Trabka, J Christian on wed 12 jul 06
I had taken a few classes in clay during high school and college.
But in the '70s there was no facility near by and I did not have=20
the resources to build a studio. Finished college (software=20
engineer), got a full time job and started a family. My wife,=20
knowing how much I liked clay suggested I sign up at a near=20
by studio in Los Gatos, CA in 1990. Two years later, I am=20
helping the "new" students and experimenting with glazes;=20
unfortunately not firing the kiln.
One frustrating year later, I located a small updraft kiln.=20
She had been sitting outside for years, grass was 6 inches=20
high on her roof. She was perfect, $300! Got her home,=20
pulled out the weeds, cleaned off the rust and hooked her=20
up to gas. It took 3 bisque firings and 2 glaze firings to get=20
all the water out of her. The first logs were detailed, entries=20
every 30 minutes writing about how she sounded, the color,=20
the cones (no oxyprobe). As time went on, I learned how to=20
fire the kiln. After each firing I looked at the pots and re-read=20
the log entries; consulted all the "authorities" on firing (Rhodes,=20
Nelson, Parmelee, Cardew) and considering what to do for=20
the next firing. After about 2 years of experimenting, I could=20
finally get consistent colors - good copper reds and rutile blues.=20
I still kept the log, but the entries were getting shorter; the start=20
time and the time for each cone to drop (015, 06, 6, 8, & 10).=20
In the last three years of firing the times between cones were=20
very consistent (start at 3:00pm, cone 015 at 4:30,=20
cone 06 at 5:30, cone 6 at 8:00, cone 8 at 9:00, cone 10 at 9:30),=20
as were the glazes.
We moved to Michigan in 1995 and I decided not to move the=20
kiln. I wanted a car kiln and built a MFT. Since I KNEW how=20
to fire a kiln I knew there was going to be a short learning curve=20
(old kiln 12ft^3 updraft, new kiln 32ft^3 down draft). Was I in=20
for a surprise; it occurred one sultry August evening. The kiln had=20
been on since 7:00 am, it was 11:00 pm and cone 6 was just=20
starting to fall. Cone 10 finally fell at 3:00 am. The next day I=20
considered the differences in kilns and their locations=20
(CA with 15% relative humidity, MI with 70% relative humidity).=20
I needed some better information about what was happening=20
inside the kiln. The oxyprobe arrived the next week. Over the=20
next year I discovered that when it is crisp and dry outside I=20
can use 3" to 3.5" of gas, when it is sultry I can only=20
use 2.5" to 2.75" of gas. The firing on a sultry day is a bit=20
longer but the cones look the same. Again the logs are getting=20
shorter, but the firing times are about as consistent as the=20
weather in MI.=20
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