February 21, 2011

Reduction Pit Firing Seminar

This weekend marked the culmination of our first team taught seminar at Radcliffe Street studios in Eutawville, South Carolina. The seminar consisted of two all day Saturday classes in the production of volcanic ash pinched and coiled vessels, tile carving, slip burnishing, surface decoration and a reduction pit firing. All materials were supplied along with a free lunch and a coffee break with a vast array of home-made desserts thrown in as well. Students could partake of everything for the very generous bargain price of $135.00. I do believe that it was quite generous. But we really wanted to do this.

Because this was a new venture for my colleague and I, there were successes, wonderful discoveries and... well...learning curves to navigate around. The carving of the vessels and tiles in Santa Clara style was a great discovery for me and a joy for our students. The heavy, non-plastic clay was highly suited to carving - with effects that looked like sculpted sandstone. The sandy quality of the clay also left clean well defined cuts. So we counted a merit point for carving and a must do for the next seminar.

Jeri Burdick provided a variety of traditional slips to cover the pottery with as well as terra sigillata. One of the slips, a red iron oxide slip that was made from a recipe that I got from the Pueblo Tewa potters, unfortunately didn’t “take” and tended to flake off in the burnishing process (which should have been a strong hint for me to dispense with it altogether) then delaminated completely after the firing. The most successful slips were the two terra sigillata ones - a white and a yellow ochre. The yellow ochre had been freshly mixed but the white was Jeri’s very big-hearted donation of a vintage slip that had been aged ten years. Aged slip to a potter is like a rare vintage wine to a connoisseur. It was a good thing that Jeri had discovered this because if it had been me I probably would have hidden and hoarded it - maybe even put it into a safety deposit box. The slip was really like butter and it burnished to a sheen just by rubbing it by hand on the vessel. We did the traditional thing, however, and burnished the slip covered vessels with polished rocks. ( I still have not discovered the quintessential burnishing rock for my pots yet. The rocks have to be truly smooth and free of flaws. These are difficult to find among commercially prepared polished pebbles so I sometimes resort to polishing with a spoon ).

The kiln we prepared this past weekend was most definitely the prettiest one yet but there were some spaces that caused the flames to oxidize a significant number of wares despite our valiant efforts to reduce everything with a ton of cow manure - also Jeri’s contribution (Should our next seminar be a bring your own bag lunch and box of manure?) We didn’t find this out, of course, until our Sunday morning opening of the kiln.

There is nothing quite like an early Sunday morning opening of a pit-fired kiln full of lovingly produced goods. The photograph above shows the pottery contents in the kiln with the metal lid just removed There were about four explosions - two of them my own tiles. Under any other circumstance I would have been disappointed. But when teaching a class, better your own work doesn’t make it through the fire than your students’.

Unlike our earlier test firings, the burnished wares were for the most part just barely reduced - as evidenced by very little blackening. The brilliant thoroughly blackened exceptions however were the small solid pieces placed inside the upside down cans that were used as shelf legs in the kiln. (Obviously there was all smoke and heat with no fire in those.) Hiding small animalitos figures in the cans was a technique used by the Santa Clara Indians to blacken the highly burnished slip. The biggest surprise from beneath a can and one which caused me world class covetous envy was a hand modeled shark tooth sculpture that Jeri had made and burnished with the aged terra sigillata mixed with a secret ingredient in her portion - copper oxide. The copper caused the perfect hints of iridescent colors to bounce off the polished black tooth. Though forged in a can, the shark’s tooth looked uncannily like the real thing and we joked that Jeri could now have a fossil shark tooth forgery business. ( From the point of the can discovery onwards I have been looking at canned goods differently - not by the contents but by the size and shape of the can. I imagine a tile in a tuna can and perhaps several statues neatly tucked inside a cafeteria size can of fruit cocktail. It doesn’t matter what’s actually in the can. I might have to eat it just to get the can. Even if its Boehner’s Baked Beans and Wieners economy size I might have to eat it. So be it).

Another pleasant surprise for me was that although the firing didn’t reduce as well as earlier ones, we believe that the temperature climbed higher than in our previous firings. The w idiophone musical instruments that went through this fire developed a higher pitched ring than my previously fired ones. This better vitrification was more suitable, too, for instruments that had parts that rattle or click against each other.

Although we didn’t plan to extend our seminar into Sunday afternoon, we had a few people who had bunked down in Eutawville join us in cleaning the vessels and applying butcher’s wax to those that were more porous. The photograph to the left shows one of my small pit-fired vessels after it has been cleaned and polished. And wouldn’t you know it? I discovered the unfired lid in the bottom of a box after the firing. I guess this means a second firing of goods so I can toss in the lid.

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