Alloy wheels look great when they're brand new, but after a few decades or even years of constant use, they can begin to look terrible, detracting from the appearance of the whole car. Unless they are polished, alloys are usually painted, and the finish can get scratches and curb rash. With the right tools and technique, most alloy wheels can be restored in a weekend, making your car look much better in the process.
Loosen the lug nuts, jack up the car and remove the wheels if they are still mounted to the car.
Dismount the tires from the wheels unless there are no tires.This is optional if there are tires mounted on the wheels. However, you will get a better looking wheel if you can restore it with the no-tire mounted.
Clean the wheels with wheel cleaner, mild detergent or a cleaner like Simple Green, using warm water for the detergent. Clean the front and the back of the wheel so there is no grease or debris left anywhere. Rinse the wheel thoroughly with a power washer or a hose.
Use Jasco paint stripper or something similar to strip the old paint. Apply it with a brush and let it sit for 10 or 15 minutes and then wipe off with a rag. Steel wool can help get off stubborn paint. Be sure to wear a respirator and gloves to protect yourself.
Inspect the wheel thoroughly for scratches and road rash. Using Bondo for larger scratches (anything deeper than around 1/16 of an inch) and spot putty for smaller flaws, fill in the areas that are scratched. If there are chunks missing or cracks, these will have to repaired and welded by a shop. If there are any major bends in the wheels, see if a shop can repair them. If not, they may not be usable.
Let the Bondo and putty dry, and then sand down with 220 and then 400 grit sandpaper, feathering and smoothing the repair into the nearby wheel surface. Sand it until it looks and feels smooth.
Wipe the wheel wherever it going to be painted with white spirit to clean it for the painting phase. Spend as much as you think is necessary to get the wheel completely clean and free of oil and grease. This is a crucial stop in the process.
Spray a light dusting of primer on the wheel and let it dry for a minute. Spray on two to four solid coats of primer. In between coats, wet sand the primer with 400 grit sandpaper. After the primer is sprayed on, visually inspect the wheel again for any scratches or pitting and fill these areas with putty. Allow it to dry and then primer again.
Let the primer dry (usually an hour or two if it is warm and dry) and then dust it with the colour coat. Let this dry for a minute and then apply two to four solid coats of colour, allowing the paint to dry and wet sanding between coats. After the final coat, wet sand up to 1500 grit, using several grits in between.
Spray on the clear coat. It is good to let the colour sit overnight before applying the clear coat. Apply two to four coats in the same way as the primer and colour coat.
Let the clear coat dry and then use a high quality wax to buff the wheels to a shine.