Cars need continuous maintenance by their owners. Keeping the car in good shape allows the car to function properly. Although rust on the roof will usually not interfere with driving, it will spread if left untreated, possibly leading to rust holes. Repairing rust holes is an expensive and time-consuming project. The best thing to do is to remove the rust when it first appears. At that point, rust removal is a simple process.
Scrape off surface rust with a steel-wool pad. For small rust a steel wool pad usually is all you need.
Pour a small amount of naval jelly onto the steel-wool pad. Apply the naval jelly to the rust. Wait about 10 to 15 minutes.
Scrub the rust with the steel-wool pad. The naval jelly has phosphoric acid that dissolves more difficult rust.
Wipe the roof clean with a rag or paper towels.
Apply rust-inhibiting primer to the rust with a paintbrush. Let dry. The primer puts on a protective seal that prevents the roof from rusting again. Use a primer made for metals.
Apply touch-up rust-inhibiting paint. Find a color that matches the car and paint on with a brush. Let dry.
