Blue and Green Spindle Form I.
Pit fired clay and clay cast glass.
13" x 16" x 13"
1997
How is clay pit fired ?
The primitive way of pit firing is the way I went
The following pictures were taken at a pit firing on the beach in San Francisco, California. They show the basic steps in a primitive pit firing and tell you what to do in each step.
The more result way to do a pit fire
(See text down below)
Pit-firing is yet another way of firing. The pieces are placed into a pit or
a container, and then covered with combustible, organic materials. Fuels such
as sawdust, pine needles, or even cow
dung can be used. The top of the
combustible layer is ignited and once
smoldering sufficiently, the pit is covered.
Just enough air is allowed inside to keep
the fuel smolding overnight (unlike at the beach).
Because of the insucifficent air supply,
carbon produced from the unburnt fuel is
deposited on the surface of the piece.
Shades of black and grey are developed
in the carbonized areas. Various hues of
the clay body (terracotta, beige, or buff)
will appear where the combustion is more
complete and carbon does not form.
High temperatures are not reached in the
pit-firing and therefore the clay body is
not matured, rendering the pieces fragile.
For this reason the pices are biscuit fired
prior to the pit-firing to provide more
durability.