"jAD

I

CCL REPORT NO. 187

EFFECT OF PAINT VAPORS cON CADMIUM PLATED STEEL

FINAL REPORT

iMI' BY

WILLIAM H. DEAVER

1 OCTOBER 1965

AMCMS CODE NO. 5025.11.295DA PROJECT NO. IC024401A329

U. S. ARMY COATING & CHEMICAL LABORATORYAberdeen Proving Ground

Marylandi,' - O~

DOC AVAILAbILITY NOTICE

Qualified requesters may obtain copies of this report from DefenseDocumentation Center, Lameron Station, Alexandri;, Virgrin 2-231 4

Copies Available at Offica af Tichnicai Services, $ 0.30.

THE FINDINGS IN THIS REPORT ARE NOT TO BE CONSTRUED AS AN OFFICIALDEPARThENT OF THE ARMY POSITIO(N, UNLESS SO DESIGNATED BY OTHERAUTHORIZED DOCUMENTS.

DESTROY THIS REPORT WHEN IT IS tJ0 LONGER NEEDED. DO NOT RETURWt ITTO THE ORIGIN4TOA.

rCL kEPORT NO. 187

EFFECT OF PAINT VAPORS ON CADMIUM PLATED STEEL

BY

WILLIAM H. DEAVER

1 OCTOBER 1965

AMCMS CODE NO. 5025.!1.295

DEPARThENT OF IHE ARMY PROJECT KS.IC024404A329

U. S. ARMY COATIKG AND CHIEMICAL LABORATORYABERDEEN PROVING WOUND)

MARYLAND

UNCLASSIFIED

A* -*CT

Studies tO determine the cause of cadmium corrosion encountered !n elec-* tronic vans showed the curina o- alkyd resin erainels in a closed systein can

create on atmosphere ,orroslve to cadmium plated steel. Proper curing andventilation shovid prevent this occurrence. It 15 also possible that the in-corporation of some acid reactive pigment, such as zinc oxide, in alkyd enaimelswiould also eliminate this type corrosion, Investigation of nine additionalcoatings representing different types of coating vehicles indicated that epoxy,vinyl, nitrocellulose-alkyd bd.W nitrocelluloss-acrytic vehicles will not createthis corrosive attmospherc.

i •

A-

STABLEOFCNET

Page No.f

S~TITLE PAGE .... . .. .. .. . .. ...............................

ABSTRACT ......................................................... H

INTRODUCTION ..................................................... I

DETAILS OF TEST .......................... ........... . I - 2

DISCUSSION ....................................................... 2 - 3

REFERENCES ....................................................... 3

DISTRIBUTION LIST ............... ................................ 4 - 6

APPENDIX A ....................................................... 7

Tables ......................................................... 7 - 8

APPENDIX B ............................................ ....... 9

Correspondence .............. o ........................ 9

DD FORM 1473 ......... ......... .. .... ............. .......... 10

• iii

~. ~ ~ --

I. INTRODUCTION

In August 1964 a contractor installing electronic equipment in M348A2HS.mi-trailer, Van., Electronic for the Missile Command encountered a powderycorrcsion product on chromate treated cadmium plated hardware such as bolts,shcrk tiounts, cable teels, spr!ngs, nuts, inserts and other miscellaneouscadmium parts. Since th electronicL equipment to be installed contained manycad•|ium plated psrts there was much concern about possible corrosion of theseparts after iv:stailat~op of the equipment with the resultant possibility ofcausing malfunzt~on3 durl,%g operat~ion.

2In a letter dated 25 September 1964 the U.S. Army Tank Automotive Command)

3 who ias responsible for Lhe procurement of the vans, requested this laboratoryfor technical assistance rn determining the cause of this corrosion and possi-ble action to take to eliminate it tn current vans and in future production.

6 During discussions with the contractor and ATAC personnel it was learnedthat these vans had been closed up shortly after manufacture and had remwnedso for several months prior to being ope~ied for installation of the electronicequipment. Analysis of this corrosion product by both the ccntractor and this

8 laboratory showed it to be a cadmium formate.

It has been reported (I) that various types of organic insulstion mater-ials subjected to high temperatures and humidity (up to 20 0 °F. and 50-100% R(H)will cause corrosion of cadmium plate ir, closed areas. It was also found bySeabright and Trezak (2) that cadmium plated p&rts will corrode when in inti-mate contact with phenolic-base materials in the p;esence of warm humid air.Work at this laboratory has shown that oils used ;n alkyd resins, when sub-jected to oxidation, wili form formic and butyric a-id. Under cofilted con-diticns the concentration of these volat~ie acids can be sufficient to attackcadmium plate.

The interior construction of these vans contained ?ntny orgenic materialssuch as adhesives, insulation, paint, sealing compounds, tapes, linoleum., andpaper which could contain resins and other ingredients susceptible to theformation of these corrosive vapors.

II. DETAILS OF TESTS

Initially samples of the materials used in construction of the vaninteriors were obtained in an effort to determine which, if any, was causingthe corrosion. Specimens of each (Table I) were Dlaced in glass jars alongwith -.admium plated steel bolts, both untreated and chromated treated, fromboth the tra.lers and Federal Stock Supply. In addition, tha adhesives ardpaints were also dip applied to steel specimens arn air iried 8 hours beforebeing placed ;n the jars. To accelerate the test and to more nearly approachthe conditions that were probably encountered es a result cf the closed vansbeing stored outside dur~ng the summer months, the sealed jars were placed inan oven at 130*F. and examined daily for a period of NO days. Test data,table I, showed only the TT-E-529. semi-gioss ernael caused sorrosion.

In afforts to providoan immediate fix on the present vans a set of panelsdip coated with TT-E-529, enae.el obtained from the manufacturer and a controlformulation, was air dried 7 days and another se- force dried at 120*F. for

72 hours. Speciimn5 then were subject4 t., t a.e..erated %st.* 111Wno corrosion evident with either systeno aiter 20 days exposure. On this in-formation It would appear that if the enamel is thoroughly dried before closingof the vans, corrosion would not occur. Both the Missile Command and ATACwere notified, via teletype, of this laboratory's recommendation to thoroughlyvent th6 vans with hot air (12O°F.' for 72 hours to cure the paint and to re-move the volatile organic acids. It was further recommended that ventilatinglouvres be Installed to afford constant ventilation to pfevent any furtherrecurrence of a corrosive atmosphere.

To ellminate the possibIlity of future problems cf this type a study wasalso initiated to determine If some other cor'tings that would not create acorrosive etmosphere could be used.

The nine organic coatings (table II) used fog this study were chosen tobe representative of the var!ous types availabAt. All coatings wmre formu-lated In the laboratory in conformance to the appropriate specIfication.

Duplicate test specimens for accelerated tests were prepared by dip coat-ing 11 X 3 inch lOl1 cold rolled steel penels. Three panels for eerh coatingwere placed in i jar along with antuntreatei ano a chromate treated cadmiumplated bolt conforming to QQ-P-416, Type I and Typo i1 respectively. One setof japs wijs clcsed after tho coating hod air Jried eight hours, a second setafter 24 hours and a third set after 72 h3urs. TT-E-529, Ciass B eruel, wasbaked at 300°F. for 60 minutes and then air dried fcr 8, 24, and 72 hours asabove. Jars waee placed in an oven at 130"F. and the bolts examined daily for20 days for signs of corrosion.

Test specimens were also prepared for outdoor exposure by painting theinside of a quart paint can with the coating under test and suspending thecadmium plated bolts from the inside of the can lid. Cans were dried the sameas in the accalerated tests. These were piaced on exposure at Aberdeen ProvingGround and examined for signs of cadmium corrosion after six months exposure.Uncoated stee, panels and uncoated zans were used as controls for these tests.

The accelerated tests results are stnmarized in table III. it is clearlyshown that the alkyd resin base coatings could cause corrosion on cadmipiate with or without a post treatment. One exception is noted in that lhe"CT-P-636 primer which utllIzes the same alkyd resin and &pproximately the iamepigment loading as the TT-E-529 enamel showed no corrosion. The major differ-ence in pigmentation is that the primer contains zinc oxide ihich may have re-acted with the organic acids to form zinc soaps. This factor is to be inves-tigated further. MIL-P-52108., a latex, water base paint, also caused corresiorbut it was of the red rust type caused byithe ;noisture from the paint. In allcases it Is noted that the amount of corrosion decreases as the drying time isextended. There was no corrosion evident with the other coatings.

Outdoor exposure studies (table iV) confirmed the results of acceleratedtest.

III. DISCUSSION

2

Froxii the resklts of thls program it is apparent that If an alkyd resinenamel is to be tisee on the Interior of the vans it must be adequately curedbefore closing the van, To eliminate the possibility of future problems ofthis type it wculd be desirable to change to one of the other coatings thathas shown no tendercy to cveate a corrosive atmosphere during Its curingperiod. Since the interiors are finiched in a semi-gloss light green colorit is recommended that Specification MIL-L-52043 Semi-Gloss Lacquer, whichcovers the required co:or, be considered as a replacement for the TT-E-529Ename I.

IV. REFERENCES

I. Garland, W. F., Effect of Electrical Insulation Materials on Pro-tective Metal Finishes Under Conditions of Heat and Moisture, Rock IslandArsenal Laboratory Report No. 64-728.

2. Seabi-Ight and Trezak, Plating, 35:715-718(1948).

3

-(

APPENDIX A

A TABLE I

ACCELERATED TEST RESULTS

MATERIAL USED IN CONSTRUCTION OF VAN INTERIORS

Material from Vans Results after 20 days

Plywood No corrosionLinoleum No corrosion

SSea! tape for aluminum post No corrosionSeal tape for plywood No corrosionGlass wool No corrosionRubetex No corrosionRubber covering (sponge) No corros ionrF•It and paper (exuding) No corrosionMI L-L-86E4 No corrosionTT-C-50 No corrosionMil-S-13518 No corrosionMIL-A-21016 No corrosionTT-P-636 No corrosionTT-E-529

Air dried 8 hours Heavy corrosionAir dried 7 days No corrosionForce dried 120'F. - 72 hrs. No corrosion

Empty jar No corrosion

TABLE II

COATINGS EVALUATED

Specification No. Title

TT-E-529 Enamel, Alkyd, Semi-Gloss Class ATT-E-529 Enamel, Alkyd, Semi-Gloss Class BMIL-E-52227 Enamel, Semi-Gloss, Quick DryingMIL-L-52043 Lacquer, Semi-Gloss, Cellulose NitrateMIL-L-I4486 Lzcquer, Vinyl Resin., Semi-r-lossMIL-L-19537 Lacquer, Acrylic-Nitrocellulose GlossMIL-P-52108 Paint, Water Emulsion Type•MIL-P-52!92 Primer Coating, EpoxyTT-P-636 Primer Coating, Synthetic, Wood and

Ferrous Metal

7

r

TABLE III

ACCELERATED TEST RESULTS

20 Days In Oven At 1300 F.

Specification No.of Organic Coating 8 hours drying 24 hours drying 72 hours drying

TT-E-529, Class A Heavy corrosion Medium corrosion Light corrosionTT-E-529p Class B No corrosion No corrosion No corrosionMIL-E-52227 Heavy corrosion Medium corrosion Light corrosionMIL-L-52043 No corrosion No corrosion No corrosionMIL-L-i4486 No corrosion No corrosion NotcorrosionMIL-L-19537 No corrosion No coreosion No corrosionMIL-P-52108 Heavy corrosion Light corrosion Trace corrosion

(red rust) (red rust) (red rust)MIL-P-52192 No corrosion No corrosion No corrosionTT-P-636 No corrosion No corrosion No corrosion

TABLE IV

OUTDOOR EXPOSURE TEST RESULTS

6 MonthsSpecification No.of Organic Coating 8 hours drying 24 hours drying 72 hours drying

TT-E-529, Class A Heavy corrosion Medium .orrosion Light corrosionTT-E-529, Class B No corrosion No corrosion No corrosionMIL-E-52227 Heavy corrosion Medium corrosion Light corrosionM:L-L-5204 3 No corrosion No corrosion No corrosionMIL-L-i4k86 No corrosion No corrosion No corrosionMiL-L-19537 No corrosion No corrosion No corrosionMIL-P-52108 Light corrosion Trace of corrosion No corrosionMIL-P-52192 No corrosion No corrosion No corrosionTT-P-636 No corrosion No corrosion No corrosion

8

• • • • • mm • I

C0

P

APPENDIX B

HEADOUARTERSUNITED STATES ARMY TANK-AUTOMOTIVE CENTER

WARREN, MICHIGAN 148090

In Reply Refer To:SMOTA-RCM.3 25 September 1964

SUBJECT: Corrosion Problem in the M348A211 Semitrailer, Van,Electronic

TO: DirectorCoating & Chemical LaboratoryATTN: AMXCCAberdeen Proving Ground, Md. 21005

I. Pursuant to numerous verbal and telephone dibcussionson subject problem, we wish to reaffirm our request for yourconcurrent technical assistance In this area. We concur withyour proposal to subject the suspected materials from SpencerStafford, lnc., to exposure to a confined atmosphere undercyclic temperature and humidity variations. Probably one ora combination of these materials is causing the acceleratedcorrosion of the cadmium plated parts in these vans.

2. Please keep us up to date on the progress of thiswork so that we can combine your findings with our test datafor the requested weekly reports to the Missile Command.

FOR THE COMMANDER:

s/ Joice 0. Cox, Jr.JOICE 0. COX, JR.Major, ArmorChief, Materials Laboratory

C0

P

9

- ANCLASSIFIEDSecurity Classification

DOCUMiNT CONTROL DATA - R&D(Security claseification of title, body of Alatract and indexlng annotatlon must be enteret, clhen the overall report sa c Is.a lted)

......... i . i G "C: ii'T fCorpors author) 2. RCPORT SECuRITY C LAMSPICAT;ON

U.S. Army Coating and Chemical Laboratory Unclassified

Aberdeen Proving Ground, Maryland 2b GROUP

3 REPORT TITLE

EFFECT OF PAINT VAPORS ON CADMIUM PLATED STEEL

4 DESCRIPTIVE NOTES (Type of report and inclusive dates)

FinalS AUTHOR(S) (Loet nane. first nome. initial)

DEAVER, WILLIAM H.

4. REPORT DATE 78. TOTAL NO. OF PAGIES 7b. NO. OF RmPs

October 196S 15 1 2Sa CONTRACT OR GRANT NO, 90. ORIGINATOR'S REP*RT NUMOCKS5)

AMCMS CODE NO. 5025.11.295b. PROJECT No. CCL #187

IC0244O1A329c 9b. OTHER REPORT NO(S) (Any other numbtrs hEat ma" be sssigwed

this report)

d.

I0 A V A IL ABILITY/LIMITATION NOTICES

Qualified requesters may obtain copies of this report from. Defense DocumentationCenter.

Cooges Available at Office of Technical Services. $0.50.11 SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIITY

U.S. Army Materiel CommandWashington, D. C. 20315

13 ABSTRACT

Studies to determine the cause of cadmium corrosion encountered in elec-

tronic vans showed the curing of alkyd resin enamels in a closed system can

create an atmosphere corrosive to cadmium plated steel. Proper curing andventilation should prevent this occurrence. It is also possible that the

incorporation of some acid reactive pigment., such as zinc oxide', in alkyd

enamels would also eliminate this type corrosion. Investigation of nine

additional coatings representing different types of coating vehicles indicated

that epoxy, vinyl, nitrocellulose-alkyd and nitrocellulose-acrylic vehicles

will not create this corrosive atmosphere.

DD 1 'N0.47,DN1473 uCLSSIFIED

Security Claufficatiou

S___NCSAS1E1LEISecunty Classific.tion

-- ~KEY WORDS I______ .L L .ýL - --- r

Cadmium corrosionAlkyd resin enamelsElectronic vansEpoxyVinyl"Nitroceilulose - alkydNitrocellulose - acrylic

I

I ~TR&CTIONSI. ORIGINATING ACTIVITY: Enter the name a•,d address 0 AVALABILTTY/L1M1TA'1qON I4OTICES Enter any tim-of the contractor, subc.•trsctcr, grantee, Dpar ent of De- itations on furtwer dlosemination of the report, other than thosefense aciivity or other organization (corporate author) issuing impoved by security cEastoificnlion, nasicg ttarsArd statementsthe report. uh s

such as:2a. REPORT SECU1ETY CLASSIFICATION: Enter the over- (1) "Qualified requesters may obtain copies of t•isa1 security classification of the report. Indicate whether report from DDr.""Restricted Data" is included. Marking is to be in accord-ance with appropriate security regulations. (2) "Foreign announcemnent and diaseminition of this2b. GROUP: Automatic downgrading is specified in DOD Di- report by DDC "a not authDrizud,"rective 5200. 10 and Armed Forces Industrial Manual, Enter (3) "U. S. Governrzntt agencies may obtain copies nfthe group number. Also, when applicable, show that optional ihis report directly from D•. Other qoalifed DDCmarkings have been used for Group 3 and Group 4 as author- u-ters shall request throughized.

3. RIMJRT TITLE. Enter the complete report title in all (4) "U. S. military agencies may obtain copis of thiscapital letters. Titles in all cases should be unclassified. rert directly from DDC. Other quatified usersIf a meaningful title cannot be selected without classifica- hall drequest thDoughtion. show title clasrification in all capitals in parenthesisimmediately following the title. •"

4. DESCRIPTIVE NOTES If appropriate, enter the type of (5S "AU distzibution of this -eport is controlled. Qual.report, e.g., interim, progress, summary, annual, or final. ified DDC users shall request throughGive the inclusive dates when a specific reporting period iscov~er" ;f the renort has been furnished tc the Office of TechnicalS. AUTHOR(S): Enter the name(s) of author(s) an shown on Services, Department of Commerce, for sale to the public, iedi-or in the report. Enter last name, first name, middle initiaL cate tide fact and enter the price, If known.If military, show rank and branch of service. The name ofthe principal author is an absolute minimum requirement. IL SLIPPLEMENTARY NUTES: Use for additional explana-6. REPORT DATE: Enter the date of the teport as day, tory notes.m~onth, year, or month, year. If more than one date appewe 12. SPONSORINIG MILITARY ACTIVITY: Ente? the name ofon the report, use date of publication. I- e depg-tmer.tal project office or laboratory sponsoring (pay*7*. TOTAL NUMBER OF PAGE. The total page 1_4ae j Mng lor) ghe research and development. Include address.should follow normal pagination procedures, Le., enter tCe 13. ABSTRACT: Enter an abstract giving a brief and factualnumýer of pages containing information. summary of the document indicattve f-1 the •,eport. even though7b. NUMBER OF REFERENCES. Entr the total number" it may also appear elsewhere in the body of the techraical re-

port. If additional space is required, a continuation sheetreferences cited in the report. shall be attached,

$a. CONTRACT OR GRANT NUMBER: If apprcpriate, enter It is highly decirable that the abstract O' clasSified re-the applicable naniber of the contract or grant untder which ports be unclassified. Each paraXoh oe 'he abCtrrtt 0h0-1the report was Written. end with an indication of tho flilitery security classification8b. 8c, & Od. PROJECT NUMBER: Enter the appropriate of the information in t~he per.grnph, represent.-d as (T'-), (S),military department identification, such as project number, (C), or (U).subproject number, system numbers, task number, etc. There is ao it-iitation on the length of the abotract. How-9a. ORIGINATOR'S REPORT NUMBER(S): Enter the ofr.- ever, the scix-d leugh is from 150 to 22$ words.cial report number by which the documen. will be identified 14. "iE WORDS- Key w',rds are technically meaningful termsand controlled by the originating activity. This numbe- must oTr il; rt phrass'r -*.t ca• s-act-rize a report snid may be uved asbe unique to this repor:. ivdex ertria.3 for ýctr.ic'-o • he roport. Key words must be9b. OTHER REPORT NUMBER(S): If the report has been celecte$ so tnsl .o a•,•u.it7 r'lasificat~on is require.1. Iden-assJgned any other report numbers (eithm, 1.y the orifgnator fiefi% sucls os equipr~tent model Oesijrkt;c-, trade na-e, mili-or 6y the sponsor), also enter this nu5 tn .- ) tary project t'- .-!to .e, jRok-3.' iic n *ay I ,: 0a

akey P-ds bat will oe followed ly a-% ind.&atio .f te•iL',caontert. The assignment of llnI, ru'ets, and -yei•gh6 isoptional.

UNCLASSIFIED

SeUrity classificat~on