Process and systems for molding or forming products from thermosetting plastics. The system utilizes a deformable container that is placed within the cavity of the housing of the mold with the resins and initiator mixed therein. As a piston slides into the cavity, the upper edges of the container engage between the housing and the piston to seal the housing form leakage. The pressure of the piston along with heat on the housing enable the curing process to be controlled to minimize shrinkage and porosity.
