How to Get Bondo to Stick

Bondo is a putty made by 3M that is used primarily for auto body repair. It was developed to replace molten lead, which was previously used to repair damage to car bodies. Car enthusiasts who want to make their own repairs to dings, nicks and dents on their cars can easily get their cars looking like new with Bondo. When the putty is mixed with a hardener, it sets and can then be sanded, primed and painted to the proper color.

Instructions

1

Wash the area of the car you want to repair with a liquid hand soap and water. Dry it thoroughly with an absorbent towel. Apply grease remover according to the product's instructions with a rag in order to remove any traces of materials that could affect the Bondo's adhesion.

2

Sand the area using a sanding block and 60- or 80-grit sandpaper or a drill and grinding disc to roughen up the surface. The Bondo must be applied on a bare metal surface in order to ensure proper adhesion. Every bit of paint must be sanded off.

3

Mix a golf-ball sized lump of Bondo with a small amount of the cream hardener, no more than 3/4-inch long, in a plastic container or bowl. Use the provided Bondo spreader to combine the mixture until the colors are completely mixed.

4

Apply the first coat of Bondo directly to the damaged area. Completely fill the dent or ding and allow it to harden thoroughly, which could take up to 10 minutes. Test if the Bondo has dried by running the back of your hand lightly over the surface.

5

Sand the area down with 80-grit paper. Your goal here is to get the surface of the Bondo level with the surrounding area.

6

Apply a second coat of Bondo, called the skimcoat, that is about 1/8-inch think to the entire sanded area.

7

Sand the skimcoat with 80-grit sandpaper after the Bondo has dried. This will smooth the section and help it blend seamlessly into the rest of the panel. Now you are reading to prime and paint the damaged area.