Sue Leabu on mon 27 oct 03
On Tue, 28 Oct 2003 08:57:31 -0500, clennell wrote:
>I'm finding atmosphere really effects the one I use. It is a lovely
celedon green in the woood kiln and a boring matt yellow in the gas kiln.
Hi Tony,
This is ancedotal at best, but something that's made me go "hmmmm..."
regarding wood ash.
This past February, I fired two loads of shino in a gas kiln. Same kiln,
same glaze, same firing schedule. Both times, I sprinkled unwashed mixed
ash onto wet shino. Ash from the same bucket that had been seived
previously, no new ash added between firings. Result of first firing:
nice "coke bottle" green glossy runs. Result of second firing: brown and
yellow matt runs. The only difference in the firings was that the first
time around, I forgot to close the damper at the end. It was a very cold
night, and the kiln cooled off very very quickly. (So fast that I was
afraid I was going to have a nice bunch of cracked pots inside.) Second
firing, damper was closed immediately at the end of the firing, and the
kiln cooled much slower. Makes me wonder what the rate of cooling does to
ash and ash glazes....
Sue
Kalamazoo, MI
Hank Murrow on mon 27 oct 03
On Monday, October 27, 2003, at 11:40 AM, Sue Leabu wrote:
> This past February, I fired two loads of shino in a gas kiln. Same
> kiln,
> same glaze, same firing schedule. Both times, I sprinkled unwashed
> mixed
> ash onto wet shino. Ash from the same bucket that had been seived
> previously, no new ash added between firings. Result of first firing:
> nice "coke bottle" green glossy runs. Result of second firing: brown
> and
> yellow matt runs. The only difference in the firings was that the first
> time around, I forgot to close the damper at the end. It was a very
> cold
> night, and the kiln cooled off very very quickly. (So fast that I was
> afraid I was going to have a nice bunch of cracked pots inside.) Second
> firing, damper was closed immediately at the end of the firing, and the
> kiln cooled much slower. Makes me wonder what the rate of cooling does
> to
> ash and ash glazes....
Hey Sue;
Now just amend that last sentence to read,
"Makes me wonder what the rate of cooling does to all my glazes.......
"
and you'll have a question big enough for a career's worth of firings!
Cheers, Hank in Eugene
clennell on tue 28 oct 03
As for sources of ash try Kenny Rogers or Outback Steakhouse. also many
cities have wood fire pizza joints. Take the owner a nice pot nd I'm sure
your source will be guaranteed.
I must say ash glazes are the biggest pain in ash. Just had all of sheilas
pots stuck to the shelf this past firing. Pain! Because we don't use it
that often our familiarity is not quite on the money.
I'm finding atmosphere really effects the one I use. It is a lovely celedon
green in the woood kiln and a boring matt yellow in the gas kiln. Craig do
you have a killer ash celedon for gas? I have dinked with the old Batterham,
Leach 221 formula 2 ash, 2 feldspar, 1 clay but I get that stringy look
which is not what i like on my pots.
I have not been washing my ash due to laziness and here in may be a problem.
Thanks for this thread Mel. I'm all ears.
Cheers,
Tony
Tony and Sheila Clennell
Sour Cherry Pottery
4545 King Street
Beamsville, Ontario
CANADA L0R 1B1
http://www.sourcherrypottery.com
clennell@vaxxine.com
Sue Leabu on tue 28 oct 03
On Mon, 27 Oct 2003 17:40:45 -0800, Hank Murrow wrote:
>Hey Sue;
>
>Now just amend that last sentence to read,
>"Makes me wonder what the rate of cooling does to all my glazes.......>"
>and you'll have a question big enough for a career's worth of firings!
>
>Cheers, Hank in Eugene
Oh man! Now ya tell me....geeze...well, best get busy I guess...ain't
getting any younger. LOL :o) (I knew I was supposed to start this 20 years
ago....sheesh!)
Sue
Kzoo, MI
clennell on tue 28 oct 03
>
> This past February, I fired two loads of shino in a gas kiln. Same kiln,
> same glaze, same firing schedule. Both times, I sprinkled unwashed mixed
> ash onto wet shino. Ash from the same bucket that had been seived
> previously, no new ash added between firings. Result of first firing:
> nice "coke bottle" green glossy runs. Result of second firing: brown and
> yellow matt runs. The only difference in the firings was that the first
> time around, I forgot to close the damper at the end. It was a very cold
> night, and the kiln cooled off very very quickly. (So fast that I was
> afraid I was going to have a nice bunch of cracked pots inside.) Second
> firing, damper was closed immediately at the end of the firing, and the
> kiln cooled much slower. Makes me wonder what the rate of cooling does to
> ash and ash glazes....
>
> Sue
> Kalamazoo, MI
Hi Sue: I always crash cool the kiln until 1900 which gives the coke bottle
green you speak of on shino. I have even taken to spinkling more ash on my
ash glaze to get this coke bottle effect. I am consistently getting the
inside of bowls green because of the additional ash but vertical surfaces in
the gas kiln are yella.
Thanks for your thoughts. You're absolutely right about the slow cool
forming matt cystals and the crash cool giving the glaze effect.
I have to rethink the whole ash thing- First of all my clay body is high
iron for shino, so I have to use a white slip, maybe a looser pack for fast
cooling, wash the ash, and test some more. just to change one thing in this
business is a couple years work. Damn!
Cheers,
Tony
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