It is a momentous day. I have completed the first firing of my new kiln. What follows is a mildly technical description of the occasion.
Attila made time last night to help me setup the kiln, in the porch. The instructions state there must be 12 inches to combustibles. The stand provided with the kiln sits 8 inches high. After discussing the ins and outs of using a sheet of metal versus tiles below the kiln, we settled on the quicker solution, tiles. Ten 12 inch by 12 inch ceramic tiles were positioned on the wooden floor of the porch, in such a way that, once the kiln was placed on them, the wooden floor was 12 or more inches from the body of the kiln. We ensured that the kiln was 12 inches or more from any of the wood framed walls in the porch. Since the screened section of the porch will surround the kiln on three sides, ventilation is excellent. It is protected from the elements by the porch roof, and covered with a waterproof plastic sheet, held down by bricks, when completely cool. We will bring it indoors when it is not in use.
The first step this morning was to get out my notes, made while talking to Ian at Cone Art Kilns. Using the heavy-duty extension cord, I plugged in the kiln and the expected message, ErrP, flashed on the control screen. I began programming from the instruction sheet provided.
Ian suggested a first firing using the following schedule:
My first attempt to program the kiln was only partially successful. Segment 1 fired as expected, raising the temperature to just over 200 degrees in 57 minutes. However, the kiln flashed CPLt when this had been accomplished and did not proceed to Segment 2. Obviously I had not successfully entered the complete schedule, back to the drawing board.
I waited until the kiln cooled to 144 degrees (an arbitrary temperature), and entered the desired schedule once again, very carefully. After hitting Enter, I sat down with a book to watch and wait. Watching the first firing is informative. It is giving me a feel for how the kiln works. The temperature goes up a little, very quickly, then it slowly drops, then it goes up a little higher than before, very quickly, then it slowly drops, and so on until it reaches the desired temperature. In this way the temperature slowly increased over the time allotted for the firing segment.
My range oven will heat to 500 degrees, so I have some experience with a device heated to that temperature. Above 500 degrees, the kiln took me into new territory. As the temperature of the kiln began to rise, I enjoyed referring to the Kiln Firing Chart, found at www.potterymaking.org. It will take quite a bit of experience before this kind of information sinks below conscious thought. I am in no hurry.
At 540 degrees the exterior surface of the kiln is only slightly warm to the touch, I did not touch the surfaces of the kiln again during the test firing.
At 1300 degrees I checked the extension cord connections at the wall where it was plugged in and where the kiln was plugged into it. Both connections were very slightly warm to the touch, slightly above the temperature of the other surfaces in the room.
At the end of the firing process I could not find instructions in the manual to display the temperature as it dropped. I made a quick call to the manufacturer of the computerized unit on the kiln, where the telephone was answered immediately by a very knowledgeable fellow who quickly and clearly provided me with instructions, and I was good to go. It did surprise me how long it took for the kiln to cool, as long as it took to heat!
A very good experience all round.
|RECIPES :: Cast
The woodshed is full! Now we are stacking wood for the winter of 2008/9.
By the Easy Chair
The God of Small Things
by Arundhati Roy
"In the year she knew him, before they were married, she discovered a little magic in herself, and for a while felt like a blithe genie released from her lamp. She was perhaps too young to realize that what she assumed was her love for Chacko was actually a tentative, timorous, acceptance of herself."
The God of Small Things
by Arundhati Roy
Hot, over 30 degrees centigrade and sunny.
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