How to Fix Rust Holes on a Car

If you don't fix rust holes on a car as soon as possible, they can enlarge to the point that your car may fail your State Inspection, especially if your rust hole is in the floor pan of your car. While it may look like a task beyond your skills, the actual process of fixing rust holes on a car can be done by anyone with an afternoon free and a few tools. You don't need to weld anything, rivets and a good sealer can do the job just as well.

Things You'll Need

• Car jack
• Socket set
• Grinder
• Metal blade
• Tin snips
• Sheet metal
• Roof tar sealant
• Brush
• Metal rivets
• Rivet gun
• Bondo auto body repair kit
• 320 grit sandpaper
• 600 grit sandpaper
• Auto spray paint primer
• Auto spray paint

Instructions

1. Park your car on a level surface. If need be, use a car jack and stands to raise the car to allow for the best access to the rust hole. Use a socket wrench to remove seats and carpets, should the rust hole be located in the floor pan of your vehicle.

2. Attach a metal sanding wheel to your grinder and use the grinder to completely remove the section of rusted metal. Once you have removed all of the visibly rusted metal, grind the edges of the hole until they are smooth.

3. Cut your sheet of metal with a pair of tin snips so that it is 1/4-inch wider than the rust hole on a car.

4. Paint the edges of the hole and the edge of your sheet metal with roofing tar sealant. Wait 10 minutes before placing the sheet metal over the hole and pressing both tarred edges together.

5. Using a rivet gun and metal rivets, attach the sheet metal to the car body. Place the rivets a maximum of 3-inches apart. You may need to use a closer spacing for the rivets if the sheet metal must follow a curve in the body panel.

6. Open your Bondo kit and mix according to the instructions supplied with the kit. Apply the prepared Bondo mixture to the edge of the hole where it meets the sheet metal path. Smooth the Bondo, let it set and sand it smooth with a 320 grit sandpaper followed by a 600 grit.

7. Spray the repair area evenly with auto spray paint primer. Make sure the entire surface of the Bondo and sheet metal patch is covered. Wait 30 minutes and then paint the repair to match your car with auto spray paint.

Tips & Warnings

• When painting the repair, hold the spray can 8-inches away from the body and beginning in the center of the repair, spray in a circular pattern to insure an even covering. Let the paint dry between coats.

• Do not use plastic rivets. Never use a rivet type repair to correct rust damage on the structural frame of the car. Structural repairs must be welded into place or the structural integrity of the car is compromised.

References

• Rust Holes and State Inspection

Resources

• A Basic Bondo Tutorial