My good friend Carolyn invited me to come to her school last month to be a part of an amazing Raku project. She and her co-art instructor at John Hay Elementary School had arranged this project with Seattle Pottery, who provided the special glazes and all of the equipment for the firing. Every child at school (and some adults) made a piece of pottery for the project. They had a whopping 500 pieces of pottery to fire! They were all done in two long days.
Setting the scene -- this picture gives you a good overall idea of the set-up... in the corner of the school playground! Across the street you can see the old Queen Anne High School, which is where my dad went to school. (That school building has been turned into condos.) You can also see one of the three huge broadcast towers that are on the top of Queen Anne. What an awesome urban setting!!
Here are some of the ceramic pieces that are ready for the kiln. Lots of cute pinch pots in this batch! Carolyn and her co-instructor had already fired them in the school kiln and then the kids glazed their pieces. They were able to choose from White Crackle, TZ Copper, or Dolphin glazes.
Here's another view of the overall setup, with the kilns, the metal cans, wet towels, and plastic buckets full of crumpled up newspaper. That's Eric from Pottery Supply. He ran the operation.
Pottery Supply makes and sells these outdoor kilns. Potter Eric pointed out that they've made improvements over time, including putting a couple little wheels on the bases for portability. The top is like in inverted glass. It's made of kaol wool in a cage.
Glazed pieces were arranged on the single shelf at the bottom of the kiln.
The kilns were heated by a propane torch. Several firings could be made from one standard (backyard BBQ-sized) propane cylinder.
The flame fits in under the shelf, and the top part of the kiln is lowered down to close it up.
A digital pyrometer is used to keep track of the temperature. 1850 was the magic number. In this shot you can barely see orange flames coming out of the hole in the top of the kiln.
Meanwhile, Eric had an assortment of metal cans with lids that we would use for the Raku/reduction part of the process. My understanding is that you put the red-hot ceramic pieces into the metal cans filled with combustible material that you can seal. The combustible materials burn and the special glazes that were painted on the pieces do strange and magical things in the absence of oxygen in the containers.
Helpers are ready for Eric to transfer the hot pieces from the kiln.
Of course, the hot ceramic pieces immediately ignited the newspaper. A few/several pieces of pottery would go in each can, with a well-orchestrated addition of newspaper occasionally.
When a can was "full", the lid was slammed down and the cans were covered with wet towels to help seal them. They would hang out and cool for a while. The pieces were still pretty hot when Eric removed them from the cans, but they cooled quickly when set out on the pavement.
Carolyn is ready for the first piece of another batch, waiting to add the first of the newspaper when Eric gives her the word.
A hot piece being added to the can.
Nice shot of the flaming can!
Can is shut and ready for wet towels.
What a successful day!! Two of the glazes made amazing multi-colored metallic-looking finishes. One was glossy and one flat/satin with a strange bumpy texture in some cases. The third glaze was White Crackle. Eric had to blow on those ones before he transferred them into the metal cans. That way the glaze would craze (crack), and those little cracks would become black from the smoke in the cans. Any part of the pieces that weren't glazed turned black, which would be a fun detail to work with when glazing a piece....