Whether the rubber bumper is just sun-faded, has a few scratches, or contains some serious dents, you can repair it at home. A damaged bumper not only detracts from the look of your car, but also negatively reflects on you. All you need to refurbish the blemished bumper is a bit of sanding, scrubbing, filling and painting. Soon you'll have it looking as good as new.
Clean the bumper thoroughly with a grease-removal cleanser such as a car degreaser or a liquid dish soap.
Sand the bumper with 80-grit sandpaper from side to side across the front to remove the previous finish and to roughen the surface just a bit. Blow all of the dust and debris off of the bumper with an air compressor.
Heat the front and back of the damaged area with a hot air gun until it becomes extremely hot and somewhat pliable. Push any gouges or dents back into place with the handle of a screwdriver while the rubber is hot.
Spread plastic filler into any scratches or areas not corrected with the hot air gun. Smooth while the filler is still wet with a putty knife. Make sure that the putty knife does not remove too much, causing the contour of the bumper to indent where it has been filled. Let the filler dry completely before moving to the next step.
Sand with 180-grit sandpaper to remove any rough edges from the patched areas. To ensure that the bumper is smooth enough for paint to be applied, refill and sand any areas that may have been missed or sanded too deeply on the front surface of the bumper.
Wet-sand across the front surface of the bumper with 220-grit wet/dry sandpaper. Rinse and let dry.
Spray on a coat of flexible bumper coat paint. Let dry and then wet-sand with 320-grit wet/dry sandpaper. Rinse and let dry. Repeat two times.
Repeat the paint process, this time wet-sanding with 400-grit wet/dry sandpaper. Spray the bumper with one final coat of paint and let dry overnight.
Use caution when handling hot rubber.