You can use the J+B weld to mold each half of the mold and coat the jig with a thin layer of vaseline so it doesn't weld it together. Same principle as alot of different moldings are done. Any type of thick lubricant will work. Oh and I wouldn't use a dremle on J+B weld as it is somewhat brittle. I would reccomend useing a medium grit sandpaper to smooth it out.