Abstract: A two component system is disclosed for forming rigid polyester reaction products in which each component is storable for an appreciable period of time but reacts upon contact with each other to form the rigid reaction product within a relatively short time. One component comprises a pre-catalyzed polyester resin which normally has a short pot life but which is extended by an excessive amount of an inhibitor. The second component is a synergistic accelerator combination consisting essentially of a metal soap and an aromatic tertiary amine. When the two components interreact, the accelerator combination overcomes the action of the excessive amount of the inhibitor and brings about a normal polymerization of the polyester resin. Optionally, the accelerator combination is part of a fibrous reinforcement and the aromatic amine is solid at room temperatures. This enables the second component to be more readily used in a dry, handleable form for easy storage.