Sunday, August 27, 2023

Plated

Even though I attempted to keep notes on my pottery work, they are a bit cryptic. I made six plates for using under plant pots, but am having a bit of difficulty figuring out which notes go with which plates. The long delay in firing did not help, nor does my sieve of a memory.

The largest plate came first, I'm pretty sure, but I'm not sure of the clay base other than not stoneware. I used a Corelle dinner plate as a slump mold, but the first attempt cracked. The kiln tech suggested I add grog to the clay, which I did on my next try, but I also put a layer of newspaper between the clay and the mold. After the bisque firing, I glazed it with 'Latte' and 'Amber'. (I didn't make note of the glaze brand.)

Amber on Latte or Latte on Amber?

Next I made two more plates, using smaller Corelle plates as slump molds. They are stoneware. I left the imperfections on the surface, to see how they turned out. After bisque firing, I coated each with underglaze, one in 'Cinnemon' and the other in 'Medium Blue', both Amaco, then wiped them to reveal the imperfections. I skipped using a clear glaze over them because, theoretically the stoneware should be vitrified after a second firing. But the kiln tech urged me to reconsider, so at a (much) later date, I poured clear glaze over them. I wish I had taken photos of them after applying the underglaze, as by the time they were fired (five months later), I could not remember what they looked like beforehand.

Cinnemon
Medium Blue

Then I made two more plates, one from clay stained blue with cobalt oxide, and one that had the cobalt oxide clay mixed with unstained clay (light blue). (I assume all the clay was stoneware.) After bisque firing, I glazed the plates with 'Indigo'.

Indigo

I don't know why I decided to glaze these plates, as the cobalt oxide color was a nice light blue. I could have applied a clear glaze instead.

Cobalt oxide

There is another plate, one that I might have made before the dinner-plate sized one, as the colors are similar.

Amber and Latte again?

This post reveals several frustrations. One is my record-keeping, which is rather poor. Hence, this blog. Another is my ignorance. I know stoneware can be fired up to cone 10, but I don't know how glazes behave outside their designated cone numbers.

And a third is kiln frustration where I have my work fired. All the greenware is bisqued at a "low" temperature; glazed work may be bisqued at "low" or "medium" or "high". I don't know what cones apply to those categories. Is cone 5 low or medium? Then having the kilns inoperable for months is another issue. I can almost see a kiln in my future.

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