a/c / heater box question
 

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?

Re: a/c / heater box question
 

since foam and gas don't mix well, I was going to give that a tomorrow

Re: a/c / heater box question
 

Why are you taking the box out? Was it leaking?

Re: a/c / heater box question
 

Read the first words of the first post,
I'm replacing and fixing everything, but that doesn't matter to the question at hand.

Re: a/c / heater box question
 

If the 'black spray foam' is any relation to the insulation foam in a can, I haven't found anything solvent wise that takes it off. It takes about a week before bits on fingers will finally let go. I have a project shirt that got some around a button. Still there many years and washings later. For your heater box, a razor blade scraper might work.

Re: a/c / heater box question
 

I used some high temp paint reducer and a plastic putty knife. It didn’t dissolve it, but it did soften it up a little. Lawyer thinner might work too, at least on the box.