How to Weld Holes in a Car Body

Welding holes in a car body requires the proper tools and techniques to avoid destroying the vehicle's body. Producing excessive heat on a thin body panel causes the panel to move toward the heat. This causes the panel to warp, creating waves along the body. Excessive heat will also melt the edges of a hole, increasing its size and the amount of heat needed to fill the hole.

Instructions

1

Sand the area around each hole with 200-grit sandpaper. Stop sanding when no paint remains within two inches of the hole.

2

Secure a step down drill bit in the chuck of a drill motor. Drill the body holes 1/16 inch larger with the step down drill bit. This exposes clean metal inside the hole, reducing the chances of porosity (holes) in the plug welds.

3

Turn on a MIG welder. Hold a piece of copper plate on the backside of a body hole. Align the MIG wire with the center of the hole. Depress and hold the MIG gun trigger for two to three seconds to fill small holes with a plug weld. Place overlapping tack welds to fill larger holes. Allow all welds to cool for 30 minutes.

4

Attach a 60-grit sanding pad to an angle grinder. Grind each plug weld even with the area surrounding each weld.

5

Spray aerosol primer on all exposed metal to prevent rust.