Painting / Powder Coating FACTORY RIMS

[VIDEOBOB]

I want to have my factory 18" Magnum RT rims powder coated black.
Has anyone else here had that done before?
What proceedure was used to remove the protective clear coating?
How much did it end up costing per wheel in the end?

I took my rims to a local yocal you says he does powder coating,
he said it would take 3 days.
After a week I went to get the rims and found that his lazy ass
hadn't finished them.
He complained that the clear coating was too hard to get off.
He showd me a little brown stain where he tried to use some sort
of paint remover with no success, just left a brown stain.
He says that he is going to have to order some sort of stripper
that is used on aircraft to strip the coating.

I have talked to some people who do sand/bead blasting, and
they tell me that the newer cars have an acrylic coating that is
tough as nails and hard as hell to blast off.
The wheels need to be stripped to bare metal for powder coating.

Does anyone else here have any stories?

[boggart]

nope, but has your car been down the whole time he had the wheels or do you have another set?

[2003z]

he can get the stripper at home depot. I used to use BIX tough job, but just discovered this other stripper they sell by kleen-strip. It takes the toughest powdercoats right off. I either do that or bake the finish off by putting the parts in my oven and running the self clean cycle before I powdercoat.

[Rev.Hammer]

That may be a really bad idea. If the part is a structural or load bearing part, the temper ( crystal structure of the metal) could be changed and make the part weak. I would VERY strongly recommend to NOT do this for wheels.

[2003z]

That may be a really bad idea. If the part is a structural or load bearing part, the temper ( crystal structure of the metal) could be changed and make the part weak. I would VERY strongly recommend to NOT do this for wheels.

While this is true, to effect structuraly changes you need to bring the piece to within 2/3's of its melting point. For aluminum alloys, the melting point is 1200 degrees, which would be 800, and it comes nowhere near that hot. (about 600 in the self clean)

[Fred]

From http://my.execpc.com/~davewrit/Powder.html a Q&A Powdercoating person.

Listers Questions

Found your article most enlightening. A metallurgist friend told me a few years ago that things like aluminum wheel spindles should not be powder coated. He explained that aluminum billet material (6061-T6 ?) changed crystal structure at a critical temperature around 410 degrees F (as I recall). The thrust was that the heating step would adversely affect the strength of the material. Non-structural components would be OK, but not something that "holds the spokes on". The metallurgist is correct. Products like wheel billets, scuba tanks, etc. can be powder coated, but only with powders which cure below peak metal temperature of 300 degrees F. The magic temperature is about 275F. The crystalline realignment at 400 degrees F causes the previous ductile aluminum to become brittle. Imagine the catastrophe when an 80 cu. ft. scuba tank explodes under 3000 psi pressure after an unauthorized powder coat (this actually happened). To my knowledge, all Aluminum wheels and other strength-critical aluminum components are powder coated with these cooler curing powders.

Heating Al alloys above this temperature causes a granular rearrangement of the metallurgical structure resulting in a significant change of bulk properties. The tensile strength of the metal is dramatically lowered, much like a stress relief anneal on a steel piece would do. The resultant metal is not as strong, nor will pressure vessels made of such treated aluminum (e.g., scuba tanks) hold near the pressure that they were originally rated for. Since wheels are essentially load-bearing structures, they should never be heated like this unless the alloy is known to tolerate it well.

[dantodd]

Silly question I am sure but.....

Could one use traditional powdercoating on a wheel and then retemper it? Might provide the tougher finish or traditional powdercoating without the potential of catastrophic failure.

[Fred]

Silly question I am sure but.....

Could one use traditional powdercoating on a wheel and then retemper it? Might provide the tougher finish or traditional powdercoating without the potential of catastrophic failure.

What's wrong with normal paint? Powdercoating isn't a 'space age technology' here, wheels are one thing I wouldn't screw around with, picture hitting a pothole, and then the wheel just shatters from being brittle... Now it does look like if you use a low melt poweder then the wheel would be ok (under like 300*)