Sanding the rust off a radiator can be a time-consuming project because some of the areas of the radiator are difficult to reach. Using a chemical rust remover speeds up the process considerably. Chemical rust removers help to remove all traces of rust from the radiator. Once the rust has been removed, prime and paint the radiator with rust-prevention products to protect it against rusting in the future
Turn the radiator off and let it cool down if it is hot. Place a small dust sheet around the radiator to protect the floor.
Clean the radiator thoroughly with an all-purpose cleaner and a lint-free cloth. Remove all the cobwebs, dirt and grease that have accumulated on the radiator.
Scrub off loose rust with a wire brush and sandpaper. Begin with the wire brush and scrape off as much loose rust as possible. Sandpaper works well for hard-to-reach areas on the radiator. Wrap the sandpaper around the end of a screwdriver to get to areas that are difficult to reach with your hands.
Apply a chemical rust remover to the rusted areas. Apply the rust remover to the rusted areas with a 1-inch foam brush applicator. Wait five to 10 minutes and then thoroughly rinse the rusted area with clean water. Allow it to dry and inspect it for traces of rust. Repeat the process if traces of rust remain.
Spray a metal primer on the bare metal. Hold the can 6 to 8 inches away from the spot as you are spraying. Apply two to three light coats of primer. Wait 10 minutes before applying each coat.
Repaint the area with a rust-inhibiting spray paint. Select a colour and sheen that matches the radiator. Use the same method used in Step 5 for applying the primer. Apply several light coats of paint.
Wear rubber gloves and eye protection when working with chemical rust removers.