So, someone gave this to me for free and I have decided to build a gravity fed smoker out of it. In it's previous life, it was an electrical box on a railway. It is about 24"x36"x 4' tall. It's getting sandblasted this week to get all of the galvanized paint off, as well as the rust. It around 10 gauge steel. I have welded a 1/4" bottom on it. I am planning on insulating it with Roxul, so I have a question. Will the Roxul burn due to the heat of the welder?