Chromed metal bumpers are commonly found on vintage and classic cars. This finish looks great and is relatively easy to care for. However, if moisture is allowed to sit on the finish, it can damage the chrome plating. If rust can be removed from a metal bumper before it begins to cause flaking and pitting, you can save yourself the trouble of having the bumper replated.
Rinse the bumper with a hose or a pressure washer to remove any loose dirt and debris.
Clean the bumper with soap and water. You can use a specific automotive chrome cleaner or a household cleaner. Dry the bumper thoroughly with a clean, terrycloth towel.
Polish the entire surface of the bumper (or any chrome parts on it) with a good quality chrome polish available online or at auto parts and hardware stores. Apply the polish to a rag and then buff the chrome until the rust starts to lift. This will remove any light surface rust and give you a better idea of where more persistent rust spots are located on the bumper.
Remove heavier areas of rust by applying polish onto the rust and then gently scrubbing it with fine steel wool (0000 grade). Work the polish into the rusted area, scrubbing and then rinsing with water to monitor your progress.
Remove final areas of rust with white vinegar and aluminium foil. Soak the foil in vinegar then rub it over the rusted areas with the palm of your hand. Continue to soak the foil and then rub it into the rust until the rust is removed.
Rinse the bumper with the hose and water again. Re-apply polish to the bumper with a clean terrycloth rag. If the bumper's finish still has rusty, pitted areas, the bumper may need to be rechromed.