Over the weekend, I fired my first glaze load in EUP's Soda Kiln. The firing wasn't absent of the usual anxieties of firing an atmosphere kiln, but I was firing tall figures that were made of earthenware. For the soda ash to collect on the pieces as a glaze the kiln must be fired to at least cone 01 ( I have been told Cone 1 too). I was feeling like the temperature would put too much stress on the figures, and my worry was somewhat right.
As I was peering into the kiln, I was keeping an eye on a 34" standing figure and made mental marks of the inside of the kiln in relation to the profile of said figure. The mental mark and the profile seemed to be getting closer together, but I kept firing. The piece was indeed starting to lean, and in fact the figure was leaning a couple of inches past the mark I had chosen inside the kiln. The kiln wasn't hot enough to melt the soda ash at that time. Was I to turn the kiln off or keep ramping up until it reached temperature? Well, I noticed that the tall figure stopped leaning because it came into contact with a support post that held another figure up. That gave me a bit more time, but I didn't want to chance affecting anything else in the kiln. At this point the cones showed that the temperature was a couple cones behind, but I was skeptical of the reading and figured that deeper in the kiln was hotter than where the cone packs were next to the door. I started spraying in the soda solution. I put some in the two front ports and peered in. Suprisingly, the work had a slight sheen to it, which meant that the soda was volotizing.
I kept spraying in soda for the next half hour and shut the kiln down 5 minutes after the last spray. here are images of the results. The work was pretty dry where the Terra Sig was but pretty juicy on raw clay.