Dipping automotive frames is nasty stuff. Frames are electrically coated or dipped in a "hot wax". These are from a structural plant that as the last process hot wax dips entire extended frames vertically into a huge pool of 250 degree wax. Above pictures are from a exhaust fan. I have measured air temps in range of 180 from these. It's nasty, sticks in boots ladders you name it. Below is a PVC pipe that is on the roof that couldn't stand the heat. It melted kind of like a wilted flower.