BS, come into the 21 century, all powder coatings are far superior to any paint. Cleaned properly the parts will be preserved for the rest of time. I restore antique aircraft and have never found a part that can't be powder coated. (except exhaust parts) that have a low melting point, are never heat treated any way so you have no worries.Originally Posted by Aaron Novak
I have even P/C white pot metal parts with no problems.
powder coated wheels. and a few other things
Here is a link,, read it.
http://www.ppg.com/coatings/truefini...s/default.aspx
I would mask the tires and anything that you might get overspray on. I used plastidip on the wheels on my car and didn't mask off the tires. I found that near the rim where I was concentrating the spray it would peel off easily but towards the outside of the tire where the spray was lighter it didn't want to peel off. Now to get it off I need to put a nice coat on the tires to peel it off. You can mask outside of the rim leaving about an inch of tire exposed just be sure that you coat the exposed section just like you would the rim and it will peel off just fine when you remove the tape.
Tom,
We have a full corrosion test lab, along with environmental test facilities around the US. Two PPG reps on site and do more powder coating in a day than most do in a year. I think I am current on the subject. If you wish, I can put you in contact with our chief coatings and corrosion engineer, who is a coatings consultant for the USN, and considered top of his field.
But since you like the internet....
http://www.magnesium.com/w3/data-bank/index.php?mgw=182
If it were me I would chromate and epoxy prime under the powder.
Last edited by Aaron Novak; 06-02-2014 at 11:39 PM.
"" If it were me I would chromate and epoxy prime under the powder. ""
You can not.
Tom,
Yes, you can. It is done every day in production of OEM auto and marine parts. Steel parts commonly get a phosphate conversion, some form of epoxy primer (Liquid or EDP preferred), and powder topcoat. Aluminum and mag get a chromate conversion ( or other ), epoxy prime (preferably with strontium chromate i.e. stitts), and powder topcoat. The only times I have not seen a primer used, is in those DIY kits sold by eastwood, PBTP and such. They market and sell it without understanding the process, and do a great deal of disservice to the customers. The biggest pitfall of using powder incorrectly is how to remove it when it fails.
Actually I have seen powder only (meaning no primer etc) in non critical applications for decorative purposes, and myself have done it, however I consider aircraft parts to be critical applications, and do all I can to prevent corrosion.
Last edited by Aaron Novak; 06-03-2014 at 10:18 PM.
For those still following this thread, paint a piece of steel with epoxy paint, then heat to 400 degrees, see what happens.
Tom,
Thanks for bringing up a reminder. The epoxy primers need to be baked before topcoating with powder, usually done at 400F for about 10min after the curing period. This is to be sure all solvents are released, preventing pinholes in the powder topcoat. As an option there are epoxy powdered primers that do almost as well as liquid epoxy (conventional or EDP), typically they are only run through a partial cure before being topcoated with a "poly" powder and then fully baked. In either case, a pretreatment of the mag is still a must.
Back in the 90's it was thought that powder paint would replace all the steps of the standard liquid paint system by being able to be applied directly to a clean substrate. This was found to not be the case. The impermeability of the TGIC powder paint actually made some forms of corrosion worse by trapping moisture under the surface, causing the galvanic corrosion cells to run rampant.
http://www.mercurymarine.com/media/m...nBro-212LR.pdf
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