Using Bondo and Filler

Bondo, which comes in many different varieties, can be used to fill holes in the metal, dents, and most all physical defects on the body of a vehicle. the best bondo to use for small areas is simply a small thread fiberglass bondo that has a separate hardener. For larger areas, one can use the long thread bondo, and for even larger areas there are fiberglass sheets that can be cut to size, then attached to the body with the bondo. For our project, and most projects that you will run across, the small thread bondo will work fine. You will also need small putty knives and a cup of water and rags to clean your knives. Before applying anything to the parts you are working on you must first thoroughly clean the part you are working on. If there are any small dust particles it will cause the bondo to not set and harden properly to the area it is being applied to.

A 1'x 1' piece of cardboard will be needed to mix the bondo on. First take your putty knife and scoop out as much and you feel is needed to cover the spot. Put this on the cardboard and add the hardener. It will mix at approximately five parts bondo to one part hardener. Thoroughly mix the two until you get one uniform color throughout the mixture, then apply. If you have ever filled a hole on drywall it is exactly the same. Get a generous portion on your putty knife and gently go over the spot. You will want to make sure you cover the entire spot as well as a small area around the place you are working, for sanding purposes. These areas where you apply the bondo should be as smooth as possible, however it is not completely necessary, because we will sand these areas as much as possible. once all areas have been filled with the bondo allow to dry. Depending on environment and temp this could take anywhere from 2 hours- 12 hours; the colder the longer it will take. After the bondo had completely dried you must sand to a smooth and flush finish. This is done by first using a 120 grit sandpaper. After completing this, use a 220 grit sandpaper for the final sand