a great device for controling the water temp. a cheap electic skillet.
be sure it is only used for the process.
Very cheap at the usual places. target, wal-mart, etc.
the one i am using can handle without diffiuclty an 8x10 piece of film.
the real trick is to find a tool to handle the floating emulsion. try a resturant supply house, or a chinese resturant supply house for very large cheap spatulas' much cheaper and do the trick .