Here are some pictures from the first pottery demo conducted during the Workshop in Taku, 2012: The Simple Teabowl. Tsuruta Sensei’s demonstration was conducted over the course of two mornings. He did all of his work on a small kickwheel, focusing on handbuilding techniques for teabowls, cups, flasks, and water jars.
The first day he demonstrated coil built bowls, cups, and a flask. The second day he trimmed the first day’s pieces, and demonstrated the coil and paddle water jar.
Thank you Kim and Minna for all of your great photos!
Unloaded the kiln yesterday and started cleaning up some of the keepers. This firing was good. A lot of keepers, some refires, and a few hammers.
Here are a few of the pots that are at least partially cleaned up and ready to go.
Here are some of the last pots to be made for the upcoming firing. Katakuchi (spouted bowls) and guinomi (small drinking cups).
The katakuchi are made from 3 blended clays, with added sand and crushed porcelain stone. I got lucky with the clay for the guinomi, clay gathered from a roadside cut more than 10 years ago by an in-law. It was really nice to throw with, and trimmed like a dream. This was the last of it, so I’m really hoping to get some keepers.
The spouts are really simple. Just a lump of clay smashed out with your thumb against the palm of your hand, then attached to the pot. If you look closely you can see the creases of my hand in the undersides of the spouts.
I realized that I tend to post pictures of unfinished work more often than not. I’ll try to remember to post pictures of the finished pots after the firing, if they come through it ok.
Karatsu potter Okamoto Sakurei just ended a show in Fukuoka this weekend at Gallery Ichibankan. For those of you who haven’t heard of him, Okamoto san is a very talented artist making Karatsu style wares. He is well known throughout the country and one of the top Karatsu ceramic artists today. He will also be doing a demonstration/lecture for the Workshop in Taku 2012: The Simple Teabowl.
During my visit we had a chance to discuss his upcoming presentation, as well as some wood firing diagnostics. Here are some of the pictures from the show. The gallery used a lot of natural light from its windows, which made for a very nice display, however it was not so camera friendly.
Who got the twisted James Taylor reference in the last post? Sorry about that, physical anthropology humor from a previous life.
Anyway, a friend came over yesterday and gave me a crash course in plaster casting. In one of his previous lives, he was a dental prosthetic technician and did casting in various materials for a living. My knowledge of plaster handling and casting jumped about tenfold in 4 hours.
We poured the mold similarly to before, with a couple of differences: he applied whipped cream consistency plaster to the backs of the originals, let it set, then turned them over and planted them in a freshly poured base, so the working side was face up. We cleaned up that surface in running water before it set completely, then applied separating agent and poured a different colored super hard type of plaster over the working surface of the originals. Then we leveled everything off with regular plaster. Mold finished.
Once completely set, I took the mold and soaked it in hot water for an hour to let it absorb as much water as possible, which helps the separating agent to work, and also keeps the plaster from absorbing liquid from the resin mix, which keeps the resin more fluid. Once the separating agent was applied to all surfaces, I put the mold together and tied it with old bicycle tire rubber, stood it up and poured in the resin. Then after letting the full mold sit for about 15 minutes, put it in a 50C bath for 30 minutes to cure the resin. This time I literally used the bath, and set the hot water temp for 55C. Much easier than a pot on the stove.
Once the curing was done, I let the mold cool, popped it open (which was easy with the proper separating agent) and out came two very nice gyubera. After trimming off the excess, and sanding them with a flap wheel and some 180 grit wet paper, they were finished. Victory! There were some small air bubbles but nothing like before, and the mold is in great condition for next time.
Here are some of the first pots to get cleaned up after the firing last week. I’ll post more over the next few days as I get things cleaned up.
Overall the firing went well, much better than the first two certainly. I’m finally starting to get a grip on how the kiln climbs, and learning not to worry about it too much. We fired both chambers this time and it took roughly 30 hours. Cone 10 flat in front, cone 9 touching in the rear, and cone 13 almost touching in the second chamber. The second chamber is a pleasure to fire, very relaxing after stoking the front. I think I can still get more aggressive with the front, taking the temp up even more, probably somewhere around cone 12 would be good for the rice straw ash glazes.
The intention was to drop cone 6 in the rear and call it quits, but it ended up getting hotter than expected, and the ware in front ended up a little too shiny. However, the middle and rear of the setting came out just about perfectly. Temp from top to bottom was quite even. We stopped stoking the second chamber when cone 11 dropped and clammed everything up after letting some of the excess heat out. Still, when I peeked in the next morning, that second chamber was still glowing, and cone 13 was mostly down. Guess that 1250kg of insulating castable does its job well.
Most of the failures this time around were caused by bad glazing, not the firing. Rice straw ash glazes were universally too thick, and an ash glaze I whipped up hoping to be a nice runny green ended up being a crusty reddish brown. Oops.