Chris trabka on thu 9 aug 07
Mel,
Druing a reduction firing, my Oxyprobe reads .625, the cones are clearly
visable, and when when I have a line of sight to the back wall I do see the
seams between the bricks.
Chris
>if the atmosphere inside the kiln is clear and you can see
>the cones perfectly, the back wall and the pots...you are not
>in a reducing atmosphere. adjust the atmosphere inside the kiln to
>be dense/turbulent/opaque. measure it. memorize it.
William & Susan Schran User on thu 9 aug 07
On 8/9/07 3:37 PM, "Chris trabka" wrote:
> Druing a reduction firing, my Oxyprobe reads .625, the cones are clearly
> visable, and when when I have a line of sight to the back wall I do see t=
he
> seams between the bricks.
>=20
> Chris
>=20
>> if the atmosphere inside the kiln is clear and you can see
>> the cones perfectly, the back wall and the pots...you are not
>> in a reducing atmosphere. adjust the atmosphere inside the kiln to
>> be dense/turbulent/opaque. measure it. memorize it.
Mel, I have to agree with Chris on this one.
Firing our Geil 24 cu ft downdraft with natural gas, the firing will go int=
o
reduction around 1800 - 1850=B0F through minor adjustments with the damper.
Primary air is set and never changed. Gas pressure has been set at it's
highest setting by 1200=B0F.
Reduction is noted when there is back pressure at the bottom spy hole.
When holding a piece of paper close to this spyhole, it will ignite.
I can always see the cones and the back wall, all the way up to ^10.
The atmosphere is not completely clear - sort of a very light fog.
We get great celadons, copper reds and shinos.
Don't have an oxyprobe, don't see the need for one.
Each kiln is designed and built differently. Each kiln will fire
differently. Took me several firings to find a good firing schedule for
ours. Each artisan will have to learn & understand their kiln in their
situation.
My hateful Olympic updraft kiln is still kicking my butt trying to get even
reduction, but I can get even temperature top to bottom.
--=20
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Overall's on fri 10 aug 07
William,
Boy Howdy do I understand your 'learning curve' on the Olympic updraft.
Inside pots are no problem, evening out the temperature top to bottom is a constant as the gas pressure fluctuates every few months. But that reduction throughout the kiln...
I believe I'm thoroughly convinced the only way you can achieve great copper reds in an updraft is fire down reductions. And I'm sticking with that until someone here proves me otherwise.
Nils Lou helped me with that one - from his book and via e-mails.
As well as going further with experimentation on my part.
Although I must insert here I've not gotten the same sort of copper reds as you (and others) get in a downdraft...Geil or others. Dam-it
Kim Overall
http://www.kimoverall.com/events.html
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