500g ALUMINA HYDRATE

While alumina is essential in stabilizing glaze chemistry and preventing excessive glaze flow, clay and feldspar are much cheaper sources of the oxide. Alumina hydrate is more often used as a refractory mixed with kaolin to make wadding or kiln wash having high resistance to molten glaze or glass attack.

For more information on alumina hydrate, see the Digitalfire.com Reference Library of ceramic materials.