This invention relates to foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an epoxy resin; (b) an acrylate; (c) an alkyl ester of a fatty acid, wherein the alkyl group of the ester is an aliphatic hydrocarbon having from 4 to 8 carbon atoms, preferably butyl tallate; and (d) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly ferrous castings.