Sand molds and cores are coated with a refractory wash after being formed. The refractory wash is a water or solvent based liquid, magnesite talc or graphite solid. The wash is applied to the mold, providing a better surface finish on the casting and protecting the sand mold from the heat as it enters the mold cavity. The molds and cores, after being washed, are dried in Wisconsin Oven conveyor ovens before casting. These ovens are often referred to as sand core dryers, mold dryers, or core drying ovens.