I need the advise and experience on this board of anyone who has cast objects in epoxy resin before. I plan on constructing a 14" dia. centrifugal blower to provide the suction needed to run a 20" diameter cyclone dust collection system for my shop. It's time for me to get serious about my health. I plan to build the cyclone itself out of fiberglass, as well as, the impeller housing. These 2 parts may be constructed as one given the design possibilities with glass. The impellar itself is a radial type. A 1/2" thick - 14" dia. disk with blades radiating from the center like pie slices that are approx. 3 1/2" high and 1\4" thick (maybe a little thicker at the base). My question here is: Has anyone cast parts, maybe with chopped glass filler for strength? I want to build a pattern for the impeller, create an RTV mold and epoxy cast in it. The balancing benefit of casting something that has uniform density throughout is very appealing to me. I know from building my canoe that the left over epoxy, when mixed with reinforcing filler, got incredibly strong even in thin cross sections. I have not intentionally cast parts before, but have popped a lot of left over stuff out of mixing pots. The only thing I see is that I may have to watch getting my mix too thick or it won't flow into the mold correctly. The impeller won't be subject to abrasion as it is a pull-through type. It will be driven directly by a 5 hp motor with a bolted on taper bushing. I can't see any reason why the material wouldn't work given the fact that one of the largest manufacturer of cyclones uses plastic impellers in there systems. Any parts casting experience out there?