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a wood firing raku kiln

updated mon 19 dec 05


Michael Lancaster on sun 18 dec 05

I was searching the web for information on hoists and cranes for our =
Raku kiln. I did find some, but went out and invented my own for about =
$175. In the search I came across several stories about folks =
unsuccessfully firing Raku with wood. I have my own stories and they =
are all pretty successful. In fact if you follow the basic concept of =
Chojiro's journey you should know what to do if faced with creativity =
and little money.

The first time I ever fired Raku with wood was happenstance. We were =
firing my 'little baby' 90 cu ft (cone 11) wood kiln in Malden Bridge, =
NY in 1977. We had some tea bowls left over from a Raku firing, that =
were unfired. We ran and grabbed them and placed them in the firebox =
while the kiln was around cone 8. They fired in about 5 minutes, with =
complications to the glazes - a little too fast!

When I moved to New Mexico in 1987, I left my Raku kiln in New York. My =
wife, Barbara Harnack, was having a healthy career of mixed media with =
clay fired in oxidation at cone 05. This was before she too would fall =
in love with Raku. So, when we loaded the truck and had to leave things =
behind; well so long Raku kiln. Then in 1988 I was asked to teach a =
workshop. When Raku came up, I was forced to test my 'real' knowledge. =
I looked at drawings of Chojiro's original wood kiln and decided to make =
a modified version. Being in the dessert I decided to build it of a =
common cheap material - adobes! An adobe brick is 10" x 14" x 4". The =
entire cost of the kiln was less than $50 plus an octangular shelf from =
our 23" electric kiln. In fact - with some 2x4 for forms and the right =
clay/sand/silt mix for bricks, one could make it dirt cheap. The fire =
box was a shallow arch 4' long x 18" tall. I made the form out of =
scrap corrugated tin roofing with 3 wooden stick crosses for support. =
The arch faced into a cylinder that had a narrowing interior which =
started at about 30" and narrowed to the top at 24". The height of the =
chamber was about 4'. It was built on a hill with a slight pitch. Dirt =
was thrown against the side so that I could stand over the box and look =
down into the chamber. I used the same corrugated, cut down, and wired =
with scrap 1" insfiber to cover half the chamber. It was actually a =
firebox and a chimney. It took hours to get to temperature and a fair =
amount of scrap wood - maybe 1/4 to 1/2 of a chord. The first few pulls =
were 45 minutes apart. However, as the adobe heated, the kiln reached =
temperature every 10 minutes. It was almost too fast. The external =
heat and the radiant heat from the firebox was a very good preheater. =
This is a great class project - allowing hands on, creative use of =
materials, and a nice intro to wood firing. There were several =
drawbacks: The access to the firebox is from the top and I lost my =
eyebrows pretty quickly by standing over the chamber. Many people would =
require firing suits. The kiln was always reaching low stoneware temps =
and this is pretty intense, however, with seasoned professionals or =
teachers, work can be cycled in and out very fast. Finally, it takes so =
long to get up to temperature that it requires an early start. We =
usually would start at 2:30 PM. Participants would arrive later with =
potluck supper. We did not start pulling until about 7 PM. The firing =
was slow till about 9 PM. At that time It was high speed and only the =
'die hards' were still standing till midnight. I have found that for =
teaching, night finishes are fun, but for my own firings I like to =
finish in the light as we have less accidents, like stumbling or =
stepping on the work.=20
The kiln was so successful that we built one for The Workshop in =
Cerrillos, NM, and fired it a number of times. Later, The Workshop, =
with UNM Ceramics, has built a small anagama kiln of about 180 cu feet. =
I'd like to think that the Raku kiln was a relative of the ancients who =
fired in the Galisteo Basin 400-700 years ago and then the anagama too =
is a distant relative, all descending from those potters who long ago =
supplied wares for the pueblo people.

Michael Lancaster
Studio 98B
Cerrillos, NM