How to Repair Rust Holes Around the Wheel Well

by Eli Laurens

Automotive body panels are painted with several layers of rust-preventative coatings, but when the vehicle is driven into salty or sandy environments these coatings will strip away, and the metal underneath will rust. This rust can be repaired by the average backyard mechanic in about four hours.

Sand the rusted area well. Use a high-grit sandpaper (100+ grain) to remove surface rust and expose any true holes in the metal. Most rusted areas look worse because the rust is spreading, even though it has only eaten through a small spot. If possible, sand the inside of the wheel well, which may be accessible by removing the plastic wheel well cover on some models. Sand around the area to completely remove paint and prepare the section.

Cut the rusted hole to even, non-rusted edges. Using a mobile, hand-held saw it is possible to get uneven areas or reach behind the panel to get hidden sections. Start at the edge of the rusted hole, and cut in an even manner to get the entire edge. Whether it is a circle or a square, the object is to get out all rust; it's important to be thorough, but remember when to stop. It is more difficult to patch a large hole than a small one.

Repair the section with a mixture of fiberglass/bondo resin over mesh. The kit will contain a small section of cloth mesh that can be used to shape the bondo resin over the holes, creating a smooth surface when dry. Layer the mesh into the paste, pressing it slightly to push it flat and make the same shape of the panel. Add more layers, to the backside if necessary, until the patch is above level with the panel. Allow the paste to dry, or use an optional dryer.

Sand the patched area until it is level with the panel. The dried paste is now extremely hard, and can be shaped to the same bends as the metal it is now attached to. Don't sand too deeply, just enough to be seamless with the metal.

Spray the area with primer paint. Several coats can be used, and the primer paints usually come in a light color to reflect colored top paints. Some types are also rust-proofing. Allow the area to dry.

Cover the area with several coats of colored enamel paint. Match the color as close as possible to the car's original paint color, as this will be the visible pigment layer. Some types come with added gloss. Allow to dry.

Tip

  • check Add gloss coats and rub with compound to make the fresh paint shine.

Warning

  • close Use protective equipment when using power tools and spraying paint.

Items you will need

About the Author

Eli Laurens is a ninth-grade physics teacher as well as a computer programmer and writer. He studied electrical engineering and architecture at Southern Polytechnic University in Marietta, Ga., and now lives in Colorado.

Photo Credits

  • photo_camera image.4wheeloffroad.com