Wednesday, August 5, 2015

Cone 6 at home

My kiln goes to cone 6! It's an old kiln that I got as a hand-me-down and I've never actually tried to fire it this high. Cone 6 is about 2232 degrees Fahrenheit or 2269 if you fire faster. I don't have pyrometer at home, so I'm not sure how fast I fired the kiln.

cone 6 glaze tests with underglaze and several different glazes 

I usually fire my home kiln to cone 04 which is just 1945 -1972 degrees Fahrenheit. The lower temperature requires glazes with a lower melting point and even clay with a lower vitrification point. 

cone 04 glaze on the left, cone 6 glaze (fired at Archie Bray) on the right

For the Archie Bray workshop I attended earlier this summer, we used cone 6 clay and cone 6 glazes. Now I have quite a few bisqued bowls and cups made with this clay. If I were to fire the cone 6 bowls with cone 04 glazes, the bowls would be likely to leak because the clay body would still be porous.

my little old kiln

So, I purchased some cone 6 glazes with the idea that I can fire these pieces to a higher temperature and, at the same time, experiment with some more glazes. I keep seeing semi-transparent celadon glazes used by nationally recognized artists, including those at the the Archie Bray, and even local artists (Bernadette Trabue Crider has carved celadon pottery at Oak Hollow Gallery in August).

my cone 6 glaze options

So I purchased two types of celadon, one that is green, another almost clear. I also purchased some darker pre-made glaze samples and I used my trusty underglazes. The nice thing about transparent glazes is that I can use my underglazes in combination with these glazes, which means I don't have to make hugely significant changes in my glazing process.

not a very full kiln

For this firing, my kiln was loaded very loosely. Since I didn't know if the kiln could actually reach this temperature and I had never used these glazes, I didn't want to glaze a bunch of pieces and have everything fail.

the cone in the sitter after firing

Happily, the firing went well, the cone melted in the sitter and the glaze tests came out just fine, everything melted well and the colors were basically good. Now it's time to get down to work and really glaze the remaining work. I have about one kiln load of low fire work (cone 04 clay) and about two kiln loads of cone 6 work. I have begun glazing the low temperature work, but not the high temperature work.

cone 6 bisqueware on the left, the mess that is my glazing process on the right

1 comment:

  1. you will have lots of fun with your new glazes...


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