UNDERCOATING SUGGESTIONS

While not the 3m product, I did use 2 coats of herculiner inside and out. I cant tell you how solid it is now, and wasnt able to chip any off with a hammer, or do any damage for that matter. It took significant effort with a grinding wheel to clean a few areas for welding. I will always recomend going this route over just paint after my experiences.

Im not sayin paint is a bad thing, just that a liner/rubberized coating adds a little more protection.