Sodium Silicate - Силикат натрия is the most important of the soluble silicates. This material is often called “water glass” and is ordinarily supplied as a colorless, viscous water solution displaying little tack. Positive pressure must be used to hold the substrates together. This material will withstand temperatures of up to 1100 °C. The main applications of sodium silicate adhesives are in bonding paper and making corrugated boxboard, boxes, and cartons. They are also used in wood bonding and in bonding metal sheets to various substrates; in bonding glass to glass, porcelain, leather, textiles, stoneware, and so on; bonding glass-fiber assemblies; optical glass applications; manufacture of shatter-proof glass; bonding insulation materials; refractory cements for tanks, boilers, ovens, furnaces; acid-proof cements; fabrication of foundry molds; briquettes; and abrasive polishing wheel cements. Soluble silicates may also be reacted with silicon fluorides or silica to produce acid-resistant cements with low shrinkage and a thermal expansion approaching that of steel.