[_SLACKER_]

I am doing the heater core and evaporator in my truck along with rebuilding the box with new seals and washing everything, I have pulled the inner and outer boxes off the firewall and have a question pertaining to the sealer the factory used on the seams where the outer box meets the firewall, I am talking about the black "spray foam" not the strip calk. Anyway, the guy that did mine went to town and got that black spray foam crap everywhere on the box and I'm trying to clean it off. Does anyone know what takes that crap off?