To clean used truck rims, make a neutralizer by dissolving 5 to 6 teaspoons of baking soda in a spray bottle half filled with water. Rinse the rim with water. Using a small brush, such as a toothbrush, scrub a small area of the rim with a cleaner containing hydrochloric acid as an active ingredient, such as The Works toilet bowl cleaner. Scrub for no more than 15 seconds, spray neutralizer over the rim and rinse with water.
Alternatively, a polishing compound also works to clean used uncoated rims. To determine if a rim is uncoated, rub a small amount of polish on a test area of the rim and wipe away the polish with a towel. If the towel turns black, the rim is coated. Polish damages a coated rim. Clean it with soap and water only. If the rim is uncoated, wash the rim with soap and water, dry, and then work a small amount of polish into a small area of the rim by hand. Wipe away the polish with a paper towel. A fine steel wool pad also works to rub the polish into the rim.
A drill also works to polish a rim. Use a foam applicator that comes with a foam polishing tool that fits onto a drill. Before turning the drill on, apply a small amount of polish to the applicator and spread the polish around a confined spot on the rim. Turn the drill on a slow speed at first, and then work up to higher speeds to polish a small area of the rim. Wipe away the polish with a towel while still wet. Continue around the entirety of the rim.