Supposed I buy some square metal tubing for structural use, and I want to epoxy some square metal struts (walls) inside it every 8 inches. How could that be done without all the glue getting rubbed off before the piece is slid to the desired location? Would I just have to rub lots of glue in there and slide them in fast before it dries? Or do they have heat activated glue I could put in there wet and then heat once everything is in place? Small plywood plugs would probably be easier to manipulate.