Finishing Talk Newsletter - September 2008

8/14/2019 Finishing Talk Newsletter - September 2008

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F in i sh i ng Spo t l i gh t :

Inside This Issue:

Class 5 is unsealed. Asummary is shown inTable 1 on page 11.

Since this paper is pri-marily discussing con-ventional chrome ver-sus sulfuric coatings,items not discussedhere but relate includeType III hardcoat ano-dizing (HCA) for highwear performance andelectrical insulation,and phosphoric acid

anodizing (PAA) usedfor metal bonding(structural adhesive)preparation. This paperwill focus only on Chro-mic Acid Anodize andthe non-chrome alter-

natives Sulfuric Acid

By Steve AnzelcPE LEED AP

Questions

What are the differ-ences between chromicacid anodize (CAA), sul-furic acid anodize (SAA)and boric sulfuric acidanodize (BSAA) for alu-minum in the aero-space industry? Whenis chromic acid anodiz-ing required versus sul-furic acid anodizing?

Since Boeing has comeup with a non-chromereplacement with BoricSulfuric, why would youstill use CAA? Addition-ally, the type, number,and class are some-

times confusing to

those not using themregularly, so I havesummarized the basics

for each.Types & ClassesChromic Acid Anodizing(CAA) is Type I or IB;Sulfuric Acid Anodize(BSAA) is Type IC; andHard Chrome is TypeIII. Suffixes are addedto these types and arecalled classes to indi-cate dyes and seal

combinations. Military(Mil) and Boeing Air-plane Company (BAC)Class 1 is non-dyed,and Mil Class 2 is dyedprior to seal. BAC Class3 is dilute chromate

seal only, and BAC

S E P T E M B E R 2 0 0 8 V O L U M E 1 , I S S U E 8

C O V E R S T O R Y

1

I N D U S T R Y E V E N T S

2

N E W S & N O T E S

3

F R O M T H EF O R U M

6

F I N I S H I N GS P O T L I G H T

9

T H E L A S TW O R D

1 5

C O N T E N T S

(page 6)

B A S I C C O M P A R I S O N S O F C H R O M E A N D N O N

C H R O M A T E A L T E R N A T I V E A N O D I Z I N G

Continued on page 4

The Perks of

Organization

Membership

(page 15)(page 9)

FromtheForum:Recurring

Powder

Defect


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Page 2F I N I S H I N G T A L K

September 14 -16:

Southern Metal Finishing

Charleston, SC

surfacefinishingacademy.com

September 15 -16:

Powder Coating School

Charleston, SC

surfacefinishingacademy.com

September 18 :

Overview of UV Coatings Tech.

Virtual Learning Conference

www.coatingstech.org

September 22 -25:

Coating 2008

Indianapolis, IN

www.thecoatingshow.com

September 23 -25:

LatinCoat 2008

Norte Sao Paulo, Brazil

www.latingcoat.com.br

October 7-10:

PDA Applicator Spray Course

Houston, TX

www.pda-online.org

October 14-16 :

FutureCoat! 2008

Chicago, IL

[email protected]

October 14-27 :

NASF Trade Tour - China

Beijing-Shanghai, China

www.nasf.org

October 15-17 :

International Coatings Expo

Chicago, IL

TBD

October 23:

ASTM Committee B08 Meeting

West Conshohocken, PA

[email protected]

October 27-28 :

Electroplating Know How Basics

Dallas-Fort Worth, TXwww.platingschool.com

Have an upcoming event? Tell

us about it at

www.finishingtalk.com!

I N D U S T R Y E V E N T S 2 0 0 8


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Page 3V O L U M E 1 , I S S U E 8

N E W S & N O T E S

New York, NY Inc. magazinehas ranked Powder-X Coating Sys-tems on its annual ranking of the5,000 fastest-growing private com-

panies in the country. The list isthe most comprehensive look atthe most important segment of theeconomy Americas independent-minded entrepreneurs. Taken as awhole, these companies representthe backbone of the U.S. economy.Ranked number 2,185 out of 5,000of the fastest-growing private com-panies in America, Powder-X Coat-ing Systems is proud to be re-corded on such a prestigious list asthe Inc. 5,000. They have beenworking for many years to build up the

brand name Powder-X nationwide.

Now their line of products is not only

recognized, it is revered as one the top

selling brands in the industry. Visitwww.inc5000.com for more info.

Boilingbrook, IL Midwesco/TDCFilter is excited to announce theirmove from their Cicero, IL locationto a state-of-the-art production/

warehouse facility in Bolingbrook,IL, the main distribution corridor inthe Midwest. Theyve made a 9million dollar capital investment inthe new building and processingequipment to better serve theircustomers needs. Please updateyour files with their new contactinformation:

TDC Filter/Midwesco2 Territorial Court

Bolingbrook, IL 60440, USAMain Phone: 630.410.6200Fax: 630.410.6201Order Entry e-mail:

[email protected]

San Francisco, CA The Alumi-num Anodizers Council (AAC) willpresent the keen observations oftheir Washington D.C. legal coun-

only improve their environmentalfootprint, but reduce energy, wa-ter, and labor costs, DuBois stated.Hence the companys ongoing ef-

forts to develop products and ap-plications that focus on these ar-eas. The U.S. Environmental Pro-tection Agency recently released alean manufacturing case study thathighlights the results of such apartnership between DuBois andSteelcase, a global leader in theoffice furniture industry. Workingtogether, they have implementedmetal cleaning and finishing solu-tions that have reduced processcosts in energy, water, and labor inexcess of 50% while reducingwaste stream discharges in excessof 80%.For more information onDuBois Chemicals, please visitwww.duboischemicals.com.

Hyannis, MA The New England

Regional Surface Finishing Confer-

ence will be held Nov 7th at the

Cape Codder Hotel and Resort in

Hyannis, MA. Technical presenta-

tions from industry experts, regula-

tory agencies and metal finishing

suppliers will be held in conjunction

with a table top trade show.

Waste Water Treatment and TURI

contact hours will be given out at

the conference. Following the day

of presentations attendees will en-

joy a New England Clambake din-

ner and all in attendance will re-

ceive a 2008 Regional computer

carry case.The Cape Codder boastsone of New England's largest in-

door wave pools for families and

friends to enjoy. For more infor-

mation contact Marc Pellessier from

Valley Plating at 413.732.7053,

John Gilbert from Gilbert and Jones

@ 800.577.2962 or Marko Duffy of

MacDermid @ 508.904.8899.

sel, Charles Simmons of Thompson& Simmons, PLLC at their Seven-teenth Annual International Anodiz-ing Conference. Simmons will dis-

cuss the potential impacts eachpresidential candidate could haveon the anodizing industry ifelected. He will attempt to put theopposing parties energy and envi-ronmental/regulatory policies inperspective and present an impar-tial analysis of what could be ex-pected under a Barack Obama orJohn McCain administration. Sim-mons practice focuses on regula-tory compliance issues involving

the Clean Water Act, along withsolid waste disposal, toxic sub-stances, and radioactive materials.Simmons has extensive experienceunder federal and state environ-mental statutes governing themanufacture, possession, use,transportation and disposal of ra-dioactive and hazardous chemicalsubstances, making him well quali-fied to offer insights into the regu-latory issues of today. The Anodiz-ing Conference is being held Tues-day, October 28 through Thursday,October 30, 2008 at the SheratonFisherman's Wharf in San Fran-cisco, California.

Global DuBois Chemicals, theindustrial division of JohnsonDiver-sey, Inc.a leading global providerof cleaning and hygiene solutionshas launched Sustainable CleaningSolutions, a program designed to

reduce customers total cost ofownership through products andapplications that are lean, green,and clean. As the price of fuel andraw materials has skyrocketed, in-dustry has been forced to find costreduction methods, including theevaluation and implementation ofgreen technologies that will not

V O L U M E 1 , I S S U E 7


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Page 4

B A S I C C O M P A R I S O N S . . . ( C O N T F R O M P G 1 )

geometries, weldments, crevices,lapped or recessed surfaces thatmay trap electrolyte. It is the

only one typically allowed to beused for assemblies for similarreasons. Assembles with dissimi-

lar materials besides aluminumare typically prohibited withoutspecial masking or other steps.On assemblies with mixed alumi-num alloys, CAA allows for aneven anodic coating, where SAAwould not. It is typically a goodprocess for castings. CAA alsopreserves the metals fatigue

strength with minimal dimen-sional changes. CAA will provide336 hours in a 5% salts praytest.

At one time, CAA used to be in-expensive, but now you shoulduse Sulfuric Acid Anodize unless

most heavily regulated processbecause of the hexavalentchrome issues in an agitated,

electrified bath. Environmentalpermitting, testing, monitoring,reporting and compliance issueswill be a priority. This falls underthe Aerospace National Emis-sions Standards for Hazardous Air Pollutants (ANESHAP). Misteliminators at the tank anddownstream hexavalent chromeair scrubbers are utilized on theprocess tank exhaust. Compli-ance is expensive and can be

time consuming.

Because the chromic acid is in-hibitive to the aluminum, it is notan issue like it is with sulfuricacid. CAA is specified for certainmilitary applications and aero-space parts that have complex

Anodize and Boric Sulfuric AcidAnodize processes only.

Type I and IB Chromic Acid

Anodize [BAC 5019, Mil-A-8625F]This process utilizes chromic acidin an electrified bath (40 Volt forType I and 22 Volt for Type IB)for building a thin, dense anodiccoating on aluminum providingexcellent corrosion resistanceand fair paint pretreatment. Halfof the coating penetrates into

the substrate and the other half

of the coating is a dimensionalincrease. It generates a .02to.05 and up to a max of about0.1 mil film thickness on partsand has a light grey color. Thefilm is usually harder than thesulfuric acid anodizing film forthe same thickness. CAA is the

F I N I S H I N G T A L K


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you absolutely have to haveType I CAA because of environ-mental compliance. In many re-gards, the SAA is actually betterand unfortunately it is gettingharder to find shops that will

even do Type I processing whenyou need it.

Type II and IIB Sulfuric Acid Anodize [BAC 5022, Mil-A-8625]This process utilizes sulfuric acidin in an electrified bath for build-ing an anodic coating on alumi-num. It has many advantages,including the elimination of theuse of hazardous chromiumbased coatings. The SAA con-ventional coatings are used forcorrosion protection, decorativepurposes, fatigue resistance andpaint adhesion, while the hard

coatings are for engineered pur-poses such as hardness andabrasion. The SAA baths will pro-duce from 0.1 mil to 1 mil thick-ness for conventional coatingsand around 4 mils for hard coat-

ings.However, this is not a suitablereplacement for CAA on aircraftparts subjected to stress as theycannot have the corrosive natureof any residual sulfuric acid lefton them. SAA parts do have agreater durability than Type I,but they should not be specifiedwhen the part geometries maytrap electrolyte. The SAA alsoproduces a much thicker oxidelayer which has a reduced fa-tigue life than the thinner oxidesspecified in BAC 5019 (CAA) or5632 (BSAA). The film growthrate occurs rapidly so the proc-ess must be controlled tightly toproduce the desired film thick-ness by varying the current oramp density and time in the

bath, but it can be successfullyaccomplished.

The Type IIB thing coat alterna-tive can be specified as a non-chrome version of Type I CAA, ifany of the above concerns areruled out by the aerospace cus-tomer and specifically specified.SAA Class 2 can have the poresof the anodic coating trap dye inthem prior to final seal; for in-stance, for architectural coatingssuch as anodized window framesfor buildings. Aerospace manu-facturers may also specify class2 to use the dye for identificationor other purposes.

BSAA, Boric Sulfuric AcidAnodize (BAC 5632 ) 2

This is a Boeing specified proc-ess developed as a chrome freereplacement for CAA in the early90s for their non critical fatiguesensitive parts that are almostalways painted afterwards. Typi-cally, it can be used in place of

BAC 5019 (CAA) but Boeingdrawings for various aircraft may

have specifics called out for spe-cific parts requiring only BAC5019. If parts are to be paintedthey may allow BAC 5632 Class 5(unsealed) as the paint adhesion

is superior to CAA parts with theunsealed BSAA coating. BSAA isapproved by Boeing in the placeof CAA for all models of commer-cial airplanes where electrolyteentrapment is not a concern withover 15 years of experience withtheir commercial fleet.

The BSAA process is more en-ergy efficient than chrome basedprocesses (lower temperature,lower voltage (15 V), 20 min-utes, 30 to 60% less time thatCAA). A dilute chromate seal

must be used in lieu of a hot DIseal and materials of construc-

tion will require 316L stainlesssteel for process materials butyou will not need the hexavalentchrome scrubber on the anodizebath. You still have somechrome to deal with for the seal

tank, but it is less than 75ppmhexchrome Cr(VI). Hot DI(Deionized) water seal works,but is not as robust. In dustyenvironments, sodium benzoateor benzoic acid can be used tohelp prevent the growth of fun-gus.

Summary (see Table 2 - pg 11) Alternatives to chrome basedanodic coatings are preferred

due to the environmental haz-ards and costs associated withenvironmental regulatory compli-ance.

Boric Sulfuric Acid Anodize(BSAA) is utilized for BoeingCommercial Airplanes (BCA) as anon-chrome substitution forChromic Acid Anodize or CAA. It

is used for corrosion protection,paint adhesion and fatigue re-

duction. It cannot be used wherethere is concern with electrolytebeing trapped in the parts or as-semblies.

Sulfuric Acid Anodize (SAA) isutilized as a replacement forChromic Acid Anodize as well,and are also utilized for corrosionprotection, paint adhesion andfatigue reduction. It is used fordying of product for identification

in the aerospace industry and fordecorative purposes in architec-tural and other industries. It can-not be used where there is aconcern with electrolyte beingtrapped in other parts or assem-blies.

Chromic Acid Anodizing (CAA) is

Continued on page 11


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F R O M T H E F O R U M : R E C U R R I N G P O W D E R D E F E C T

For September, our From the Forum column has

been provided through the correspondence be-tween Finishing Talk Forum members jfieker,

DustinGebhardt, Travis Stirewalt, and

DCInc. Their discussion revolves around a de-

fect in a polyester powder finishing on a steel

enclosure door. Feel free to add your thoughts to

their ongoing discussion by visiting the forums at

www.finishingtalk.com/community and choosing

the Powder Coating forum. For more From the

Forum discussions, check out our internet televi-sion show, Finishing Talk Live, where hosts Paul

Fisher and Paul Skelton bring the boards to life!

www.finishingtalklive.com

jfiekerWe have an issue with one of the parts that wefabricate and powder coat. It is a 37" X 52" steelenclosure door with several brackets welded to theback side. On about half of the panels, we get a"wrinkle" type of a defect in the powder finish(polyester). The defects only show up after thepowder is cured, only on the front surface of thepart and only on this particular item of several thatmake up the final unit.

We are confident that this is not a cleaning or pre-treatment issue. There is another door panel thatis a little smaller, and it does not have brackets

welded on its back. It is processed in the exactsame way with no problems at all.

The attached photos are ofone of the panels. It is curi-ous how the defect hasshown up as two identicalpatterns, one above theother. It doesn't always hap-

pen this way, and it isn't always in the same loca-tion. Possible grounding issue? Any ideas?

DustinGebhardt You say that there are brackets welded to the backof the panel. Do the wrinkles appear behind thebrackets? Looking at the photos, you say that theblemish occurs above a certain line. Are you cer-

tain that there is nothing in your oven that couldbe disturbing the powder? Or even something be-tween your painting area to the oven? Is youroven a batch oven or continuous? What type of

heat source?JfiekerWe use a gas-fired batch oven for curing. Theseparts are not processed any differently than any ofthe others that we do, including a very similar part(without the brackets). They are staged in thesame location as all other parts between coatingand curing. I have attached a picture of the backside of the panel showing the location of the

Posted on July 10, 2008


7/16


welded brackets. The defects never really seem tocoincide with the location of the brackets, but theydo only appear on the front side of the panel. Thewrinkles usually (90% of the time) occur anywhereon the upper third of the panel as it is hung. Ourcustomer is extremely picky about the location of

hook marks, so we don't have any other options inthe way that we hang these.

Travis StirewaltGood morning. That is a fun problem you havethere. It is always the unknown that takes the funout of this, isnt it. I have a couple of questions:

1 .Please give me the steps in MFG. Are these parts

handled by 1 or more operators as they are beingpunched, cut, welded?

2.What is your pretreatment method? Batch, Auto-mated, 3 stage, 5 stage, spraywand?

3.Are there any silicones in your plant? WD-40 etc?

I worked with a company in the Charlotte area thathad similar problems; we narrowed it down to 1 of4 of the metal workers in the plant that was sneak-ing WD-40 onto his work station because it was hispreference in lubrication chemistry. It was disas-trous. The problem was not quite as bad as whatwe see with yours in the photos; however, theparts failed quickly in use from UV and weather-ability.

Let me know about this. We might also be able tosend someone in to help you. I am not so con-vinced that this problem is cure related, as it wouldbe more predominant throughout the part. I amthinking there is something there. Even if properly

cleaned, if there is a history of a silicone contami-nant, it will show itself with adverse properties fol-lowing cure. Good luck here. I will look for yourresponse.

JfiekerThese parts are handled by many people through-

out the manufacturing process. We shear the rawmaterial and move through laser-cutting, pressbrake forming, self-clinching hardware installation(nuts and studs), mig welding, grinding on to pre-treatment and paint. At a minimum, we have noless than seven individuals handling them beforeassembly.

Our pretreatment system is of the batch type -combination cleaner/coater (iron phosphate), clearwater rinse and final seal/rinse coat. All chemicalsare applied using manual spray wand technol-

ogy. Cleaned parts are dried using a gas-firedoven, and powder is applied the same day, usuallywithin one hour after cleaning.

We use several oils and lubricants during many ofthe production stages, but I could not find any thatwere silicone based or contained any silicone aftera "quick check". I will have to look into this morethoroughly. We do, however, install silicone mask-ing products (caps and plugs) on the hardware

prior to cleaning. Of course, we also use the samemasking products on thousands of other parts with

no problems.

Before they go into the curing oven, we connectthe coated and racked parts with spreader barsthat maintain a distance of about 10" betweenparts. We usually cure them six at a time lined upfront-to-back. I am wondering if the brackets arecreating some interesting convection currents inthe oven that may be affecting the front surface ofthe adjacent panels. We will change the loadingpattern or spacing to see if that helps. Would thatproduce a defect like this? Thanks for the help!

DustinGebhardt With a strange problem like this, it is often helpfulto break the steps down (just like you have) andgo through them with a fine-toothed comb. Iagree with Travis that this is probably not a curerelated item, per se. What I mean is that it isprobably not related to temperature or time. Let'screate a simple test procedure and see what hap-pens:

Continued on next page


8/16


R E C U R R I N G P O W D E R D E F E C T ( C O N T )

1) Isolate the cleaning process by cleaning theheck out of the part. Go over the part 2 or 3 or 4or 5 times instead of the normal process. Makesure you are using good spray wand practices by

cleaning it starting at the top and working yourway down. Rinse the part several times andwatch for water breaks. Apply the seal the sameway. It can also help if there is a supervisor or,better yet, a manager present to overseethis. Employees have a tendency to do thingsdifferently when "nobody's looking", (rightTravis?). By the way, Travis, you have a greatstory that illustrates this point perfectly, but in

regards to applying the powder itself.

Process the parts as normal. If the parts come

out good, then your problem was in cleaning. Ifthe parts come out bad, move on to the next partof the process.

2) Try running only 1 part at a time in theoven. This can help isolate the air currents and afew other intangibles related to the oven. Try ori-enting the parts differently. Try a rack with all ofthe parts front-to-back. Try another rack with the

parts front-to-front and back-to-back. Space theparts out further.

3) Try making a panel without the brackets. Orchange some other part of the manufacturingprocess. Compare the exact process used bythese problematic parts with the ones that comeout fine every time. The environment can some-

times affect the quality of the finished part. Areyou always running the larger parts at the sametime of the day? Try mixing it up.

DCIncNot sure if this will help but I have seen similardefects in my shop. Some of my fabricators use

anti-splatter oil when welding and any of this resi-due left over causes wrinkle type defects.

There is one more things that caused/causesthese type of imperfections but it is mostly during

the hot months. I have seen sweat from employ-ees drop onto parts before spraying and it createsthe same pattern when the coating is cured. I didnot see whether you are pre-heating the part be-fore spraying after it is hung on the rack. Maybe

the larger panels cause the employees to comeinto closer contact with them when they are

hanging. Just a thought, but it does look exactlylike your picture when it happens here.

JfiekerThanks for all of the great ideas and advice. Wewill be running another batch of these panelswithin the next couple of weeks, and I now havea list of several things that we will try doing differ-

ently. Hopefully, we'll determine the cause andget the problem cured. I'll let you know whathappens.

Do you have something to add? Log onto the Finishing Talk forums today to

join in on this discussion or start a

discussion of your own!

www.finishingtalk.com/community


9/16


F I N I S H I N G S P O T L I G H T : A S T M C O M M I T T E E B 0 8 E X P L O R E D

As a follow up to lastmonths Last Word column,

Seattles Space Needle and aCentury of Standards, weve

decided to shine this months

Finishing Spotlight on the ASTM

(American Society for Testing

and Materials), and more spe-

cifically on the ASTM Committee

B08 on Metallic and Inorganic

Coatings. The ASTM Committee

B08 is very near and dear to the

Metal Finishing industry in that

they dedicate much of their

time and energy to issuing

specifications on metallic and

inorganic coatings and electro-

formed materials and products.

Some of these coatings include

those produced via the electro-

plating process, autocatalytic

(electroless) plating, immersion

plating, vacuum processes

(such as vacuum metallizing,sputtering, and ion plating),

chemical conversion, anodic oxi-

dation, hot dipping, thermal

coating processes, porcelain,

enamel, and ceramic metal

coatings, and so on.

Amazingly, despite such a large

jurisdiction (they are in charge

of over 132 standards, main-

tained by 8 technical subcom-

mittees) ASTM Committee B08

is only comprised of a handful

of volunteers, representing a

couple finishing suppliers,

OEMs, and practitioners. As Milt

Stevenson, Jr, CEF, Chief Tech-

nology & Environmental Officer

of Anoplate Corporation puts it,

With 132 specifications tomaintain, as well as new coating

methods and processes coming

on the scene that require stan-

dardization (such as non-hex

chromates, cad replacements,

etc.) the B08 Committee could

certainly use some new mem-

bers from the ranks of the fin-

ishing industry willing to volun-

teer their time and talent to this

all too often overlooked and un-

derappreciated work.

The committee is in charge of

developing and preparing

specifications, methods of tests,

practices, guides, definitions and

terminology applicable to the

properties of the coatings and

electroforms, to their perform-

ance in use and test, and to the

processes and materials used to

produce them. (Source :

ASTM website). Additionally,

Committee B08 is responsible

for organizing and presenting

meetings and exchanges where

technical information can be

shared and disseminated. They

also publish a variety of techni-

cal publications and other docu-

ments and papers. Some ofthese include their contribution

to the Annual Book of ASTM

Standards, Special Technical

Publications like STP 947 Test-

ing of Metallic and Inorganic

Coatings, and so forth (visit

their website for the full list).

Formed in 1941, ASTM Commit-

tee B08 has a long history of

involvement with the finishingindustry. Currently, the Commit-

tee meets for technical meet-

ings, twice a year, generally in

April and October. Membership

is approximated at 121 industry

professionals and experts, with

about 15 to 20 actively attend-

ing the bi-annual meetings.

The B08 October 2008 Meeting

will take place at the ASTMInternational Headquarters in

West Conshohocken, PA, on

Tuesday, October 28, 2008. If

you would like to learn more

about volunteering or becoming

a member of the ASTM Commit-

tee B08 or any other ASTM

Committee or sub-committee,

please visit their website at

www.astm.org. Currently, new

members get a free book of

standards upon joining.

For more details about ASTM

B08, you can contact the Com-

mittee Staff Manager, Kate

McClung, at (610)-832-9717.


10/16


On many occasions, powdercoating failures can be traced to

improper pretreatment and cure.

The improper use of pretreat-

ment chemicals, or lack of pre-

treatment in general, is often

linked to coating failures. On the

other hand, if the substrate is

perfectly pretreated and the

powder is improperly cured, this

may certainly lead to color and

gloss failures as well as an over-

all breakdown of the powder

coating. Poor quality powder

may also be blamed for coating

breakdowns due to inferior ma-

terials and a great deal of filler

material .

I have, however, been involved

with testing on parts that devel-

oped failure on edges and sharp

corners. The parts, shown in

the photos, were used as brack-

ets to secure an electrical panel

in place. These brackets were

failing from the sharp edged

corners and over a short time

were beginning to creep back-

wards, as is always the case.

The powder coating was tested

for cure, as well as backed up

with oven temperature docu-

mentation. In addition, the pre-

treatment was tested and the

part exhibited a perfect surface

preparation. From the field

notes, we were able to find out

that the powder would not peel

due to the proper cure and

treated surface, but over a short

period of time, the powder

would continue to fail further

from the original point of corro-

sion.

After examining the parts fur-

ther, we were able to obtain

some reasons for the failure.

The powder and pretreatment

were performing well together,

as determined by both the other

parts in the field without bent or

sharp edges and the testing on

F R O M T H E F I E L D - E D G E / C O R N E R F A I L U R E S B Y T R A V I S S T I R E W A L T

Continued on page 12


11/16

under heavy environmentalregulation so there are subse-quent compliance costs andactivities required by the ano-

dizing shop but it is still a re-quired coating for certain mili-tary applications as well as oncommercial airplane parts thatmay trap electrolyte (crevices,complex geometries, weld-ments, lapped or recessedparts). It is also used for multi-ple alloy assemblies. Suitablereplacements have not beenfound for those types of appli-cations.

References:1 Mil-A-8625F Military Specifi-cation Anodic Coatings for Alu-minum and Aluminum Alloys

2 Nonchromate ConversionCoatings in use at Boeing. Os-borne, Joseph H., Boeing Phan-tom Works - Seattle. Presenterat Hazmat Alternatives - MetalFinishing Workshop May 16 &17, 2007.

h t t p : / / w w w . h a z m a t -alternatives.com/documents/meetings/mfw-5-07/briefings/osborne%20DoD%20CrVI%20workshop-Boeing JHOB.pdf

About the Au thor:Steve Anzelc, PE LEED AP, is a

Senior Project Manager with

Burns & McDonnell. He has 20years of business experience,including design, project andproposal management on someof the largest anodizing, platingand paint finishing lines in theworld. Burns & McDonnell is aGlobal Engineer-Architect-Environmental Consultant &

Contractor with projects in 70countries. You can reach him [email protected] or(816) 823-7083, USA CST.

Steve is the Winner ofour 2008 article contest!Congratulations, Steve!

B A S I C C O M P A R I S O N S . . . ( C O N T I N U E D F R O M P G 5 )


Table 1:Summary of Anodic

Types and Class

Types

- Type I: Chromic Acid Anodize (CAA)

- Type IB: CAA Low Voltage Bath 22 V

- Type IC: Non-chromic Acid Anodize

Boric Sulfuric Acid Anodize (BSAA)

-Type II: Sulfuric Acid Anodize (SAA)

- Type IIB: SAA - Thin coat version

- Type III: Hard ChromeMil Classes

- Class 1 Non-Dyed -

Dichromate seal

- Class 2 Dyed with Seal

Seals: Hot Deionized water,

nickel or cobalt acetate bath, orduplex acetate and dichromate

Boeing Classes

- Class 1 Same as Mil SpecClass I and IC. Great for paint ad-hesion.

- Class 3 Dilute Chromate Sealonly

- Class 5 An unsealed coating.No salt spray requirement. Maxi-mum organic coating adhesion.

Example

- Mil-A-8625F Black T2C2 wouldbe a Sulfuric Acid Anodized

Dyed Black. If the particular sealis required than it should bestated otherwise it is the manufac-turers choice within the spec.

Table 2: CAA, SAA and BSAASummary

Chromic Acid Anodize (CAA)

Used on parts that trap electrolyte

Used on multiple alloy assemblies

Excellent Corrosion Resistance

Fair Paint Adhesion

Harder Surface than SulfuricCoating

Heavy Environmental Compliance

Issues

Sulfuric Acid Anodize (SAA)

Non-chromate AlternativeDecorative Seals

Corrosion Protection

Superior Paint Adhesion

Fatigue Reduction

Boric Sulfuric Acid Anodize(BSAA)

Non-chromate Alternativefor Commercial Airplanes

Corrosion Protection

Superior Paint Adhesion onunsealed BSAA

Fatigue Reduction

Dilute Chromate Seal(


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F I N I S H I N G T A L KPage 12

faces can be measured from a

fraction of a micro inch to 2000

micro inches. It is ultimately

not important to always be ca-pable of measuring surface pro-

files, but it is important to un-

derstand the relative relation-

ship between final surface pro-

file and adequate powder cover-

age.

As a further clarification, we

wanted to point out that an-

other concern is substrate

preparation, or more precisely,pretreatment rinse. When the

part is hung on the rack or hook

and pretreated, the rinse stage

can leave sediment (oils, dirt,

metal shavings, chemical, water

salts) at the lowest point of the

part. When the part is dried, the

sediment dries in place and be-

comes a relatively certain future

failing point. In this particular

case, that situation was ruled

out do to the way the parts

were pretreated.

We hope this helps you in the

field. If you have any questions,

please do not hesitate to call or

email.

Travis Stirewalt, CSI

TIGER Drylac USA

615-400-1220 cel l

[email protected]

sible to powder coat edges well

enough to prevent corrosion is-

sues in the field with any

amount of material. It is ulti-mately important to properly de-

bar all edges if possible to insure

coating integrity.

As just previously mentioned,

one aspect of powder coating

that can be particularly problem-

atic are media blasted parts. A

talented blaster is always careful

of the blasting media ratios be-

tween virgin and used media. Agood mixture of media, virgin

and used, is very important. Too

much virgin material will dig too

deeply into the substrate and

can cause failures when the

powder flows and exposes the

high tips of the metal substrate.

Very small percentages of the

virgin material should always be

used and mixed some-

what thoroughly

with the

used media.

Without be-

coming too

complicated,

surface profiles

can often be

measured in micro

inches, commonly

known as RMS. (root

mean square) There

are approximately 27

standard RMS averages

for processes and sub-

strates that range from

flame cut surfaces to die

cast substrates. These sur-

the pretreatment and powder. As

we looked closer at the sub-

strate, we were able to deter-

mine that the edges of the metalin the corners had not been de-

burred or ground (smoothed)

down properly. The microscopic

raised metal peaks were evi-

dently not being adequately cov-

ered by the powder coating.

When the powder gelled and

flowed out, it left small tips of

the steel protruding (or way too

close) to the surface of the pow-

dered finish. This resulted in a

fairly quick failure in the field.

Powder coverages for standard

smooth coatings are most com-

monly rated at 2.5 3.5 cured

mils. These mil requirements are

there for a number of reasons;

adequate substrate pro-

tection, hiding, and

color accuracy to

name a few. When

you powder coat a

surface that has

varying surface

profiles, such as

blasted metal or

sharp metal

edges, you

must either

smooth out

these sur-faces or

apply an

ade-

quate

thickness to

maintain corrosion resis-

tance. Many times it is not pos-

F R O M T H E F I E L D - E D G E / C O R N E R F A I L U R E S , C O N T I N U E D . . .


13/16


In August, the EPA announced plans to launch aninterim policy that offers incentives to new ownerswho correct environmental violations at recentlyacquired regulated facilities. Under the interim pol-icy, new owners may receive lower penalties thanlong-time owners.

"This is an opportunity for new owners to make a'clean start' by correcting environmental problemsthat began under the previous owner's watch," saidGranta Y. Nakayama, assistant administrator of theEPA's Office of Enforcement and Compliance Assur-ance. "This can lead to big gains for the public andthe environment."

Under the current EPA Audit Policy, the Agencyoffers reduced penalties to companies that self-audit their facilities; promptly disclose and correctany violations discovered; and take steps to pre-vent future violations. Under the interim policy, anowner who acquires a new facility may get addi-

tional penalty reductions from disclosing an evengreater range of violations.

EPA encourages companies with newly acquiredfacilities to: examine compliance of their new fa-cilities; correct environmental problems that beganbefore the acquisition; make changes to ensurethey stay in compliance; and reduce pollutantsgoing forward.

According to the EPA, more than 3,500 companiesat nearly 10,000 facilities have used the audit pol-icy to disclose and resolve violations since 1995most of these involved improper recordkeepingand reporting. With the incentives announced ear-lier this month, EPA hopes to encourage new own-ers to disclose violations that, once corrected, willyield significant environmental benefit and directpollution reductions.

The new interim policy will be in effect immedi-ately, and the EPA will accept public comment un-til Oct. 30, 2008. Note: The policy may change inlight of these comments.

For more information, or for a copy of the officialFederal Register Notice, visit http://edocket.access.gpo.gov/2008/pdf/E8-17715.pdf

N E W E P A P O L I C Y O F F E R S I N C E N T I V E S T O C O R R E C T V I O L A T I O N S


14/16

F I N I S H I N G T A L KPage 14

5-6

Only One Location Left!

San Diego, CA . November 5-6


15/16

Page 15

T H E P E R K S O F O R G A N I Z A T I O N M E M B E R S H I P B Y A N N A L E V I T S K Y

We all know the old sayingthat two heads are better thanone. We also remember how

back in high school everyonewanted the support and backingof having a clique or a group offriends to associate with. There isa reason why we have thesenatural drives to be part of a big-ger group, to embrace the idea ofcommunity and participate andengage with others. Back in highschool, depending on who youassociated with, your group mayhave supported you through

times of crisis, listened to yourave about the injustices thatyour parents were subjecting youto, let you hitch rides with themto school, help you with yourhomework (or let you copytheirs) and even have your backduring the occasional fist fightbehind the football field bleach-ers.

Today, groups are just as valu-able to us as they were back inour teen years; only now, wehave different issues to contendwith. Whether you own a smallplating business, work for a largemanufacturer, spend your timeinstructing the next generation offinishers or adding extra-value toan experienced Powder Coatersresume, it is always helpful andencouraging to know that thereare a multitude of others whoface similar struggles and cele-brate shared accomplishments.These are the people you want tosurround yourself with for addi-tional feedback and support asyou make your way through life.

In past issues, weve mentionedthe NASF (National Associationfor Surface Finishing), and here I

cations, industry reports, andother items in the online book-store. A full time government re-lations staff helps convey mem-

bers needs to Washington andeducate policymakers on industryrelated issues. Members also re-ceive discounts on all NASF spon-sored events throughout theyear, including the premier indus-try conference and trade show,Sur/Fin. The organization alsooffers extensive educational train-ing opportunities, which mem-bers can attend at a discountedrate, and many local and regional

branches to allow members tomeet and network on a regularbasis.

Executive Director of the NASF,John Flatley, summarizes it likethis: NASF provides you withmany benefits through continu-ous professional development,providing education programsand events that feature speakersand topics related to your profes-sion, both directly and indirectly.We offer networking opportuni-ties that allow you to make im-portant contacts; new informa-tion on a wide range of industrytopics in a timely manner, and anindustry voice in your professionwhere you will have some influ-ence over government and indus-try regulations.

If youre interested in learningmore about becoming a member

of the NASF, check out John Flat-ley at the Southern Metal Finish-ing Conference on September 15,where he will be giving the key-note address. If you cant makeit, be sure to visit their website atwww.nasf.org. When youre upagainst the world, its good toknow youve got your industry torely on!

would like to expound upon it abit more.

If youre looking for industry sup-port, a greater voice in the regu-

latory arena, new contacts, op-portunities to network and ex-pand your knowledge base, andabove all, a group that sharesmany of the same concerns asyou do, look no further. TheNASF, which not too long ago

joined forces with three otherindustry organizations, the AESF(American Electroplaters and Sur-face Finishers Society), the MFSA(Metal Finishing Suppliers Asso-

ciation) and the NAMF (National Association of Metal Finishers),covers all the bases relevant tothe finishing industry. In regardto the merger of these organiza-tions several years ago, NASFswebsite states that As a moreefficient and unified operation,the reorganization will provide allmembers, including platers, sup-pliers, managers, owners, techni-cians, researchers, academicsand students with a stronger in-dustry voice; an optimized volun-teer pool; a reinvigorated com-mittee structure; and enhancedmember benefits.

And membership does come withits benefits.

Depending on your level of Mem-bership (which is categorizedbased on an Individual or Corpo-rate basis, and then filtered into

subcategories built upon a mone-tary tier structure) you can takeadvantage of exclusive network-ing opportunities, members-onlyaccess to online journals andother parts of the NASF website,a subscription to the industrymagazine Plating and SurfaceFinishing plus discounts on publi-

T H E L A S T W O R D


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Finishing Talk Newsletter - September 2008