'N a'tlbnaJ bureau of Standards

NOV 1 0 1944
BUILDING MATERIALS AND STRUCTURES REPORTS

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BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 100

BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions lOp

BMS3 Suitability of Fiber Insulating Lath as a Plaster Base loji BMS4 Accelerated Aging of Fiber Building Boards 10^ BMS5 Structural Properties of Six Masonry Wall Constructions 150 BMS6 Survey of Eoofing Materials in the Southeastern States 15^ BMS7 Water Permeability of Masonry Walls 100 BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 100 BMS9 Structural Properties of the Insulated Steel Construction Co.'s "Frameless-Steel" Constructions for WaUs, Partitions, Floors, and Roofs 100 BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 100 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 100 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

Sponsored by Steel Buildings, Inc 150 BMS13 Properties of Some Fiber Building Boards of Current Manufacture 100 BMS14 Mentation and Recovery of Low-Cost Floor Coverings 100 BMS15 Structural Properties of "Wheeling Long-Span Steel Floor" Construction Sponsored by

the Wheeling Corrugating Co 100 BMS16 Structural Properties of a "Tilecrete" Floor Construction Sponsored by Tilecrete Floors, Inc 100 BMS17 Sound Insulation of Wall and Floor Constructions 100 Supplement to BMS 17, Sound Insulation of Wall and Floor Constructions 50 BMS18 Structural Properties of "Pre-fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation 100 BMS19 Preparation and Revision of Building Codes 150 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors, Sponsored

by Connecticut Pre-Cast Buildings Corporation 10^

BMS21 Structural Properties of a Concrete-Block Cavity-Wall Construction Sponsored by the National Concrete Masonry Association 10^ BMS22 Structural Properties of "Dun-Ti-Stone" WaU Construction Sponsored by the W. E. Dunn Manufacturing Co 10^ BMS23 Structural Properties of a Brick Cavity-WaU Construction Sponsored by the Brick

Manufacturers Association of New York, inc 10^ BMS24 Structural Properties of a Reinforced-Brick Wall Construction and a Brick-Tile CavityWaU Construction Sponsored by the Structural Clay Products Institute 10|

BMS25 Structural Properties of Conventional Wood-Frame Constructions for Walls, Partitions,

Floors, and Roofs 150 BMS26 Structural Properties of "Nelson Pre-Cast Concrete Foundation" Wall Construction

Sponsored by the Nelson Cement Stone Co., Inc 10$

BMS27 Structural Properties of "Bender Steel Home" Wall Construction Sponsored by the Bender Body Co - 100 BMS28 Backflow Prevention in Over-Rim Water Supplies 100 BMS29 Survey of Roofing Materials in the Northeastern States lOg

BMS30 Structural Properties of a Wood-Frame Wall Construction Sponsored by the Douglas

Fir Plywood Association 100 BMS31 Structural Properties of "Insulite" WaU and "Insulite" Partition Constructions Sponsored by The InsuUte Co — 150

(List continued on cover page iii]
UNITED STATES DEPARTMENT OF COMMERCE • Jesse H. Jones, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, Director

BUILDING MATERIALS

and STRUCTURES

REPORT BMS102

Painting Steel

by

WILBUR C. PORTER

ISSUED OCTOBER 16, 1944

The National Bureau of Standards is a fact-finding organization;

it does not "approve" any particular material or method of construction. The technical findings in this series of reports are to be construed accordingly

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • 1944

FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, U. S. GOVERNMENT PRINTING OFFICE

WASHINGTON 25 D. C. • PRICE 10 CENTS
Foreword

This is the third and final report issued by the National Bureau

of Standards covering the investigation of pretreatments and paints

for protecting plain and galvanized steel surfaces against corrosion.

A description of the tests and an explanation of their limitations were published in a previous report, Methods of Investigation of

Surface Treatment for Corrosion Protection of Steel, BMS8. The

results of the tests made on pretreatment processes have been published as report BMS44, Surface Treatment of Steel Prior to Painting.

The present paper describes the relative durability of primingcoat and topcoat paints for plain and galvanized steel surfaces when

subjected to accelerated laboratory and outdoor exposure tests.

Lyman J. Briggs, Director.

[n]
Painting Steel

by WILBUR C. PORTER

CONTENTS

Page

Foreword ii I. Introduction 1 II. Priming-coat paints I III: Painting plain steel surfaces 3

1. Preparation of the surface 3

2. Results of accelerated-weathering

and outdoor-exposure tests of priming coats on plain steel 5 IV. Painting galvanized-steel surfaces 5

1. Preparation of the surface 5

Page

IV. Painting galvanized-steel surfaces—Con.

2. Results of accelerated-weathering

and outdoor-exposure tests of priming coats on galvanized

steel 6

V. Topcoat paints 9

1. Results of tests of topcoat paints. _ 11 VI. Summary and conclusions 12

VII. Selected references 12

ABSTRACT

More than 60 priming paints for plain and galva- nized steel surfaces were tested. Because some of these primings were duplicates or near duplicates and others were considered unsuitable, only 41 have been selected

for this report. Accelerated laboratory and outdoor

exposure tests were employed to determine the relative protective value of these primings when applied to treated and untreated galvanized and plain steel panels.

Particularly effective protection against corrosion was

observed when primings of the synthetic resin zinc chromate type were used over a phosphate-treated

surface. Special attention was given to the effect of pretreating new galvanized steel before painting. More

than 2,000 galvanized and plain steel panels were pre- pared for exposure in the various tests. The relative durability to outdoor exposure of 15 topcoat paints is also discussed.

I. INTRODUCTION

As part of the general research program ot the National Bureau of Standards on building

materials and structures, a study has been made

of the surface treatment and painting of steel for protection against corrosion. The results

obtained in the early phases of the work have

been published as two Building Materials and

Structures Reports, BMS8 and BMS44.1 This

paper concludes the investigation with a desscription of the results of the tests on primingcoat and topcoat paints.

In the painting of steel structures, durability

of the paint film is a recognized factor in pre- venting corrosion. Climatic conditions, the

composition and preparation of the metal, the

adherence and composition of the paint coating, as well as the conditions under which the coat- ing was applied, influence the serviceability of the paint film. Nearly all steel structures are painted either for protective or decorative

1 BMS8. Rolla E. Pollard and Wilbur C. Porter, Methods of inves.

ligation of surface treatment for corrosion protection of steel. BMS44 . Rolla E. Pollard and Wilbur C. Porter, Surface Treatment

of Steel Prior to Painting.

purposes, and the paint coating must remain as a

continuous film over the metal if it is to fulfill these functions properly.

For practical purposes, corrosion tests are made to ascertain which of a number of processes or coatings will protect the metal most

completely. It is clear that no laboratory

test can fully take the place of a long-period,

full-scale service test, and it is not to be ex- pected that these tests, reduced in scale to economize space and increased in intensity to save time, will produce results directly measurable in terms of so many years of actual service.

However, it is believed that comparisons can

be made from the results of accelerated tests which will indicate to some degree the relative

protective value of paint systems. The conclusions in this paper are drawn on the basis of

factors aft'ected by conditions peculiar to the

individual test, and the results of the outdoor

exposure tests may not correlate those in other

parts of the country.

II. PRIMING-COAT PAINTS

The fundamental factors governing the retention of paint film integrity on metal may be

expressed in a few essential requu'ements

;

namely, permanent adhesion, distensibility,

water resistance, chemical inertness, and the

presence of a rust-inhibitor. The extent to which these characteristics are manifested in

paint coatings determines their efficacy for

protecting metal against corrosion. The advent of S3rnthetic resins and the proper formulation of these for use in paint vehicles has

made possible the improvement of some of these

properties.

A synthetic resin may be defined as a resin

made by synthesis from nonresinous organic

compounds. The alkyd resins, used princi607349°—44 [1]
pally in paints, varnishes, and lacquers, are a group of condensation products synthesized

by reacting polyhydric alcohols, such as glycerine and the glycols, with dibasic organic acids,

such as phthalic, maleic, succinic, and sebacic.

The condensation product is almost always

modified to give properties to the resin desirable or essential to the specific application

contemplated. The modifying agent may be

a drying, semidrying, or nondrying oil; the

fatty acid of an oil; a natural resin, such as

rosin; a synthetic resin of the phenolic group

or of the urea-formaldehyde type. Good adhesion, color and gloss retention, durability,

toughness, and flexibility are some of the out- standing characteristics imparted to primings

containing properly formulated alkyd vehicles.

They are exceptionally well adapted for the

baking type of priming and enamel.

The phenolic resins used in paints, varnishes,

and other sm-face coatings are usually oil- soluble types. Modified phenolic resins are phenol-formaldehyde condensation products

rendered oil soluble by chemical combination

or by physical dispersion in other materials,

such as rosin and copal. Unmodified or 100-

percent soluble phenolic resins are condensation

products made from tar acids other than simple

phenol, which are themselves soluble in dr3^ing

oils and thinners. The unmodified resins are extensively used in long-oil chinawood varnishes, to which they impart greater drying

speed, durability, and resistance to alkalis and

gases. The modified types impart the same

properties to tung-oil varnishes but to a lesser extent. In addition, they possess considerable

hardness and gloss. Tn general, the phenolic

vehicles have very good water, acid, and alkali

resistance. The long-oil unmodified types are

especially useful in the formulation of exterior

marine finishes, which require superior resist- ance to severe water and weathering conditions.

Oil and phenol modified alkyds are very

versatile and combine many of the qualities

needed to produce durable paints for general

interior and exterior use on metal.

More than 60 priming paints for steel and

galvanized surfaces were tested in this investigation. Because some of these primings were

duplicates or near duplicates and others were

considered unsuitable, only 41 have been in- cluded in this report. The primings have been

rated in groups according to their protective

value, which in this paper means the extent to which the paint coatings fiJfill the function of protecting the underlying metal. The ratings are discussed under the results of the tests and

for convenience are included in table 1. The

following table gives the designation, description, and group ratings of these primings:

Table 1.

Designation, description, ana group ratings of the priming-coats

Description of primings

Red lead paint. Federal Specification TT-R-191a, Type I, Grade B

Dry red lead. 20 pounds. Raw linseed oil _ 5 pints. Turpentine 2 gills. Liquid drier 2 gills. 25. 2 pounds per gallon. Blue lead paint Blue lead paste in oil 100 poimds. Raw linseed oil 23^ gallons. Turpentine.- \% gallons. Liquid drier. 1 quart.

18.2 pounds per gallon. International orange paint. Federal Specification TT-P-59. Type A . 18.0 pounds per gallon Metallic lead and carbon paint. ._ 38 percent pigment by weight:

90 percent metallic lead.

10 percent carbon black. 62 percent vehicle by weight, oil and phenol modilied .glyceryl phthalate resin varnish:

56 percent nonvolatile.

44 percent volatile. Iron oxide-zinc chromate metal priming. Post Oflice Department Specification, revised as of April 7, 1937 Aluminum paint. 2 pounds aluminum powder

Federal Specification TT-A-476, Type A, per

gallon of varnish Federal Spec. TT-V-81

Quick-drying red lead in alkyd (oil type) vehicle.

19.4 pounds per gallon Zinc chromate priming. Navy Aeronautical Specifi- cation P-27b, June 1, 1937 Zinc dust-zinc-oxide-glyceryl phthalate paint. Federal Specification TT-P-641 . Type II, Class A

Asphalt varnish. Federal Specification TT-V-51

Metallic lead and carbon in phenolic resin vehicle Metallic lead in phenolic resin vehicle Graphite in linseed oil paint Metallic lead in phenolic resin vehicle Metallic lead-blue lead in phenolic resin vehicle

52 percent metallic lead in pigment.

48 percent blue lead in pigment.

Zinc dust-zinc oxide priming

68 percent pigment by weight:

60 percent zinc dust.

26 percent zinc oxide.

11 percent siliceous matter.

3 percent white lead. 32 percent vehicle-vegetable oil and spar varnish. Zinc dust-zinc oxide priming

76 percent pigment by weight:

35 percent zinc dust.

65 percent zinc oxide. 24 percent vehicle-vegetable oil and spar varnish. Gray paint for galvanized steel 56 percent pigment by weight:

59 piTccnt zinc oxide.

9 prrccnt wliite lead. 29 percent siliceous matter. Carbon tinting material present. 44 percent vehicle-vi'getatile oil and thinner. Natural rubber clear priming. (Aluminum paint in natural rubber vehicle. Topcoat 'or number 25) . . _ Pigmenteii natural rubber priming. (Aluminum paint

in natural rubber vehicle. Topcoat for number 27)_ Iron oxide-zinc chromate priming

52 percent pigment by weight:

50 percent iron oxide (85% Fe203).

25 percent zinc chromate.

15 percent asbestine.

10 percent silica. 48 percent vehicle by weight: Phenol-formaldehyde resin-chinawood oil varnish. See footnote at end of table.

[2]
Table 1.

Designation, description, and group ratings of the priming-coats—Continued

Group rating i

Description of primings

oil

Zinc chromate priming

45 percent pigment by weigtit: 80 percent zinc chromate.

20 percent magnesium silicate. 55 percent veiiicle by weiglit: Phenol-formaldeliyde resin-chinawood

varnish. Zinc chromate priming

45 percent pigment by weight:

80 percent zinc chromate.

20 percent magnesium silicate. 55 percent vehicle by weight: Para phenyl phenol-formaldehyde resin. Oil is 50 percent linseed oil and 50 percent chinawood oil. Zinc chromate-aluminum priming. Similar to No. 31 with the addition of one pound of aluminum powder per gallon of primer

Zinc dust-zinc-oxide priming

60 percent pigment by weight:

80 percent zinc dust.

20 percent zinc oxide. 40 percent vehicle by weight: V-10 Naval Aircraft Specification Spar Varnish. Zinc dust-zinc oxide-linseed oil paint. Federal

Specification TT-P-641, Type I, Class B

Zinc dust-zinc oxide-phenolic resin paint. Federal

Specification TT-P-641. Type III, Class B

Zinc dust-zinc oxide-iron oxide paint60 percent pigment by weight:

60 percent zinc dust.

20 percent zinc oxide. 30 percent iron oxide. 40 percent vehicle by weight: Phenolic resin-chinawood oil varnish. Chlorinated rubber paint pigmented with 27 percent aluminum, 41 percent zinc chromate, 14 percent black iron oxide and 18 percent carbon black Chlorinated rubber paint pigmented with 56 percent

zinc chromate, 19 percent black iron oxide, and 25 percent carbon black Chlorinated rubber paint pigmented with 88 percent

metallic lead, 7 percent zinc chromate, 2 percent black iron oxide, and 3 percent carbon black Red chromate priming

43 percent pigment by weight:

32 percent lead chromate.

10 percent lead sulfate. 37 percent iron oxide.

21 percent siliceous matter.

57 percent spar varnish vehicle by weight.

Iron oxide-zinc chromate priming

48 percent pigment by weight:

41 percent zinc chromate.

38 percent iron oxide.

21 percent siliceous material. 52 percent vehicle by weight:

011 and phenol modified glyceryl phthalate resin varnish.

60 percent nonvolatile. 40 percent volatile. Iron oxide-zinc oxide paint

60 percent pigment by weight:

59 percent metallic brown (68% FejOs).

18 percent Spanish iron oxide (86% FeaOa).

12 percent zinc oxide.

11 percent asbestine. 40 percent vehicle by weight: Long oil spar varnish.

65 percent nonvolatile.

35 Dercent volatile. Zinc dust-zinc oxide-linseed oil paint

79 percent pigment by weight:

78 percent zinc dust.

20 percent zinc oxide.

2 percent litharge. See footnote at end of table.

Galvanized

steel

Table 1.Designation, description, and group ratings

of the pri7ning-coats—Continued

74

75

77

82

Group rating

Description of primings

21 percent vehicle by weight: Linseed oil, thinner and drier. 90 percent nonvolatile.

10 percent volatile. Aluminum-zinc dust paint.-. 30 percent pigment by weight:

58 percent zinc dust. 22 percent aluminum.

8 percent zinc oxide.

12 percent inert pigment.

70 percent vehicle by weight: Treated oils and natural resin varnish.

64 percent nonvolatile. 36 percent volatile. Metallic lead in alkyd resin varnish

39 percent pigment by weight.

61 percent vehicle by weight:

46 percent nonvolatile containing 38 percent

of glyceryl phthalate.

54 percent volatile. Metallic lead-red lead in alkyd resin varnish

51 percent pigment by weight:

75 percent metallic lead. 25 percent red lead. 49 percent vehicle by weight (same as 74). Iron oxide-zinc chromate in alkyd resin varnish

38 percent pigment by weight:

67 percent Spanish iron oxide (84% Fe2 O3). 33 percent zinc chromate.

62 percent vehicle by weight:

45 percent nonvolatile containing 44 percent

glyceryl phthalate.

55 percent volatile. Blue lead in phenolic rpsin varnish

72 percent pigment by weight.

28 percent vehicle by weight. Blue lead in ester gum modified alkyd resin varnish - - 72 percent pigment by weight.

28 percent vehicle by weight.

Galvanized

steel

J 1 is the best group; 2, the second best group, etc.

III. PAINTING PLAIN STEEL SURFACES

1. Preparation of the Surface

Several theories have been advanced to explain the mechanism of corrosion, but the elec- trochemical theory is now generally accepted

as the best explanation of most types of corrosion. The ordinary metallic surface is not truly

homogeneous, chemically and physically, and

points of potential difference are sure to exist. In the presence of moisture containing small

amounts of dissolved salts, which serve as the

electrolyte, a tiny electrolytic cell is formed

between anodic and cathodic areas. Under

proper conditions, an electric current flows

through the electrolyte from the anode to the

cathode and from the cathode back to the anode

through the metal itself, thus completing the

circuit. This electrochemical action causes the

metal to dissolve at the anode and hydrogen to

[3]
be evolved from the electrolyte at the cathode.

Obviously, if this action continues, the metal at the anodic areas will gradually disintegrate.

The complete absence of moisture precludes the

possibility of corrosion by electrochemical action. In other words, the presence of moisture

to form an electrolytic medium through which

an electric current can flow is necessary for corrosion to take place. Accepting this theory,

it is evident that the less water permitted to come in direct contact with the metal, the less corrosion will take place. Since no paint film

today is absolutely impervious to moisture, the

need for a pigment possessing sufficient rust

inhibitive power is obvious. The flow of eletric currents between the anodic and cathodic

areas can be retarded by using chemical treat- ments that form a nonmetallic coating on the

metal.

The fundamental requisite of a priming coat paint for any metal surface is that it adheres

permanently to the metal. This important requirement should be kept in mind constantly

in preparing the surface, and certain precautions should be taken to insure the best per- formance of the priming coat. All steel sur- faces to be painted should be thoroughly cleaned

free of grease, rust, loose mill scale, dirt, and

other foreign materials that might cause in- ferior bonding of the priming. Usually this

may be accomplished by the use of scrapers, wire brushes, pickling, sandblast, mineral

spirits, or other methods that produce a satis- factory surface. In addition to having a clean

surface, it has also been found beneficial to treat the metal with certain chemical solutions.

The main objective of these chemical treat- ments is to form a nonmetallic coating, inti- mately attached to the metal, which retards

corrosion and provides greater adhesion of applied paints. Building Materials and Structures Report BMS44, Surface Treatment of Steel Prior to Painting, discusses the pretreatment processes which were included in this

Panel Fe-H-77 Panel Fe-77

Figure 1.

Comparison of treated and untreated steel panels with same priming and topcoat.

Panel Fe-H-77: Hot-dip phosphate treatment; accelerated-weathering, 12 months' exposure. Panel Fe-77: No cleaning or treatment; accelerated-weathering, 2 months' exposure. (Panels as shown are three-fourths actual size.) [4]
investigation. The hot- dip phosphate treat- ment showed outstanding merit in improving

the protective value of paints in all the tests. Particularly effective protection was obtained

when this treatment was used in combination

with a priming of the inhibitive type, such as

zinc chromate. Reference should be made to Report BMS44 for a detailed discussion of the

pretreatment processes tested. Figure 1 shows

two panels having the same priming and topcoat, but the panel on the left was cleaned and

given a hot-dip phosphate treatment before

painting, whereas the panel on the right was

neither cleaned nor treated. The left-hand

panel was exposed 12 months to the acceleratedweathering cycle, the right-hand panel 2 months.

Extremely poor adhesion is illustrated by the

panel at the right. The comparison is shown

to emphasize the importance of properly preparing the surface before painting.

2. Results of Accelerated-Weathering

AND Outdoor-Exposure Tests of Priming Coats on Plain Steel

Of the primings listed in table 1, 32 were

tested on plain-steel panels. The panels were

cut from hot-rolled, 22-United States Gage

sheet steel and were pickled in an acid solution

to remove rust and mill scale. The kind of

acid used for pickling—whether hydrochloric,

sulfuric or phosphoric—made no perceptible

difference in the results. The hot-dip phosphate treatment improved the protective value

of the primings, but the relative ratings are

essentially in the same order whether the

primings were applied to phosphate-treated or

to acid-pickled steel. After pretreatment, the

panels were brushed with two coats of priming, a week being allowed for drying between application of coats. A topcoat of outside finish

paint was then applied, in some cases to onehalf and in other cases to the entire surface of each panel. The painted panels were scratched

diagonally to the metal before being tested. All panels exposed to the accelerated-weathering and outdoors were 3 by 6 inches.

According to the results obtained from the

accelerated-weathering machine and the out- door exposure tests, the primings on steel have

been rated in groups in the following decreasing

order of merit with regard to durability and

effectiveness in protecting the metal:

Group 1: Primings 5a, 8, 29, 30, 31, 32, 56, and 77. Group 2: Primings 1, 3, 7, 36, 37, 38, and 54. Group 3: Primings, 2, 4, 15, 17, 34, 35, 39, 60, 68, 74,

75, 82, and 83. Group 4: Primings 11, 14, 25, and 27. The primings in group 1 are composed of zinc

chromate or a combination of zinc chromate

and iron oxide in a water-resistant, tough, very

adherent, hard-drying vehicle. Synthetic resin

varnishes, such as the phenol-formaldehyde

and glyceryl phthalate types, undoubtedly play an important role in the performance of these

primings. A paint system consisting of this

type of priming over a phosphate-treated

surface, and having a properly formulated

top coat, combines to a high degree the essential properties governing paint-film protection

of steel against corrosion. The primings in

group 2 gave very good results in the outdoorexposure test, but in the more severe accel- erated-weathering test they were less effective

than those in group 1. The primings in groups

3 and 4 were definitely inferior to those in

groups 1 and 2. The rating of any paint coatings on steel is necessarily influenced by the degree of such

conditions as chalking, checking, cracking,

flaking, scaling, peeling, and rusting. Since

the failure of a paint film is usually a gradual

deterioration from one condition to another, it

is very difficult to designate the transition

point at which the film suifers a finite change.

It is admitted that some of these ratings might

possibly be shifted to a neighboring group, and

it is also emphasized that all the primings in

any one group are not to be construed as being

equal in protective value. However, it is believed that the primings in groups 1 and 2 will last longer and give better protection against

corrosion than those in groups 3 and 4 under

equal service conditions.

IV. PAINTING GALVANIZED-STEEL

SURFACES

1 . Preparation of the Surface

Hot-dip galvanizing ordinarily produces a smooth and spangled stiaicture, to which organic

finishes do not readily adhere. It is well known

that it is difficult to get paint to adhere satis- factorily to new zinc-coated surfaces. Many

explanations have been advanced for this lack of adhesion. For example, zinc salts may be left on the surface during the galvanizing process, certain chemical reactions may take place in the

paint film itself, and reactive decomposition

products in the presence of moisture may react with the metal at the interface. Zinc formate

has been isolated ^ at the interface between the

paint and the metal zinc surface. This formation of zinc formate has been suggested as one

of the possible causes for the poor adherence of

paints to galvanized steel. Pretreating new galvanized steel before painting it was found beneficial. Many chemical

solutions have been recommended for this pur2 H. J. Wing, Ind. Eng. Chem. 28, 242(1936)

[5]
f

/

Panel A-9 Panel A-68

FiGUBE 2.Panels showing paint in good condition after 5 years' outdoor exposure.

Panel A-9: Untreated galvanized surface; two coats priming 9. Panel A-68: Untreated galvanized surface; two coats priming 68. (Panels as shown are three-fourths actual size.)

pose. Some of these merely etch and roughen

the surface. The test results in Report BAIS44,

indicate that the best treatments do more than

merely roughen the surface to hold paint—they

change the surface chemically, depositing a nonmetallic film that prevents reaction between

metal and paint, increases the adherence of the

applied paint, and retards corrosion under the

paint film. Solutions of the zinc-phosphate

type, sold under proprietary brands, apparently

accomplish these functions to a great extent. Galvanized-steel panels treated with such zincphosphate solutions showed marked improvement when compared with untreated panels in

increasing the protective value of paints applied over them and gave the best results in all the

tests. Phosphate-treated galvanized steel sheets are available commercially.

Dirt or greasy material should be removed

by cleaning with a solvent, such as turpentine

or mineral spirits, before pretreating or painting.

2. Results of Accelerated-Weathebing and

Outdoor-Exposure Tests of Priming

Coats on Galvanized Steel

Of the primings listed in table 1, 35 were

tested on galvanized-steel panels. The results

indicate that great care should be exercised in

the selection of a priming coat to be applied to the smooth, spangled surface of hot-dip galvanized steel. Very few primings proved to have

satisfactory adhesion on the untreated panels.

For this reason two ratings have been given, one for primings on untreated panels and the

other for primings on phosphate-treated panels.

It should be noted that there is a decided

difference in the two ratings. The property

of adhesion was given major importance in

classifying the performance of primings on

galvanized steel. The ratings on untreated

galvanized panels are given in groups in order

of decreasing merit as follows:

[6]
Group 1: PrimiiiKs 9, 34, 61, and 68. Group 2: Primings 1, 3, 4, 6, 7, 8, 12, 21, 35, 36,

60, and 74. Group 3: Primings 2, 5a, 11, 13, 14, 15, 17, 23, 24,

25, 27, 29, 30, 31, 32, 33, 37, 38, and 39. Here again, as in the rating of the primings on

plain steel, it is admitted that some of the

primings might be shifted to a neighboring

group, and that all the primings in any one group are not to be construed as being equal in protective value. There are many factors to be considered in the interpretation of the

results of exposure tests, and the importance

attached to each will influence the final rating

of the paint. All the primings under group 1 on untreated galvanized panels have good adhesion and are satisfactory for use on untreated

galvanized metal. They are also satisfactory

as finish coats under normal outdoor conditions

and may be used in one or more coats. One

coat hides completely and is adequate for many service conditions on new galvanized

steel. Two coats are ample for old and slightly

h: Panel B-S

Figure 3.

Panels showing chalkin

Panel B-8: Phosphate treated galvanized surface; tw( Panel B-1: Phosphate-treated galvanized surface; tw( (Panels as shown are thre(

rusted galvanized steel surfaces, except under

exposure conditions that may require addetl

pi-otection by special finish coats. These

primings retain their color very well on prolonged exposure. Number 9 is a zinc dustzinc oxide alkyd type paint conforming to Federal Specification TT-P-641, Type II, and is especially suitable for use on zinc coated

metal.

The primings in group 2 showed fairly good

adhesion, especially when a soft drying topcoat, such as lampblack in oil was used over them. However, when they were coated with

a hard-drying white topcoat, the tendency to

flake, scale, or peel was evident from the results

of the accelerated weathering machine. Primings 4, 6, 12, 35, 36, and 60 are suitable for use without a topcoat finish, and when used alone

in one or two coats will give good service under

ordinary climatic conditions.

In group 3, under untreated galvanized

panels, the zinc chromate and iron oxide-zinc

Panel B-1

7 after 3 years' outdoor exposure.

) coats of priming 8 and one of topcoat paint 113.

1 coats of priming 1. '-fourths actual size.) [7]
chromate primings failed by lack of adhesion.

As will be shown below, the performance of the

primings in groups 2 and 3 is much better when

applied to a phosphate-treated surface. In

testing primings on untreated galvanized metal

it was noticed that thin coats adhere much

better than thick coats. Since lack of adhesion

is one of the chief causes of failure of paints on new galvanized metal, it is advisable to use as few and as thin coats as will give the desired

appearance.

The ratings of primings on phosphate-treated

galvanized panels are given in groups in order

of decreasing merit as follows:

Group 1: Primings 1, 3, 4, 5a, 6, 7, 8, 9, 12, 30, 31, 32,

33, 34, 35, 36, and 61. Group 2: Primings 2, 14, 21, 23, 24, 25, 27, 37, 38,

39, and 60. Group 3: Primings 11 and 13. Primings 15, 17, 29, 68, and 74 were not

tested on phosphate-treated panels. From the

above ratings it will be seen that the protective

value of most primings on galvanized metal is distinctly improved when applied to a phosphate-treated surface. Many of the primings

that fell in groups 2 and 3 under the ratings of

untreated panels are placed in group 1 on

phosphate-treated panels. The improvement

in the adherence of zinc chromate and ironoxide-zinc chromate primings wasp articularly

significant. These primings were found to have

good rust-inhibitive properties and were very

effective in preventing corrosion on phosphatetreated galvanized steel. Economy, availability, type of surface

(treated or untreated), and climatic conditions

are important factors to consider in selecting a

paint. By referring to the description of the

primings in table 1 and their ratings given

above, the painting of galvanized steel should

present no great problem. In some cases

Panel A-1 Panel A-oa

Figure 4.—The panel on the left shows slight flaking along the sci-atches. and the panel on the right shows peeling after 3 years' outdoor exposure.

Panel A-1: Untreated galvanized surface; two coats of priming 1 and one of topcoat paint 113. Panel A-Sa: Untreated galvanized surface; two coats of priming 5a and one of topcoat paint 113. (Panels as shown are three-fourths actual size.)

[8]
Paxkl B-7 Panel B~9

Figure 5.Panels showing checking and cracking after 1 j/ear's exposure in the accelerated-weathering machine.

Panel B-7: Phosphate-treated galvanized surface; two coats of priming 7 and one of topcoat paint 114. Panel B-9: Phosphate-treated galvanized surface; two coats of priming 9 and one of topcoat paint 114. (Panels as shown are three-fourths actual size.)

Federal spf cification paint may be required,

but for the general buying public, similar

products are usually available under trade

brands from most paint dealers. Figures 2 to 5, inclusive, are shown to illus- trate the different stages of breakdown in a paint

film. Figure 2 shows two panels in good condition after 5 years of outdoor exposure. The

two panels in figure 3 show chalking and dis- coloration. To accentuate this effect, the paint

film was rubbed intentionally in one spot before

photographing. The left-hand panel in figure 4

shows slight flaking along the scratches, and the

right-hand panel shows peeling along the

scratches. In figure 5 the left-hand panel

shows checking and cracking; the panel on the

right shows checking only.

The effect of a phosphate treatment is illus- trated in figure 6. The panel on the left was

untreated before painting, whereas the panel on

the right was phosphate treated. Both panels

have the same priming and topcoat and were

exposed for 6 months in the accelerated-weathering machine.

V. TOPCOAT PAINTS

In table 2 is given the designation, description, and group rating of the topcoat paints

tested.

Table 2.Designation, description, and group rating of topcoat paints

Designation

102

103

104

Description of paint

Aluminum paint. 2 pounds aluminum powder Federal

Speeificatiim TT-A-476, Type A, per gallon of varnish, Feiirral Specification TT-V-81

Black paint in oil vehicle. Federal Specification TT-Pfil.TypeB. March 31, 1931 __. Lampblack in oil paint

13 percent lampblaclc pigment by weight.

S7 percent linseed oil, thinner and drier. Blaclv iron oxide paint. _ 39 percent pigment by weight:

94 percent black iron oxide.

6 percent red lead.

61 percent vehicle by weight: 85 percent linseed oil. 15 percent thinner and drier.

Group

rating

[9]
Panel A-33 Panel BS3

Figure 6.

Comparison of untreated and phosphate-treated galvani zed-steel panels. Both panels have two coats of priming S3 and the top half of each panel is covered with one topcoat of outside white paint 114-

Panel ASS: Untreated galvanized surface; accelerated-weathering, 6 months' exposure. Panel B-33: Phosphate-treated galvanized surface: accelerated-weathering, 6 months' exposure. (Panels as shown are three-fourths actual size.) Table 2.

Designation, description, and group rating of

topcoat paints—Continued

Table 2.

Designation, description, and group rating of topcoat paints—Continued

105

106

107

Designation

Iron oxide paint ... 43 percent pigment by weight:

100 percent Spanish iron oxide (84% FeaOs).

67 percent vehicle hy weight (oil and phenol modified alkyd resin varnish)

45 percent nonvolatile containing 19 percent of glyceryl phthalate.

55 percent volatile mineral spirits.

Olive green enamel, glyceryl phthalate type. Post Office Department Specification, revised as of October 31, 1939 Titanium barium-zinc oxide (cream) in alkyd resin vehicle

46 percent pigment by weight:

50 percent titanium-barium.

40 percent zinc oxide.

10 percent asbestine. 54 percent vehicle by weight:

57 percent nonvolatile oil-resin, containing 31 percent glyceryl phthalate.

43 percent volatile mineral spirits. The paint was tinted cream with yellow oxide in oil.

108

109

110

111

Description of paint

Gray house paint

64 percent pigment by weight:

20 percent lead titanate. 25 percent basic lead carbonate.

26 percent zinc oxide. 29 percent magnesium silicate.

.36 percent vehicle by weight:

87 percent processed linseed and tung oil. 13 percent thinner and drier. Internationa! Orange Paint

70 percent pigment by weight:

9U percent basic lead chromate.

10 percent magnesium silicate. 30 percent vehicle by weight:

80 percent raw linseed oil. 10 percent spar varnish, TT-V-121a.

10 percent drier. Chrome Green Paint. Federal Specification TT-P-71, Type B. August 19, 1930 Titanium dioxide-zinc oxide (cream) in alkyd resin vehicle

36 percent pigment by weight:

80 percent titanium dioxide, nonchalking.

20 percent zinc oxide.

Group

rating

[10]
Table 2.

Designation, description, and group rating of topcoat paints—Continued

Designation

112

113

114

115

Description of paint

Titanium dioxide-zinc oxide—Continued.

64 percent vetiicle by weight:

50 percent nonvolatile oil-resin, containinj; 2u per- cent glyceryl phthalate.

50 percent volatile mineral spirits. Lead titanate-zinc oxide (cream) in alkyd resin vehicle- - 48 percent pigment by weight:

80 percent lead titanate. 20 percent zinc oxide. 52 percent vehicle by weight:

50 percent nonvolatili' oil-resin, containing 20 percent glyceryl plithalate. 50 percent volatile mineral spirits. Titanium dioxide-zinc oxide (white) in alkyd resin vehicle 34 percent pigment by weight:

80 percent titanium dioxide.

20 percent zinc oxide. 66 percent vehicle by weight:

50 percent nonvolatile oil-resin containing 20 percent glyceryl phthalate.

50 percent volatile mineral spirits. White lead-zinc oxide in oil paint. Federal Specifica- tion TT-P-36a, Type II, Class B. July 23, 1938 Titanium-zinc-lead in oil paint. Federal Specification TT-P-lOla, Type A. March 11, 1936

Group

rating

1. Kesults of Tests of Topcoat Paints

All the paints listed in table 2 were exposed

outdoors on primed steel panels. A selected

number were exposed in the accelerated-weathering machine on galvanized and plain-steel

panels, both pruned before application of the

topcoat.

The function of the final coat on structural

steel is to protect the underlying coats and to give the desired color. In one case the protective value of the finish coat may be of major

importance, whereas in another case the decorative effect may hold prominence. From the

results obtained in these tests it was found

that aluminum, black, and dark-colored paints

are more durable than white or light-colored

paints. This appears to be in general agree- ment with actual service performance. Also, it was noted that, if a white lead-zinc oxide base

paint is tinted, for example to a light- or mediumgray color, the durability is improved. The

retention of color, gloss, and general appearance

of dark-colored linseed-oil paints can be improved by adding a small amount of spar var- nish to the paint. This should not exceed 1 pint of varnish to 1 gallon of paint, and care should be taken to select a varnish that will mix properly with the particular paint. Some

of the newer specification paints contain a small amount of varnish in the ready-mixed

paint as received. For example, Federal Specification TT-P-71a, April 9, 1941, superseding

TT-P-71, states that the liquid in the readymixed paint shall be a fortified linseed-oil vehicle

consistuig of a mixture of 70 percent of linseed

oil, 20 percent of nomeactive spar varnish, and

10 percent of combined drier and thumer.

From the exposure results, the topcoat paints

have been rated in groups in the following decreasing order of merit with regard to durability:

Group 1: Paints 101, 102, 103, 104, 105, and 106. Group 2: Paints 107, 108, 109, 110, 111, and 112. Group 3: Paints 113, 114, and 115. In group 1 will be found aluminum, iron

oxide, olive drab, and black paints. These

paints have exceptional resistance to the efl^ects of sunlight and outdoor weathering. They are recommended particularly for structures where

the maximum protective value is desired and

decoration is of minor importance. Aluminum

paint would be the best where moisture and

high humidity prevail.

Group 2 contains the tinted and dark-colored

paints.

Paint 109, International Orange, and paint

110, Chrome Green, are very durable and are recommended where their respective colors are

desired. On exposure, these paints show fairly

good color retention, but the color becomes

rather "dead" and somewhat "faded" because

of mild chalking. In the latest Federal specifications covering these types of paints, the

vehicle contains a small amount of spar varnish,

which improves the color retention. Paint

108 is a house paint of the slow-drying oil type

tinted to a light-gray color. It dries overnight

to a soft film, and several days should be allowed

for drying between coats. Paint 107, 111, and

112 are cream tinted, synthetic resin alkyd (oil) type topcoats, which dry to a smooth, glossy

finish. They dry faster than the orthodox type

of oil paint and on outdoor exposure tend to show some chalking and fading.

All the paints in group 3 are white. Paint

114 and 115 are the linseed-oil type and are widely used house paints. The white lead-zinc

oxide paint. No. 114, can be obtained in a great

variety of tints that will remain fairly stable. Federal Specification TT-P-lOla, type A,

represented b}^ paint 115, covers the requirements for a white oil paint for general outside

use. Since tints made with this type of paint

are likely to show early fading, it should be used

onlv as white. A paint conforming to Federal

Specification TT-P-40, Type I, Class B (not

included in these tests), is a special fume-proof

(lead-free) paint intended for use where sulfide

fumes, which will darken paints containing lead,

may be encountered. Federal Specification

TT-P-40, May 19, 1943, entitled Paint ; Oil,

Exterior, Ready-Mixed, Light-Tints and ^\Tiite,

now supersedes Federal Specifications TTP-36a, TT-P-lOla and TT-P-156. Paint

113, in group 3, is an alkyd (oil) type of white

paint that dries to a smooth, glossy finish. From a decorative point of view, this paint

retains its whiteness for a long time as it chalks

rather freely, and any accumulation of dust or

[11]
dirt on the surface is readily washed oft" by

rain. Although not as durable as the tinted

paints in group 2, it does have the advantage

of giving a very white appearance especially

during its early exposure period.

In many cases, the selection of a finish-coat

paint for metal structures, buildings, and

equipment is entirely a matter of choice, and

depends on whether the protective value or the

decorative effect is of primary significance.

For warehouses, storage houses, bridges, water

tanks, agricultural implements, and industrial

buildings, the paints in group 1 above would

probably be most satisfactory. On the other

hand, for residences and dwellings, the less durable white and tinted paints will be preferred for esthetic reasons.

VI. SUMMARY AND CONCLUSIONS

A large number of priming- and finish-coat

paints, representing various types, were tested

for durability and protective value against

corrosion by means of accelerated laboratory

and outdoor-exposure tests. The composition

of the paints and the relative ratings, based on

their performance in these tests, are discussed in

detail in this publication. Many paints have

satisfactory properties that make them suitable

for use in protecting metal structures. Locality,

temperature, humidity, kind of surface (galvanized or plain-steel) , interior or exterior exposure, and general climatic conditions should be

considered before selecting a protective coating.

Careful cleaning and preparation of the sur- face are considered more important than the

quality of the paint. The performance of the

best paint materials available will be doubtful if little or no attention is given to cleaning and pre- paring the surface. The tests showed that clean

phosphate-treated surfaces materially improve

the adherence and protective value of paints.

Zinc chromate and iron oxide-zinc cliromate

primings, when properly formulated with a synthetic-resin vehicle, make very good rust-inhibitive coatings. A system composed of phosphatetreated galvanized steel, zinc chromate priming,

and aluminum topcoat paint combines to a high

degree the essential requirements necessary

to withstand corrosive atmospheres.

The types of primings rated in group 1 for

plain steel surfaces should be used where

atmospheric conditions may be severe. For

locations where climatic conditions tend less to induce corrosion, the primings in group 2 should be satisfactory.

Treating new galvanized steel before painting is recommended . Emphasis is given to the import- ance of preparing the metal surface, and the

improved performance of synthetic resin primings'when applied to phosphate-treated surfaces.

The zinc dust primings rated in group 1 under untreated galvanized steel, are intended for application on new or old galvanized surfaces, and no chemical treatment of the metal is contemplated before using these primings, but accepted

treatments may be used if it seems desirable.

Under the ratings on phosphate-treated galvanized steel, primings in both groups 1 and

2 have satisfactory adhesion and will give good

service when applied to such surfaces. Naturally, in the more corrosive atmospheres, the

rust-inhibitive primings in group 1 should be

given preference.

Appearance and local custom will likely be

the dominating factors in choosing finish paints for low-cost steel houses. Except in the

neighborhood of industrial centers or marine

atmospheres, the conventional white or tmted

linseed-oil house paints will be satisfactory.

In some cases the enamel-like long oil alkyd

topcoats may be preferred. As long as the

metal is protected from attack by the elements,

the question of when to repaint a house depends

largely upon individual opinion, but painting

should be often enough to keep the appearance

consistent with local standards.

Since the cost of application is the major

item in painting any structure, price should not

be the deciding factor in selecting the materials.

However, higher initial cost of materials may

in the end be more economical.

Grateful appreciation is hereby expressed of

the very helpful assistance given by Holla E.

Pollard in the planning of the investigation

and m the correlation of the different phases

of the work. Acknowledgment is given to the

manufacturers, who submitted paint and pre- treatment solutions, for their cooperation and

helpful suggestions in this investigation. It is regretted that more specific acknowledgment

cannot be given, but in accordance with the

initial agreement, all references to products

and treatments have been made by code.

VII. SELECTED REFERENCES

R. M. Burns and A. E. Schuh, Protective Coatings for Metals, (Reinhold Publishing Corporation, 330 West

42 St., New York, N. Y., 1939). Ulick R. Evans, Metallic Corrosion Passivity and Protection, (Edward Arnold & Co., London, 1937). Frank N. Speller, Corrosion: Causes and Prevention

(McGraw-Hill Book Co., Inc., New York. N. Y., 1935). Improved Maintenance of Metal Surfaces with Zinc Dust Paints, (The New Jersey Zinc Co., 160 Front

Street, New York, N. Y., 1939). A. H. Sabin and F. M. Hartley, Structural Metal

Painting, (National Lead Co., Ill Broadway, New

York, N. Y., 1934). The Painting of Structural Metal (Steel, Galvanized

Metal, Tin Plate and Copper). National Bureau of Standards Letter Circular LC422. Obtainable free from Bureau. Washington, May 1, 1944.

[12]


BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page ii] BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association. _ 10^ BMS33 Plastic Calking Materials 10^ BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 10^ BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging lOji BMS36 Structural Properties of Wood-Frame Wall, Partition, Floor, and Roof Constructions

with "Red Stripe" Lath Sponsored by The Weston Paper and Manufacturing Co... 10^ BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and

Floors, Sponsored by Palisade Homes 10^ BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. Dunn Manufacturing Co 10^ BMS39 Structural Properties of a Wall Construction of "Pfeifer Units" Sponsored by the Wisconsin Units Co 10^ BMS40 Structural Properties of a Wall Construction of "Knap Concrete Wall Units" Sponsored

by Knap America, Inc 10^ BMS41 Effect of Heating and Cooling on the Permeability of Masonry Walls (*) BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions with "Celotex"

Insulating Boards Sponsored by The Celotex Corporation 15^ BMS43 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 2 10^ BMS44 Surface Treatment of Steel Prior to Painting lOjS BMS45 Air Infiltration Through Windows 10^ BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by The Globe-Wernicke Co 10^ BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions,

and Floors Sponsored by American Houses, Inc 10)5 BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 10^ BMS49 Metallic Roofing for Low-Cost House Construction 10^ BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 10^ BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the

Tilecrete Co lOjS BMS52 Effect of Ceiling Insulation Upon Summer Comfort 10^ BMS53 Structural Properties of a Masonry Wall Construction of "Munlock Dry Wall Brick"

Sponsored by the Munlock Engineering Co 10(S BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 10^ BMS55 Effects of Wetting and Drying on the Permeability of Masonry Walls 10^ BMS56 A Survey of Humidities in Residences 10^ BMS57 Roofing in the United States—Results of a Questionnaire lOji BMS58 Strength of Soft-Soldered Joints in Copper Tubmg 10(5 BMS59 Properties of Adhesives for Floor Coverings 10^ BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of Building

Bricks Produced in the United States 15^ BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete Wall Constructions lOjJ BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association 10^ BMS63 Moisture Condensation in BuUding Walls 10^ BMS64 Solar Heating of Various Surfaces 10(4 BMS65 Methods of Estimating Loads in Plumbing Systems 100 BMS66 Plumbing Manual 200 BMS67 Structural Properties of "Mu-Steel" Prefabricated Sheet-Steel Constructions for Walls,

Partitions, Floors, and Roofs Sponsored by Herman A. Mugler 150 BMS68 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 3 150 BMS69 Stability of Fiber Sheathing Boards as Determined by Accelerated Aging 100 BMS70 Asphalt-Prepared RoU Roofings and Shingles 150 BMS71 Fire Tests of Wood- and Metal-Framed Partitions 200

BMS72 Structural Properties of "Precision-Built, Jr." Prefabricated Wood-Frame Wall Construction Sponsored by the Homasote Co 100 BMS73 Indentation Characteristics of Floor Coverings 100 BMS74 Structural and Heat-Transfer Properties of "U. S. S. Panelbilt" Prefabricated SheetSteel Constructions for Walls, Partitions, and Roofs Sponsored by the Tennessee

Coal, Iron & Railroad Co 150 BMS75 Survey of Roofing Materials in the North Central States 150 BMS76 Effect of Outdoor Exposure on the Water Permeability of Masonry Walls 150 BMS77 Properties and Performance of Fiber Tile Boards 100 BMS78 Structural, Heat-Transfer, and Water-Permeabihty Properties of Five Earth-Wall

Constructions 200

BMS79 Water-Distributing Systems for Buildings 150 BMS80 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 4 150

[List continued on cover page iv]

•Out of print
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page iii] BMS81 Field Inspectors' Check List for Building Construction (cloth cover, 5 x 7)>^ inches) 20^

BMS82 Water Permeability of Walls Built of Masonry Units 20^

BMS83 Strength of Sleeve Joints in Copper Tubing Made With Various Lead-Base Solders 10*^ BMS84 Survey of Roofing Materials in the South Central States 15^ BMS85 Dimensional Changes of Floor Coverings with Changes in Relative Humidity and

Temperature 10^ BMS86 Structural, Heat-Transfer, and Water-Permeability Properties of "Speedbrik" Wall

Construction Sponsored by the General Shale Products Corporation 15(i BMS87 A Method for Developing Specifications for Building Construction—Report of Subcommittee on Specifications of the Central Housing Committee on Research, Design,

and Construction ^ 10^ BMS88 Recommended Building Code Requirements for New Dwelling Cons*uction with Special

Reference to War Housing 20^

BMS89 Structural Properties of "Precision-Built, Jr." (Second Construction) Prefabricated

Wood-Frame Wall Construction Sponsored by the Homasote Co 15^ BMS90 Structural Properties of "PHC" Prefabricated Wood-Frame Constructions for Walls,

Floors, and Roofs Sponsored by the PHC Housing Corporation 15^ BMS91 A Glossary of Housing Terms 15^ BMS92 Fire-Resistance Classifications of Building Constructions 25^

BMS93 Accumulation of Moisture in Walls of Frame Construction During Winter Exposure 10^ BMS94 Water Permeability and Weathering Resistance of Stucco-Faced, Gunite-Faced, and

"Knap Concrete-Unit" Walls 10^

BMS95 Tests of Cement-Water Paints and Other Waterproofings for Unit-Masonry Walls 15<^ BMS96 Properties of a Porous Concrete of Cement and Uniform-Sized Gravel 10<5 BMS97 Experimental Dry-Wall Construction With Fiber Insulating Board 10^ BMS98 Physical Properties of Terrazzo Aggregates 15^ BMS99 Structural and Heat-Transfer Properties of "Multiple Box-Girder Plywood Panels"

for Walls, Floors, and Roofs 15^ BMSlOO Relative Slipperiness of Floor and Deck Surfaces 10^ B MS101 Strength and Resistance to Corrosion of Ties for Cavity Walls 10^ BMS102 Painting Steel 10^