My Posts: All Forum Topic
On the other hand, there's a lot to learn about tool-making(creating molds) before you start any lay-ups. You need to know where to part the sections, how to create the overlaps or butt joints, how to inset, and the biggie-how NOT to create negative drafts that will lock your parts into the tool forever unless you want to destroy them in the process of removing them. Anybody who gives you a simplistic explanation of creating a plug and the molds isn't being real honest. You're going to have to create the perfect plugs anyway-the very same thing you'll do in making one via the lost-foam method. The difference will be that the plug will be hard so it doesn't warp or change shape as you build the tools over it. You'll have to make the plugs in pieces that will give you molds that will yield sections that will mate together in a way that allows assembly, installation of the mechanics, replacement of broken parts, and so on. If it was my first time and I knew very little about making molds, I'd use the lost-foam method just as a proof-of-concept model that I'd fly and see if I liked everything about it before I invested the cash in plug and tool making.
I've been in that business for many years, have my own kit line, and have done both. While I prefer to make plugs and molds, I'm that way because that's how I was taught and have been doing it for so long. A lot of the finer models out there have been done with the lost-foam method. The epoxy CAN be sanded and filled very nicely and if you do the intial laminations right, it won't take all that much work. It certainly takes less work, and a WHOLE lot less money! Molds aren't anywhere near as thin as the bodies-they're laid up to be extremely rigid, and this means many layers of heavy cloth and resin.
For the first time, I'd go with the lost-foam method until I had some more experience working with the materials-you can waste a lot of time and cash if you jump right into it. If you want to do molds, by all means go ahead but read up on it first, contact WEST SYSTEMS or FIBERGLAST for instructional info, and ask questions of those who do it already.