Coating Ispector Guide

8/10/2019 Coating Ispector Guide

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Guide to Protective Coatings:Inspection and Maintenance

Tom N. Bortak

United States Department of the Interior Bureau of ReclamationTechnical Service Center

September 2002


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Acknowledgments

Several Reclamation em ploy ees help ed p rep are t h is g u id e, an d th eir con tr ib u tio n isgreat ly ap pre ciated. These p eople are Kurt F.von Fay, mater ials engineer, w ho set upfund ing and show ed g rea t pa t i ence over thew ri t ing interval ; D. Thom as (Tom) John son,m ater ials engineer, for his corrosion exp ert isecontr ibut ion; Gregory J. Myers a nd Richard A.Pep in, mater ials engineering technicians, for their ini t ia l review in ferret ing ou t obviou s

errors; an d Robert Rood , ed i tor, for hisn u m e r o u s I d o n ' t u n d e r s t an d co m m e n t s th a tforced m e into w ri t ing a clearer, more concise,a n d u n d e r st a n d a b l e d o c u m e n t .

A d eb t o f g ra ti tude i s expressed to NA CEInternational, Society of Protective Coatings,and Un iversity of M issou ri-Rolla , Coat ingInst itute for prov iding al l the courses andre fe rences that m ade th i s gu ide poss ib le .


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Preface

In recent years , coat ing techn ology haschanged d ram atically. The d riving force

beh ind the change h as been regu la t io nsaffec ting the env i ronm ent and personne lheal th and safety. For exam ple, regu lat ionsrelated to d u st par t ic les from ab rasive blasting,volat i le organic comp ou nd (VOC) emissions,and hazardou s m ate r ia l s such as l ead ,chromate , and o ther heavy me ta ls havec h a n g e d .

Before the lat e 1980s, coating m aterials w ere

more to le ran t o f l ess than op t im um sur face p rep aratio n con d iti o n s b eca u se p ain tformu lat ion contained high VOCs to al low them ater ial to wet or p enetrate steel surfaces. Themos t success fu l wer e red l ead p r imers andvinyl resins; ho wev er, regulat ions hav ed iscoura ged the use of these mater ials . Paintm anu factu re r s re fo rmu la ted the ir coa t ings tocomp ly wi th new regu la t ions . Th is has l ed tothe d evelopm ent of a w ide variety of high-techcoat in g m ater ials th at are m uch m ore sensi t iveto su r face p repara t ion and env i ronm enta lapp l icat ion pra ct ices . Th e Fede ral H ighw ay

Ad m in is t ra tion has es t imated tha t up to 80 p ercen t o f a ll p rem atur e co at in g failu res on

b r id ge s tr u ctu res ar e p ar tia lly or com p let elycaused by d eficient surface prep arat ion or app l icat ion p ract ices . Several organizat ionssuch as the Am erican Society for Test ing an dMaterials , N ACE Intern at ional , and theSociety for Protect ive Co at ings hav e issuedconsensu s s t an dard s to m in imize sur face

p rep ar a ti on a n d ap p lic at io n in a d eq u ac ie s.

This gu ide is not intend ed to be al lencomp assing; rather, i t is intend ed to be anintrodu ct ion to specif ic referen ce s tandard s

and test p roced ures re la ted to su r face p repar at ion , ap p licat ion , te s tin g , andm aintenance of coat ings. Explanat ions and

p r oc ed u res of r efe ren ce s ta n d ard s c it ed w ith inth i s gu ide a re abbrev ia ted to d eve lop aw orking basis . Th e user is encourag ed to readre fe rence standard s and coa t ing m anua l s fo r am o r e t h or o u g h u n d e r s t an d i n g . T h e g u id efocu ses on n ew con struct ion coat ings, exis t inginfrastructure coat ing m aintenance, andgalvanized coat ings of ferrous sub strates for m etalwork i tems coated in the fie ld . Ingeneral , this gu ide follows the Bureau of

Reclam ation s (Reclam ation ) coat in g gu idespecifications.


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Contents

Page

Chapter IIntrod uction and Backgroun d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11. Sta nd ar d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12. Coa tin g Re fe re nc es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13. Ter m ino log y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14. Co rr os io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15. Ser vice Ex po su re . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Chapter IIMaterials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56. Co m po n en ts o f Co at ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57. Coa tin g T yp es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

8. Ge ne ric Co at ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Chapter IIISp ecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119. Con stru ction Spe cification Ins titu te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

10. Reclam ation C oat ing Sp ecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1111. Coat ing Tab u lations an d Cate gor ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1212. Man u facturer' s Prod u ct Data an d Ap p lication Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1313. Ad d en du m s a nd Mo dificatio n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Chapter IVInspe ctor's R ole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1514. Pr im ar y Re sp on si bi lities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1515. Dai ly Resp o ns ib ilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1516. M at er ial Ap p ro va l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

17. Do cu m en ta tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1618. Inst ru m en ts, Gau ges , and Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1719. Su bs tr at e Ins p ectio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1720. Coat ing Ins p ection Ch ecklist Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1721. Pre coa tin g C on fer en ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Chapter VM aterial Storage, Con tainers, and Sh elf Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1922. Sto r ag e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1923. Co nt ain er s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1924. Sh elf Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Chapter VISurface Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2125. Su rfa ce C on ta m ina n ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2126. P re sur face Trea tme n t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2327. Ab ra si ve Blas t Ma te ria l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2328. N ozz le Blast P res su re . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2429. Su rf ace Pr ep ar at ion M et ho d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2530. Ph ot og ra ph ic Insp ection Stan da rd s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2731. Alt ern ative Su rfa ce Prep ara tion M eth od s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30


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Chapter VIIEnvironmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3332. En vir on m en ta l Facto rs Af fecting Co atin gs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Chapter VIIIAp plication and Curing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3533. Ap p lication Tem p eratu re an d H u m idity Re strictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3534. Co at ing L ay ers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3535. M ixin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3636. Ap plic ation M et ho d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3637. Ap pl icat ion T echn iq ue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3938. Dr yin g, Recoa ting , and Cu rin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Chapter IXField In spection and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4139. Su rf ace Pr ep ara tio n Tes ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4140. W et Film Th ickn ess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4241. H ar d en ed Pai nt ed Su rf aces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4242. De st ru ct ive T es t Me th od s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Chapter XMa intenanc e Coating s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4743. De fini tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4744. Pu rp ose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4745. Risk Ev alu at ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4746. Ins p ectio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4747. Tox ic-Based Pai nts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4948. W ork er Pr otec tion f rom Toxic-Based Pain ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5049. Lea d Ex pos u re Le vels by Rem ov al Me tho d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5050. Co rr ec tive A ction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5151. Ma te ria l Selectio n F acto rs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5252. Sched u ling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Chapter XIGalvani zing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

53. Ga lv an iz ing M eth od s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5354. Zin c Cor ros ion an d Serv ice Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5455. Z inc C h em i cal React io n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5456. Con tam inan ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5457. Su rf ace P re p ar at ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5558. Co at ing s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Chapter XIICoating Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5959. M at er ial Select ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5960. Fo rm u latio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5961. Ad he si on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6162. Su bst rat e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6163. Ap p lica tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6264. De s ign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6365. Ex teri or For ces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69


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Appendices

A Organ izat ional Sou rces for Stand ard s and ReferencesB R ea d i ng S o ur ce sC Inspec tion Check lis tD R ef er e n c e S ta n d a r d s C it ed i n G u i d e

E Inspec tion Equ ipm en tF Example o f Inspec t ion Dai ly Check Shee tG Proced ur e for Detect ing Moistu re and Oil in Com p ressed A ir (ASTM D 4285)H Procedu re fo r De tec ting Chlor ides and So lub le Sa l ts in A bras ives by Cond uc t iv i ty MethodI Procedures fo r De tect ing Chlor ide Ion in W a te r J P rocedu res fo r De te rmin ing Blas t C lean ing Ai r PressureK Dete rmina t ion o f Envi ronm en ta l Facto rsL Procedures for De tec t ing Chlor ide Sa l t s on Prepared o r Ex is t ing Sur facesM Determ ining Surface Profile of Blast-Cleaned Steel Using Rep l ica Tap e

(NAC E RP0287 or ASTM D 4417, Method C) N Proc ed u res for M ea su r in g W et Fi lm Th ick n es s ( A STM D 4414)O Wet F ilm Thickness Formu las and Examp le Ca lcu la t ionsP Proced u res for Dry F ilm Thickness Gau ges (SSPC-PA2) and Examp le

Q Proced ur es for Discon tin ui ty (Holid ay) Test in g (NA CE RP 0188)R Proced ur e for Mech anical (Pu l loff) Ad hesion Test ing (ASTM D 4541; Ann ex A2)S Proced u re fo r Hyd rau l ic Ad hes ion Test ing (ASTM D 4541; Annex A3)T Procedu re fo r Measur ing Dry F ilm Thickness by Des t ruc t ive Means Wi th Tooke Gauge

(ASTM D 4138)U Procedu res for SSPC-VIS 2 (2000 Revision)V Procedu re to Determine the Presence of Soluble Lead and Insoluble Lead Chr om ate in Coat ingsW Procedu re to Determ ine the Presence of Chro m ate in Coat ingsX Determ ina tion o f Toxic Meta ls in H ardened Pa in t

Figures

Figure Page

1 Co m po n en ts of coat ing s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Tables

T able Page

1 N u m ber of spot m easurem ents based on total coated surface area . . . . . . . . . . . . . . . . . . . 442 Ty p i ca l a n d m a x im u m l ea d e xp o s u r e l e ve ls in m i cr o g ra m s p e r c u bi c m e te r

by rem ov al m ethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 Gal van izing m etho d s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 Form ula tion-related failures for org anic coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605 Form ula tion-related failures for inorg ani c coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 616 Ad hes ion -re lated failur es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 Sub str ate- related failur es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 638 Ap p lication-re late d failu res . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 649 Des ign -re lated failur es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6610 Failur es rel ated t o ext eri or forc es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67


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1

Chapter I

Introduction and BackgroundProtect ive or indu str ial coat ings are the

p r imary m eans e m p lo yed by the Bu reau of Reclam ation (Reclama tion) to controlcorrosion. Hy d rau lic s tructu res are typ ical lycons t ruc ted wi th fe r rous meta l s and a resub ject to corrosion. Man y Reclama tions t ruc tures a re 50 years o ld , and some a reapp roach ing 100 years . These st ruc tures a reexpec ted to con t inue fun c t ion ing in to theforeseeable futur e. Protect ive coat ingsinfluence th e l i fe, safety, op erat ing efficiency,

app earance , and econom y of these s t ru c tures .

A coat ing 's effect iveness d ep end s on select ingcoa t ing m ate r ia l tha t cor rec t ly matches thein tend ed se rv ice exposure fo r th e meta lwork .In the pa st , coat ing m aterial select ion wa s

based on Fed e ra l, m il it a ry , o r Recla m at io nformu lat ions; how ever, nearly al l theseformula t ions have been w i thdraw n. Today,se lec t ion i s based on se rv ice exposure type andthe resu l ts of accelerate d p erform ance test ingof comm erc ial ly av a i lable p rod uc ts .

1. Standards. Form erly, Reclam ation p rov id ed narra t iv e s tand ard s and d efin i t io nsfor specifying mat erials , surface prep arat ion,app l ica t ion , and inspec t ion . H ow ever,Rec lamat ion now ad opts indus t r ia l s t and ard s ,w here ap p l icab le . The fo l lowing organ iza t ions(see append ix A for addresses , t e lephon enu m bers , and w eb s i tes ) a re re fe rencedthrough out th i s gu ide :

A m e r ica n So cie ty fo r Te st in g a n dMa terials (ASTM).

N A C E In te rn a t io na l (f or m er ly ca lle d N at io na l Associa t io n of Cor rosio nEngineer s) (NA CE).

So cie t y fo r P r ote ct iv e C o atin g s(form erly cal led Steel StructuresPaint ing Cou ncil) (SSPC).

2. Coating References. The coat inginspec tor i s no t expec ted to have th e exper t i seof a coat ing chem ical form ulator or a coat ingengineer, bu t shou ld be reasonably fami l ia r w i th the m ate r ial s being app l ied . This gu ide isin tended to p rov ided th e m os t bas ic

b ac k g ro u n d on g en er ic m at er ia l ty p es , s u rfa ce p rep ara t io n , app lica tion, and in sp ect io nm e t h o d s . T he r e a d e r i s en c o u r a g e d t o p u r s u ere la ted coa t ing re fe rences l is ted in app end ix B.

3. Terminology. The word coa ting i s agener ic t e rm and inc lud es pa in t . In them ost genera l terms, a coat ing is protect ionaga ins t cor ros ion , wh ereas a pa in t m ayhave add i t iona l p rop er t i es such as co lor o r u l t rav io le t screen ing p igm ents . The te rmscoa t ing and pa in t a re used in te rchange-ab ly throu ghou t th i s gu ide .

Other t e rm s of ten u sed toge ther a re coa t ingsand l in ings . In genera l , w hen d escr ib ing theinter ior surfaces of pipes or tank s, the termlinings is us ed to iden tify the inter ior sur faces and coa t ings i s used to iden t i fy theexterior surfaces.

4. Corrosion. The pr imary reason for coat ing steel is to preven t corrosion. Corrosionof me tals is an electrochem ical react ion thatcan be con t ro l led by in te r fe r ing w i th one or m ore of the four requ i red e lem ents o f acorrosion cel l : (1) anod e (corrod ing area);(2) cathod e (non corrod ing area); (3) electrolyte(wate r o r mois tu re in a tmosph ere , imm ers ion ,or soi l); and (4) metal l ic path (betw een tw o

di ffe ren t m eta ls o r w i th in th e sam e m eta l) .E limina te any one of the four requ i rede lements and the cor ros ion p rocess w i ll s top .

The mos t comm on typ es o f cor ros ionencounte red on Reclamat ion fe r rousm e t a l w o r k a r e :


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Guide to Protective Coatings: Inspection and Maintenance

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(a) Uniform Corrosion. Corros ion tha toccurs m ore or l ess u n i form ly and resu l t s inrus t and meta l loss over the m eta l sur face .

(b) Galvanic Corrosion. Corros ion tha toccurs on the m ore ac t ive meta l o f twod issim ilar m etals that are electr ical ly coup ledtogeth er in the sam e electrolyte (e .g., water) .The m ore ac t ive m eta l wi l l cor rode .

(c) Crevice Corrosion. Crevice corrosionis a form of local ized corrosion tha t occurs increv ices where the env i ronm ent d i ffe r s fromt h e su r r o u n d i n g b u lk e n v i r on m e n t . T h edi ffe ren t env i ronments resu l t in cor ros ion

because of d iffe rences in concent ra t io n(e.g. , oxygen, pH , an d ferr ic ions) . I f there is

an oxygen concentrat i on difference, corrosionw i ll p roceed a t c rev ices w here there i s l esso x y g en t h a n in t h e e n v ir o n m e n t s u r r o u n d i n gthe c rev ice . Crev ices a re fo rm ed w hen tw osur faces a re in p rox imi ty to one a no ther, suchas when two m eta l sur faces a re aga ins t oneanother, w hen a gaske t i s aga ins t a sur face , o r w hen an gle irons a re p laced back to back .Crev ice cor ros ion can occur und er dep os i t s(e .g. , barnacles, dir t , grease, and sl im e) on ametal surface.

(d) Pitting corrosion. A form of local izedcor ros ion w here the d ep th of pen e t ra t ion i sgrea te r than the d iameter o f the a ffected a rea .

(e) Cavitation corrosion. The m etal losscaused by the fo rmat ion and co llapse of vap or

bu bb les in a li qu id n ear a m et al su rf ace . Th eapp ear ance of cavi tat ion is similar to pi t t ing,excep t tha t p i t t ed a reas a re c lose ly spaced andthe sur face is cons iderab ly rough ened .

(f) Erosion-corrosion. The acceleratedm etal loss from an ini t ial corrosion m echan ismassociated w ith high-veloci ty flows andabrasion. Erosion-corrosion is character ized

by g roov es, g u l li es, w aves, and rou nd edr idges o r va l leys and exhib it s a d i rect iona lf low pa t te rn .

(g) Dealloying or Selective Leaching. Th eselect ive rem oval of one of the element s of ana l loy by e i ther p re fe ren t ia l a t t ack or com ple ted issolut ion of the mat r ix, followe d by

redep os it o f the cathod ic cons t ituen t . Thee lement rem oved i s a lways anod ic to them atr ix. With deal loying, there is no m etal loss ,d im ens ion changes , c racks , o r g rooves ;how ever, the a ffec ted a rea may be ev iden t

because of a co lor ch a ng e . Th e a ffec te d area be co m e s lig h t e r , p orous , a n d lo se s i t s o r ig in a lm echan ical p rop ert ies (i .e. , i t becomes bri t t leand loses t ens i le s t reng th) . Two comm onforms of d ea l loy ing a re :

Dezincification. The select ive d issolut ionof zinc from bra ss al loys. I t is recognized by acolor change (e .g., f rom i ts or iginal yel low

br a ss co lo r t o a d i st in c tly re d , co pp e r yappearance) .

Degraphitization. The select ived issolu t ion of iron from som e cast i rons,usu a l ly g ray cas t irons . I t norm al ly p roceedsun i formly inw ard f rom the sur face , l eav ing a

p orou s m at r ix a llo y tha t i s c omp osed m os t ly o f ca rbon . Degraphi t iza t ion can be recognized bya change fro m an or iginal s i lver-gra y color to adark gray. The a ffec ted m eta l can be eas i ly cu tor p ie rced w i th a kn i fe .

5. Service Exposure. Coatings are sp ecif ied by se r vice exposu re or th e env ironm en t thecoat ing w ill be subject to . The following ar e

the b as ic se rv ice exposur es def ined b yReclamation:

A tm os p h er ic

N I n d o o r sN O u t d o o r s

Bu r ia l

Im m ersion

C om p let e, p a rtia l, or f lu ctu a t in gimm ers ion cond i t ions

A tm o sp h er ic ex p osu r e su b je ct t ocondensa t ion , h igh hu m id i ty, sp lash ,or spray

T he fo llo w in g su b e xp os u r e co nd i t io nsm a y a p p l y t o a n y o f t h e a b ov e :


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Introduction and Background

3

N Direct sunlight or UV: sever alcoat ings, su ch as ep oxies, wil lde te r io ra te by cha lk ing w henexposed to sun l igh t .

N Che m ical resis tance: exposure smay inc lud e ac id ic o r a lka l ineconcent ra t ions , ind us t r ia l smog,acid rain , sew age, or sp ecif icchem icals .


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5

Chapter II

MaterialsCoat ing formu la t ion i s genera l ly based onorgan ic , inorgan ic , po lym er, and co-po lym er chem istry. I t is not th e inten t ion of th ischap te r to d i scuss coa t ing chem is try bu t ,ra ther, to p rov ide a bas ic know led ge of coa t ingcomp onents and gener ic coa t ing typ esspecif ied by Re clam ation.

6. Components of Coatings. All org aniccoat ings consist of thr ee basic com po nen ts:(1) solvent , (2) resin, and (3) pigm ent . N ot al lcoa t ings con ta in solven t and p igm entedcomp onen ts . There are solv ent-free (100

p ercent sol ids) coa t ing s an d c lear , p igm en t-free coat ings, but n ot resin-free coat ings.

Coa t ing chemical fo rm ula tors com m onlygroup so lvent , res in , and p igment comp onentsinto two gene ral categor ies . T he fi rs t categorycombines the so lven t and the res in toge th er.The solv ent p ort ion is cal led th e volat i leveh icle , and the resin port ion is cal led th enon volat i le veh icle . The com binat ion of theso lven t and the res in , wh ere the res in isd issolved in the solvent , is called th e veh icle .

The second ca tegory i s the p igmen t . P igmentsa re ad d i t ives tha t im par t sp ec if ic p rop er t i es tot h e c oa t i ng a n d a r e su b d i v id e d i n to t w o

gener al categories: (1) color and (2) inert an dreinforced. Figu re 1 i l lu strates the relat ionsh ipof these com pon ents .

When a coa t ing i s app l ied , the so lven tevapora tes d ur ing th e cu r ing process, leav ingo n l y t h e r e sin a n d t h e p i g m e n t c o m p o n e n t s o nthe subs t ra te . The remain ing res in and

p ig m en ts ar e s om et im es ca lle d th e co a tin gso lids , and they form the p ro tec t ive f i lm for cor rosion pro tec t ion .

(a) Solvent. Organ ic solven ts a re fo rmu la tedin to coa t ings to per form three essen t ia lfun ct ions: (1) dissolve the resin comp onen t;(2) contro l evapora t ion for f i lm forma tion; and(3) red uc e the coat ing viscosity for ease of ap plicat ion . Solven ts wil l also affect d ry f i lmadh es ion and d urab i li ty coa t ing prop er t ies . Ingene ral , resins that are less soluble wil l requ iree i ther more so lven ts o r s t ronger so lven ts tod issolve the resins.

The te rms so lven ts and th inners a reof ten used in te rchangeably, bu t there a red is t inc t ions w i th in and be tween the two te rm s .The te rm so lven t can imp ly two d i ffe ren tusag es: (1) the solv ent or solvent blend s inthe coa t ing formu la t ion a t p red e te rmined

Solvent(Volatile)

Resin(Nonvola t i l e )

Color P igments

Iner t andReinforced

Ve h icle P ig m e n t

Coat ing

Figure 1.Components of coatings.


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6

concentra t ion levels; or (2) cleaning solvents ins t ron g con cen t ra t ion s t reng th for c lean ing

b ru sh es, r o lle r s, h ose s, a n d o th er eq u ip m en t.The usage of the t e rm th inner (a th inner i s asolvent) is m ost often associated w ith thecoa t ing ap p l ica tor add ing a th inner to acoa ting con ta iner (norm al ly abou t 1 p in tthinne r to 1 gal lon of coat ing) to redu ce theviscosi ty for ease of ap plicat ion . Ad d ingthinn er to a coat ing in th e f ield is often cal ledfield thinning.

The man ufactu re r s p rod uc t da ta shee t w i lls p e ci fy a t h i n n e r a n d a m a x i m u m a m o u n t t o b eused for each coa t ing typ e . Use of a th inner n o t r e co m m e n d e d b y t h e m a n u f ac t u re r c a ncause num erous app l ica t ion prob lems or

p rem atur e fa i lu res such as separa t ion of comp onen ts , coagula t ion, too fast or too slowd rying, changes in f low c haracter is t ics, or l i ft ing of p reviou s coats . The fol lowin gcomm on th inners a re used w i th the assoc ia tedgeneric coat ing types:

Th in ne r s C oa t in g s

M ineral sp ir its O ils an d alk y d s

Arom at ics (benzene ,xylol , toluol e)

Coal t a r ep oxies ,alkyds, chlorinated

r u b b e r s

Ketones (MEK,MIBK)

Vinyls , epoxies,u r e t h a n e s

A l coh o ls ( iso p r op y l) P h en o lic s, in or g a n iczincs

W ater Acryl ics, som einorganic zincs

Solven ts p rod uce vapors tha t a re he av ie r thanair and w ill col lect in tank bo ttom s or confined

areas . The ke tones have the lowes t fl ashp oin tof the o rgan ic so lven ts ; however, any so lven tin the r igh t combina t ion w i th a i r can c rea te anexplosive combinat ion.

Fed eral , State , coun ty, ci ty, an d local air qua l i ty con t ro l d i s t r ic t s regu la te the am ount o f volat i le organ ic solvents (VO C) in coat ings. A sthe coa t ing cures , VOCs evap ora te in to the

a tmosp here and reac t wi th su n l igh t and a ir p o llu ta n t s to fo rm oz one , a k now n h u m anhea l th hazard . In respon se , coa t ingm anu fac ture r s hav e re form ula ted th e ir

p rod u c ts w i th low er so lvent content to m ee tcur ren t VOC r egula t ions.

Reclam ation specif icat ions requi re the coat ingsto m ee t the VOC regula t ions in -the-can or as-ma nu factu red before f ield th inning . Fieldth inn ing of a coa t ing tha t wi l l exceed ther e g u l at e d V O C m a x im u m i s n o t p e r m i t te d .Reclam ation sp ecif ies coat ings based on thecur ren t Envi ronm enta l Pro tec t ion A gency(EPA) VOC l imits .

(b) Resin. The resin (frequ ently cal led

b in d er ) i s t h e f ilm for m in g com p on en t o f acoat ing. Resins are typical ly a high m olecular w eigh t so lid po lymer t ha t fo rms la rgerepea t ing m olecu les in the cured f ilm. The

p ri m ary p u rp ose of the resin is to w et the p igm ent p ar t i cles a nd bind the p igm ent p art icl es t oge ther a nd to the su bst ra te (h en ce ,the t e rm b inder ) . The res in imp ar t s mos t o f the coa t ing p roper t i es . The var ious types o f res ins fo rmu la ted in a coa t ing w i ll d i sp layd is t inc t p rop er t i es . These proper t i es a re :

M e ch a nism a n d t im e o f cu r in g

P e rfo r m a nc e in s er v ice e xp o su r e ty p e P er fo rm a nc e o n s ub st rat e t yp e C o m p at ib ilit y wi t h o th e r co a tin g s F le xib ili ty an d t ou g h n ess Ext er ior w ea th er in g Ad hes ion

N o s in g le res in can a chie ve a h ig h d egree of success in m ee t ing the above coa t ing

p rop er t i es w i th w ide v aria t io ns associa tedw i th each p roper ty. Therefore , gener ic coa t ingtypes a re genera l ly c lassi fi ed by t he p r imaryres in type u sed in th e coa ting formu la tion .Typical resins are acryl ics , a lkyd s, and ep oxy

p ol ym ers .

(c) Pigment. Pigment s a re inso lub le and a rethe heav i e r so lid p or t ion of a coa t ing tha ttyp ical ly set t les to th e bottom of th e container.P igments a re ad d i t ives to the coa t ingformu la t ion th a t imp ar t spec i fic p roper t i es to


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Materials

7

ach ieve the d es i red f i lm p roper t i es . Thefo llowing p roper t i es a re accorded by

p igm ents , and a br ie f d escr ipt ion i s p rov idedfor each.

Color. N a tu ra l e a r th p ig m en ts (k aol inclay, magn esium si l icate , calcium carbona te)

p ro v id e col or st ab il i ty fr om u ltra v iole t (U V)sunl igh t d e te r iora t ion. Natu ra l ea r th p igmentsa re m ore UV s tab le than syn th e t ic o rgan ic

p ig m en ts.

Opacity. Titan ium oxide h ides thesubs t ra te o r p rev i ous coa t ing co lor and

p r o t e ct s t h e b in d e r fr o m UV s un l ig h tde te r io ra t ion .

Wet paint. Sil ica an d talc controlviscosi ty, wet f i lm level ing , an d set t l ing bu t p r o v i d e li t tl e h id in g ( op a c it y ) p o w e r .

Weather and moisture resistance.Alum inum leafs and micaceou s iron ox ide(MIO) increase barr ier thickness and forcemo is ture to de t our a roun d th ese p la te -l ikeaddi t ives .

Corrosion resistance. P i gm e n t s a d d e d t oinh ib i tive (p r imer ) coa t ings im ped e cor rosionof ferrou s substrat es . Past form u lat ions

i n cl u d e d c h r o m a te a n d l ea d p i g m e n t s , b u tthey a re se ldom u sed today because of env i ronm enta l and h ea l th concerns . Thefo llowing chromate and lead p igments a rera re ly used in cur ren t coa t ing formu la t ions :

R ed le ad W hi te le ad Ba si c l ea d sil ic o-c hr om a te Stron tium chrom a te Zinc chrom a te

The fol lowin g are accep table al tern at iveinh ib i t ive p igm ents :

Bariu m m etabor ate C al ciu m p ho sp ho si li ca te Z in c ox id e Zinc p ho sp ha te Zinc m olybd ate Zi nc p h osp ho si licate

Mildew resista nce . M i ld e w c id e s p r e v e n tmi ldew grow th on the d ry f i lm coa t ing .

Skid or s lip resistan ce. A l u m i n u m o xi d eor min era l aggrega te i s add ed in theformula t ion or app l ied to the w et f ilm toach ieve non s lip sur faces . Alum inum oxide i sthe be t te r cho ice because m inera l aggrega tem a y b e c r u sh e d u n d e r w e ig h t , p r o v i d i n gmois ture a ccess to the subs t ra te , and

p rom ot in g fur t he r c oa ting d e gra d a t io n andcor ros ion .

7. Coating Types. The fo llowing a re th ree ba si c t yp es of coa t ing s:

(a) Barrier. A coa t ing tha t fo rm s a

bar r ier betw een the m eta l su r fa ce an d theelectrolyte a nd electr ical ly isolates the m etal .Examples a re ep oxies and coa l t a r epoxies.

(b) Inhibitive. Pigmen t in a coa t ing p r im er t ha t is sl ig h t l y so lu b le in w at e r th a tforms a chem ical in hibi tor and effect ivelyinterferes w ith the electrolyte. Examp les arered lead and chromate p r im ers (no longer accep table) .

(c) Galvanic. Zinc-r ich primer coat ingstha t p rov ide ga lvan ic o r ca thodic p ro tec t ion to

ferrous m etal (zinc sacrif ices i tself to pro tectthe ferrous meta l). Galvani c coat ings areeffect ive on ly i f app lied d irect ly to bare m etal .

8. Generic Coatings. The fo l lowing gener iccoat ings and general descript ions are typical lyspecif ied by Reclam ation:

(a) Acrylics.In w ate r-born e acry l iccoa t ings , the res in i s d i spersed in w ate r toform a wate r em uls ion . Water-born e acry l icsare specif ied for atm osph eric exposu res as a

p r im er o r t op co a t a nd ha ve e xce lle n t co lo r a ndgloss retent ion. Acryl ics cure by coalescence.

(b) Alkyds.A l k y d s a r e n o r m a l ly n a t u r a loi ls (soya, tu ng, s tyrenate) that h ave beenchemica l ly m odi f ied to improve cu re ra te ,chem ical resis tance, and h ard ness. Phen olic-m odi f ied a lkyds a re spec i fied as a p r imer, andsi licone alkyd s are specif ied a s the topco at for a tmosph er ic se rv ice exposures . They a re no t


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8

sui table for alkal ine (concrete or mas onry)sur faces o r env i ron m ents . Alkyds cure by a ir oxidat ion of dry ing oi ls.

(c) Bituminous. Bi tuminou s coa t ings a reheavy-bod ied mate r ia l s ap p l ied w i th a cu tback so lven t . They have good m oistu re bar r ie r resistan ce an d fair to good chem ical resistan ce

b u t a re no t r es is t an t t o so lv e n ts . Co m m ercia l bi tum inou s pr od u c ts a re sp ec if ied on a l im ite d basis by Re cla m at io n for p ro tec t ion of a lum inum sur faces in contac t wi thcem ent i t ious m ate r ial o r s tee l an d cop per cab lew eld connec t ions . Bi tuminou s coa t ings cure

b y so lv en t e va p o ra tio n .

(d) Epoxy, Amine.Am ine epoxies a re

two-comp onent coa t ings tha t a re ca ta lyzed(hardened ) by an am ine cur ing agen t to p rod u ce a ha rd , t ig h t ly bo nd e d , ch em ica lresis tan t (alkal i , acid, and solven t) pr od u ct , bu tthey a re mois tu re and temp era ture sens i t ivedu r ing app l ica t ion . They a re spec i fied fo r

bu r i a l a n d im m e rsion se rv ice e xp o su r es, bu tthey w i ll fad e and cha lk in d i rec t su n l igh t .Am ine epoxies cure by chem ica l reac t ion .

(e) Epoxy, Polyamide. Polyamide ep oxiesare two com ponen t coa tings tha t a re ca ta lyzed

by a p oly am id e cu ri n g ag en t to p ro d u ce

sup er ior res i s tance to w ate r and sa l t solu t ions , bu t t he y do n o t p ro v id e th e ch em ica lres is tance of the am ine epoxy. Po lyamideshave a g rea te r f lexib i li ty th an th e am ineepoxies. They are specified for bu rial andimm ers ion se rv ice exposures , bu t they wi l lfad e and cha lk in d i rect sun l igh t . Po lyam ideepo xies cur e by chem ical react ion.

(f) Epoxy, Coal Tar. Coal t a r epoxies a regenera l ly an am ine or p o lyam ide epoxym odi f ied wi th coa l t ar p i t ch res in to p rodu ce ah igh-bui ld f ilm tha t ha s good chem ica lresis tance and excel lent wa ter resistance. Theyhave a t end ency to become br i t t le wi th age andde lam ina te betw een coa t s o r benea th repa i r

p a t ch es . The y a re sp ecified fo r bu r ia l a n dimm ers ion se rv ice exposures , bu t they w i llfade and cha lk in d i rec t sun l igh t . Coa l t a r epo xies cur e by chem ical react ion.

(g) Epoxy, Fusion-Bonded. Fusion- bon d ed ep oxie s (com m only call ed p ow d er coa t ings) a re comp le te coa t ings in p ow der fo rm. There a re tw o ap pl icat ion m ethods ,f lu idized -bed and electrostat ic . In thef lu id ized -bed me thod , the meta l it ems a re

p r eh e at e d to a fu s io n te m p e r at u r e a n dimm ersed in the pow der-epoxy so lu t ion . Inthe e lect ros ta t ic method , the epoxy p ow der

p ar t icl e s a re c ha rge d w it h h ig h vo l ta ge , a ndthe meta l it em i s then sprayed . Afte r spray ing ,the i t em i s p laced in an oven to cure a t abou t350 to 650 d egrees Fahren heit (F). Fusion-

bon d ed e poxie s a re s pe c ifie d fo r b u r ia l a ndimm ers ion se rv ice exposures , bu t they w i llfade and ch a lk in d i rect sun l igh t and a re

b ri t t le . A n ew m ater ia l i s fu sio n-bon d ed

nylon. This materi al is sup erior to the fusion- bon d ed ep ox y an d w ill be in corp orated intoReclam ation 's sp ecif icat ion. Pow d er coat ingscure by fusion (heat) .

(h) Inorganic Zinc Primers. Inorgan icz incs a re p r imers tha t incorpora te a h ighload ing (pou nd s per ga l lon) o f meta l l ic z inc fo r

p ig m e nta t io n ( hen ce, t he t er m z in c-r ich ) a ndare e i ther so lven t o r wate r based . Depend ingon the so lven t and res ins used , the coa t ingm ay be a z inc- r ich epoxy or u re th ane . Thesecoat ings are exclusively prim ers because they

p rovid e galvan ic o r ca thod ic p rotec t ion to s tee lsub strate . Inorgan ic zincs are spe cif ied for a tmosp her ic and imm ers ion se rv ice exposures ,

b u t t h ey can b e t op co a te d to ex te n d th ei r service l ife . Suitable topcoat m aterial select ionis requ i red to p rev en t ou t -gass ing f rom theinorgan ic z in c tha t p rod uces smal l p inholes inthe topcoat . Reclam ation sp ecif ies inorg aniczinc coat ings only to fraying surf aces or heatedt rea ted meta lw ork (ASTM A 325 or ASTMA 490). Ap plicat ion requ ires spe cial skil ls andknow ledge . Inorgan ic z incs cure by e ither reac t ion to w ate r ( so lven t redu c ib le ) o r reac tion to carbon d iox ide (wa te r red uc ib le) .

(i) Organic Zinc Primers. Organic zincsare p r imers tha t incorpora te a h igh load ing(pou nd s per gal lon) of meta l lic zinc for

p igm en ta t ion w i th a w ide v arie ty of solven tsand res ins . D epen ding on the so lven t and


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Materials

9

resins used , the coat ing m ay be a zinc-r icha lkyd , d ry ing o i l , epoxy, o r m oistu re -curedu retha ne. These coat ings are exclusively

p r im er s b eca u se th ey p rov id e g a lv an ic p rot ect ion to st eel sub str ate or th ey ar e u sed torepa i r dam aged ga lvan ized coa t ings on stee lsub strates . Org anic zincs are spe cif ied for a tmosp her ic , bur ia l , and imm ers ion se rv iceexposures bu t a re norm al ly topcoa ted toextend the service li fe of the coat in g. Suitabletop coat material select ion is required to

p rev en t o u t- g ass in g fr om th e org an ic z in c.Ou t -gass ing p rodu ces sm al l p inholes in th etopcoa t . The w ay organ ic z incs cure d epend son the coa t ing typ e .

(j) Polyurethane. Technical ly,

p o ly u re than e is a subc la ss o f u re than e . A tw o-compon ent po lyure thane i s crea ted bychemica lly combin ing a p o ly isoyana te an d a

p o ly o l to p rod u ce a n i socy an a te tha t has a tw o-mod e cure mecha nism of so lven t evapora t ion

and chem ical react ion. Reclamation specifies p o ly u re th an es fo r to p co a ti n g co m p ati b le (i. e .,s a m e m a n u f ac t u r er ) a m i n e a n d p o ly a m i d eepoxies to p ro tect ag a ins t d i rec t sun l igh tor UV an d to p rovid e specific colors .Po lyu re thanes a re sp eci fied fo r a tm ospher icand par t i a l o r f luc tua t ing imm ers ion se rv iceexposures .

(k) Urethane. Urethane coa t ings varyw idely in form ulat ions for specif ic serv iceenvi ronm ents and ap pl ica t ion requ i rements .Reclam ation specif ies s ingle-compon ent ,m ois tu re -cured u re thanes . They cure f rommois ture in the a tm osphere and can be ap p l iedto dam p sur faces tha t do no t hav e freem ois ture p re sen t . Th ese ure thane s a re

formu la ted wi th var ious p igmenta t ions andare specified in sever al com binat ions to sui tthe in tend ed se rv ice exposu re . Theseure than es a re sp eci fied for a tmosp her ic , bur ia l,and immers ion exposures .


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11

Chapter III

SpecificationsReclamation constru ct ion jobs are ad vert isedto con t rac tors to per form the requ i red w ork ,and con t rac tor se lec t ion i s mad e by a b id

p rocess . The m ost co m m on b id typ es a re low p r ice , n egoti a te d , f ixe d co st , a n d so le so u rce .On ce Reclama tion accep ts a contr actor s bid , acont rac t exi s ts be tw een Rec lamat ion and thecontractor. The contract is of ten called aspecif icat ion. The specif icat ion can be definedas a wri t ten, de tai led, technical descript ion of w ork to be per formed, de scr ib ing them ater ia l s, quan t i ti es, and mod e of cons t ruc t ion .

Spec if ica t ions a re d iv ided in to m any d iv i s ionsto descr ibe the var ious job requ i remen ts andmay inc lud e gen era l job de scr ip t ion ,subm it tals , pre-exist ing cond it ions,env i ronm enta l requ i rements , and technica larch itectu ral, civil, electrical, m echa nical,coat ing, and cath od ic p rotect ion discipl ines.Each d ivision is sometim es called a te chn ical

p a r ag ra p h o r s e ct io n .

9. Construction Specification Institute.Reclam at ion h as chan ged f rom a nar ra t ive

p aragra p h form a t to th e Con st ruc t io nSpecificat ion Inst i tute (CSI) form at for specif icat ions. CSI format s tyle is more conciseand u ses imp era t ive l angu age . References tandard s a re spec i fied to descr ibe qua l i ty o f ma te r ia l s , w ork m ode , t es t method s , andacceptance cr i ter ia that are a recognizedindu s t ry p rac t ice , thus redu c ing the need for l eng th y verb iage . The m os t comm on re ferences tandar ds used in the coa t ings indus t ry a reASTM, NACE, and SSPC.

CSI specif icat ions are d ivided into 16 divisionsfor a l l the bu i ld ing t rad es , and each d iv i s ionma y be fur ther d iv ided in to spec ia l ity sec t ions .Finishes are Division 9, and pa int and

p ro te ct iv e c o at in g s a re Sect io n 09900. Ea chsection is su bd ivided into the fol low ing basic

p art s:

Pa rt 1 : Genera l .Includes cost ,references, su bm it tals , qu al ity assur ance,d el ivery , storage, han d ling, and restr ict ions.

P a rt 2: P rod uct .Inc ludes requ i remen tsfor mate r ia l s to be used

Pa rt 3 : Exec ut ion .Inc lud es mod e of construc t ion, test meth od s, acceptance cr i ter ia ,a n d r e p a i r

10. Reclamation Coating Specifications.The Techni cal Service Center (TSC) in Denv er m aintains C SI gu idel ine coat ing sp ecif icat ions.The gu idel ine coat ing sp ecif icat ions are the

ba s is fo r sp ec ific p r o ject requ i rem e nt s a nd a re b ase d on h ist or ica l Re cla m a ti on st r u ct u res.The gu idel ine specificat ion s con tainins t ruc t iona l no tes and foo tno tes to a id thespec if ica t ion wr i te r in p rep ar ing thespecif icat ion s to m eet sp ecif ic projectrequ i rem ents . The gu ide line coa t ingspecif icat ions are av ai lable on Reclamation s

in t rane t w ebs ite : .Reclam ation u ses the fol low ing special i tysect ions fo r coa t ings and hazard ous based -

p ai nts :

Sec t io n 0 9902 .Coat ings fo r n ew meta l l icsub strates that includ e: s teel , cast or d u ct ilei ron ; ga lvan ized , a lum inum ; brass ; b ronze ; o r c o p p e r

Sec t io n 0 9908 .Maintenance coat ings for p re v io us ly co a t ed m e ta llic subs t r a t es th a tinclud e: s teel , cast or du ct i le i ron; galvan ized,a lum inum ; brass ; b ronze ; o r copper

Sect io n 0 9980 .Coatings for concrete andmasonry subs t ra tes

Sect io n 1 3283 . H a n d l in g a n d d i sp o s in gof paint containin g heav y m etals ( i .e . ,chrom ate, lead, etc . . .)


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12

(a) Part 1: General. Par t 1 includ es thefol lowing general out l ine:

C os t p ro v is io ns fo r e it he r l um p s u m o r b id i t em

R efe r en ce s fo r in d u s tr ia l s ta n d a rd suse d in the s p ecificat ion sect ion

Su b m i tt als ar e r eq u i re d to en s u re th econtractor is supp lying the spec if iedm aterials . The fol low ing subm it talsare essential :

" Man ufac ture r s p ro duc t da ta andapplicat ion sheets

"Ma nu facturer s cert i f icat ion of comp lian ce, s tat ing that m aterialsw e r e m a n u f a ct u r e d i n a cc o rd a n c ew i th qua l ity assu rance and qua l i ty

p ro gra m s t o in cl u d e b at chnu m bers , quan t i ty, and co lor

" Pur chase orde rs , ensur ing tha t thecont rac tor us ing ap provedmater ia l s to inc lud e ba tchnu mbers , quan t i ty, and co lor

Q u ality as su ra nce

D eliv e r y, sto r a ge, a n d h an d l in g

En v i ro n m e n t a l r e st r ic ti on s fo r s u rfa c e p rep ara t io n a n d a p p lica tio n

(b) Part 2: Products. Par t 2 inc lud es thefo llowing m ate r ia l requ i rem ents ou t l ine :

Ab rasives M IO Co a t in gs

(c) Pa rt 3: E xecution. Par t 3 includ es thefo llowing ou t l ine requ i rements to comp le tew o r k :

P rot ect ion a n d r ep a i r of e xist in gsurfaces

Em b ed d e d m e ta lw o rk in c on cr et e

Su r fa ce p r ep a ra tio n m e t ho d s

A pp lica tio n eq uip m e nt

C oa t in g a p p l ic at io n r eq u i re m en t s

In sp e ct ion m et h od s a n d a cce p ta n cecriteria

Re p air of d a m ag ed an d n on a ccep t a blecoa ted a reas

C oa ti ng t a b u la tio ns a n d c at eg or ie s (s eefollowing sect ion)

C olo r sch ed u le

11. Coating Tabulations and Categories.The format o f the coa t ing tabu la t ions andcategories in the CSI specificat ions wil l bes im i la r to the o ld n ar ra t ive paragrap h format .The coa t ing t abu la t ions and ca tegor ies changeover t ime because of lower VOC r egula t ions,l ead- and chromate- f ree requ irements , newcoa t ing technology deve lopm ents , and o ther factors . The following sect ions describe thetabu la t ions and ca tegor ies .

(a) Coating Tabulations. The coat ingtabula t ions a re based on Rec lamat ions

h i s to r ica l exper ience w i th coa t ing m eta lw ork i tem s , se rv ice exposu re , and ma te r ial s used indam s and wat e r conv eyance pro jec t s. Thetabula t ions a re in th e fo l lowing tab le form at :

I te m s to be co at ed a r e i de n t if ie d .

C oa t in g m a te ri al s ar e id e n t ifi ed i n t hef ir s t co lumn b y an a lph anu mer ic l abe lfor a manufac ture r s b rand na m e or aFedera l / mi l it a ry spec i fica tion nu mb er.Several equivalent coat ing materialsm ay be l is ted w i th in the sam e mat e r ia lo p t i o n n u m b e r. M o r e th a n o n ecoa t ing mate r ia l op t ion m ay be l i s tedin the tabu lat ion. For smal l jobs, theco lor m ay be sp eci fied in th i s co lum n.

N u m b er of co at s (p ri mer ,in te rmed ia te , and topcoa t ) , th ickness


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Specifications

13

of each ap pl ied coa t , and to ta l d ry f i lmthickness (DFT) of the coat ing systemare id en t i fi ed in the secon d colum n.

Su rf ace p re pa ra tio n m e th od s ar eiden t i fi ed by le t t e r or a lph anu m er iclabe l in the th ird co lum n and a redef ined in th e execu t ion p ar t fo r sur face prepara t ion .

In s tr u c tio n a l n ot es , if s pe c ifie d , ar eloca ted a t e i ther t ab le f ron t o r end .

(b) Coating Categories. The coat ingcategories specify, by alph anu m eric labels, them anu fac ture r s b rand nam e or the Federa l o r m il itary specificat ion n um ber of th e coat ing

ma terial l is ted in the tabula t ion s. Th eca tegories a re subd iv ided accord ing to thefol low ing th ree essential character is t ics:

Compos i t ion .List the gen eric chemicalcoa t ing nam e

P hy si ca l c ha ract er is t ics .Weight p er ga l lon , VOC conten t , min imu m app l ica t iontemp era ture , cur ing t im es a t spec i fict e m p e r a t u r e a n d h u m i d i ty, e tc .

Per fo rm an ce requ i rement s . Accelerated

ASTM test ing and accep tance cr i ter ia

12. Manufacturer's Product Data and Applica tion Sheets. Reclamationspecif icat ions requ ire the subm it tal of thecoa t ing m anu facture r s p rod uc t da ta(sometime s called techn ical d ata) andap plicat ion sheets . These shee ts specifythe m anu facture r s ins t ruc t ions andrecom men dat ions . The m anu fac ture r ' sins t ruc t ions and recomm end at ions have

becom e sp ecif icat io n requ irem en ts , u nless the

specif icat ions are mor e restr ict ive. Prod uctda ta and app l ica t ion shee t s should be kep t for fu ture re fe rence to ver i fy the mate r ia l typeapp l ied . The prod uc t da ta and appl ica tionshee t s vary in con ten t and format f romm anu fac ture r to manu fac ture . Som em a n u f a ct u r e r s co m b i n e p r o d u c t d a t a a n dapp l ica t ion in to one shee t . How ever, theshee t s p rov ide u sefu l in format ion for thespecific m aterial .

(a) Product Data Sheet. The following a ret h e m o s t c o m m o n i t e m s o n t h e p r o d u c t d a t asheets:

G en er ic ch em i ca l co at in g n a m e(acryl ic , a lkyd , epo xy, pol yure than e)

Ty p ica l u s es , s uc h as on b r id g es , p i p e s , o r w a t er t a n k s

Ser v ice ex p os u re for at m o sp h e ric, bu r ia l, im m er sio n (fre sh w ate r or sa ltw ate r ) , and chemica l res is tance

C ol or a n d gl os s a va il ab ili ty

P h y si ca l o r t ec h n ic al p r o p e r ti es , su c h

as weigh t per ga l lon , so lids byvolum e, VOC conten t , p igmentad d it ives, flashp oint , and servicetemp era ture res i stance

Re co m m en d ed d r y or w et filmthickness

T he o re t ic a l c o ve r ag e r a te pe r g a llo n

M ix ra tio ( if m u ltico m p o n en t s yst em ), p ot li fe , a n d in d u ct io n or sw ea t- in tim e(e lapsed t ime in te rva l to a l low the

chem ical react ion to begin for mu l t i comp one nt mate r ia l s beforeappl ica t ion)

D r y, re c oa t, cu r i n g , an d f u ll cu r e t im e p eriod s at tem p era tu re an d hu m idityranges

P e rf o rm a n c e te st re s ul t s (a c ce l er a te dASTM tes t s tha t ma y or may no t bel is ted)

Sh elf life

Sa fe ty p re ca ut io ns

Sh ip p in g d ata

Wa r r an t y a n d l im i t a tio n s o f li ab i li ty

(b) Application Sheet. The fol low ing are them os t common i t ems on the app l ica t ion shee t :


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Su b st r ate ty p e s th a t a r e co m p a tib lew ith the coat ing m aterial (e .g.,a lum inum , concre te , ga lvan ized , s tee l ,cast i ron, or exist ing coated surfaces)

Su r face p r ep a r a tio n m et h od , n or m a llyl is ted as a m in imum

Thinn e r p r od u c t nam e an d a m ou nt to be ad d ed

P ot -li fe -t im e o f m u lt ic om p o n e ntcoa t ing m ate r ia l a t va r ioust e m p e r a t u r e a n d h u m i d i t y r an g e s

Lo we r a n d u p p e r te mp e ratu re a n dhum idi ty range res tr i ct ions du r ing

appl ica t ion

M o st ma n u fa ct u r er s s ta te th a t t h ecoa t ing i s to be app l ied on ly when thesubs t ra te t emp era ture i s 5 degrees F,m i n i m u m , a b o v e t h e d e w p o i n t

D ry i ng , r e co at , a n d cu r in g ti me s a tv a r i ou s t e m p e r a t u r e a n d h u m i d i t yranges

A p p l ica t io n m e t h o d: b r u sh , ro lle r ,conven tional air less spray , or airlessspray. May include specif ice q u i p m e n t a t r e c o m m e n d e d p r e ss u r e s ,hose d iam eter s izes , sp ray gun , nozz letip sizes , etc.

13. Addendums and Modifications.Specif icat ions are som etimes chang ed to al ter d esign s, correct error s , or r ed ress om issions.The fo l lowing tw o genera l method s a re u sed torevise specif icat ions: (1) ad d end um s (alsoca lled amen dm ents ) a re wr i t t en page inser t s

tha t change p art(s) of the specif icat ion before b id d in g oc cu r ; a n d (2) m o d i fic a t io n s a rew r i t t en page inser t s tha t mod i fy p ar t ( s) o f thespecificat ion after the contract is aw ard ed .Mod i fica t ions can incur cost ad jus tme nts to thecont rac t and a re o f ten ca l led chan ge ord ers .


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15

Chapter IV

Inspector's RoleThe coat ing inspector ensures that : (1) thew ork i s accompl i shed in a t imely man ner inaccorda nce w ith the sp ecificat ions; (2) w ork ac tiv i ti es a re docum ented ; and (3) work i s

p erform ed safely. The coat in g insp ector at the job si te is ei th e r th e contra c t ing officers or th efield engineer s representat ive.

The insp ec tor shou ld no t verba l ly change therequi rem ents o r requ i re more r ig idrequi rem ents on the con t rac tor than w ere

original ly specified . The insp ector shou ldcontact his sup ervisor for resolut ion if thespec if ica t ions a re inade qua te . Cont rac tors mayreques t a var ian t f rom spec if ica t ions tha t mayor may not be s ignif icant . Regardl ess of varian t s ignif ican ce, the insp ector sh ou ldinform h is superv i sor o f any reques tedchanges . If a coat ing ap plicator is notfol low ing the specif icat ions, the inspector should n o t conf ron t the app l ica tor. Instead , heshould a sk the coa t ing con t rac tor superv i sor tode te rm ine w hy th e spec if ica t ions a re n o t be ingfo llowed . In some cases, a dev ia t ion m ay have

been a l lo w ed or the coa ting con t rac tor sup erv i sor may need to cor rec t h i s ownw orker s p ract ices.

14. Primary Responsibilities. The fol low ingare pr imar y respon sibi l it ies of th e insp ector:

Ve r ify in w r i tin g th a t co a tin g w o r k is being p erform ed in acco rd an ce w i ththe specif icat ions

M o n it or w o rk a c ti vi ty on a d a il y b as is ,

inc lud ing d ev ia t ions f rom thespecifications

R ep o rt a n d r ec or d d e f ic ie n cie s t o th efield engi neer for resolut ion

En su r e w o r k is co n d u cte d in a s afem a n n e r

15. Daily Responsibilities. The fol low ing isa p art ial l is t of dai ly insp ect ion resp onsibi l i t ies:

(a) Preparatory.

En s u r e s p e cifi ca t io n s co n t a in alla d d e n d u m s a n d m o d i fi ca t io n s

E ns ur e a ll sp e cifica t io n s ub m i tt a lr e q u i r e m e n ts a r e m e t

(b) Presurface Preparation.

E ns ur e w ea th er co nd i tio ns ar econdu c ive to b las t ing op era t ions

D et er m in e p r eb la st s ur fa ce co nd i t io nfor rus t g rade

E ns ur e t ha t t he su rf ace is fr ee of i rregu lari t ies (weld spat ter , slag burrs ,sharp edges , p i t s , l amina t ions , o r o ther object ionable i rregu lari t ies)

E ns u re t ha t a b ra si ve s m e etspec if ica t ion re qu i reme nts and a rew i th in contam ina t ion limi t s

E ns ur e t he a ir c om p r e ss or is fr ee o f m ois tu re and o i l con tamina t ion

(c) Postsurface Preparation.

E ns ur e t he su rf ace p re p ar at io nm ethod m eets spec if ica t ionsr e q u i r e m e n t s

En su r e t h e s u r face ( an c h or ) p r ofilem eets spec i fica t ions r equ i remen ts

E ns ur e th e su rf ace is fr ee o f con tam inants and meets c lean linessspecif icat ions requirements


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(d) Precoating Application.

E n su r e a ll co a tin g m a t er ia ls a rea p p r o v e d

C h ec k s to ra ge ar e a f or pr o p er env i ronm enta l and sa fetyr e q u i r e m e n t s

E ns ur e e nv ir on m e n ta l co nd i tio ns(ambien t and sur face temp era tures ,h u m i d i ty, a n d d e w p o i n t ) m e e tspecif icat ions requirements

En su r e m i xi ng a n d th in n in g m e etm anu facture r s requ i rem ents

(e) Coating Application.

En su r e a p p lic at io n m e t ho d s m e etman ufac ture r s requ i rem ents

E ns ur e in t er m e d ia t e co a t a n d t o pc o atapp l icat ions a re w i th in recoa t t imei n te r v a l fo r t e m p e r at u r e a n d h u m i d it yr a n g e s a n d t h a t t h e y m e e t t h especif icat ions or the man ufactu rer sr e q u i r e m e n t s

C h eck a mb ie n t te m pe r atu r e a n d

h u m i d it y d u r i n g c u r in g p e r i o d

(f) Postcoating Application.

E ns u r e t h e d r y f ilm t hi ck ne ss m e et sspecif icat ion requirements

I ns pe ct d r y f il m f or h ol id a y (p in h ol e)defects

E ns u re th at d e fe ct iv e , d a m a g ed , a nddef icien t a reas a re repa i red to m ee tspecif icat ion requirements .

For a more comp rehens ive l is t o f respon sibi l it ies , see ap pen d ix C.

16. Material Approval. Cont rac tor subm i tted coa t ing m ate r ial s a re norm al lyrev iewed by th e Rec lamat ion office tha t e i ther

p rep ared or i ssu ed the sp ecif ica t ions. Th e

resp onsible review ing off ice is l is ted in therequi red subm i tta l nu mb er (RSN) tab le inSection 01330 (Su bm ittals) of th e CSIspecifications.

The coat in g inspector is not u sual lyrespons ib le fo r ap proving or d i sap provingcont rac tor subm i t ted m ate r ia l. H ow ever, theinspec tor should t rack con t rac tor andReclamat ion cor responde nce to ensure tha to n l y a p p r o v e d m a t e r ia l s a r e u s e d o n t h e

job si te.

If the TSC in the Den ver Office is theresp onsible specif icat ion rev iewing office, itw i ll p rov ide a con t rac tor subm i t ta l w i th one of the fo l low ing respon ses :

A p prov ed . In d ica t es ma t e r ia l c a n b e p u rchased and ap p l ied .

Condit iona l ly approved .Indicates them aterial select ion is accep table and themat er ia l may b e purchased ; how ev er, thesub m it tal is incom plete or is m issingdocum enta t ion . Resubm i t ta l o f incomple te o r miss ing d ocum enta t ion is requ i red .Cond i tiona l ap prov a l does no t implyaccep tance for m ate r ia l app l ica t ion .

N o t a pp rov ed .Indicates the se lectedmat er ia l is no t ap prov ed for ap p l ica t ion .

The inspec tor should check ba tch nu mbers onmater ia l con ta iners aga ins t the ap prova l l e tt e r

batch n u m bers for m ate ri als th a t a rri ve o n th e jobs it e . C ont a in e rs w it h ba tch n u m be rs th a td o n o t c o r r e s p on d t o t h e a p p r o v e d m a t e r ia l

b atc h n u m b er s s h o u ld b e re m o v ed fr om t h e job si te.

17. Documentation. The inspec tor shouldacqui re the fol low ing docum ents :

Sp e c if ic at io ns th a t in cl ud e a d d e nd u m sand m odi fica t ions

T he m a nu fa ct ur er s p ro d u ct d at a,ap p licat ion, and Material Safety DataSheet (MSDS)


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Inspector's Role

17

R efe re n ce st an d a rd s r ef er re d t o i n t h especificat ion s that r elate to th e f ieldinspect ion

Re fer en c e s ta n d a r d s a r e d i scu s sed inmore d e ta i l for the p er t inen tinsp ec t ion m ethod in o ther chap te rs.Ap pen dix D l is t s refe rence s tandard sc ited in th i s docum ent

18. Instruments, Gauges, and Tools. Th einspec tor should acqui re the equ ipm ent ,ins t rum ents , and ins t ruc t iona l m anu a lsnecessary to p er form the insp ec t ion w ork .Spare ba t ter ies sh ou ld be av ai lable i f e lectron icins t rum ents a re used . The types o f ins t rum ents w i ll be d i scu ssed in the fo l lowing

chapte rs and a re l is t ed in ap pen dix E .

(a) Conflicts. At t imes , the re a red isagreeme nts be twe en the con t rac tor and theinspec tor over ins t rum ent read ings such assurface anch or pr ofiles or d ry f i lm thicknesses.There may be reasonable exp lana t ions fo r suchd iscrepa ncies. Th ese discrepan cies shou ld beinves tiga ted to avo id fu ture conf l ic t s and todeve lop a w ork ing re la t ionsh ip w i th thecontra ctor. Th e following are some

p oss ibi li t ies for inst r u m en t d isa gre e m en ts:

T he tw o p a r t ie s a re n ot us in g t he sa metype of ins t ru m ent se t s :

" O n e i n s t r u m e n t m a y b emal func t ion ing

" O n e i n st r u m e n t m a y b e o u t o f cal ibrat ion

T he t wo p a rt ie s ar e u s in g t he sa m etype of ins t rum ents bu t :

" They a re u s ing d i ffe ren t p roced u res

" They a re t ak ing read ings a tdifferen t locat ion s

" O n e i n s tr u m e n t m a y b e o u t o f cal ibrat ion

19. Substrate Inspection. The inspec tor should i nspec ted the su bs t ra te sur face beforesur face prep ara t ion . Fer rou s subs tra tes w i thloca l ized rus t o r m i ll sca le a re m ore p rone to

p rem atu r e c o a tin g fa ilu re. Ru st an d m il l sca leareas should be inspec ted more thorou ghly for clean liness af ter su rface pr epa rat ion. If mil lscale is noted and abrasive blast ing is notspecif ied , not ify the f ield en gineer becau seabras ive b las ting i s requ i red . For m ain tenan cecoa t ing w ork w here overcoa t ing i s spec if ied ,the ex is t ing coa t ing m ate r ia l should beinspec ted for loose coa t ings by sc rap ing w i th asharpen ed pu t ty kn i fe . Overcoa t ing loose lyad herin g exist ing coat ing w il l resul t in

p rem atu re fail ure .

For i tem s coa ted in a shop , the coa t ings shou ld be in sp e ct ed a n d id en t ifi ed fo r d a m ag e an dfailed coat ing ar eas that w il l requ ire rep air ei ther befor e or af ter instal lat ion.

20. Coating Inspection Checklist Sheet.Reclam ation sp ecificat ion coat ing tabu lat ions(see chap ter III , subsect ion 11) ident ify th ei tems to be coated , coat ing m aterials , the DFTs,a n d t h e s u r f ac e p r e p a r a t i on m e t h o d s ;how ever, the inspec tor may w ish to expand onthe coa t ing tabu la t ion s by c rea t ing a coa t inginspect ion checklis t u niqu e to th e job. Since

specificat ion coat ing tabu lat ion s can iden tifysevera l it ems to b e coa ted w i th in a s ing letabu la t ion , an inspec t ion shee t can prov id e fo r the ind iv idu a l coa t ing opera t ions and for thecomple ted insp ec t ion for a s ing le i t em to becoa ted , such as a p ipe l ine in te r io r o r a rad ia lga te . The check l is t can become a perm eantrecord of the job . A check li s t example app earsi n a p p e n d i x F.

21. Precoating Conference. Reclamationcoating specif icat ions d o not requ ire a

p r eco a ti n g co n fe ren ce w it h th e co n tr act or .H ow ever, a m ee t ing w i th the con t rac tor tod i scuss coa t ing- re la ted i s sues w ould behelpful . A preco at ing confere nce wil l a l lowthe con t rac tor to know wha t i s expec ted and toout l ine the w ork program . This m ee t ingshould es tab l i sh a w ork ing re la t ionsh ip

be tw een th e co n tra ct or a n d Rec la m at io n . Th efol low ing are p ossible items for d iscu ssion atthe mee t ing :


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T he c o nt ra c to r s jo b- s pe c if ic w o r k er hea l th and sa fe ty p lan (a submi t tedw r i t t en p lan i s requ i red for lead or o ther hazard ous m ate r ia l removal anddisposa l )

T he i ns p e ct or s a cce ss a nd s af et y

Th e co n tr act o rs p r o p os e d o p er a tio n ,i n c lu d i n g e qu i p m e n t a n d p e r s o nn e l

T he co n tr a ct o rs w o rk i ng ho u rs

Th e m a te r ial s to r ag e a r ea , in clu d i n gtemp era ture , ven t i la t ion , and secur i ty

T he ap p r ov ed s u rf ace pr e p ar at io n

meth ods , abras ives , coa t ing m ate r ia l s,app l ica t ion m ethods , and cur ing t imes

T he m e th od o f d u st co lle ct io n an ddisposa l o f used abras ives

U nf av or ab l e w e at he r r el at ed t o p rep ared sur face s, a p p lied coa tings, o r cur ing

T h e p l a n fo r co a t in g in a cce s sib le a re a s

In sp e ct io n m e t ho d s a nd t he nu m b e r o f m e a s u r e m e n t s

T he ty p e s of in sp e c tio n in st ru m e n t s t o be u sed

T he NA C E/ SSP C r efe re nce st an da rd stha t a re spec if ied , the v i sua l s tandards

to be m et , and the accep tance cr i t e r ia


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Chapter V

Material Storage, Containers, and Shelf LifeCoa ting ma terials arr ive on th e jobsi te beforeapp l ica tion beg ins , and they requ i re sto rage .Manu fac ture rs recom mend spec if ic p rov is ionsfor s to rage to p reven t coa t ing d e te r io ra t ion .Coa t ing mate r ia ls mu s t be u sed w i th in aspec if ied t ime f rom m anu facture o r sh ipm ent .

22. Storage. Coat ing ma te r ia l s shou ld bes tored in a covered , wel l-ven t i la ted a rea aw ayfrom sp arks, f lam es, an d d irect sun ligh t .Man y coa t ings requ i re a l im i ted temp era turerange for p roper s to rage . Cold s to rage mayrequ ire a coat ing to be excessively thinn ed for ap plicat ion, resul t ing in low s ol id s conte nt anda less- than-intend ed DFT. At or belowfreez ing temp era tures , coa t ings ( such as w ate r

ba sed m a te r ia ls ) can d e gra d e t o th e p o in t th a tthey a re unu sab le . Mater ia l s in co ld s to rages h o u l d b e m o v e d t o a h e a t e d a r e a b e fo r eapp l ica t ion . At h igh temp era tures , a mate r ia lsuch as so lven t -based coa t ing m ay ge l o r

be co m e fla m m a ble o r exp lo s iv e . Th e st o r ages it e s h o u ld b e m o n i t o re d u s in g a h i g h / l owt h e r m o m e t e r.

Coa t ing mat e r ia l s shou ld be s to red toge ther bythe same ba tch or lo t num bers . Two-comp onent coa t ing sys tems should be s to redc lose toge ther bu t be d i s t ingu ishab le from oneanother. For sto rage of severa l month s o r longer, con ta iners should be inver ted on am onth ly b as is to avo id excess ive se t t l ing an dfor ease of futu re mixing. The oldest coat ingmater ia l s shou ld be u sed f i r st .

Solven ts and th inners should be s to red

separat ely from coat ing m aterials . Sepa rat ionof so lven ts and th inners i s a sa fe ty concern

because m an y of these m ate rials hav e lo w er f lashpoin t t em pera tu res than mos t coa t ings ,and they pose a po te n t ia l f ire hazar d .

Contr actors wil l often s tore coat ing m aterial a tthe jobsi te in t rai lers . Trai lers w ith no heat ing,cooling, or venti lat ion system s are u nsu itablefor s torage because they become co ld in w in te r

a n d h o t in s u m m e r a n d h a v e l im i t edvent i la t ion . Coa t ing mate r ia l s should bes tored in c limate con tro l led en v i ronmen ts .The followi ng are general ly acceptedregu lat ions for storing coat ing m aterials :

Indoor storage. N o m or e t h an 25 g a llon souts ide of app roved cab ine t s in a s ing le a rea .

Outdoor storage. N o m or e t h an 1,1 00ga l lons o f ma te r ia l s g rou ped toge ther. N o

more than 60 ga l lons in ind iv idu a l con tainers .

For fu r ther in format ion on the s to rage of f lamm able and combu s t ib le l iqu ids , re fe r tothe manu fac ture r ' s MSDS and Reclamat ionSafe ty and H ea l th Stand ard s .

23. Containers. Conta iners vary large ly inv o lu m e a n d c o m m o n l y r a n g e f ro m 1 q u a r t t o55 gal lons. Because of app licat ion equ ipm entl imi ta t ions , the m os t comm on conta iners on a

job sit e w il l b e ei th er 1-g a llo n or 5-g a llo n p a ils .S ing le componen t mate r ia l s a re sh ipped in onec o n ta in e r, a n d t w o o r m o r e c o m p o n e n tmate r ia l s a re sh ipp ed in separa te con ta iners ,each of which has the capac i ty to ho ld the to ta lc o m b i n ed v o l u m e .

Any conta iners tha t a re d am aged , leak ing , o r un labe led shou ld be re jec ted and removedfrom the job si te .

24. Shelf Life.Shelf l ife is th e length of t imeaf te r m anu fac ture th a t a coa t ing ma te r ial w i llr e m a i n u s a b l e w h e n s t o r ed i n a n u n o p e n e d

conta iner, accord ing to the man ufac ture r.Ma nu factu rers norm ally sp ecify the shelf l i feof a coa t ing on the con ta iner o r u se a spec ia lcode or bar cod e tha t spec i fies the da te o f ma nu fac ture o r the exp i ra t ion da te . For special cod es or bar codes , the insp ector mayneed to ca l l the m anu facture r to read the code .In gene ral , m ost coat ings have a shelf l ife of

be tw ee n 6 a nd 12 m o nth s a t a n op t imaltemp era ture , bu t th i s wi ll va ry wi th


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m anu factu rer and m aterial typ e. Shelf l i fe isn o t e d o n t h e m a n u f a ct u r e r s p r o d u c t d a t ashee t . The inspec tor should check the da te o f man ufac ture o r the exp i ra t ion d a te tode te rm ine tha t the exp i ra t ion da te has no t beenreached . Coa t ing m ate r ia ls tha t have exceeded

the she l f l if e shou ld be rem oved f rom the job si te. C on se q u en ces of e xce ed in g th e s h el f l ife include gel l ing, odor, chang es in viscosity,fo rmat ion of lum ps , p igment se t t leme nt , andcolor o r l iqu id separa t ion .


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Chapter VI

Surface PreparationThe se rv ice l i fe o f a coa t ing d epen ds on thede gree of sur face prepara t ion ach ieved asmu ch as it dep end s on m ate r ia l se lec t ion andap p licat ion. All coat in g system s w il leven tu a l ly fa i l ; how ever, p rem ature fa ilu resare o f ten the resu l t o f inad equa te su r face

p re par a t ion . Ev en su r fa ce pre p ara t io ns tha tachieve an accepta ble margi n of cleanliness butleave con tam inants on the sur face wi l l t end tolessen the coat ing service l ife . Thu s,cleanliness o f the su bstra te is an essential and

in tegra l com ponen t o f a coa t ing sys tem.

25. Surface Contaminants . Surfacecontamina t ion i s one of the m os t comm oncauses of coat ing fai lures. To achieve them aximu m service li fe of a coat ing system , it isessen t ia l to rem ove su r face con tam inants .

(a) Types of Surface Contaminants. Th efo llowing a re the mos t comm on types o f sur face con tam inants and the consequences o f n o t r em o v i ng t h e m :

Rust.Rust is the cor ros ion byp rodu c t(ferrou s oxid e) of s teel and m ay be loose or m ay ad here re la t ive ly t igh t ly to the subs t ra te .Rus t is porous and m ay inc lud e mois tu re ,oxygen , and so lub le sa lt s . Rus t wi l l expand upto e igh t t imes the vo lum e of the base met a lc o n su m e d a n d f u r t he r c o r r o d e t h e s t e e lsubs t ra te , thu s d i s lodging any coa t ing ap p l iedover i t .

Mill scale. Mill scale is a heav y oxidelayer fo rme d d ur ing h o t fabr ica t ion or hea t

t rea tment o f m eta l s and i s a b lu i sh color. Mi l lscale wil l even tual ly break loose from the s teelsubstra te , taking the coat ing w ith i t. Steel isanod ic to m il l scale (s teel has a low er electr ical-chem ical p otent ial difference than m il l scale) ;there fore, s teel wi ll corrod e (sacrifice i tself) to

p rotect th e m ill sc ale .

Grease and oil. Grease and o i l p reven t acoa t ing f rom adher ing to the subs t ra te .

Dirt and dust. D i r t a n d d u s t o n t h esur face preven t the a pp l ica t ion of a sm oothuni form f ilm and w eaken the adhe s ion of thecoa t ing to the su bs t ra te .

Solu ble sa lts. Soluble sa l t s depos i ted on asur face can remain on the sur face , even a f te r abrasive cleaning. Soluble sal ts wil l increasemois ture perme at ion th roug h the coa ting(osmotic bl is ter ing) and can accelerate th ecor ros ion ra te u nd er the coa t ing f i lm

(und er fi lm cor ros ion or und ercu t t ing) . Themos t comm on so lub le sa l t s encounte red in thecoat ing ind us try are chlorides, sulfates , andm etal l ic sal ts . The ch loride ion is the m ostaggressive.

Water. Water wi l l p rev en t adh es ion andma y e i ther p rodu ce f lash rus t ing beforecoat ing ap plicat ion or i t may accelerateun d erf i lm corro sion af ter coating ap plicat ion.Mois tu re in the l iqu id or f rozen s ta te w i ll

p rev en t ad he sion of the coa t ing to th esubs t ra te and can d i s rup t cur ing reac tions o f coa t ings . Mois tu re con tamina t ion can causeseveral typ es of fai lur e.

Chalk.Ch alk is the residu e left af ter thed eteriorat ion of th e coat ing s org anic bind er.Cha lk resu l t s f rom exp osure o f the coa t ing tod irect sun light or ar t i f icial UV l igh t . Allcoa t ings cha lk to some degree , bu t epox ies a rem ore prone to cha lk . Overcoa t ing cha lkedsur faces wi ll r esu l t in poor adh es ion and mayresu l t in d e lamina t ion ( separa t ion of onecoa t ing layer from another coa t ing layer )

fai lure.

Deteriorated coatings. Old , loose,de te r io ra ted coa t ings tha t a re overcoa ted m ay

p e el , d e la m in a te , o r li ft fr om t h e su b st r at e an dt a k e t he n e w c o a tin g w i th t h e m .

(b) Compressed Air Contaminants. A ir comp ressors con tam ina ted w i th m ois tu re andoil can resu l t in ad hesion-related fai lures. The


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fo llowing a re two comm on ope ra t ions tha tt rans fe r o il and w ate r con taminants f rom thecomp ressed a i r supply to the subs t ra te :

A b ra siv e su r fa ce p r ep a ra tio nopera t ions

Bl ow i ng d o w n th e p re p are d s u bst ra tea f ter sur face prepara t ion to remov edu s t before app l y ing the coa t ing

A i r c om p r e s so r s s h ou l d b e e q u i p p e d w i t h i n -l ine m ois tu re a nd o il separa tors ( t raps ) on a l ll ines . The inspe c tor should have the con t rac tor check the a i r sup ply fo r con taminan ts inaccordan ce with ATM D 4285. (Seeapp end ix G for th i s p roced ure . ) I t i s

recomm end ed tha t the compressed a i r lines bechecked once every 4 hours o r a f te r thecomp ressor has been tu rned off .

(c) Flash Rusting. Flash ru s t ing ( somet imescal led f lashback ru st ing or rust bloom ing) is al ight oxida t ion (corrosion) of the ferrou ssur face a f te r sur face prep ara t ion has beencomp leted . F lash rus t ing deve lops on f resh ly

p rep a red su r fa ce s in th e p rese n ce of m oist u r e.Af te r the m ois tu re d r ies o ff, any resu l tingcorrosion is called f lash ru st in g and can occu r w i th in min utes a fte r sur face prepara t ion . The

fo llowing tw o c i rcum stances a re the m os tcomm on m ois tu re sou rces resu l t ing in f lashrus t ing :

C on d e n sa tio n is o ccu r rin g

Wat er is u se d in th e s u rfa ce p rep ara t io n m ethod

Cond ensa t ion i s the fo rmat ion of liqu id w ate r f ro m w a t e r v a p o r i n t h e su r r o u n d i n g a i r a tc e rt a i n a m b i e nt t e m p e r at u r e s a n d h u m i d i tyranges . Cond ensa t ion can occur us ing anysur face p repara t ion m ethod becau se it isw ea ther d epend ent . Sur face prep ara t ionmet hods tha t emp loy wate r a re wat e r je t t ingand w et abras ive b las t c lean ing . F lash rus t ingcan be m in imized w hen u s ing w ate r je t t ingand w et abras ive b las t c lean ing by th efo llowing method s :

Using an inhibitive agent. Inhibi t iveagent o r wash p r imer, norm al ly a p hosph a te , i sin jec ted in to the w ate r o r b las t s t ream or app l ied a f te r c lean ing . Reclamat ion does no t

p ro h ib it th e u se of in h ib it or s, b u t th e su rfa ces h o u l d b e t h o r o u g h l y w a t e r w a s h e d b e f o r ecoa t ing beca use heav y inh ib i t ive res idu es canadverse ly a ffect coa t ing ad hes ion .

Using hot forced (blown) air. Dr y off thew et ted sur face im med ia te ly a f te r c lean ing w i thhot a i r b lowers .

Using high-pressure, water-jet vacuumcleaning method. High-wate r p ressuret rans fe rs enorm ous energy to the sur face , thuse leva t ing the sur face temp era ture to evap ora te

a n y m o i st u r e , a n d t h e v a c u u m r e m o v e se v a p o r a t e d a n d l iq u i d m o is t u re a w a y.

To prevent f lash ru s t ing , i t is a genera lindu s tr ia l p rac t ice no t to p roceed w i th su r face

p rep arat ion u nless the s tee l su b stratetemp era ture i s 5 degrees F, min im um , abovethe dew poin t . (See chap te r VII,Envi ronm enta l Cond i t ions . )

Sur face prep ara t ion s tandard s N ACE 1 / SSPC-SP-5, N AC E 2/ SSPC-SP10, N ACE 3/ SSPC-SP-6, N AC E 4/ SSPC-SP-7, N AC E 8/ SSPC-SP14,

SSPC-SP15, and SSPC-SP11 provid e for recleaning or reblast ing to rem ove f lashrus t ing . The sur face prepara t ion s tand ardsSSPC-SP2, SSPC-SP3, and N AC E 5/ SSPC-SP12do no t spec i fica l ly add ress fl ash rus t ing bu trequ i re tha t the su r face be rec leaned accord ingto c lean l iness requ i rements o f the s tandardused i f rus t fo rms on the su r face . Reclamat ionspec i fica t ions requ i re tha t any sur face w heref lash ru s t o r cor ros ion byp rodu c ts haveformed be rec leaned

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Coating Ispector Guide