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breathing kilns (long)

updated thu 15 jul 04


mel jacobson on wed 14 jul 04


it has always been the case in america, when
folks build kilns, they plop the kiln on a hard surface.
in the old days we used a sheet of asbestos.

we needed to get a flat solid surface that would not
burn. concrete blocks became uneven, bumpy. and
of course, they had holes in them.

in many conversations with feriz delkic and nils etc.
it seemed that commercial ovens were actually
lifted off the ground...on wheels, or in a metal base/casing.

the claim is:

we have the kiln open on four sides and the top...and
squash the kiln on the ground. not good. this did not
make sense to me. i started to look for an alternative
base for the kilns i built. found expanded metal, went to the
steel yard...talked to the guys about it...and found the perfect
answer. my kilns are lifted into the air about a quarter of an
inch. air flows beneath them. they fire better, dry out in
wet weather better, and, i think, they are breathing from
the bottom. feriz says that they will fire faster and more
even. so far, he is correct. again, a bit of `seat of the pants
science`. problem, observation, action taken, problem solved.

it leads from my attitude that when you have a problem
it is best to take action. `or, hell, do something, even if it
is least you take action.` then you have something
to work against. to correct.
doing nothing never helps. kilns, firing, is like going to war.
if you just sit there, they are going to kill you. take action.

i have written on clayart many times about the call in the night.
`mel, my kiln stalls`.
`talk to me, how long has it been stalling?`
`14 years.`
`crap, add stack, take away stack, make your flu smaller,
make your flu larger, take away gas, add gas pressure.`.
do them all, one at a time`. take notes, see changes,
make changes.`

`well fred at the junior college told me in 1966 that my
kiln was just fine, don't want to mess with it`.

`call someone else please...goodbye`. if you are not willing
to take action....pee in the wind. scientific observation, wind
blows pee back on to your legs. turn around.

so yes, wheels, lifted kilns, itc spray on the inside, on fiber
on soft brick. on coils, smaller flu. 35 square inches, double
venturi, fiber lined metal stacks, fire paint, gas/electric kilns.
they all work. make for better pots.
and, that is the point. save fuel, fire better pots, do it faster.
better, less wear and tear on you and the kiln.
(like tony's story of the couple, man and woman that fired
the kiln in japan. no fuss, no rushing around, no noise.
add wood, sit down, add wood, observe, add wood, watch
the smoke. no yelling, no heat in the face, no mess.
they worked with professional grace and efficiency. i have seen
it many times.)

i could say without question. most folks fire with too much
gas. way too much gas. add air, it is free. get burners to
balance. gas/air/pressure/volume. most people just
want to boost the gas. i even mount my burners on high
pressure rubber hose. no noise. not a sound. no smoke
ever from my stack. the neighbors have never known when
i fire. never. no flames, no smoke.
keep that in the kiln. why waste it in the air.

it happened again at the farm. the salt kiln was firing away...
the gas pressure got turned up, about cone 9 the kiln stalled.
they turned up the gas. the kiln stalled more.
`mel, can you get us more gas, are we running low?`
sure...up i turned it. smiled. stalled more, then we,
without putting them down...turned the gas pressure to
12 pounds...from 26. cone 10 dropped like a 5 minutes
it began to move. cone 11 was dropping in 25 minutes...kiln
done. what happened? we got balance. up she went. all the
back pressure from too much gas was strangling the kiln. it
did not work. it is like hank murrow's wonderful lift up
kilns. smooth as glass, well thought out, quiet, everything
in balance. a total beauty. but, then....look at the source.
thoughtful, intelligent man. looking for perfect balance.
art/science/observation/craft. the most perfect balance
in the world.

Minnetonka, Minnesota, U.S.A.
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