It can be very disappointing when you come into contact with the curb when you are parking, the moment you feel the contact you know you have marred your beautiful alloy wheels. If the damage is extensive you may have to have the repairs made professionally, however, if all you have to do fix gutter rash this is something that can be done by the car owner. It will take some time but if you follow a few simple steps you can eliminate unsightly marks and scrapes.
The first thing that you have to do is determine if the wheel has a clear coating to protect it. Using course sandpaper, perhaps a 220 grit, sand the spot which has sustained damage; if the dust from the procedure is white the rim has been coated, if the dust is grey it has not.
Although the gutter rash may be limited to a small section of the rim, if the rim has been clear coated it must be removed all the way around otherwise when you are finished the repaired section will be very noticeable. When you fix gutter rash you do not want to trade one problem for another. Sand the rim all the way around, removing the clear coating; when the dust turns grey you can move on to the next step.
Start the repair using courser sandpaper; start with 80 grit working slowly up to 220 grit. Once you have managed to remove the most obvious scratches switch to a finer sandpaper again, feather the damaged area about a half inch either side of the rash, blend the damaged and undamaged surfaces. Take your time, use steady pressure to level the surface, wipe the dust off periodically so you can see your progress.
It is now time to refine the surface of the area that was damaged, to do this you will want to move to extremely fine grit sandpaper, 2000 grit is recommended. Using very light pressure and dry sandpaper slowly blend the edges and smooth the surface. To do this right will take time. Once you think you have reached a satisfactory finish, go over the same area using a circular motion and dampened sandpaper.
The final step to fix gutter rash is to apply polish. Using a generous amount to aluminum polish and a soft cloth; rub hard; when this is finished the cloth should be black. Once this has been completed give the area a final buffing, the area should shine as bright as the rest of the rim.