Savage_Rob wrote on 12/31/69 at 16:00:02:Bondo is a putty used to fill in dents and then sanded and primered/painted. It's much heavier than fiberglas but is pretty easy to use. However, if not done properly it has a propensity to fall off in chunks at the slightest provocation. That's from memory in my teens... the stuff has probably improved since then.
I got into a project in the winter of '03 that involved welding mounting tabs on the frame for my engine guard (no u-bolts). While I was there, I attended my first self-help class on bondo since I had never used it before. It takes a little practice, but isn't too bad, and you do have to keep track of time while applying it.
This is where I smoothed the factory frame welds and filled other holes before I repainted the frame.