How to Repair Trunk Rust

Any nick, gouge or scratch on your trunk, whether on the underside of the carriage or top of the hatch, can result in rust; this happens because the scratch or nick removes the paint, which exposes a small part of the metal to moisture and oxidation. Once rust forms, it will continue to spread outward and create a much larger problem if left uncorrected. Severe rust damage usually requires large parts of a vehicle's body to be cut away and new metal to be welded in place. It's time consuming and requires precision and skill. Repair any rust spot as soon as it forms to prevent such a task.

• 1

  Sand away the rust spot until you see solid, rust-free metal. Make sure that all segments of rust have been removed. You can sand away rust by hand using sandpaper for small spots, but you may need a power sander or power brush tool to remove large segments of rust.

• 2

  Apply a rust neutralizing agent to the spot to neutralize any small particles of rust that you may not have removed by sanding. Rust neutralizers are also sometimes called rust removers or rust converters; they work by altering the chemical composition of the rust into ferric phosphate. Sand away the rust neutralizer after it has sat for the duration listed on the bottle.

• 3

  Fill in the sanded spot with automotive body filler, which is usually a pastelike fiberglass solution. Fill the sanded area with body filler and rub away any excess. Let it sit until it has hardened, then sand it smooth using sandpaper so that it matches the rest of the trunk.

• 4

  Coat the sanded area with a metal primer that is specifically designed to inhibit rust formation. Failure to prime the metal before painting could result in new rust formation. Paint or spray the primer onto the sanded location and let it sit for the duration prescribed on the bottle.

• 5

  Paint the sanded area with automotive paint using either an air compressor and air brush or a fine-bristle brush. You can either purchase premixed tubes of automotive paint and use the one most similar to your car's color, or you can take the paint color code to an automotive shop to have a custom paint mixed. Your car's paint color code can usually be located on a sticker inside the door or glove box.