Tom;
There is a good web site by Mike James concerning the procedures that are necessary for fabricating tools and molds for a composite airplane.
You might want to try making a few small parts such as wheel pants before attempting a large project such as a 7' airplane.
http://www.nextcraft.com/rcbuildingt...dbuilding.html
The Epocast resins are for tooling that is cast or poured while the Shell Epon 828 resin is used primarily for laminating. The 828 resin can be used to laminate glass cloth for making tools also.
I have experemented with different resins and hardeners and had some success but you run the risk of reinventing the wheel so to speak. There are many resin formulators out there that allready have most of the problems figured out for you. West Systems makes a Pro Set resin that is good. Aerospace Composite Products and CST Composite Structures Technology and Fiber Glast in Dayton Ohio carry the proper resins for many applications. This is not to say you shouldn't experement with different resins but you might find it easier to purchase from one of these sources rather than chasing down products that you will have to get through an industrial supplier.
Dan