A discoloured or damaged bumper decreases the value of any vehicle, and black bumpers tend to expose every little blemish. Luckily, bumpers can be repaired and restored to their original glory from home, saving car owners money and boosting the value of their vehicle in a day. Whether the bumper is only faded or has some collision damage, it can be repaired by almost any car owner with products that are available at most auto supply stores.
Wash the entire bumper until the rinse water runs straight off instead of beading. Let the bumper dry completely.
Sand across the entire front of the bumper and along the back of any damaged areas with 80-grit sandpaper. Make sure to remove any gnarled plastic around the damaged areas.
Apply an adhesion promoter to the back of a damaged area and let it sit for 10 minutes.
Apply a bonding adhesive to the back of the damage and embed a piece of wire mesh into the adhesive to support the back of the bumper where is has been weakened from the damage. Let the bonding adhesive dry completely.
Apply a layer of adhesion promoter to the front of the damage and let it sit for 10 minutes. Next, apply a flexible body filler to the front of the damage to fill in any scratches, dents or gouges. Smooth the filler with a putty knife and let the bumper dry for 1 hour. Coat the bumper with a flexible bumper sealer to promote paint adhesion and protect the repair work.
Spray the bumper with an aerosol texture spray if needed. Coat the bumper with one layer, let it dry and then sand with 180-grit sandpaper. Spray once more and let it dry.
Apply a layer of aerosol primer surfacer to further prepare the bumper for paint. The primer acts as a protective barrier for the surface of the bumper. It also promotes good paint adhesion. Let the primer dry before moving on to the next step.
Spray the bumper with a thin layer of bumper colour coat that matches the previous colour. A colour match can be made at most auto supply stores when buying aerosol bumper colour coat. Let the paint dry and then wet-sand the bumper with 320-grit wet application sandpaper. Rinse well and let the bumper dry again.
Repeat the previous step four times, applying a thin layer of paint each time and letting it dry thoroughly before sanding.
Repeat the painting step once more, sanding with 400-grit wet application sandpaper this time instead of the 320-grit sandpaper. Rinse well and let dry. Apply the final coat of paint, allowing it to dry overnight. Do not sand this final coat of paint.
Metal bumpers with excessive damage need to be repaired by a professional mechanic and will most likely need to be replaced.
These instructions are best suited for mild-to-moderate damage on plastic or rubber bumpers.