Buff School Firing Clay, Earthenware/Stoneware – 10kg

Buff School Firing Clay

Key Features Highly versatile and easy to use - can be fired to either earthenware or stoneware Ideal for throwing hand-building and much more Earthenware matures at 1120degC-1180degC Stoneware matures at 1220degC-1280degC Fired colour is a warm buff greyThe price versatility and forgiving nature of this clay make it a natural choice for schools hobby potters as well as established craftspeople.

Compared to alternatives it is smoother and more plastic featuring a 10 addition of sand to give a slightly open texture.

This makes it an ideal body for hand building throwing modelling and converting into casting slip.Preparing the ClayThe clay is prepared by pugging and de-airing in a pugmill.

This consolidates the clay and removes the air producing a clay with a hardness of 5 to 7 when measured with a clay penetrometer.

Clay of this type is soft enough for throwing hand building and modelling yet still hard enough to retain its shape for stacking and storing.As a dual-purpose clay it can be used for making either earthenware or stoneware pottery - the difference lies in the way the pot is biscuit fired.EarthenwareEarthenware firing is known as the high fired biscuit and low fired glost route.

The clay is fired to 1120degC to produce a mature but porous biscuit piece which can then be glazed using the low firing earthenware glazes and glost fired between 1000 - 1060degC.

This is the temperature range that these glazes mature between.If using as a once-fire clay the clay piece will need to be coated with high firing earthenware glazes which mature together with the clay at 1120 - 1140degC.

StonewareStoneware firing is the low fire biscuit fire route in which the clay pieces are fired to just 1000degC.

The fired pieces are then coated with high firing stoneware glazes and fired to the maturing temperature of both the clay and the glaze usually between 1200 - 1280degC.Stoneware bodies can also be used with earthenware glazes.

This requires a high biscuit fire to 1200 - 1240degC followed by firing the earthenware glaze as normal to the glaze temp of 1020 - 1060degC.