First firing wrap up
28 August 2007 Leave a Comment
The terra sig I made up last week and fired this weekend didn’t turn out like I expected. The color is nice, a really creamy white, but I was hoping for a pure white. I know I put together a bright white a few years ago; apparently I didn’t right down the recipe where I could find it again. The texture was also a bit disappointing. There seemed to be a lot of large particles in the sig, which surprised me. I thought I was really careful when siphoning off the settled mixture.
My next sig will be an XXSagger (this one was a Gold Art). I may try and get my hands on a different deflocculant too. For the Gold Art I used epsom salt, which seems to be less favored among potters who use terra sigs than some other things.
Sunday I tried smoking the terra sig. I couldn’t find the instructions I wanted, the ones I read on how to do this a few weeks ago. I started with the largest piece of the work which blew up in the firing. I laid some butternut squash peels, corn husks and newspaper over the shard and wrapped it in tinfoil. This is what came out:

The dark brown, glossy areas are the burned out red underglaze.
I turned the lower section of the kiln on medium and checked the tinfoil saggar at half an hour. When I looked in I saw the the second element up from the bottom was not hot. I’m not surprised one of the elements is bad on a kiln this old. The elements themselves are pretty crusty. I called Euclids for a quote on new elements, which will run me about $140 ($38 for four elements, minus a 10% discount for buying a full set). I also learned while talking to the element man that my kiln — a Knight model 103 according to the kiln itself — is missing a section. Model 103 is supposed to have three sections; mine only has two.
I don’t know if I can spring for the new elements right now. The kiln still made it to cone 04, although probably in a very inefficient way. I’ll be eager to see our electric bill this next cycle. After test firing our bill wasn’t any different than normal. This first firing, however, took a lot longer.
Correction: It appears all of the elements actually do function. I’m smoking some more of the terra sigs today and noticed the questionable element was red. Apparently, as I read a couple weeks ago, the kiln’s bottom element fires up before the second from the bottom in order to heat the kiln more evenly.
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