Friday, February 20, 2009

Dinner Break Update

It was time to eat some dinner. I'll head back into the studio for another couple hours when I'm full, and this time it'll be for some throwing. But throwing on an empty stomach is as poor choice; throwing takes a lot of physical exertion, and if I want to tackle a couple large pieces, I need to be filled up and focused.

The first leg of the evening's work was to deal with the clay I recycled. All 38 pounds of it. Here's a picture of 38 pounds of clay.
After it's been "recycled," it needs to be kneaded. Kneading the clay has two primary purposes: to homogenize the clay, and to remove all air bubbles/pockets. Here's a bisection of the clay displaying some lovely unwanted air pockets:
Those little streaks in there are the air pockets. They look small, but small bubbles cause big problems in the throwing process. Because an air bubble is not the same density as the clay, it becomes essentially a lump (lumps of hard clay are also removed in the wedging/kneading homogenization process) in the clay. With every pull in the throwing, the air bubble will push the piece ever off-center. Even if an air bubble does not cause any problems in the throwing, it will increase the chances of something exploding in firing.
I knead my clay using a double-ram's horn method, so-called because of the shape made by the kneading motion. Here's my ram's horn:
That's a decent picture, I guess. The horn is created when the mass of clay is rolled over the table surface while applying pressure both inward and downward. Applying the pressure in two directions simultaneously is what removes the air bubbles, squishing them with the pressure, rather than just moving the bubble around with in the clay.

I generally will knead about 10 pounds of clay at a time. It seems to be a nice amount to work with to be efficient without being too much clay to handle. Here's the finally kneaded clay, sans air bubbles. Nice and smooth, huh?

Finally, I got to actually work on some pots - trimming and doing some final shaping on the two vases thrown last weekend. All told, I was able to trim about 2 pounds of clay off, between the two of them. Both by necessity of achieving the desired shape, and also to remove some unnecessary weight from the base. In the end, trimming a pound of clay out of a vase is not too bad, and I'm pretty pleased with the shape I'm getting. Here's the two vases.

The one on the left has not been trimmed at all, and the one on the right is mid-way through the process. They stand about 10 inches high and perhaps 7-8 inches at the widest. I've since applied some slip, and they'll be ready to decorate when I get back into the studio.

I'm off - I'll give a final update when I return. As always, if any of the process was confusing, or you have a question about my working methods, leave a comment. I'd love to have an idea what my readers are looking for, content-wise. In the meantime, I'll just keep writing whatever I want.

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