Wheels changed color

[pRS317]

Hi, I recently purchased a 2002 Boxster S and it has some slots on the wheels that won't clean off. Since they're aluminum, I thought a quick polish would sort it out. When I began to polish, the rag immediately blackened, but the wheel was gray and wouldn't wipe off, or polish any brighter. Any ideas what happened or how to fix it (hopefully something other than making them all gray)?

[paulofto]

Originally Posted by pRS317

Hi, I recently purchased a 2002 Boxster S and it has some slots on the wheels that won't clean off. Since they're aluminum, I thought a quick polish would sort it out. When I began to polish, the rag immediately blackened, but the wheel was gray and wouldn't wipe off, or polish any brighter. Any ideas what happened or how to fix it (hopefully something other than making them all gray)?

Aluminum is susceptible to oxidation if exposed to strong acidic or alkaline cleaners and polishes unless the surface is anodized. What polish did you use? I recommend getting a cleaner and a polish specific for use on aluminum.

[Cbonilla]

Are you sure these wheels aren't painted with a clear coat. Unpainted aluminum will tarnish rather rapidly. As far as I know Boxsters all had painted or clear coated wheels from the factory. My BBS wheels have clear coat over polished metal wheel lips and painted/clear coated centers.

Rather than a metal polish I'd recommend a wheel cleaner (non acidic) and a coarse sponge, assuming that you haven't damaged the finish with the polish

CB

[jakeru]

More/better pictures would help us better understand what you're working with here. Some factory Porsche wheels are chrome plated (it was an available option), but it's not clear what you're working with here. The reaction to the metal polish (you didn't state what kind of polish you were using), suggests potentially bare aluminum wheels, which is really rare for original equipment wheels, as it's labor intensive to keep looking good (requiring periodic polishing to remove tarnish).

I'm not sure if chrome plating on wheels, if that's what you've got, could potentially react in the way you are describing to the unknown "polish" you are using. Generally speaking, chrome is pretty durable and chemical resistant.

[pRS317]

I used an aluminum polish and a chrome polish. Both quickly reacted the same way with the wheel with gentle application. It seemed to be the same reaction that I've seen in the past with aluminum. I'm guessing that since it was a painted rim, whatever weak coating it had is pretty much erased. Given that, would powder coating be the best route? I'd prefer to that to painting, provided the powder coating process doesn't damage the wheel.