Room temperature hardening aluminum filled epoxy-casting systems were developed for use in heat resistant tooling applications such as for wax injection molding operations. The aluminum filler increases the thermal conductivity of the mold. This along with the application of a high temperature surface coat gives a tool useful for prototyping and short to medium quantity production runs in an investment foundry. When simple shapes are involved, a tremendous cost saving can be achieved with a jump from an already formed shape directly to the tool production process. The preformed shape can be a sample part or a wood pattern used in sand casting operations. Almost anything with the desired end shape can be the starting point for the production of an investment-casting tool.