Alternative Firing Methods Study Guide
Pit firing
Oldest method of firing
Layering of materials in a brick-lined hole in the ground
Layers from top to bottom:
 Corrugated metal
 Wood
 Cow dung
 Newspaper
 Greenware pots
 Sawdust
Pots are not water-tight
Pieces may be wrapped with newspaper and bailing wire
Steel rod and cinder block at either end can create a flue
A distinctive black oval appears on the side of the piece
that was resting on the pit floor
Raku
“Raku” means “joy” or “happiness”
Started in 16th century Japan by Korean potters under Japanese rule
Raku is linked to Zen Buddhism, and the Japanese Tea Ceremony
After bisqueware is glazed, it is fired and removed at peak
temperature with tongs
Glowing pots are placed metal drums filled with sawdust
Carbon from the smoke gets into the cracks caused by thermal shock
Pots are doused in water and scrubbed clean, but the dark crackle
lines remain
Raku ware is not water-tight, and thus, are decorative rather than
functional
Salt Firing
Salt firing started in Germany in the 15th C.
Salt, or sodium chloride, is introduced into a hot kiln when the
temperature reaches 2350 F. or higher.
Sodium combines with silica on the surface of pots creating an
“orange peel” effect.
Salt becomes an active vapor through the kiln
A diluted form of hydrochloric acid is released as a vapor
Salt fired kilns can not be used for other kinds of firing.
Anagama Firing
A Japanese term meaning "cave kiln"
The fire box is stoked with wood every ten minutes for about 3 days
or more. Cool down time is the same as the time it takes to fire
Ash must be raked regularly from the mouse hole so that the ember
bed is kept alive
Ash melts and forms the glaze on the pots
Gas Firing
Melting pyrometric, observed through a peep hole, cones determine
temperature levels
Flames come out of every opening, unless they are plugged
Gas reduction firing uses a fuel such as natural gas or propane.
The temperatures of a gas fired reduction kiln may exceed 2300F,
Cone 10
Gas is a combustible fuel and the potter can control the ratio of
oxygen to gas during firing.
Depriving the kiln of oxygen creates a “reduction” atmosphere, where
carbon monoxide can be produced. This only occurs in gas
fired kilns.
Burning of chemically combined oxygen in the clay and glaze
minerals gives reduction fired pottery its unique characteristics
and rich colors