Monday, February 16, 2009

More Practice, Tough Lessons

I haven't been thrilled to make this post, because I'm not horribly pleased with my time in the studio this weekend. If you'll recall, I had a very productive Thursday evening, and I was excited to move forward with my section-thrown piece. Well, it didn't go that well.

I did decide to throw a new bottom section, which was a good choice - the new one was 2-3 inches taller, and was not much more than 1/2-inch thick most of the way, which is a good thickness for something which will need to support weight. Unfortunately, the original top portion was not so cooperative, on a number of levels.

First, it had firmed up too much since I last worked on it - I failed to wrap it thoroughly in plastic on Thursday. It was still soft/moist/plastic enough to bond the two pieces, but it was too far gone to do any further shaping.

Second, the top portion was not so swell, throwing wise, as I thought it was to begin with. It too was significantly thicker on the bottom than it should have been, making it heavier, and also causing it to not line up very well with the bottom portion. (I'm thinking a pictorial narration of my next section piece may be in order - this verbal walk-through is already confusing me).

In any event, the piece was in the neighborhood of 21 inches tall - with the amount of clay that was in it, another 2 or 3 inches would have been preferable. I scrapped the clay, which is now waiting for a second shot at it. The upside is that the entire process gave me plenty of time to practice centering and throwing cylinder forms. In retaliation for my piece's unwillingness to cooperate, I threw two lovely little vases, which i forgot to photograph, but which are quite lovely, and uniformly thrown, with just the right amount of weight left in the base.
It was a gentle reminder to me that it's continually a learning process, a practice, and every failure is very educational, if I take the lessons from it. So, pros: practice throwing cylinders, technique-honing experience, reminder of fallibility and humility. Cons: nothing concrete to show for my efforts.

The rest of the afternoon was spent doing some trimming and decorating of my little teacups/tumblers, seen below. The one in the middle is not part of the set - it's a separate mug, a giant among teacups.

I also had to do some general housecleaning stuff with my studio space, including moving dry greenware off of my shelves and into the firing area, and sorting/shelving my bisqueware that came out of this week's firing. I've decided, in an effort to reduce costs, not to glaze fire anything unnecessarily through the month of February. Bisqueware stores just fine, and I'll be happy to wait and have just one large load of glazing to do at the beginning of march.

Here's some greenware ready for firing. It has to be bone dry before it's ready for firing, that is, minimal water left in the clay. Any water left in the clay can become a problem in firing. Like all things clay, the variable circumstances make the difference. The most common problem comes from firing clay that is too wet too quickly. If fired slowly enough, the water in the clay should steam out slowly and pose no threat. However, if the firing moves too quickly, the water in the clay will boil, expanding rapidly in an attempt to escape the clay and that's when pots expode. It's not fun. Not fun at all. Well, you can get some good stories from it, but opening your kiln and discovering that an entire shelf of work is kaput is no good. Therefore, it's better to be safe than sorry. These bowls are from the last couple weeks, and are nesting nicely.

Pots can be nested (stacked) for the bisque firing, which is nice. You can fire more "stuff" in the same amount of space, which cannot be said for glaze firing. The reason is this: glaze is sticky stuff. Glazed surfaces will stick to anything they touch in the firing, so pieces cannot be stacked, and also must have more clearance room in all directions to avoid any contact during the expanding and contracting of the firing process. Like exploding pottery, this is also rarely fun. But the bisque kiln can be nested. Cram that sucker full. And make sure the pots are dry, or everything crammed in that tight space will be clay crumbs.

Check out last week's big bowl above. It's good and dry. I did have an interesting experience with a bisque piece this weekend, but I'll need a picture before I go into it. After trying to describe the failure of my section throwing, I'm pretty hesitant to describe anything without pictures now. So there.

And now, just for fun, here's a little bowl I threw with the last of my Calico clay. I'm not sure I'll be buying any more, as I'm not such a fan of the shrinkage rate, but it also is pretty fun to work with in larger bowls, so we'll see. I think it's a cute little bowl. And that yardstick is in inches.

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