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Lacquer Clear Coat Not Sticking To Finished Parts



We are having a lot of trouble with our finishing process, regarding oil or film on parts. We process Bronze, Nickel, Copper and Silver in mostly 1 or 2 step processes. A one step process would be to abrade the metal using an abrasive ceramic media in 15 lb capacity rotary tumbler. A two step process would be to use abrasive ceramic media first, then a steel shot media for a high gloss finish.

These 2 processes are fairly consistent. The trouble is a lot of processing goes into the parts before they reach finishing. Many of these processes leave either WD-40 [on eBay or Amazon (adv.)] (used as lubricant), Flux (from soldering), or other metal tarnishing chemicals on the parts. After they are ran though our finishing processes a residual film is left on some of the parts (not all). This film interferes with the last step in our process; witch is a clear lacquer spray application.

The film is very hard to detect before the clear coat is applied and most often then not we do not know if they are bad parts until they have already been clear coated and dried. The clear coat on bad parts is easily removed with ones finger nail.

Also, if we take those bad parts and strip them in lacquer thinner [on eBay or Amazon (adv.)] then re-clear coat them they will be fine. At this point we have to strip all clear coated parts in lacquer thinner [on eBay or Amazon (adv.)] just to be sure that are ok.

Washing parts after finishing with soupy water: Did Not Work
Running parts through our ultrasonic cleaner: Did Not Work
lacquer thinner [on eBay or Amazon (adv.)]: Worked

Is there any type of degreaser is recommended using before, during, or after our finishing process?

Looking forward a reply,

Israel Ortiz
- Eugene, Oregon



Ouch! WD-40 is nasty stuff to clean off. I would try to knock the problem out before it starts and try a different lubricant. I have had pretty good success using an inhibited reverse current electrocleaner removing WD-40, but it didn't always work. We have since banned the use of the stuff plant wide. WD-40 was formulated as a water displacer (the WD, on the 40th try) and applied to missile casings for the aerospace industry. It is made to not come off. The formula is still a secret, but you might try calling them to see if they can suggest anything to help.

Trent Kaufman
Trent Kaufman
electroplater - Galva, Illinois

Trent, Thanks for the useful info regarding WD-40 [on eBay or Amazon (adv.)] . I think that we may fallow you in phasing it out of our production processes. If you do not mind me asking, what did you guys end up using in its place?

Thanks again,

Israel Ortiz
- Eugene, OR, USA



We switched to a water soluble oil (most lubricant suppliers jumped on this bandwagon a while ago) in one instance and something called "vanishing oil" (has a large solvent component) in another. Shelf life will decrease a bit, but both are much easier to clean.

Trent Kaufman
Trent Kaufman
electroplater - Galva, Illinois

Try three chlor ethlene.

Dr Halim Polat
- Istanbul, Turkey

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