A clay deflocculant used sparingly (~2 or 3 g/ litre of water plus ~1 g soda ash) to lower the amount of water necessary to produce a fluid slip or as “Magic Water” (same proportions) to join together softer and stiffer pieces of clay. In higher concentrations its bonding power is exploited to produce decorative crackle effects on fresh clay or as the air-dry and hi-temp “glue” in insulating brick mortar.
For more information on sodium silicate, see the Digitalfire.com Reference Library of ceramic materials.