Oxidation occurs on rims from road grime and other contaminants getting on the wheels and not being cleaned off. Oxidation also occurs on wheels with clear coats because UV rays dry out the clear coat, leaving it dull and yellow. Oxidized rims can be repaired to look like new with a few steps and some materials from an auto parts store. The rims don't even have to taken off of the vehicle to be repaired.
Use the 400-grit sandpaper to gently sand the surface of the rim. This sandpaper is not rough enough to sand gouges into the rim, but it is rough enough to remove all oxidation and most blemishes. Keep the sandpaper flat and level and sand the entire surface. Rinse the wheel with water when you are done to make sure the entire rim surface is dull and sanded.
Wet the 800-grit sandpaper with water, and sand the rim again. This smooths the rim and removes any deeper scratches left by the 400 grit sandpaper. Rinse the rim clean when finished sanding. Allow it to dry completely.
Polish the rim using the appropriate polish for the type of metal your rim is made of. Aluminum, chrome and steel will need different types of polishes to get the brightest shine. Apply the polish with a cotton towel and follow the specific instructions for the polish you have. Most polishes need to remain on the wheel for several minutes. Buff the polish away by hand with a clean cotton towel to get a bright, clean looking rim.
