Firing With Wood
This is the wood firing kiln at Brushy Creek Pottery.
It is a 50 cubic foot, sprung arch, fast firing, wood kiln,
It was built by Ken George and includes over 3,000 firing bricks.
Loaded with glazed pottery
There are approximately 150 pieces in this kiln load
A pyrometrical cone pac is placed in a spot
that will be visible from a spy hole left open in the kiln door.
The cones are used to measure inside kiln temperatures.
These cones will become soft and melt at individual temperature ranges during the firing. Cone pacs are placed strategically throughout the kiln, this allows the potter to see how hot the kiln is in various places. It is important to maintain good even temperatures though out the kiln during firing to obtain maximum performance.
A pyrometer is also used by some potters as a means of measuring temperatures.
The door is bricked up and the kiln is ready to light
The spy hole brick is in the middle of the kiln door.
Getting the fire started
The object is to make a nice hot bed of coals that
will spread evenly across the bottom of the kiln
This is a slow process and usually takes approximately 4 hours.
Constant attention to stoking or feeding the fire is essential
during the entire firing process. Improper stoking can cause your
internal temperature to fluctuate and not rise at the proper rate .
Proper stoking acts in the same manner as a control on your oven,
Adding wood in just the right amounts at just the right time,
allows the potter the ability to raise the internal
kiln temperature over time.
The fire is spreading across the kiln
The other stoking side of the kiln far right window
Notice the smoke coming from the top of the chimney
Approximately 3 hours into the firing
The orange glow from the right side firing box,
indicates the fire has spread across the bottom of the kiln
A nice bed of coals is apparent by the red glow in the kiln chamber
At 4 hours Ken and his crew are gradually feeding the fire.
Many things are going on inside the kiln at this point:
1) Temperature Changes are occurring
a. stoking one firing chamber then the other
b. gradually increasing the amount of wood being added,
while slowly raising the temperature.
2) All of the excess moisture from the pottery and
the kiln bricks is evaporating,
steam can be seen rising from the kiln
3) Tempering the kiln, evening the kiln temperature throughout
4) Creating a hot enough atmosphere that will
spontaneously combust the wood