Corrosion Hole or Deep Damage Repair

Remove all paint from the area to be repaired and approximately 25 mm (1 in.) around it using a wire brush fitted in a drill. If these tools are not available, this can be done by hand with sandpaper. After removing the paint, evaluate the severity of the corrosion and decide whether to replace the panel entirely (if possible) or repair the damaged area. New body panels are not as expensive as most vehicle owners think, and panel replacement is often a faster and simpler solution than attempting to repair a heavily rusted surface.

Remove all components installed in the damaged area except those that will be needed to form the original surface. Then cut away all metal severely damaged by corrosion using metal snips or a hacksaw blade. Bend the edges of the hole inward with a hammer to create a support for the body filler.

Remove loose rust powder from the remaining metal using a wire brush. Apply rust converter to the damaged area; if the inside of the rusted area is accessible, treat it as well.

Before filling the damaged area with body filler, the hole must be covered in some way. This can be done with aluminum or plastic mesh, or aluminum foil.

For large holes, aluminum or plastic mesh or fiberglass cloth is best. Cut a piece of material approximately to the size and shape of the hole, then place it in the hole so that the edges of the patch are below the level of the surrounding metal. Secure this position with a few drops of body filler.

For small or very narrow holes, aluminum foil can be used. Unroll a piece of foil from the roll, cut it approximately to the shape of the hole, and attach it to the edges of the hole. If the thickness of one layer is insufficient, fold the foil into several layers. Rub the edges of the patch with the handle of a screwdriver to press them more firmly against the metal.