Bondo is a two-part putty manufactured by 3M for auto-body repair, and wood repair around the home. Bondo is epoxy-based, strong and resistant to extremes of heat, cold, water and other chemicals. Mix the two parts in equal amounts, and apply the putty; it dries in approximately 30 minutes. Bondo will not shrink or crack.
Wear gloves to protect your skin from sticking to the Bondo. Clean the surface to which you are applying the Bondo.
Mix the two parts in a small, plastic container with your putty knife. It has the consistency of chewing gum when properly mixed.
Spread the Bondo on your repair. Spread the putty and push it into dents with a putty knife. Wipe off the excess. It is better to apply too much Bondo than too little.
File down the excess Bondo. File as closely along the surface as you can.
Put on a face mask. Sand the spot being repaired with medium-grit sandpaper; sand in a circular motion. Switch to the fine-grit sandpaper when the putty is flush with the surface.
Wipe the sanded area with a damp rag. Wait for it to dry completely. Put on your face mask.
Spray auto primer onto the repaired surface. Wait one hour for it to dry, and then spray the auto-body paint color of your choice.
