Definition: Borax (noun) is a source of boron and sodium oxides. It is used as a low-fire flux, but is more often found in fitted form as it is soluble in water.
Borax is a complex compound and has odd chemical characteristics. It is able to act both as a glass-former (acid) as well as a flux (alkaline). Chemically, it is written as Na2B4O7.1OH2O. Since for ceramic purposes the water is inconsequential, potters often prefer to work with the formula of borax as Na2O.2B2O3.1OH2O when doing glaze calculation.
Warning: All boron compounds are toxic. Use proper precautions when handling.
Also Known As: tincal (Asian borax)
Examples:
Borax and borax frits are used to make leadless low-fire glazes.