicity/LD 50 in Rabbits study was to determine the potential for toxicity of the test article when applied dermally to New England white rabbits. If the limit test of 2,000 mg/kg of body weight produces no m ortality, a full LD 50 test series is not required. If any mortality occurs at the ini tial dose level, at least two a dditional groups need be dosed in
order to de termine the LD 50 . All anim als survived the 2000- mg/kg dermal application of Alodine 1200S, TCP, Alodine 5700, and Alodine 5200. No c ases of mortality indicated that the
dermal LD 50 of Alodine 1200S, TCP, Alodine 5700, and Alodine 5200 are greater than 2000mg/kg of body weight

The objective of the Acute Inhalation Toxicity test was to determine the potential for toxicity of the test article due to short-term inhalation exposu re. Five male and five fe male rats were used as subjects for this test. The tes t article conc entration was expressed as the we ight of a tes t substance per unit volume of air (mg/l). If no mortality happens during the limit test, no further testing is required. If com pound-related morta lity is produced, further study m ay be needed to establish the Median L ethal Concentration (LC 50 ) value. The LC 50 is a s tatistically derived approximation of the concentration of a substance that can be antic ipated to cause death to 50 percent of the test subjects duri ng exposure or within a fixed tim e after exposure. All anim als survived the four hour 2.31 m g/l exposur e of Alodine 1200S, therefore the LC 50 is greater than 2.31 mg/l. Every animal su rvived four-hour 2.25-mg/l exposure to TCP so the LC 50 is greater than 2.25 mg/l. All anim als survived 4-hour 2.02-mg/l exposure to Alodine 5700 and 2.18-m g/l exposure to Alodine 5200. The L C 50 value is for Alodine 5700 is therefore greater than 2.02 mg/l and the LC 50 value for Alodine 5200 is greater than 2.18 mg/l.

The objective of the Derm al Sensitization test – Buehler test was to d etermine the effect of a product to promote skin sensitiza tion after repeated applications. The guinea pig was used as the test subject. Erythema and edema are the external signs of a reaction during this test. Erythema was absent to faint during the induction phase and the challenge phase of Alodine 1200S, TCP, and Alodine 5700. Body weight changes and necr opsy results were normal. Based on the results

88NCAP Phase I Report August 2003

of these tests, Alodine 1200S,TCP , and Alodine 5700 are classified as non-sensitizers. Alodine 5200 wasn’t subjected to th e skin sensitization test.

All the non-chrom ate alte rnatives appeared better than Al odine 1200S from an environm ent, health and safety perspective, with Alodine 5700 being substantially less harmful than Alodine 1200S. Alodine 5200 is only slightly better than Al odine 1200S. Exposure to it will need to be evaluated since it will be used to produce Al odine 5700 by dilution and making up and adjusting
immersion tanks.

Since no mortality occurred in any of the test subjects during any of the toxicological testing for any test article, all test articles met the 2000 milligrams of test artic le per kilogram of test subject bodyweight limit test requirem ent. Additionally, the alternatives were less h azardous than Alodine 1200S from an environm ental, health a nd safety perspective. Consequently, Alodine 5700 and TCP are suitable and desirable replacem ents for Alodine 1 200S for pre-treating aluminum substrates from a toxicological point-of -view. Waste treatment of any metal finishing waste will need to be evaluated in addition to toxicolog ical data, including the impact of total chromium on treatment systems (in the case of TCP).

5.11 Repairability

The JTP contains multi-service DoD technical re quirements and associated tests necessary to quantify non-chromate conversion coatings for pr etreating aluminum a nd its alloys, including reparability testing. Leveraged funds from NDC EE/CTC were used to evaluate alternatives as used in repair or rework coatings. The proj ect was called “Nonchromated Conversion Coatings for Weapon Systems Rework and Repair”. The ob jective was to test a variety of nonchromated pretreatment alternatives as part of a coating system for use in the repair/rework environment. The project tested the following coatings:

• Henkel Surface Technologies Alodine® 5700

• Fortune Chemical Company X-It PreKote,

• MacDermid Chemidize® 727ND,

• Brent OxSiLAN® AL-0500,

• NAVAIR TCP,

• Boegel Sol-gel, and

• 3M Scotch-Weld 3901 Structural Adhesive Primer. Two chromated coatings (Alodine 1200S and Touch N Prep Pen) were also tested. The test program included: dry and wet tape adhesion, a nd neutral salt fog exposur e. All the coatings passed the dry tape adhesion resu lts for uncross-cut samples, but cross-cut results were m ixed and inconclusive. The wet tap e adhesion test was acceptable for all p anels coated with MILPRF-23377 primer, however, results for sam ples co ated with MIL-PRF-8 5582 were mixed. All samples performed as well or better than the co ntrols in the salt spray tests. (Reference #??)

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90NCAP Phase I Report August 2003



### 6.0 ISSUES IN EVALUATING NON-CHROMATED SYSTEMS

A number of issues concerning the evaluation of non-chromate coating systems and the coatings that make up these systems are important to consider in the search for high-value alternatives to chromate-based systems. Color change, product maturity, robust inhibition characteristics of hexavalent chromium, and accelerated test methods will be discussed and comparisons made for each issue between chromate and non-chromate coatings.

Chromate conversion coatings yield a practical co lor change that is relied upon by quality control and assurance personnel as visu al proof that coatings were deposited during a given production shift. Only one product evaluated in this pr oject, Sanchem 7000, yi elded coatings with a practical color change. Technical performance asid e, the lack of color ch ange is an important weakness in alternative coatings when a mate rials engineer needs to decide whether to implement a product. At least one strong perfor mer from this project (Alodine 5700) is not being implemented by a large user in part becau se of this issue. A recommendation to all developers of alternatives is to strongly consider color change during the optimization of new products.

Chromate conversion coating products are very mature and typically have good technical support
behind them from established manufacturers. They are widely available around the world and are relatively inexpensive. The alternatives in this test are all new to the market. Alodine 5200 is probably the most mature of the group but still unproven in the long term for high volume production. Other products rang e from medium maturity to new single-batch products from research and development laboratories. This may result in varying consistency between alternatives as tested in this pr oject and what may be available in the future. Specific sources of variability include batch-to-batch variations, marketing and or ganizational changes and product reformulations. During the course of this e ffort, one product (Boegel) was licensed from the developer to a manufacturer with a change in the source of the product. The manufacturer of another product (OXSiLAN AL-0500) was acqui red by a different manufacturer, which is considering discontinuing the specific alternative tested in this project. These types of events can possibly affect the consistency or availability of any alternative and need to be considered when selecting alternatives for field-testing or implementation.

Another complicating factor in the testing and evaluation of non-chromate pretreatments, primers, and topcoats is the inherent robust corrosion inhibiting pr operties of hexavalent chromium. It passivates numerous metals and alloys by multiple mechanisms and very small amounts are necessary to be effective. Non-chromate inhibitors are not as robust as their chromated counterparts. High-quality non-chro mated organic coatings typically rely on a synergistic combination of inhibitors to achieve th eir performance. Each pretreatment alternative has a unique chemistry and in many cases offe rs no corrosion inhibi tion, only adhesion promotion. Combining alternative pretreatments and primers or self-p riming topcoats creates additional coating system performance uncerta inty due to largely unknown, and sometimes synergistic, effects between pretreatment and pr imer or topcoat. The most desirable coating systems are those that perform well despite the alteration of components. Systems containing

91NCAP Phase I Report August 2003

some chromated components can accommodate cha nges in other components without necessarily compromising system performance. This co-depe ndence of inorganic and organic coatings must be taken into consideration when evaluating new coating combinations and contemplating implementation on complex systems.

Finally, the corrosion tests used in this evaluation were conceived to a large extent based on the performance of chromated systems. Discrepanc ies in the performance of non-chromated versus chromated systems have been observed by NAVAI R beyond the normal test time of 500 hours in

SO 2 salt fog testing. This may lead to an increase in the duration of the SO 2 salt fog test to better discriminate amongst candidate coating systems. Ca re must be taken when using these results to not make sweeping conclusions about actual performan ce. Rather, this data can be used to lower the risk of field-testing promising alternatives. In the end, while laborator y testing might be able to give a good indication of performance, the only true dete rmination of coating system performance is in-service, on a platform over an extended period of time.

This leads to the next phase of this ESTCP project, which is de dicated to the field-testing of alternative pretreatments. Section 7 describes several efforts underway to field-test or implement alternatives, several of which ar e leveraged with this project.

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### 7.0 IMPLEMENTAION STATUS OF ALTERNATIVES IN DoD AND
NASA

7.1 NASA (Alodine 5700)
The Space Shuttle So lid Rocket Booster (SRB) ha d only one set of c oati ngs and one type of pretreatment qualified for protection of alum inum hardware. All of the m aterials contained chromate compounds. A project was conducted to identify and qualify alternatives for the currently qualified coating system and pretreatm e nt. Three altern atives each for p retreatment and coating systems were tested for SRB Program qualification. Baseline materials for candidate comparison were Alodine 1201 (Henkel Corp.) and 44- GN-7 primer with 03W127A t opcoat (Deft, Inc). The three pretreatment nominees were Okem coat 4500 (Oakite Products, Inc.), Alodi ne 5700 (Henkel Corp.), and Chemidize 727ND (MacDerm id Inc.). The coating systems chosen for evaluation were: Hentzen CoatingsInc. 05510WEP-X/05511CEH-X primer with 4636WUX3/4600CHA-SG topcoat, Lord Corp. 9929A/B prim er with A276 topcoat, and PRC-De Soto International, Inc. EEAE152A/B primer with EUAW 098A/EUAC082B topcoat. T he Okemcoat 4500 pretreated panels were dropped from the qualification program due to poor performance during the Bond Strength – Flexibility and Water Resistance qualification testing. The PRC-DeSoto EEAE152A/B primer and EUAW098A /EUAC082 B topcoat were dropped from the qualification program due to the manufacturer ceasing production of the topcoat.

Figure 7.1.1: Launch Photo of the SRBs

For More Information Contact: Paul W. Hayes
Phone: 321-853-5774 HayesP@usasrb.ksc.nasa.gov

Testing gathered inform ation on c orrosion protect ion, bond strength, com patibility with other SRB materials, batch-to-batch consistency, and thermal environments data. Two pre treatments and two coating systems met the SRB program c r iteria. The recommended products are Henkel Alodine 5700, MacDermid Chemidize 727 ND, and the coating systems submitted by Hentzen and Lord. Coatings were tested in both a prim er only and a primer/topcoat configuration. Both were found to be acceptable for flig ht. There ar e significant processing advantages for each of the materials depending on how they are used. Th e Hentzen coatings are chromate free and have very good processing characteristics along with good overall properties and are recomm ended for first implem entation as an alternate. Li kewise, Alodine 5700 had very robust processing parameters and is recommended for first impl ementation as a pretreatment alternate.

93NCAP Phase I Report August 2003

NASA’s changed to the Hentzen / Alodine 5700 syst em in June 02. This change affected all structural aluminum (2219, 6061, and 7075) part s of the solid rocket boosters. The first
hardware flew in the fall of 2002.

7.2 US Army TACOM (Alodine 5700)
The Army/Tacom is planning to implem ent Al odine 5200 for use on Al 2024-T4 and 2014-T6 roadwheels. They plan to implement Alodine 5200 in Red River Army Depot's (RRAD) Rubber Products Operations in the Feb-Mar 2003 timeframe.

For More Information Contact: Heidi Nicely
Phone: 814-269-6461 nicelyh@ctc.com

7.3 USAF (X-It PreKote)
A multi-year effort at Hill Air Force Base (AFB) was under taken to reduce or eliminate the use of chromate compounds in the paint preparation process for aircraft, predom inantly F-16s. Of the four products tested, three wer e eliminated early through laboratory testing. The fourth candidate, X-It PreKote, was tested extensivel y against the curren t process. X-It PreKote performed better than chrom ate conversion coating in adhesion/fl exibility tests and performed equally well in other testing. In addition, it was found that X-It PreKote could elim inate the solvent wipe down and the acid br ightener used in conventional paint preparation procedures.
Use of X-It PreKote also reduces th e need to sand anodized surfaces before repain ting, but the limitations are that the application process is labor intensive.

Operational tests have been conducted on severa l aircraft and are ongoing. Air Education & Training Command (AETC) used X-It PreKote on two aircraft in 1996. In March 1997 an F-16 was scuff sanded and repainted using X-It PreKote in the prep for paint process. In Nove mber 1997 two fully stripped F- 16 aircraft had their right wings tr eated with X-It PreKote while the
rest of the aircraft was treated with chrom ate conve rsion coating. These aircraft are in service at Eglin and at Homestead. Hill AFB and the owning un its have examined each of the test aircraft.

The results so far are very positive and no detrim ental effects from the X-It PreKote have been discovered. By September 1999, Hill AFB had painte d over fifty aircraft using the X-It PreKote process. The T-38, F-16, A-10, a nd C-130 aircraft were prepared half with Alodine and half with PreKote. X-It PreKote performed bette r than the Alodine side in all cases.

The F-16 System Program Office (SPO) has approved the use of the X-It PreKote process in 1F16-23 Technical Order (TO). All F-16 that are painte d at Hill AFB are X-It coated. For the F-16 Program at Hill AFB, the use of X-IT has resu lted in 35 % increase in productiv ity, hazmat reductions, reduction on paint system failures, a nd no paint failures have occurred in the last three years. The T-1, T-37, and T-38 SPOs are cu rrently revising their TOs to include the use of

X-It PreKote.

94NCAP Phase I Report August 2003

Figure 7.3.1: Application of X-It PreKote

For More Information Contact:
Richard H. Buchi
Phone: 801-775-2993 richard.buchi@hill.af.mil

7.4 NAVSEA/MARINES (TCP)
A Navy message stipulating non-use of hexavalent chromate coati ng systems was released in the early 1990’s. For potential fiel d testing on the Marine’s Landi ng Craft, two candidates were
selected: Brent Chemcote and TCP. The selecti on criteria was targeted at performance on 5000
series aluminum for anti-corrosion and coatin g adhesion enhancem ent properties. TCP was
selected for field and beachfront coupon studies. Brent Chemcote is no longer in production.

TCP test patches for use as a su rface preparation alternative to abrasive blasting were installed on the decks of the oily waste ta nk and another void in a Landing Craft, Air Cushion (LCAC) at Assault Craft Unit Four (ACU-4), Naval Am phibious Base, Little Creek, Virginia. LCAC hulls are predominantly aluminum alloy 5456.

A beachfront exposure rack was erected at A CU- 4 nearly 1.5 years ago. Coupons of alloys 5083, 5086, and 5456 either receiv ed no surface prepar ation, preparation w ith TCP, preparation with garnet blasting, or were abrasively blasted and treated w ith TCP. The coa ting used was MIL-P-24441B Ty III F 150/151 and each coated c oupon was scribed. After appro ximately six months, the coating on coupons with no surface preparation began to fail by delam ination at the scribe mark. As of Dec 02, with the excep tion of one coupon, coatings on coupons without surface preparation had entirely d elaminated. Coupons with eith er TCP treatment, abrasiv e blasting, or both, have not shown a ny failure due to delamination.

For another com ponent of the coupon study, TC P is being evaluated for its anti-corrosion properties. What appears to be critical for the success of TCP as an anti-corrosion method is the
deoxidation of the substrate surface prior to application of TCP. Two test patches of TCP have just been installed on the deck of the starboard air inlets of the test platform LCAC. These test

95NCAP Phase I Report August 2003

patches will be m onitored every six m onths as part of the standard craft corrosion inspections and compared with the port side inlets.

7.5 NAVAIR TCP
To date 4 S -3Bs, 2 F/A-18s and 2 H-46s have been partially or fully coated with TCP during depot maintenance on outer moldine of vehicle. The S-3Bs use a self-prim ing topcoat and thushave a chrom ate-free coating on th e TCP test areas. The F/A-18s and H-46s use MIL-PRF85582 C primers and thus the coating system relies heavily on the chrom ates in the prim er for corrosion protection. The last platf orm was tr eated in 2001. One F/A-18, with TCP on entire outer surface, inspected after a carrier tour an d one year in se rvice was equivalent to other airframes the sam e squadron and looked, on averag e, better than m ost after typical carrie r deployment. The 2nd F/A-18 is scheduled for inspection in 2003. Bo th H-46s have been inspected after 1 year in service and no differen ce in performance of test coating and control areas were noted. For the S-3s, the first two were treated with TCP on the aft section only. The 3rd and 4th were completely covered with TC P. Of the tail only birds, both have shown equivalent performance to the rest of the airframe over 2 years of service.

Figure 7.5.1: F/A-18 after TCP Application and Painting

Of the fully coated airf rames, one has shown norm al corrosion co mpared to s imilar controls. The 4th S-3 saw a full deploym ent on the Conestoga , the Navy’s last fuel-burning carrier, which generates large amounts of stack gases. The tour wa s in the South Pacific as well. This airframe showed more corrosion than com parable planes in the sq uadron. A specific cau se was no t identified but two potential causes were identif ied: insufficient corrosi on protection by the TCP / (Self Priming Topcoat (SPT) coating system or in adequate rinsing during processing. Excessive TCP residue left during processi ng may cause corrosion in non-chro mate coating systems. Since neither can be proven independently or acting t ogether no conclusion can be reached other th an more testing with this coating syst em is required before use in the field. Another outcome is that

96NCAP Phase I Report August 2003

the 500 hour SO 2 salt fog test done at NAVAIR on th e TCP/SPT coating did not show a difference in performance between the TCP/SPT and Accelagold/SPT system that is currently
used on the S-3. When the test was extended to 1000 hours, corrosion in the unscribed areas did appear on non-chrom ated systems but not system s that had chrom ate in the pretreatm ent or primer. More testing is under wa y to investigate this issue.

For More Information Contact: Craig Matzdorf
Phone: 301-342-9372 matzdorfc@navair.navy.mil

7.6 USMC (TCP and Alodine 5200/5700)
The Advanced Amphibious Assault Vehicle (AAAV) is a n ew acquisition platform in the SDD phase. Environmental, safety and health restrictions on the platform require the use of chromate and cadmium free coating system s. As a resu lt, the program has evaluated TCP and Alodine 5200 on aluminum 2519 with a variety of non-chrom a te coating systems for potential use on the platform. In addition, the platform is participa ting in the f ield test po rtion of this project by having a variety of AAAV hulls coated with co mbinations of TCP and Alodine 5200 with MILPRF-85582N and MIL -P-53022 primers. These vehi cles will be evaluated over a two year period. Additionally, two rebuilt AAAV prototype s were coated with TCP and a chrom ate conversion coating control on hull s urfaces. These ve hicles are currently in service and will be evaluated in 2003 for coating system performance.

Figure 7.6.1: Spray Applied Alodine 5700 to AAAV

For More Information Contact: Craig Matzdorf
Phone: 301-342-9372 matzdorfc@navair.navy.mil

97NCAP Phase I Report August 2003

7.7 Joint Boeing/Air Force/Navy (Boegel)
The objective of the program is to develop/de monstrate a coating s ystem process including environmentally friendly cleani ng and sol-gel-based conversi on coating processes and the Advanced Performance Topcoat. The project wa s funded by the Aging Aircraft Division of the Aeronautical Enterprise Progr am Office (ASC/AAAV). The surf ace treatment system used was Boegel/AC-131 from Advanced Chemistry and Technology in Garden Grove, CA.

The first significant m ilestone of the project was to investigate ways to m ake Boegel/AC-131 visibly inspectable. Pigments or fillers where added to Boegel/AC-131, however they did not provide sufficient differentiation between coated and uncoated surfaces. The addition of the pigments and fillers caused degradation of the adhesion promoting characteristics of the coating. Dyes, on the other hand, were successfully heat-a dded to the conversion coating promoting color
definition. . Additional work is needed to define the adhesion perf ormance of the colored coatings and to determine the effect of the dye on long term coating system performance.

Steve.Szaruga@wpafb.af.mil The second milestone was to valid ate the adhesion promoting char acteristics of Boegel/AC-131 on a variety of metal substrates and metal surf ace conditions. To accomplish th is goal, the team worked to define the cleaning and deoxidizing requirements for aluminum and titanium surfaces required for good adhesion. Based on the ability of Boegel/AC-131 to bond to oxidized surfaces, the goal was to reduce the aggressiveness of the de oxidation/brightening st ep or to e liminate it.
Adhesion to all of these surfaces was good when a conversion coating, either Boeg el/AC-131 or
Alodine 1200S was used. W hen no conversion coa ting was applied, wet a dhesion failures were observed. The waterbo rne primer (MIL-PRF-85582) showed poor adhesion to surfaces treated with Cee-Bee R-66C. The solvent borne prim er (MIL-PRF-23377) showed poor adhesion to surfaces rinsed with water or exposed to high hum idity. In other adhesion tests, ad hesion of a solventborne coating system to Boegel/AC-131 or Alodine 1200 on titanium and bare and clad aluminum were equivalent. The values for we t tape adhesion and HATE adhesion were the same for the two conversion coatings. In reverse im pact testing, interfacial fa ilure between the primer and Alodine conversion coating was observed whereas the failure mode was prim arily in the primer for the Boegel/AC-131 coated panels. Furthe r testing will be conducted to fully determine adhesion performance of coatings to a luminum, titanium, magnesium, and ste el substrates. (Osborn, 2003)

For More Information Contact: Steve Szaruga Phone: (937) 255-9064

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### 8.0 CONCLUSIONS AND RECOMMENDATIONS

All alternatives are aqu eous solutions designed to deposit a very thin coating on the alum inum substrate to enhance paint adhesion and painted co rrosion protection. Some alternatives provide unpainted corrosion protection as well as electrical c onductivity in corrosi ve environments. Alternatives face the challeng e of the low co st and eas e of application of the chrom ate conversion coatings while providing a coating th at provides acceptable technical p erformance. Along with technical perform ance, processing and toxicity issues are important to consider in capturing the overall impact of an alternative.

The only compositions that come close to matching the technical, process, cost, and flexibility of chromates are based on trivalent chromium. They offer coatings with excellent u npainted or bare corrosion resistance on a broad range of alloys, most notably on 2000-series alum inum where performance excels over an y other alternat ives. T hey also provide excellent paint adhesion and painted corrosion perf ormance as well as m eeting the requirements for electrical conductivity. These form ulations are used at room temperat ure and can be applied by immersion, spray or wipe on tec hniques. The m ain drawback to the process is the presence of
trivalent chromium. Although trivalent chromium is present in the solution and coating, toxicity studies and OSHA PELs suggest that the use of TCP is ac ceptable, especially given its wellrounded performance. Users will need to balance total chrom ium, heath and technical performance requirements when deciding if TCP is a viable chrom ate substitute for their facilities and platforms.

The second-best product in these tests was Al odine 5200/5700. Althou gh it does not perform well in unpainted applications, it perform s simila rly to TCP in m ost painted system s. One important exception is the f iliform corrosion te st where T CP was clearly superio r. Alod ine 5200/5700 contains no chrom ium, is process fl exible and can be applied like chrom ate conversion coatings.

The remaining alternatives perf ormed variably in the evaluati on. So, although none can compete with the overall perf ormance of TCP and Alodine 5200/5700, many could be selected for specific coating sy stem application and ach ieve the desired performance. The ch oice of any alternative will dep end on prio r testing an d co mfort with products, institutional leverage, an d other sources of information regarding performance.

A clear outcome of this study is the superior perfor mance of ch romate-based primers compared to their non-chrom ate counterparts. For the more challenging a lloys, the better non-chrom ate systems in som e cases approached or equale d the perform ance of system s with chrom ate primers, but generally, perform ance is not as good. More work needs to be put tow ard developing improved non-chromate organic systems as well as pretreatments. In most cases with the better performing pretreatments, the primer s drive the corrosion perfor mance. This is good in the sense that there are oppo rtunities to replace chrom ate conversion coatings used under chromated primers and maintain overall system performance.

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### 9.0 REFERENCES

Technology Demonstration Plan “Dem onstration and Validation of Non-Chrom ate Aluminum Pretreatments,” Science Applications Internatio nal Corporation for the Naval Aviation Systems Command (NAVAIR), May 2002.

Joint Test Protocol, “Joint Test Protocol for Validation of Non-Chrom ate Aluminum Pretreatments,” Naval Air Systems Command Inorganic Coatings Team, December 13, 2000.

Section 2.1: 40 CFR 156, “Labeling Requirements for Pest icides and Devices,” United States Federal Environmental Regulations, 1998.

Sections 2.1, 4.1, 5.2, 5.11: MIL-C-81706, “Chemical Conversion Materials fo r Coating Aluminum and Aluminum Alloys,” U.S. Department of Defense, Washington, DC, 1999.

Sections 2.2, 4.2, 5.11: MIL-PRF-85582, “Primer Coatings, Epoxy, W ater borne,” U.S. Departm ent of Defense, Washington, DC, September 1997.

Sections 2.2, 4.2: MIL-P-53030A, “Primer, Epoxy Coating, Water Re ducible, Lead and Chromate Free,” Revision A, Amendment 2, U.S. Department of Defense, Washington, DC, 1992.

Sections 2.2, 4.2: MIL-P-53022-10, “Primer, Epoxy Coating, Co rrosion Inhibiting, Lead and Chromate Free,” U.S. Department of Defens e, Washington DC, February 1992.

Sections 2.2, 4.2, 5.9, 5.11: MIL-PRF-23377G, “Primer Coatings, Epoxy, High Solid,” U.S. Departm ent of Defens e, Washington, DC, September 1994.

Sections 2.3, 5.1, 5.5, 5.6, 5.7, 5.9, 5.11: ASTM D1654, “Standard Method for Evaluation of Painted or Coated Specim ens Subjected to Corrosive Environments,” ASTM, Philadelphia, PA, 1984.

Section 4.1: ASTM F22-65, “Standard Test Method for Hydr ophobic Surface Films by the Water-Break Test, ASTM, Philadelphia, PA, 1965.

Lab Report #LR02-004, “Coating Weights and Pro cessing of Alternativ es for ESTCP NCAP Project PP0025,” Craig Matzdorf ESTCP for th e NCAP Project PP0025, July 24, 2002.

101NCAP Phase I Report August 2003

MIL-C-53039A, “Coating, Aliphatic Polyuretha ne, Single Component, Chemical Agent Resistant,” U.S. Department of Defense, Washington DC, May 1993.

Sections: 5.11: MIL-PRF-85285, “Coating, Polyurethane, High Solids,” U.S. Departm ent of Defense, Washington, DC, April 1997.

MIL-T-81772, “Thinner, Aircraft Coating,” U.S. Department of Defense, Washington, DC, Oct 25, 1991.

Sections 5.1, 5.2, 5.5, 5.6, 5.7, 5.11: ASTM B117, "Standard Method of Practice for Operating Salt Spray (Fog) Apparatus," ASTM, Philadelphia, PA, 1990.

Section 5.5: Plazankis, Brian E. and Miller, Chris E., “AST M B 117 Screening of Non-Chromate Conversion Coatings on Aluminum Alloys 2024, 2219, 5083, and 7075 using DoD Paint System s,” Army Research Laboratory Report, Ab erdeen Proving Ground, Maryland.

Sections 5.5, 5.7: GM 9540P, “Accelerated Corrosion Test; GM 9540P,” General Motors Engineering Standards,

1997.

Section 5.6:
ASTM G85 “Standard Practice for Modified S alt Spray (Fog) Testing,” ASTM International, West Conshohocken, PA, 2002.

Section 5.6: Matzdorf, Craig and Kane, Dr. Michael J., “Eva luation of Non-Chromate Conversion Coatings in DoD Coating Systems using ASTM G85 SO 2 Salt Fog,” NAVAIR, Patuxent River, MD.

Section 5.7: Plazankis, Brian E., Miller, Chri s E., Matzdorf, Craig, “Analy sis of Nonchrom ate Conversion Coatings on Alum inum Alloys 2024, 5083, and 7075 with DoD Coatings Using GM 9540P Cyclic Accelerated Corrosion Exposure,” Proceedings from the Triservice Con ference on Corrosion, San Antonio, TX, January 2002.

Section 5.9: ASTM D1654-92, “Standard Test Method for Evaluation of Pa inted or Coated Specim ens Subjected to Corrosive Environmen ts,” ASTM, Philadelphia, PA, 1992.

102NCAP Phase I Report August 2003

Sections 5.3, 5.4, 5.11: FED-STD-141, “Paint, Varnish, Lacquer, and Related Materials: Methods of Inspection, Sampling, and Testing,” 1986.

Section 5.4, 5.11: ASTM D3359, “ Standard Method for Measur ing Adhesion by Tape Test, Method A & B” ASTM International, 1997.

Section 5.10: “Demonstration Report (Technology Improve ment Report) for Non-Chromate Pretreatments of Non-Ferrous Metals,” Na tional Defense Center for Environm ental Excellence/Concurrent Technologies Corporati on for the Environm enta l Security Technology Certification Program, September 20, 2002.

Section 5.10:

Section 5.10: “Acute Oral Toxicity/L D50 in Rats,” MB 02- 10327.01, Cerven, Daniel R. for MB Research Laboratories, 2002.

Section 5.10: “Acute Dermal Toxicity/LD50 in Rabbits,” MB 02-10327.02, Cerven, Daniel R. for MB Research Laboratories, 2002.

“Justification Report (Technology Improvem ent Re port) for Non-Chrom ate Pretreatments of Non-Ferrous Metals,” National Defense Center for Environm ental Excellence/Concurrent Technologies Corporation for th e Environmental Security Tec hnology Certification Program, September 24, 2002.

Section 5.11: “Nonchromated Conversion Coatings for W ea pon Systems Rework and Repair,” National
Defense Center for Environm ental Excellence/ Concurrent Technologies Corporation for the Environmental Security Technology Cer tification Program, September 24, 2001.

Section 7.0: Zook L., Clayton C., and Raley R, “Alternate SRB Aluminum Coating System Qualification Test Report,” CPC-025-00MP, United Space Alliance, May 1, 2000

Buchi, Richard H., Patterson, Ken, and Gowers , Clyde J. “Non-Chromate Conversion Coating,” Ogden Air Logistics Center, April 3, 1998.

Section 7.4: MIL-P-24441B Ty III F150/151, “Epoxy Polyam ide Formula 150 & Form ula 151,” U.S. Department of Defense, Washington, DC, 1994.

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104 Section 7.7: Osborn, Joseph H., “Advanced Aircraft Corrosion Protection Final Report for period Septem ber 2002 through April 2003”, Prepared by Boeing for Univer sal Technologies Corporation under contract #02-S470-009-C1, April 25, 2003.