Re: foam insulation

[TWIH]

What you saw was someone that used cheap industrial packaging for installation. The foam board in the building supply places is not that expensive but has two sides of covering. I highly recommend it. I think that I spent less than $60 doing my whole van. I sprayed it black before final installation in the window and it was basically invisible. The stuff on the walls was covered by bead board and I had a nice insulated cave. The solar panels on top gave a nice shade.

So when gluing two 1/2 panels together (due to needing to curve), is there an adhesive thats recommended?  I’ve read that some adhesives react with and “eat” the foam.  So far I’ve heard of using: clear silicone, pl100/200 or other brand (caulk gun) tubes, liquid nail, 3M spray and even small amounts of the “Great Stuff” low expansion product.  

Any thoughts?  

Obviously the Great Stuff spray would be wasted once it is opened/used some, same with the tubes of caulk-type adhesives (panel or PL100/200 types) but the 3M spray would stay good for awhile.