Ugh! PItting, PInholing and CRaZiNg!!

I ran the kiln yesterday. I'm not surprised that of the two creative commitments I've sustained over life, ceramics is one of them; photography is the other. I used to stand in the dark room waiting to see what the final outcome of a print was. It took so many chemical experiments to get the right print quality and color. It wasn't like it is today with digital photography. I had to match paper contrast, to negative quality to chemical composition and printing techniques. I enjoyed the surprise and the science of it. Eventually, I had the science so down that I could get a print just the way I wanted.

Now it's ceramics. I'm not even close to understanding the complex science of it. I open the kiln like it's Christmas. Sometimes its an awesome Christmas, and sometimes, like today, it's a disaster! I had slaved over these pieces and they went into the kiln with big dreams-- looking entirely different from what they came out as. Luckily, I've recently learned how to throw on the mound like production potters do, so losing the original piece to glaze disaster is not as painful as it used to be.

Here are studio notes on today's kiln opening (Cone 5 glaze firing, incl. Laguna Hagi Porcelain and Aardvark Cassius Basaltic. Approx. 6 hr firing):



1) Blue and yellow yunomi. Hagi Porcelain. Cone 5. Laguna Clear Matte interior, and Laguna Versa 5 yellow and blue on exterior. Glaze surface ok but application is inconsistent. Versa does not run enough. Hagi cracked, which became apparent when I ran a liquid test on it. Crack was exposed through glaze.There is also some slight crazing in the yellow, which cannot be seen in this photo.




2) Cassius Basaltic Tea Bowl with Amaco Tenmoku glaze. I usually fire this combination at Cone 4 because the Cassius is very unpredictable, but this turned out great with Tenmoku. This glaze fires very predictably on Cassius, however does not usually fire as glossy at Cone 4, so I am happy with this experiment.





3) White Hagi Porcelain Yunomi with Mayco 2000 Series Natural Clear Glaze and black and neon chartreuse underglaze. Though usually a low fire glaze, the Mayco was recommended to me as useful mid fire glaze. Every piece that I used it on had serious pitting issues and some crazing. The glaze application may have been too thick, firing time may have been off and I'm pretty sure this glaze is not right for this glaze body, as there was also some pitting. I have to stay aware that Cassius was fired in this run, and there may have been strange reaction to any off-gassing from Cassius. Pitting can be seen top left edge of cup.




4) Hagi Porcelain sake cup with black underglaze applied with scratching inlay technique to greenware. Laguna clear matte overglaze applied on bisque. This is the only piece that came out as I visualized. No glaze flaws.



5) Hagi porcelain tea bowl with dark green foam underglaze and Mayco 2000 Series Natural Clear Glaze. This cup has the same pitting issues as the black and green yunomi.