Clay glossary

Removal of air from clay. Various means are used to achieve this but the most common with clay is via the de-airing chamber of a pugmill.

The dispersion of clay slip or glaze by the addition of an alkaline electrolyte e.g. sodium silicate, Dispex, etc.

The crystallization of a vitreous material.

The property of a suspension such that when it becomes mechanically disturbed it appears to stiffen but becomes mobile again when the disturbing force is removed.

The application of a glaze by immersion and then allowing the excess to drain off.

The separation of clusters of particles into their original separate units i.e. grinding.

Absorption of glaze by an unglazed surface situated near to a kiln during firing.

Globules of glaze found on open gloss ware, usually from glaze accumulations on the roof of the kiln.

Cracks or cracking in the clay caused by the too rapid cooling or heating of ware, and due to thermal stresses set up in the body.