Wood firing is done by a relatively small number of potters because wood kilns are labor intensive and sometimes not practical for highly populated locations due to air quality regulations. But what if you could get the results of firing in a traditional anagama kiln in a quick-firing, compact kiln that produces very little smoke? I’m thinking a lot more people might give wood firing a try.
In today’s post, an excerpt from Japanese Wood-Fired Ceramics, Masakazu Kusakabe and Mark Lancet explain the concept behind the Sasukenei Smokeless Kiln. Plus, we’ve thrown in a couple diagrams in case you’d like to build your own. – Jennifer Harnetty, editor.
The Sasukenei Smokeless Kiln features several unique characteristics. The finished pieces are of a quality associated with a much longer firing than in a traditional anagama kiln. The kiln fires almost effortlessly and quickly climbing naturally, sustaining high temperatures and achieving dramatic wood-fire effects in 24 to 36 hours. As the name implies, the Sasukenei Smokeless Kiln produces virtually no smoke during firing.
Kusakabe first became interested in smokeless firing when invited to build a kiln for Burnaby City in British Columbia, Canada. One of many requirements for the kiln was that it could not produce smoke, since the kiln was sited in a very populated area. Kusakabe met the challenge by producing Umbu (piggyback) kiln, a large, double-chambered, smokeless kiln.
The Sasukenei Smokeless Kiln begins with two features employed in the Umbu kiln: a large bourry box and a large chimney typically associated with bigger kilns.
The large bourry box is a double-chambered, downdraft fire box that burns efficiently. Wood is stoked in the top chamber and rests on a grate above the second chamber, which catches the ash and embers from the firing. Air drawn down trough the burning wood results in a fire that burns upside down.
The Sasukenei ware chamber is compressed and measures slightly larger than a cubic meter. The ash and firing effect also are compressed, and the results are dramatic and beautiful. Kusakabe’s insight here was that rather than spread ash and firing effects over a large kiln space to produce good wood-fire results, he would compress the ware chamber and concentrate ash and firing effects on in small chamber for dramatic wood-fired results.
Some of the subtleties found in larger kilns with longer firing cycles are less likely to occur, but the Sasukenei Smokeless Kiln concentration of ash and firing effects produces work so inundated with natural ash glaze that it appears to have been fired over 10 days, rather than the actual day and a half. In addition, work fired under the bourry box and in the flues leading to the ware chamber exhibits qualities unique to the Sasukenei Smokeless Kiln.
By comparison, the Dancing Fire Wood Kiln typically can be fired three to five times per year due to its firing cycle, wood and crew.
Another difference between the kilns is that the Sasukenei Smokeless Kiln ware chamber is less than 25 percent of the size of the combined ware chambers of the Dancing Fire Wood Kiln. The opportunity to fire more frequently and the range of effects unique to the Sasukenei Smokeless Kiln compensate for the size differences.
The ease of operation, stellar results and smokeless firing combine to make the Sasukenei Smokeless Kiln one that lives up to its name. Sasukenei is a work from the dialect spoken only in Miharu, where Kusakabe lives. It translates as “No problem!” or “No worries, mate!”