Noticed there are quite a few Wheel polishing questions. Because detailing is mostly about cleaning and preserving surfaces other than metal, I thought it might help provide an easy test method so people don't waste time trying to fix metal when they really are fixing paint. The way to test is take any metal polish (household or automotive) and rub on clean spot. If it turns black it is a metal surface (aluminum alloy mostly). If it is any other colour it is not metal. Oxidation causes the black. Correcting Aluminum Alloy (only thing I have done) is not really detailing (it's more like a detail). I would be happy to share metal polishing tips but this forum is for detailing not restoring Alloy Wheels.