My first foam dio with insulation sheet foam was a disaster. I spent a good amount of time carving all the walls for a building. When it came time to glue I took it all into the garage and glued all the pieces together, like a dummy, with contact cement. Left garage, never noticed it melting. Came back in an hour with it in pieces. Glue ate straight through everywhere I applied it. Dont know what I was thinking using that glue. I knew better.