Formulating Multifunctional Protective 

Ammunition Coatings 

by Kestutis G. Chesonis and Pauline M. Smith 

ARL-TR-2795 August 2002 

Approved for public release; distribution is unlimited. 
NOTICES 

Disclaimers 

The findings in this report are not to be construed as an official Department of the Army position 

unless so designated by other authorized documents. 

Citation of manufacturer’s or trade names does not constitute an official endorsement or approval 

of the use thereof. 

Destroy this report when it is no longer needed. Do not return it to the originator. 
Army Research Laboratory 

Aberdeen Proving Ground, MD 21005-5069 

ARL-TR-2795 August 2002 

Formulating Multifunctional Protective 

Ammunition Coatings 

Kestutis G. Chesonis 

Weapons and Materials Research Directorate, ARL 

Pauline M. Smith

Independent Contractor 

Approved for public release; distribution is unlimited.
ii

Abstract 

The U.S. Army Research Laboratory (ARL) Coatings Team and the U.S. Army Armament 

Research, Development, and Engineering Center (ARDEC) Munitions Metal Parts Team have 

established a major collaborative effort to eliminate various obsolescent coatings and consolidate 

them into a universal coating system. The exterior ammunition coatings provide ready 

identification and corrosion protection for long-term storage stability. The fast-drying exterior 

coatings used on large-caliber projectiles are susceptible to contamination and staining by 

explosives. Staining of the topcoat can occur during the loading process when explosives are 

poured into the steel projectiles after fabrication and painting. 

The ARL Coatings Team, in conjunction with ARDEC, has developed a modification to the 

ammunition coating specifications by combining the properties of the primer and topcoat into 

one coating. The new coating is ammunition-explosive compatible, highly resistant to corrosion, 

fast drying, low in cost, and can be used as a single coat for the medium- and large-caliber 

ammunition systems. A research and development effort is ongoing to substantially increase the 

chemical resistance of the coating. These coatings will comply with environmental regulations 

including The National Emissions Standard for Hazardous Air Pollutants, which eliminates the 

use of hazardous air pollutant solvents. 
iii

Contents 

List of Figures v

List of Tables vii

1. Background 1

2. General Characteristics 2

3. Experimental Challenge 2

4. Laboratory Formulations 2

5. Resin Modifications 3

6. Pigmentation 4

7. Additives 4

8. Solvent Modification 4

9. Experimental 5

9.1 Stain Removal .................................................................................................................5 

9.2 TNT Cleaning..................................................................................................................7 

9.3 Composition B Cleaning .................................................................................................9 

10. Experimental Results 14

10.1 Adhesion Testing ASTM D 3359 Method B Adhesion [5]...........................................15 

10.2 Wet Adhesion Testing...................................................................................................15 

10.3 General Motors (GM) Standard Test 9540P [6]............................................................16 

10.4 Salt Fog Testing in Accordance With ASTM B117 [4]................................................16 

11. Results 17

11.1 Acetone Resistance........................................................................................................17 
iv

11.2 Corrosion Resistance 120 hr in ASTM B117 [4] .......................................................17 

11.3 GM 9540 [6] ...............................................................................................................17 

11.4 Corrosion Resistance 144 hr in ASTM B117 [4] .......................................................18 

12. Observations 18 

13. Summary 18 

14. Conclusion 19 

15. References 21 

Bibliography 23 

Report Documentation Page 25 
v

List of Figures 

Figure 1. Basic composition of formulation. ..................................................................................3

Figure 2. Masked panels before staining. .......................................................................................7 

Figure 3. Masked panel during exposure to TNT...........................................................................8 

Figure 4. Performance comparison of two ARL panels. ..............................................................10 

Figure 5. Composition B staining. ................................................................................................11 

Figure 6. Panels steam cleaned. ....................................................................................................12 

Figure 7. Panels cleaned with acetone. .........................................................................................13 

Figure 8. Panels cleaned with acetone. .........................................................................................13 
vi

INTENTIONALLY LEFT BLANK.
vii

List of Tables 

Table 1. Stain removal experiment. ................................................................................................5 

Table 2. Vendor sample results for TNT staining...........................................................................8 

Table 3. ARL panel results for TNT staining. ................................................................................9 

Table 4. Vendor results for Composition B..................................................................................10 

Table 5. ARL results for Composition B......................................................................................11

Table 6. Acetone wipe test............................................................................................................14 

Table 7. Acetone cleaning results. ................................................................................................14 

Table 8. Adhesion testing. ............................................................................................................15 

Table 9. Wet adhesion testing.......................................................................................................15 

Table 10. GM 9540P cyclic corrosion test details. .......................................................................16 

Table 11. ASTM B117 [4] results.................................................................................................17 

Table 12. Samples tested in B117.................................................................................................18 
viii

INTENTIONALLY LEFT BLANK. 
1

1. Background 

The traditional protective coatings for mortar and artillery projectiles are based on quick drying 

enamels. The main requirements are thin, fast drying, corrosion-resistant, durability, ease of 

application and low cost. The coatings that have been used for ammunition were developed over 

time from diverse origins, both from military and federal specifications. 

Coatings on these various ammunition components typically contained substances that were 

either toxic or hazardous, with high levels of volatile organic compounds (VOCs), hazardous air 

pollutant (HAP) solvents, hexavalent chromium, and other heavy metals. The need to reduce or 

eliminate these hazardous substances is dictated by environmental regulations and changes in the 

coating process, federal and state regulations mandating lower levels which control the types of 

solvents and methods for disposing of these organic coatings. This regulatory and performancedriven process led to a major consolidation effort by the U.S. Army Research Laboratory (ARL) 

and the U.S. Army Armament Research, Development, and Engineering Center (ARDEC) to 

eliminate coatings with hazardous materials and high levels of polluting solvents. 

In 1972, the military specification MIL-L-11195D [1] was issued for use as a nitrocellulose (NC) 

lacquer topcoat in many colors for automotive and ammunition use. It had very good adhesion 

to bare metal due to the mandated use of semi-oxidizing castor oil with NC. This specification 

also mandated and permitted the use of lead chromate in various colors. For improved corrosion 

resistance, MIL-L-11195D is used with an analogous red oxide primer, MIL-P-11414D [2], 

formulated with zinc chromate. 

In 1993, the primer and topcoat were completely revised from NC to oil-based, oxidizing alkyd 

as military specifications MIL-E-11195E [1] and MIL-P-11414E [3]. These specifications had 

no lead or chromate and met federal regulation limits of 420 g/L of VOC. Since then, these fastdrying enamels are being used on containerized mortars. MIL-E-11195 has a few limitations and 

cannot be used by itself on some projectiles because of inadequate corrosion resistance. Some 

coatings require both a topcoat and a primer while certain systems require only a topcoat because 

of close dimensional tolerances. 

ARL, in conjunction with ARDEC, has recently qualified and implemented HAPs-free, VOCcompliant, fast-dry MIL-P-11414E and MIL-E-11195E into large-caliber ammunition 

production. 

In order to address the aforementioned coatings issues, this effort has been executed to improve 

and modify these ammunition specifications by combining the properties of the primer and 

topcoat into one coating. Some projectiles require single-coat systems to combine functions of 

primer and topcoat and yet remain fully functional. Generally, single coats are used on products 

that need only basic corrosion protection. In all cases, this fast-drying coating should meet all 

the current specification requirements but with enhanced durability and performance. 

Additionally, this coating should provide protection and less susceptibility to explosive staining 

and contamination. The use of environmentally friendly corrosion-inhibiting pigments in the 

topcoat specification was evaluated in addition to the resistance properties to solvents and 

propellants. 
2

2. General Characteristics 

The ammunition coating system is in one word “multifunctional,” with a multitude of 

requirements to fulfill. The coating system must be durable for long-term storage stability and 

corrosion resistance. The laboratory criterion for corrosion resistance is a minimum of 120 hr in 

a salt spray environment [4] on 0.8 to 1.2 mils thickness of paint. Another crucial requirement is 

fast dry at ambient temperatures and specifically “dry hard” in 12 min after application. 

3. Experimental Challenge 

The topcoat is occasionally stained when it comes in contact with explosives during the 

explosive-loading process into the steel projectiles after fabrication and painting. Trinitrotoluene 

(TNT), symmetrical 2,4,6-TNT, and Composition B are the explosives most generally employed 

in loading mortars and projectiles. Composition B is a mixture of 60% TNT and 40% wax. TNT 

is a pale yellow crystal of specific gravity 1.6 with a melting point of 82 °C or 180 °F. This low 

melting point allows it to be melted and poured into artillery shells and other explosive devices. 

In the absence of a detonator, it is a stable material and does not attack metals nor does it absorb 

moisture. It dissolves in benzene and acetone but is practically insoluble in water. 

A driving force of this formulation is the development of a stain-resistant coating to TNT and to 

Composition B. During experimentation, the most effective solvent for explosive residual stain 

removal was acetone, or a mixture of acetone diluted with a weaker solvent. Any reformulated 

topcoat should have moderate resistance to limited application of acetone to the film and also to 

explosive staining. 

Environmental regulations require the VOC to be less than 3.5 lb/gal (3.3 lb/gal for Scranton 

Army Ammunition Plant T) and the total HAPs less than 1% of the formulation. Some 

ammunition items require that the coating has to be chemical agent decontaminable. After 

neutralizing chemical agents and removal of the paint with the decontamination solution, the 

ammunition should pass the chemical agent resistance testing. 

4. Laboratory Formulations 

The basic composition of the formulation is listed as found in Figure 1: 
3

Figure 1. Basic composition of formulation. 

5. Resin Modifications 

The properties of particular topcoats are controlled by the resins used as the principal binder. 

Various blends of alkyd and amino resin were evaluated for dry time and stain resistance. Alkyd 

resins comprise a group of synthetic polymeric materials generally defined as reaction products 

of polyols, polybasic acids, or anhydrides. Alkyds tend to be lower in cost than other polymers 

and offer easy and foolproof applications. The systems are generally economical and provide 

moderate performance and chemical resistance. 

Amino resins are the main cross-linking agents for coatings. The amino resins of greatest 

commercial importance are the condensation polymers formed by the reaction of urea or 

melamine with formaldehyde. 

Melamine-formaldehyde types are dominant for thermosetting coatings and have gained 

popularity because of their ability to improve properties of baked alkyd coatings. In general, the 

urea-formaldehyde (UF) resins are more economical and the most reactive. With a sufficient 

acid catalyst, coatings formulated with UF can cure at ambient or slightly elevated temperatures. 

Some of their properties include excellent durability, hardness, flexibility, and alkali resistance. 

The chemistry of amino resins is complex because of the large number of variables and the fact 

that amino compounds are known to exist in tautomeric forms. Amino resins are almost never 

used by themselves in coatings; they are used to cross-link resins having hydroxyl, carboxylic 

acid, and/or amide groups. For ambient cure, they demand the use of a strong, ionizing acid such 

as sulfonic acids. 
4

Various polymeric resin modifications for chemical resistance were evaluated with different 

polymer systems along with various manufacturers and technologies including acrylic resins, 

styrene modified acrylics, hydrocarbon resins, high solids acrylic copolymer alkyds, and some 

styrene modified alkyd copolymers. The system that provided the best results was the high 

solids chain-stopped tall oil fatty acid (TOFA) alkyd, exhibiting acceptable dry times, gloss, and 

hardness. Formaldehyde amino resin was used to enhance cross-linking density and chemical 

resistance. Room temperature curing was achieved by using para-toluene sulfonic acid (pTSA) 

at various levels. 

6. Pigmentation 

Pigments are the finely divided insoluble solids that are dispersed in the vehicle and remain 

suspended in the binder during film formation. They are used in the coatings industry for several 

reasons, including color, hiding, application, and economics. Specific functional pigments are 

used to control gloss and surface roughness. Inert inorganics are used for prime pigments, and 

siliceous extenders are the primary flattening agents. 

For improved corrosion resistance, numerous anticorrosive pigments were evaluated including 

some basic and neutral pH anticorrosive pigments. Some showed reactivity with the sulfonic 

acid, adversely affected the drying properties, and therefore were eliminated. 

7. Additives

Additives are materials that are included in small quantities to modify some property of the 

coating. By nature, drying oils are slow drying and need metal salt driers to catalyze the drying 

rate. The most widely used catalysts are a combination of oil insoluble metal salts. The amounts 

used are system specific and are kept to a minimum. The type of fatty acid, drying oils, and oil 

length all govern the rate of cure. These alkyd coatings can be made more resistant to impacts 

by incorporating a few percent of slip agents, usually very small particle polyolefins. 

8. Solvent Modification 

Coatings contain volatile materials that evaporate during application and film formation. The 

selection of these volatile components is very critical and has effects on solubility, viscosity, 

toxicity, air pollution, film properties, corrosion, and durability. Our major objective is to reduce 

the amounts of solvents used and to specify compliant types, thus eliminating VOCs and HAPs. 
5

9. Experimental 

9.1 Stain Removal 

Besides meeting HAPs regulations, another thrust of the formulation is the development of a 

stain-resistant coating to TNT and Composition B. During experimentation, the most effective 

solvent for explosive residual stain removal was acetone, or a mixture of acetone diluted with a 

weaker solvent. However, a side effect of using acetone for stain removal was coating removal 

of the standard alkyd enamel system. Diluting the acetone with isopropyl alcohol (IPA) or 

hexane to lower acetone concentrations resulted in a reduction of coating removal, but sacrificed 

the ability of the solvent to remove the stain. 

Primarily, the aim in modification of these specifications is to give them stain resistance to TNT 

and Composition B, as well as to acetone. The improvement to acetone resistance will reduce 

the coating removal when wiped with the solvent. 

Table 1 summarizes the results of the stain removal experiment and the development of proper 

solvent proportions for stain removal without damaging the coating. 

Table 1. Stain removal experiment. 

Removal 

Test No. 

Panel Etching No. 

Paint Solvent Result 

1 #15/MIL-E-11195E 

(Brown stain migrated to film.) 

H2O No effect. 

 #15/MIL-E-11195E Ethanol No effect. 

 #15/MIL-E-11195E Hexane No effect. 

 #15/MIL-E-11195E NMP Dissolved Composition B but discolored the 

coating to a grayish purple color. 

 #15/MIL-E-11195E Toluene Removed stain, no color change of coating. 

 #15/MIL-E-11195E Acetone Dissolved Composition B, no color change, 

removed stain. 

 #15/MIL-E-11195E MIBK Dissolved Composition B. 

2 #18/MIL-P-53022Ba

Material stained 

(migrated into coating) 

Acetone No effect. 

 #18/MIL-P-53022B NMP No effect (slight lightening). 

 #18/MIL-P-53022B Toluene No effect. 

 #18/MIL-P-53022B H20 No effect. 

3 #2/MIL-E-11195E N/A Weakly removed stain and coating. 

 #2/MIL-E-11195E N/A N/A 

 #2/MIL-E-11195E Acetone 

(100%) 

Effectively removed stain, but also removed 

coating. 

4 #8/MIL-E-52798b Acetone 

(100%) 

Removed stain and some coating. 

 #8/MIL-E-52798 Acetone/H2O 

(1:1) 

No effect. 

 #8/MIL-E-52798 IPA Whitens area. 
6

Table 1. Stain removal experiment (continued). 

Removal 

Test No. 

Panel Etching No. 

Paint Solvent Result 

5 #20/MIL-E-52891Bc Acetone/IPA 

(1:1) 

Weakly removed the stain and some coating. 

 #20/MIL-E-52891B Acetone 

(100%) 

Removed the stain and some coating. 

6 #13/“Ammo CARC” Acetone 

(100%) 

Moderately removed surface stain. 

 #13/“Ammo CARC” NMP No effect. 

7 #19/MIL-C-46168d Acetone 

(100%) 

Removed the stain, but left a glossy 

area/highlights. 

8 #12/MIL-C-53039A Acetone 

(100%) 

Removed the stain, but left a glossy 

area/highlights. 

9 #1/TT-E-516e Acetone 

(100%) 

Removed the stain and coating. 

 #1/TT-E-516 MIBK Removed the stain and some coating. 

10 #5/Satin Black Acetone 

(100%) 

Removed the stain, no coating removed, 

coating only slightly discolored. 

11 #12/MIL-C-53039A Acetone/IPA 

(3:1) 

Removed the stain, but left a glossy 

area/highlights. 

12 #13/“Ammo CARC” Acetone/IPA 

(3:1) 

Did not remove the stain. 

13 #20/MIL-E-52891B Acetone/IPA 

(3:1) 

Removed the stain and a little bit of coating. 

 #20/MIL-E-52891B Acetone/IPA 

(2:1) 

More dilute acetone removed less coating. 

14 #17/MIL-P-22332Bf Acetone/IPA 

(1:1) 

No effect. 

 #17/MIL-P-22332B Acetone/IPA 

(2:1) 

Removed some of the stain and coating. 

 #17/MIL-P-22332B Acetone 

(100%) 

Removed the stain and coating. 

15 #6/MIL-P-11414 Hexane/acetone 

(1:1) 

Removed the stain and coating. 

16 #7/MIL-P-11414E Hexane Removed very little of the stain. 

 #7/MIL-P-11414E Hexane/acetone 

(1:1) 

Removed coating. 

17 #4/MIL-E-11195 Hexane/acetone 

(2:1) 

Removed coating. 

18 #10/TT-P-1757A Acetone 

(100%) 

Removed coating down to the panel with very 

little effort. 

19 #11/120 mm Topcoat 

(Crystalline stain below the surface.)

Acetone 

(100%) 

No effect. 

a

 U.S. Department of Defense. “Primer, Epoxy Coating, Corrosion Inhibiting, Lead and Chromate Free.” MIL-P-53022B, 

Washington, DC. 

b

 U.S. Department of Defense. “Enamel, Alkyd, Camouflage (Future Procurement MIL-C-46168).” MIL-E-52798, Washington, DC. c

 U.S. Department of Defense. “Enamel, Lusterless, Zinc Phosphate, Styrenated Alkyd Type.” MIL-E-52891B, Washington, DC. 

d

 U.S. Department of Defense. “Coating, Aliphatic Polyurethane, Chemical Agent Resistant.” MIL-C-46168, Washington, DC. e

 U.S. Department of Defense. “Enamel, Lusterless, Quick-Drying Styrenated Alkyd Type (No S/S Document).” TT-E-516, 

Washington, DC. 

f

 U.S. Department of Defense. “Paint, Priming, Exterior and Interior (For Ammunition).” MIL-P-22332B, Washington, DC. 

Notes: CARC = chemical agent resistant coating. 

IPA = isopropyl alcohol. 
7

The following illustrations and tables summarize the results for the panels stained with TNT after 

melt pour, explosive removal, and steam cleaning. 

The amount of staining and blooming was measured on a scale of 1–4, with 1 being the best 

result (i.e., least staining and/or blooming) and 4 being the worst. In evaluating each panel, 

comments were made to better assess the results of the experiment. Table 1 summarizes the 

results and evaluation of the vendor panels after solvent cleaning. 

9.2 TNT Cleaning 

Figure 2 is an illustration of the panels before staining with explosives. The panels were masked 

with aluminum foil and duct tape to keep one half of the coated panel clean from explosive 

staining. 

Figure 2. Masked panels before staining. 

Figure 3 illustrates a panel after the explosive was melted, poured, and kept in an oven for the 

required time. All of the panels stained with TNT were placed in an oven at 220 °F for 4 1/2 hr. 

Afterwards, the residual TNT was scraped off the panels, and the panels were steam cleaned. 
8

Figure 3. Masked panel during exposure to TNT. 

The following tables summarize the results for the panels stained with TNT after melt pour, 

explosive removal, and steam cleaning. The amount of staining and blooming was measured on 

a scale of 1–4, with 1 being the best result (i.e., least staining and/or blooming) and 4 being the 

worst. In evaluating each panel, comments were made to better assess the results of the 

experiment. Table 2 summarizes the results and evaluation of panels after steam cleaning. 

Table 2. Vendor sample results for TNT staining. 

Panel Ranking Comments 

1 3 Stain 

4 3 Stain and blooming 

6 3 Stain and blooming 

9 3 Stain 

12 2 1/2 Stain 

14 2 Minor stain and minor blooming 

16 4 Severe stain 

19 4 Severe stain 

22 3 Stain 

26-a 2 1/2 Stain 

27 2 Minor stain and minor blooming 

28 2 Minor stain and minor blooming 
9

ARL prepared the panels and the results show that PS 41-1, PS 43-1, and PS 44-1 were the 

panels that performed the best. Two panels from each group were stained and steam cleaned in 

concurrence with the batch of panels from the vendor sample. Table 3 summarizes the results 

and evaluation of the ARL panels after steam cleaning. 

Table 3. ARL panel results for TNT staining. 

Panel Ranking Comments 

99E12a 3 Wrinkled paint 

99E12b 3 Wrinkled paint 

52891a 2 1/2 Stain/minor blooming 

52891b 2 1/2 Stain/minor blooming 

PS 39-1a 3 Stain/minor blooming/some wrinkling 

PS 39-1b 3 Stain/minor blooming/some wrinkling 

PS 39-2a 2 1/2 Minor wrinkling/stain 

PS 39-2b 2 1/2 Minor wrinkling/stain 

PS 39-3a 2 1/2 Stain/more blooming than others 

PS 39-3b 2 1/2 Stain/more blooming than others 

PS 40-1a 3 Stain/some blooming 

PS 40-1b 3 Stain/some blooming 

PS 41-1a 1 No blooming/no stain 

PS 41-1b 2 No stain 

PS 42-1a 3 Stain/blooming/wrinkling 

PS 42-1b 3 Stain/blooming/wrinkling 

PS 43-1a 2 1/2 Stain/blooming 

PS 43-1b 2 1/2 Stain/blooming 

PS 44-1a 2 Stain/minor blooming 

PS 44-1b 2 Stain/minor blooming 

Figure 4 illustrates the difference between two panels after TNT staining and before steam 

cleaning. The panel on the right (PS 41-1a) showed no evidence of TNT staining, while the 

panel on the left (PS 42-1b) had staining and residual TNT adhering to the surface. 

The panels that showed the best performance were the panels prepared with PS 41-1, PS 43-1, 

and PS 44-1. The best performer from that group was PS 41-1, which had the best resistance to 

TNT and the least blooming. 

9.3 Composition B Cleaning 

The panels stained with Composition B were placed in an oven at 220 °F for 10 min. The oven 

was then turned off, and the panels were kept in the oven and cooled for an additional 90 min. 

Afterward, the panels were cleaned of any residual Composition B and selected panels were 

cleaned with acetone. 
10

Figure 4. Performance comparison of two ARL panels. 

The following tables summarize the results for the panels stained with Composition B after melt 

pour and explosive removal before acetone cleaning. Two panels from each group prepared by 

ARL were stained, and one panel from each group prepared by Vendor sample was stained. The 

amount of staining was measured on a scale of 1–5, with 5 being the best result (i.e., least 

staining) and 1 being the worst. The vendor sample results are summarized in Table 4, and the 

ARL results are summarized in Table 5. 

Table 4. Vendor results for Composition B. 

Panels Ranking 

2 2 

5 3 

7 2 1/2 

10 2 1/2 

13 2 

15 2 1/2 

17 2 

20 1 

23 1 

25 2 

30 3 

31 3 
11

Table 5. ARL results for Composition B.

Panels Ranking 

99E12C and D 1 

52891C and D 1 

PS 39-1C and D 1 

PS 39-2C and D 3 

PS 39-3C and D 2 1/2 

PS 40-1C and D 1 

PS 41-1C and D 2 

PS 42-1C and D 1 

PS 43-1C and D 3 

PS 44-1C and D 4 

Figure 5 compares the results after Composition B staining and before acetone cleaning. Figure 6 

illustrates the panels with the best performance before acetone cleaning. 

Figure 5. Composition B staining. 
12

Figure 6. Panels steam cleaned. 

Figure 7 shows two panels cleaned with acetone. Above each panel is the cheesecloth used to 

clean the panel. The cheesecloth was wetted with acetone, and the panels were rubbed with 

pressure four times in the same direction. The same procedure was used to clean the panels 

illustrated in Figure 8. The panels that showed the best acetone resistance were panel 10 from 

vendor sample and panel PS 41-1c. However, panel 10 exhibited a stain after acetone cleaning, 

and panel PS 41-1c did not exhibit any stain after acetone cleaning. 

The panels that showed the best resistance to acetone and Composition B staining were panels 

PS 41-1, PS 43-1, and PS 44-1. The panels with the best performance were the panels from 

group PS 41-1. 
13

Figure 7. Panels cleaned with acetone. 

Figure 8. Panels cleaned with acetone. 
14

10. Experimental Results 

Table 6. Acetone wipe test.

Sample 

Alkyd Resin/Formaldehyde/ 

Acid Catalyst Ratinga

PS 41-1 5720/933/5% 4 

PS 41-1 5720/933/5% 5 

PS 41-1C 5720/797/5% 2 

PS 41-1B 5720/100% 4 

PS 41-1A 5720/933/0% 1 

MIL-E-52891 Control 3 

MIL-E-52891 Control 3 a

Rating of 5 is best and 1 is worst. 

Table 7. Acetone cleaning results. 

Panel Resin 933 PISA Before Acetone After Acetone 

43-1 MIL-E-52891 N/A N/A Blooming Paint removed/clean, no visible stain 

41-1 5720 Yes Yes Little blooming Little paint removed/clean, no visible stain 

41-1 5720 Yes Yes Little blooming Little paint removed/clean, no visible stain 

41-1C 5720 No Yes Blooming Paint removed/clean, visible stain 

41-1B 5720 No No Blooming Less paint removed/clean, no visible stain 

41-1A 5720 Yes No Blooming Substantial paint removed (down to bare 

metal)/clean, no visible stain 

52891 MIL-E-52891 N/A N/A Blooming Paint removed/clean, no visible stain (few 

spots) 

On the systems that showed a blooming problem, it seems that steam or hot water physically 

removes all of the explosives from the film surface and at the same time insolubilizes and/or 

precipitates out a portion of the propellant and/or its minor constituents that have penetrated 

deepest into the film. The most penetrating are the ones with the lowest molecular weight. And 

possibly they may be solubilized at steam temperature and become insoluble at room 

temperature. It is a standard test for the solvency power of some of the solvents used in coatings 

such as ketones and esters where a small percentage (1 part NC to 8 parts solvent) solution of NC 

is added to a solvent, for instance, toluene until the NC precipitates out of solution. A good 

strong solvent like methyl ethyl ketone (MEK) will require increased toluene to precipitate out 

while a good weaker solvent like ethyl acetate will precipitate out with less amounts. 
15

10.1 Adhesion Testing ASTM D 3359 Method B Adhesion [5] 

Table 8 lists the panels used in adhesion testing and the results. The ASTM Cross-Cut Adhesion 

testing was performed with 2-mm line spacing, appropriate for dry film thickness between 2 and 

5 mil (1 mil = 0.001 in). 

Table 8. Adhesion testing. 

Substrate Control 

(Styrenated Alkyd) 

Control 

(Styrenated Alkyd) 

Olive Drab Olive Drab 

 Panel Result Panel Result Panel Result Panel Result 

Bondrite B37 P60 9 5B (pass) 10 5B (pass) 2 5B (pass)

Bondrite B37 P60 

+ 

53022 (2.8 VOC) 

1 5B (pass) 13 5B (pass) 7 4B (pass) 5 5B (pass)

Cold roll steel S412 15 5B (pass) 12 5B (pass) 14 5B (pass) 8 4B (pass)

Cold roll steel S412 

+ 

53022 (2.8 VOC) 

11 4B (pass) 6 4B (pass) 4 4B (pass) 3 4B (pass)

Notes: 5B rating means no removal. 

 4B rating means <5% removal. 

 3B rating means 5–15% removal. 

 2B rating means 15–35% removal. 

 1B rating means 35–65% removal. 

10.2 Wet Adhesion Testing 

Coated samples were partially immersed in water for 24 hr and subjected to cross-cut adhesion 

testing within 5–10 min. Samples were also evaluated for changes in color, blistering, softening 

and loss of adhesion, upon removal and also after a 24-hr recovery period. 

Table 9 lists the panels used in adhesion testing and their results. The cross-cut adhesion was 

performed with 2-mm line spacing, appropriate for a dry film thickness between 2 and 5 mil 

(1 mil = 0.001 in). 

Table 9. Wet adhesion testing. 

Substrate Control 

(Styrenated Alkyd) 

Control 

(Styrenated Alkyd) 

Olive Drab Olive Drab 

 Panel Result Panel Result Panel Result Panel Result 

Bondrite B37 P60 9 5B (blister) 10 1B (100% 

blister) 

 2 5B (pass)

Bondrite B37 P60 

+ 

53022 (2.8 VOC) 

1 3B (blister) 13 4B (100% 

blister) 

7 5B (color 

soft) 

5 4B (soft)

Cold roll steel S412 15 5B (pass) 12 5B (pass) 14 5B (color 

stain) 

8 5B (pass)

Cold roll steel S412 

+ 

53022 (2.8 VOC) 

11 1B 6 4B (pass) 4 1B (color 

change) 

3 2B 

Notes: 5B rating means no removal. 

 4B rating means <5% removal. 

 3B rating means 5–15% removal. 

 2B rating means 15–35% removal. 

 1B rating means 35–65% removal. 
16

10.3 General Motors (GM) Standard Test 9540P [6] 

A cyclic corrosion test chamber was used to evaluate the MIL-E-11195 [1] coated test panels. 

The panels were placed into the chamber and tested using GM Standard Test 9540P [6], Method 

B10, which provides a more realistic accelerated environmental test than conventional salt spray. 

The test consists of the repetition of 18 separate stages including salt (1.25% by mass: 0.9% 

NaCl, 0.1% CaCl2, 0.25% NaHCO3) water mist, humidity, drying, ambient, and heated drying. 

The environmental conditions and duration of each stage for one complete 9540P cycle are given 

in Table 10. The above process repeated 80 times to a scribed panel is claimed by industry to be 

equivalent to 10 years of field exposure in South Florida. For this test, the groups of scribed 

coupons were exposed until failure or termination. The panels were observed after testing for 

22 cycles. As with B117 salt fog, the extent of damage was assessed using ASTM D 1654 [7]. 

Table 10. GM 9540P cyclic corrosion test details. 

Interval Description Interval 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 

10.4 Salt Fog Testing in Accordance With ASTM B117 [4] 

Salt fog testing in accordance with ASTM B117 [4] was used to screen the coated panels. The 

solution used was the standard 5% NaCl. The panels were all inspected prior to testing, upon 

significant changes, and at failure. The coated panels (three each) for each coating were exposed 

for 120 hr of salt fog. These panels were "X" scribed using standard carbide-tipped hardened 

steel scribe. Final detailed ratings for the 120-hr duration were assessed using ASTM D 1654, 

which quantitatively indicates the damage caused by pitting or delaminating outwards from the 

scribe. Panels were air dried for 7 days, and a subset was also baked at 105 °C for 30 min. 
17

Table 11. ASTM B117 [4] results. 

Data on Test Series #24, KC-76 -1 

(#1 to #3) 

Modified 5720 Tall Oil Alkyd 

a) 19-1002 amino resin 

b) With and without anticorrosive @ 2× 

c) 3% pTSA 1040 

(#4 to #6) 

Modified 5720 Tall Oil Alkyd 

a) UF resin 

b) With and without anticorrosive @ 2× 

c) 3% pTSA 

(#7 to #9) 

Modified 5720 Tall Oil Alkyd 

a) UF resin 

b) With and without #1552 @ 2× 

c) 3% pTSA 

(#10) 

Controls – Olive Drabs – MIL-E-52891 [8] 

N/A 

(#11) 

Controls – Olive Drabs – MIL-E-11195 [1] 

N/A 

(#12) 

Qualified Products List (QPL) sample (99E13) 

N/A 

11. Results 

11.1 Acetone Resistance 

Ratings (5 = best, 1= worst) 

On these coatings, with a decrease to 3% catalyst level, we found a borderline resistance for 

acetone. The air-dried films showed no improvement over the controls (1 to 2 out of 5). The 

baked films showed very good resistance to acetone with the use of the catalyst, pTSA (5 out 

of 5) slightly better than the acid phosphate (4 out of 5). The two controls had showed slight 

improvements (3 out of 5) after baked. Force drying for 30 min at 60 °C did not improve 

acetone resistance in these systems. 

11.2 Corrosion Resistance 120 hr in ASTM B117 [4] 

For control MIL-E-11195 [1], after exposure both the air-dried and the baked samples were 

acceptable. For control MIL-E-52891 [8], the air-dried samples showed a moderate amount of 

small-scattered blisters. Baked samples were satisfactory. The experimental samples KC- 76 

(#1 to #12) showed no blisters but displayed surface rust on all panels with KC-76, (#3) with the 

least and KC-76 (#5, #12) with the most. Baking provided only a marginal improvement. 

11.3 GM 9540 [6] 

After 14 cycles in GM 9540, the system supports ASTM B117 [4] results. The standard MIL-E52891 passed, but the systems with the acid catalyst had severe blistering and surface rust. As a 

result, a series (KC #25) was prepared with increased (4%) acids catalyst and maximized 

anticorrosive additives. 
18

11.4 Corrosion Resistance 144 hr in ASTM B117 [4] 

Several attempts were made to improve salt spray results of the acetone and corrosion resistant 

topcoat, which will be revised as MIL-E-11195, TYP 111, using MIL-E-52891 as the control and 

the base MIL-E-11195 formula, and 8 variations to improve corrosion resistance. Formulations 

were analyzed using different anticorrosive pigments (Sicorin RZ, SAPP) and additives (Nacorr 

1552 and Ciba 153). 

12. Observations 

Using as criteria acetone resistance and corrosion resistance, there is no one formula where both 

properties can be maximized. 

The basic formulation, with corrosion-inhibiting phosphate pigments SAPP and the anticorrosion 

liquid Nacorr 1552, has excellent resistance to acetone, significantly better than MIL-E-52891. 

However, it fails the salt spray B117 at 120 hr. There is a possibility that it may have good 

corrosion resistance in the real world but verifying that would require running cyclic weathering 

and humidity cabinet exposures. 

13. Summary 

The anticorrosive additives Sicorin RZ and Ciba 153 promote corrosion resistance in the salt 

spray environment but also reduce the acetone resistance. 

There were several attempts to further improve salt spray results on the TYP III formulation, 

Sample C. Panels were prepared and primed. Topcoats were applied after intervals of 5 min, 

15 min, 30 min, 60 min air drying, and after a force dry of 30 min at 105 °C. In addition to using 

MAK as the reducer for the catalyst, a change to a faster solvent was used in this formula. An 

epoxy primer was also tested and was compared to the existing primer with the same time 

intervals. A decrease in the catalyst level to 4% was also applied. A list of the samples tested 

are in Table 12. 

Table 12. Samples tested in B117. 

Sample Identification Formulation 

Sample B MIL-E-52891 [8] olive drab 

Sample C Acetone resistant MIL-E-11195 [1] olive drab 

TYP III 

Sample D Acetone resistant MIL-E-11195 TYP III/ 

MIL-P-11414E [3] red oxide primer 

Sample E Corrosion resistant MIL-E-11195 on 

no fire/olive drab TYP II 
19

After 120 hr in the salt chamber, sample C, acetone-resistant coating without the primer failed 

severely with blisters and discoloration; the remaining panels showed very little degradation. 

14. Conclusion 

We have completed in-house formulation for a corrosion-resistant coating and incorporated it 

into MIL-E-11195 [1] as TYP II. A 50% improvement in salt spray resistance is evidence of 

enhanced durability, and production line results indicate less handling damage. 

The product is currently used on the 155-mm and 120-mm projectiles. The QPL includes the 

approval of the colors olive drab, green, white, black, and blue. 

Work is being continued to revise chemical resistance coating MIL-E-11195 as TYP III, to 

permit better corrosion resistance, maintain acetone resistance with the use of neutral and acidic 

anticorrosive pigments, and also to evaluate the compatibility of these anticorrosive pigments. 
20

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21

15. References 

1. U.S. Department of Defense. “Lusterless Finish Coat for Phosphate or Primed 

Ammunition.” MIL-L-11195D and MIL-L-11195E, Washington, DC. 

2. U.S. Department of Defense. “Quick Drying Rust Inhibitive Lacquer.” MIL-P-11414D, 

Washington, DC. 

3. U.S. Department of Defense. “Primer Alkyd, Fast Dry Corrosion Inhibiting (L&C Free) 

VOC Compliant.” MIL-P-11414E, Washington, DC. 

4. American Society for Testing and Materials (ASTM). “Standard Method of Salt Spray (Fog) 

Testing.” ASTM B117-90, Philadelphia, PA, 1990. 

5. American Society for Testing and Materials (ASTM). “Standard Test Method for Measuring 

Adhesion by Tape Test.” ASTM D 3359-37, Philadelphia, PA, 1998. 

6. American Society for Testing and Materials (ASTM). “Accelerated Corrosion Test. GM 9540P.” 

Standard GM 9540, General Motors Engineering, Detroit, MI, 1997. 

7. American Society for Testing and Materials (ASTM). “Standard Test Method for Evaluation of 

Painted or Coated Specimens Subjected to Corrosive Environments.” ASTM D 1654, 

Philadelphia, PA. 

8. U.S. Department of Defense. “Enamel, Lusterless, Zinc Phosphate, Styrenated Alkyd Type.” 

MIL-E-52891, Washington, DC. 
22

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23

Bibliography 

Wicks, Z. W., Jr., F. N. Jones, and S. P. Pappas. “Organic Coatings.” Science and Technology, 

vol. 2, Canada: John Wiley & Sons, Inc., 1992. 
24

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25

coatings, ammunition, corrosion, stain resistant 28

The U.S. Army Research Laboratory (ARL) Coatings Team and the U.S. Army Armament Research, Development, and

Engineering Center (ARDEC) Munitions Metal Parts Team have established a major collaborative effort to eliminate

various obsolescent coatings and consolidate them into a universal coating system. The exterior ammunition coatings

provide ready identification and corrosion protection for long-term storage stability. The fast-drying exterior coatings

used on large-caliber projectiles are susceptible to contamination and staining by explosives. Staining of the topcoat can

occur during the loading process when explosives are poured into the steel projectiles after fabrication and painting. 

The ARL Coatings Team, in conjunction with ARDEC, has developed a modification to the ammunition coating

specifications by combining the properties of the primer and topcoat into one coating. The new coating is

ammunition-explosive compatible, highly resistant to corrosion, fast drying, low in cost, and can be used as a single coat

for the medium- and large-caliber ammunition systems. A research and development effort is ongoing to substantially

increase the chemical resistance of the coating. These coatings will comply with environmental regulations including

The National Emissions Standard for Hazardous Air Pollutants, which eliminates the use of hazardous air pollutant

solvents. 

*Mail care of: U.S. Army Research Laboratory, ATTN: AMSRL-WM-MA, Aberdeen Proving Ground, MD 

21005-5069

ARL-TR-2795

U.S. Army Research Laboratory

ATTN: AMSRL-WM-MA

Aberdeen Proving Ground, MD 21005-5069

Kestutis G. Chesonis and Pauline M. Smith*

Formulating Multifunctional Protective Ammunition Coatings 622105.H84

August 2002 Final, February 2000 – December 2001

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