What Epoxy & release agent to use for making a laminate Archtop Top (and Back) Mold?

[Bryan Jeppson]

Okay,
I just got Making a Laminated Hollow Body Electric Guitar by Jim English. Not a bad book, but very light on the details of the one section I was most interested in - creating a mold for the plates. The basic gist is simple enough - dip the top or back of an archtop instrument you like into plaster of paris, let it set, then sand it down to make a negative mold. Once that's done, build a containment fence around it and then pour in an epoxy resin to make the mold. Spray the epoxy mold with a releasing agent, make a fence around that, and then pour in more epoxy for the top mold. All he says is use a "good two part epoxy resin" and a releasing agent between the plaster, the first, and the 2nd epoxy applications. It would've been nice if he'd mentioned/suggested some brand(s) and what/where to get them or the releasing agent. The two molds have to be pressed together with several tons of pressure, so this definitely has to be an epoxy that is uber hard and durable. Anybody tried something like this, and what brand is best (or at least feasible)? My apologies if this belongs in the Glues and Finishes or the Tools and Jigs section....I just made my best guess where to put it.

[Barry Daniels]

I do not have the Jim English book so I made up my own technique for making a two part form and I use it in a vacuum bag. I initially carved an internal form out of 3/4" MDF. It carves like butter. The edges ended up quite thin so I glued it to another piece of MDF. I sealed the MDF with several coats of shellac and then applied about 10 coats of paste wax to use as a release agent (one answer to your questions). I then made the external form using fiberglass layup methods and materials. I used three layers of glass cloth and poured on the resin. Before removing the fiberglass I drilled a couple of holes off the side of the waist to install wood dowel pins for registration.