Fireclay Firebricks

Firebricks line kilns, forges and furnaces because they stand heat that would slump or crack ordinary brick. They are refractory fireclay bound round a large share of grog. Potters' guides give about 20–40 % grog for general kiln bricks and up to 60–80 % for the hottest parts such as fireboxes; the bonding clay should be a little less refractory than the grog. Factory firebricks are fired at about 1,100–1,400 °C. Make test bricks first, fire them, and check them for cracks before making a whole batch.

中级

A day, plus weeks drying and a firing

说明

Choose the mix

For general kiln walls weigh about 70 parts fireclay to 30 parts coarse grog; for a firebox about 30 to 70. Write the mix on a label.

所需工具：

称重秤

Mix

Mix the dry fireclay and grog in the trough, then add water a little at a time and tread or turn it until it is stiff and holds together.

此步骤所需材料：

耐火黏土14 公斤

熟料（碎烧结陶片）6 公斤

水3 升

所需工具：

拌料槽

平头锹

防尘口罩

Mould

Dust the wet brick mould with sand, throw a lump in hard so it fills the corners, strike off the top with the straightedge and tip the brick out onto a board.

此步骤所需材料：

砂1 公斤

所需工具：

木制砖模

直尺规

Dry slowly

Dry the bricks on pallets under cover, out of sun and wind, for several weeks, turning them now and then. They must be dry right through before firing.

所需工具：