Originally Posted by Pew
Originally Posted by MacManus99
I have heard the curing process of powder coating to mess with the metallurgy of a heat treated aluminum wheel, later causing possible structural defect and/or failure. I have no experience with this, and I am just regurgitating warnings I have heard other drivers in grid.
Can anyone smarter than me support or refute this? A quick google search found numerous examples, but I don't want to go off of that alone.
Yea, RPF1s and other Enkei/Koeing wheels that use the same manufacturing process have a big issue with this - although it doesn't seem to be consistent with every wheel. I had a friend's crack within a few months of just DD while another lasted as long as he had the car + a few track days. The one that did crack was done at a well-known powder-coat shop. The one that didn't crack was done by another friend that just got into powder coating but was very meticulous and he did my brake calipers too.
Mac and Pew:
I've long heard the same story - that is is unsafe to power coat an aluminum alloy wheel.
One of the posters said they heated the wheel to 400 degrees and cured the power coat for two hours. This is far, far hotter than a wheel normally gets. I've had rotors steam and spit when sprayed with water. But I've never had the center portion of the wheel where it bolts to the hub spit and steam. That means the hottest part of the wheel, the hub area, is under 212 degrees (a wheel is a giant heat sink).
Also too, 400 degrees would destroy the bead of the tire. Said another way, how do you think your tire fair in a giant 400 degree oven for two hours. Would it be ruined? I think so.
In other words, wheels never reach 400 degrees in normal circumstances, not even close.
Another thing, the BBS wheels I have come from the factory "varnished" (their terminology). And the BMW Style 225 wheels I have have a distinct orange peel pattern on the inner barrel. To me that means they were spray painted, not power coated.
Given all this, I wouldn't power coat an aluminum alloy wheel. FWIW.
Scott
PS Just looked up the temperature that a tire is cured out during its manufacture. 300 degrees F. To me that means the bead of a mounted tire is not engineered to survive 400 degrees, which means the rim area of a wheel never reaches that temperature.