Soda fired ridged bottle with one lug
Bottle vase with thrown ridges. Tenmoku glaze.
This Japanese glaze usually fires black breaking to red under normal reduction firing. But in the soda kiln, the action of the soda on the hot glaze "bleaches" the iron in the glaze, turning it a deep olive green breaking to white.
Vapour fired to 1300 C in a gas kiln.
Soda, or vapour, firing is a firing process where sodium in some form - sodium carbonate or bicarbonate, is introduced into the kiln as a solution when the temperature is at 1250˚C.
The soda immediately volatises, and combines with the silica in the clay to form a lustrous glaze with often spectacular surfaces where the flame has licked around the pot, taking the soda with it.
The randomness of this process gives each pot its own unique character.
Prior to firing, the pots are dipped into different clay slips (liquid clay) to give different colours and effects.