Sodium silicate is a well known binder for molding sands. It is compatible with various carbonaceous materials used in core making, such as starch and dextrin. Silicates successfully replace the more costly vegetable oils and resins used in forming certain types of molds. Silicate-based mold compounds give a hard bond at moderate temperatures, appropriate porosity for the release of Hp gases, and friable texture.

For fast production methods, sodium silicate is applied in combination with acid reacting CO gas.

Self-hardening foundry molds can be achieved with a binder made by mixing portland cement of organic estges with sodium silicate.