Abstract: An apparatus and method for forming foundry cores and molds of superior hardness and uniformity in a wide range of sizes includes staging hoppers for storing a first mass of sand coated with a catalyst-polymerizable resin film, and a second mass of sand coated with a catalyst film for polymerizing the resin. In forming the cores or molds these masses are simultaneoulsy and evenly dispersed into a high velocity carrier air-sand stream and directed through a static mixer, wherein the resin and catalyst-coated sand particles are intermingled and at least a partial integration of the films takes place, into a shaping mold cavity, wherein the sand mixture hardens into a desired shape.