Crushed pottery, used to temper (q.v.) the clay.
Small pieces of crushed pottery or fired clay sometimes added to the primary fabric for strength or applied to a vessel's surface as decoration.
Clay that has been fired and crushed in a variety of mesh sizes. It is added to clay to reduce shrinkage and to add texture and/or tooth.
Clay that has been fired and then ground into granules of more or less fineness. Grog is considered a filler, and is added to clay bodies for several reasons; it helps open a tight or dense body, promotes even drying, which reduces warping and cracking, and reduces overall shrinkage. Grog also adds tooth and texture to a clay body aiding in the ability of the body to maintain its form during construction.
Clay which has been fired and then ground into granules of more or less fineness. Grog provides texture, opens the body to help in uniform drying and cuts down shrinkage in clay bodies. From 20 to 40% grog may be used in a body depending upon the amount of detail desired and whether the pieces are free standing of made in press molds.
Crushed brick that is blended with clay to form new brick.
usually made of fireclay or a comparable type of clay that has already undergone the firing process, grog is added to clay to diminish shrinking and cracking as the clay dries; to increase durability, workability and strength; to protect against thermal shock and to add texture. Grog is often added to wares such as Raku and flameware because of their vulnerability to thermal shock.
A sand-like substance that is added to a claybody to add workability and strength to the clay. Grog is actually high-fired clay that has been ground down to a granular state. Because it has already gone through the firing process, it lessens the shrinkage of the claybody. In clays that require great resistance to thermal shock, such as Raku and flameware, large amounts of grog are usually present. See also shrinkage, claybody, raku, flameware.
Gritty material added to clay to modify its behaviour in firing. It is usually ground clay that has already been fired, and can be course or fine depending on the type of work for which it is being used.
Crushed or ground-up fired clay, purchased commercially or made by the potter; used to reduce shrinkage, yield texture, give fired clay more resistance to temperature change, help in even drying and firing, and help large pieces to stand up during construction.
Grog (also called firesand or chamotte) is a ceramic raw material. It can be produced by firing seletecd clays to high temperature before grinding and screening to specific particle sizes. It can also be produced from pitchers (ceramic material).