Does anybody know if the foam inside a 3500 frame is flammable? or if there is suppose to be foam inside the frame ?
just trying to weld some plates on the outside of the frame until I can get a new frame

 

I am thinkin' that if you get it hot enough, it'll burn, and likely give off toxic fumes. Welding will certainly get it hot enough......Think I would make an adapter for my garden hose, with a stiff, small diameter pipe, for putting out fires inside frame rails, before getting started.

 

Lol yeah I know I need to be ready but did these frames come with foam inside them from the factory or did some dumb *** put it in there to sell the truck

 

No clue on that. It *might* be factory, and was used to dampen vibrations/quiet the ride...... The factory doesn't consider rust repair when they are rolling off the floor.