SatokoBarashCeramics

Clay, Fire and Hands

 

Atmospheric firing is time consuming, especially wood-firing. It is physically demanding; splitting wood, grinding shelves, sanding pots and so on. We also lose sleep during firing, because it takes two people to stoke wood around the clock to keep the fire going.  Salt or soda firing in a gas kiln is less demanding, but still a lot more work than electric or non-atmospheric gas high-firing.  The shelves and posts still need to be ground after every firing and each pot needs to be wadded while loading to prevent them from sticking to the kiln shelves.

Compared to non-atmospheric firing, I'm much more intimately involved in the firing process.  So, it seems ironic in a way that I don't have much control over the final surface of each piece.  Each firing is different and a piece is one of a kind.  I may get something similar from a different firing, by using the same clay-body, slip and glaze, but I cannot duplicate a work identically.  I love the surface created by the vapor dancing through the kiln and around the pots. I enjoy loading while imagining and attempting to influence the way the vapor flows between pots and goes out the flue. I see beauty in my piece as well as in friendship that develops around firings. 

 Soda/Salt kiln at my house

Salt firing dates back to mid-fourteenth century Germany when salt-impregnated wood was used for firing, taken from barrels formerly used for storing salt herring. An attractive natural glaze forms when salt or soda chemically interacts with the clay at high temperature. I spray 4 lbs of soda ash mixed with hot water 12 times each in four different soda ports, for over 90 minutes, when the temperature of the kiln is around 2200 degrees. I also place about 12 salt cups here and there on shelves closer to the door of the kiln, where the soda vapor doesn't reach. I only use 4.5 ounces of rock-salt in a firing. The firing continues till the temperature reaches about 2350 degrees, but the decision to shut off the kiln is guided by the movement of the colored cones pictured in the lower right corner of the photograph above. 

The result is a combination of a subtle salt glazing in the front of the kiln and more dramatic soda surfaces in the back of the kiln. At my studio, I form my work, either wheel thrown, hand or slab built.  Then they are fired to 1830 degrees in an electric kiln, called "bisque-firing."  When cooled, glazes are applied to the interior of the pots.  The outer surface is either unglazed or has a thin coating of a "slip," or liquefied clay.  Flashing slip is a particular type of slip that reacts with the atmosphere in the kiln and creates the deep orange surfaces, also allows the clay surface to more effectively catch the footprint of the soda/salt vapor traveling through the kiln.  Brush works, with Japanese calligraphy brush, may be added to the work after the slip is dry.

Since the beginning of 2007, I transported my work, following bisque-firing, for salt and soda firing to the Mendocino Art Center.  In 2008, I built a soda kiln in my yard with the help of Doug Browe (the head of the ceramics department at Mendocino Community College) and other potters in our community, who were participating in a kiln-building class at Mendocino College.  Many thanks to my firing friends and supportive patrons.