CLAY

What is clay?

Clay is very fine particles of dirt which float in a stream or river and then sink to the bottom, where they press on each other and stick together.

You generally find clay along the banks of a river or stream, wherever the river is pulling dirt down off the mountains or hills and dropping it in a

quiet part of the river lower down.

Clay can be divided into several classes, based on characteristics and at what temperature the clay must be fired to in order for it to

become mature, or reach its optimum hardness and durability.

1. Earthenware- light grey to dark grey or brown because of high iron content, most common clay, fires at 1850 degrees

2. Stoneware -light grey to buff color. Fires at 1950 degrees, good plasticity= good for wheel throwing , used often for bakeware

3. Porcelain- white, Fires at 2200 degrees, less common

Handbuilding Techniques

1. Coils- roll clay until it forms a long roll (rope)

2. Slabs- flattening and stretching out a base of clay (pancake)

3. Pinching and Forming- pressed, pulled and pinched

When a clay project has been created and it is fully dry, it is at its most fragile state and is called greenware

Once a clay project has been fired in a kiln, it becomes hard and is referred to as bisqueware

A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Various industries and trades use kilns to harden objects made from clay into pottery, tiles and bricks.

Electric kilnAnagama kiln

Gas kiln

GlazeCeramic glaze is layer or coating of a vitreous substance (silica- which is the main ingredient in glass). Glaze can serve to color, decorate or waterproof an item.