raku firing fail
Dec. 18th, 2010 11:29 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
jinianI am catching up on posts, but don't get too excited -- the raku firing did not give me a beautiful raku-ware pot. The process was great fun, though.
Here's the furnace. It has a jet of burning propane shooting in at the bottom, but the outside is almost cool enough to touch. We were all very impressed with the insulation.
We peered through the holes in the furnace to watch for glaze liquefaction. When we saw it in the uppermost pieces (all we could see), the instructor turned off the fire and opened the furnace with a long metal stick. We were ready, some with long metal tongs and some poised to open the trash cans full of paper. Part of the coolness of raku is the random effects caused by the burning carbon the pieces are surrounded with; often sawdust is used, but the studio customarily uses newspaper. I didn't get any photos of the glowing orange pottery because we were all so busy, but here are some shooting flames!
We closed the cans to encourage slow burning of the carbon and let the pottery cool. Wet towels helped keep the smoke from killing us all.
Maybe 45 minutes later, we had our pieces out. They were cool enough to handle with just thick gloves by then. Sadly, only a couple of pieces had been fired properly. Most of the glazes didn't melt. Very disappointing! On the left, what it's supposed to look like; on the right, my piece.
The woman who made the pot on the left said that she'd been pointed to raku glazes by the studio manager and glazed at a different time than most of the class, so we think that she used the current run of glazes and we used another set of old ones. Usually you do want to fire multiple glazes together, so they're designed to work, but we were using formulations from different areas of the studio and ours must've needed more heat than hers. No one felt like redoing the whole process that night, so I'm not sure what will become of my little pot. I could probably wash the glaze off and do a regular firing, or just save it for a future raku firing and make sure it's on the top.
I'm signed up for a class called "Altered Forms" next quarter, since this was so much fun. Cutting up wheel-thrown stuff and combining it with hand-building sounds awesome. Maybe next quarter I can find my leaf bowl -- it still hasn't shown up, and I'm starting to be worried that someone made off with it. (At least that would imply that it turned out well...)
Here's the furnace. It has a jet of burning propane shooting in at the bottom, but the outside is almost cool enough to touch. We were all very impressed with the insulation.
We peered through the holes in the furnace to watch for glaze liquefaction. When we saw it in the uppermost pieces (all we could see), the instructor turned off the fire and opened the furnace with a long metal stick. We were ready, some with long metal tongs and some poised to open the trash cans full of paper. Part of the coolness of raku is the random effects caused by the burning carbon the pieces are surrounded with; often sawdust is used, but the studio customarily uses newspaper. I didn't get any photos of the glowing orange pottery because we were all so busy, but here are some shooting flames!
We closed the cans to encourage slow burning of the carbon and let the pottery cool. Wet towels helped keep the smoke from killing us all.
Maybe 45 minutes later, we had our pieces out. They were cool enough to handle with just thick gloves by then. Sadly, only a couple of pieces had been fired properly. Most of the glazes didn't melt. Very disappointing! On the left, what it's supposed to look like; on the right, my piece.
The woman who made the pot on the left said that she'd been pointed to raku glazes by the studio manager and glazed at a different time than most of the class, so we think that she used the current run of glazes and we used another set of old ones. Usually you do want to fire multiple glazes together, so they're designed to work, but we were using formulations from different areas of the studio and ours must've needed more heat than hers. No one felt like redoing the whole process that night, so I'm not sure what will become of my little pot. I could probably wash the glaze off and do a regular firing, or just save it for a future raku firing and make sure it's on the top.
I'm signed up for a class called "Altered Forms" next quarter, since this was so much fun. Cutting up wheel-thrown stuff and combining it with hand-building sounds awesome. Maybe next quarter I can find my leaf bowl -- it still hasn't shown up, and I'm starting to be worried that someone made off with it. (At least that would imply that it turned out well...)
