Next, sand an area two to three times larger than the dent you want to fix down to bare metal (remember, filler needs to be applied on a clean, bare-metal surface) using 60- or 80-grit paper or a ...

Bondo is a name brand body filler for automotive repairs. ... the correct way to repair it is by removing that metal and replacing it with fresh metal, especially if it’s a valuable car.

Don't mix the Bondo yet! The next step is to hammer all the dents as straight as possible first. The flat head of the hammer is used to pound the metal against the flat surface of the dolly.