Structural Foam for chassis stiffening

That expanding foam out of the can with the big straw on it...I shot it behind some tub tiles after I replaced the tub spout and the stuff popped the tiles right off. I sliced it flat and put the tiles right back on it, good as new. I used the stuff again for another project and I left a vent hole that produced a 6" long 'worm' after it cured. We use that stuff now to fill ducts after we run a cable so it wont leak. We got this crazy 2 part syringe type applicator that blows up on you if you dont follow the directions to the 'T'. throws that **** everywhere in a 10 foot radius and its hard to get off your skin and hair...baby oil!