C Pike on sat 22 jun 96
We are planning on lowering our temperature from cone 10 reduction and
doing cone 6 oxidation in our gas kiln. Just wondering if anyone out there
has had any experience with this.
Thanks Connie
----------------------
Bob & Connie Pike pikec@cadvision.com
1303 10th Ave SE High River,Alberta T1V 1L4 Canada (403-652-5255)
----------------------
Patrick Veerkamp on tue 25 jun 96
Connie: I have been firing at cone 6 for about 3 years now. At first
this was a condition imposed by the limitations of the facilities that
were available to me, but now I have made a willful decision to continue
firing at this temperature. I find that with a properly formulated clay
body my pots are every bit as able to withstand the wear and tear of
day-to-day use as cone 10 stoneware. At first I had only an electric
kiln at my disposal so I was firing oxidation (now I do both in a 24 cu
ft updraft natural gas kiln). I think the best advice I can give you is
not to expect cone 10 reduction effects from cone 6 oxidation. In other
words the look is quite different and you need to come to terms with that
right away. Here are a couple of articles you might like to read on cone
6 oxidation firing:
"Firing In Oxidation", Val Cushing (Studio Potter,
Vol 5, No 2--in fact there are several articles on oxidation firing in
this issue).
"A Palette of Cone 6 Oxidation Glazes", Jeff Dietrich (Ceramics
Monthly, April 1991).
"Cone 6 Oxidation Slips and Glazes", Gerald Rowan (Ceramics
Monthly, Summer 1983).
Good luck, and as our colleague Russel Fouts used to say:
electric is good: oxidation is good!
Patrick Veerkamp
Southwestern University
veerkamp@southwestern.edu
On Sat, 22 Jun 1996, C Pike wrote:
> ----------------------------Original message----------------------------
> We are planning on lowering our temperature from cone 10 reduction and
> doing cone 6 oxidation in our gas kiln. Just wondering if anyone out there
> has had any experience with this.
> Thanks Connie
>
> ----------------------
> Bob & Connie Pike pikec@cadvision.com
> 1303 10th Ave SE High River,Alberta T1V 1L4 Canada (403-652-5255)
> ----------------------
>
meadow on mon 27 jun 05
On Sat, 22 Jun 1996 20:07:04 EDT, C Pike wrote:
>----------------------------Original message----------------------------
>We are planning on lowering our temperature from cone 10 reduction and
>doing cone 6 oxidation in our gas kiln. Just wondering if anyone out there
>has had any experience with this.
>Thanks Connie
>
>----------------------
>Bob & Connie Pike pikec@cadvision.com
>1303 10th Ave SE High River,Alberta T1V 1L4 Canada (403-652-5255)
>----------------------
i was searching the archives looking for an answer to this very question. so, did you do it? did it
work? has anyone else had experiences with this?
and what about ^6 reduction? how would normal ^6 glazes (designed for oxidation) transfer?
basically, i've got a gas kiln, and a bunch of ^6 clay and glazes to use up.
i remember an article by val whatsizname about how ^6 is overlooked and undervalued. but he
spoke only of ^6 oxidation in electric kilns......
also in the archives, i found where some poor sop such as myself asked about oxidation in a gas
kiln, and sparked a tanget theoretical discussion about kiln atmosphere, while the practical
question of how to do it was entirely overlooked.
how, how, how???? is it as simple as just NOT reducing? do you have to open it up extra? and
would it then be more or less fuel efficient than reduction firing?
i know, too many questions. i only recently discovered this clayart whatever-you-call-it, and i'm in
love.
-m.
Marcia Selsor on mon 27 jun 05
I changed to ^6 reduction in 1980 to save time and gas for the
ceramics program at MSUB. The glazes for ^6 reduction are difficult
to tell they are not ^10. You can see them in Michael Bailey's new
book on Oriental Glazes. There is a Tenmoku, Copper red, celedon,
Iron reds, etc. I think they are the only ^6 in his book. Many of
these glazes are listed in the archives. By dropping the temperature,
you save considerable BTUs consumption and time. I had to get the
firing schedule down to be completed by my assistant in an 8 hour
shift. Got this down but lost the assistant after a semester or two.
Marcia Selsor
On Jun 27, 2005, at 11:12 AM, meadow wrote:
> On Sat, 22 Jun 1996 20:07:04 EDT, C Pike wrote:
>
>
>> ----------------------------Original
>> message----------------------------
>> We are planning on lowering our temperature from cone 10 reduction
>> and
>> doing cone 6 oxidation in our gas kiln. Just wondering if anyone
>> out there
>> has had any experience with this.
>> Thanks Connie
>>
>> ----------------------
>> Bob & Connie Pike pikec@cadvision.com
>> 1303 10th Ave SE High River,Alberta T1V 1L4 Canada (403-652-5255)
>> ----------------------
>>
demaine pottery on tue 28 jun 05
For 32 years I have fired my domestic work in gas kilns to cone 10. I never
had any problems. I did this by making sure that I had minimum back
pressure in the kiln, that is opening the damper so that there is no back
pressure from the spy holes. My glazes were very sensitive to reduction.
There has to be a balance in the damper positioning as too much would make
the kiln fire unevenly. Nowadays I have the luxury of an oxy probe to make
sure.
Hope this helps
Johanna DeMaine
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of meadow
Sent: Tuesday, 28 June 2005 3:12 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: use gas kiln for oxidation
On Sat, 22 Jun 1996 20:07:04 EDT, C Pike wrote:
>----------------------------Original
>message----------------------------
>We are planning on lowering our temperature from cone 10 reduction and
>doing cone 6 oxidation in our gas kiln. Just wondering if anyone out
>there has had any experience with this.
>Thanks Connie
>
>----------------------
>Bob & Connie Pike pikec@cadvision.com
>1303 10th Ave SE High River,Alberta T1V 1L4 Canada (403-652-5255)
>----------------------
i was searching the archives looking for an answer to this very question.
so, did you do it? did it work? has anyone else had experiences with this?
and what about ^6 reduction? how would normal ^6 glazes (designed for
oxidation) transfer?
basically, i've got a gas kiln, and a bunch of ^6 clay and glazes to use up.
i remember an article by val whatsizname about how ^6 is overlooked and
undervalued. but he spoke only of ^6 oxidation in electric kilns......
also in the archives, i found where some poor sop such as myself asked about
oxidation in a gas kiln, and sparked a tanget theoretical discussion about
kiln atmosphere, while the practical question of how to do it was entirely
overlooked.
how, how, how???? is it as simple as just NOT reducing? do you have to open
it up extra? and would it then be more or less fuel efficient than reduction
firing?
i know, too many questions. i only recently discovered this clayart
whatever-you-call-it, and i'm in love.
-m.
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John Baymore on tue 28 jun 05
Meadow,
Yup ..... the very short answer is that it is perfectly possible to do
that. Industry has been doing it for a long time. So have
numerous "art / craft" potters.
With the awful conversion factor of "centralized power" for creating
electricity to generate heat out of burning fossil fuels, the typically
poorly insulated electric kilns most potters use, and the inherent
inefficieny of firing a small volume periodic kiln repeatedly versus a
larger volume periodic kiln once, it makes more sense environmentally than
using an electric kiln.
The slightly longer answer is that while it is certainly possible... it
DOES place some issues on the design of the exact gas kiln to be used for
this purpose. There are many gas kilns out there in use by artist potters
that are designed in a manner that might limit their ability to easily
entrain and mix sufficient primary and secondary air to get oxidizing
conditions evenly throughout the chamber.
So while it works for potter A with kiln X, it might not work as well for
potter B with kiln Y. I guess that is a "caveat emptor" statement. Your
milage may vary, not available in all states, see package for details .
In general, you need a decent well matched combustion system.
The "system" is composed of the burners, the kiln itself, and the
ventialtion / exhaust system. All of which can be affected by the
building housing all of this stuff. The kiln system has to be capable of
supplying not only 100 percent of the air needed for combustion... but
also a bit more to create "oxidation" conditions for the wares. Also, the
air is supplies has to be mixed into the combustable gas(es) so that by
the time it actually reaches the ware, all of the fuel has been burnt....
(ie. - no H or C compounds other than H2O and CO2).
Again generallly speaking, the "lower tech" the kiln and burners are......
the less the probability that this will happen well. The higher tech...
the more likely that it WILL work well. But even that is not an absolute
guarantee because then there is also the vairable of the person firing the
unit.
All in all....... don't be afraid to experiment with trying it. And cone
6 reduiction is a field that is WIDE OPEN. So do some research, and then
do some experiments.
My $0.02 from a pro kiln builder of some 30+ years .
best,
................john
"Please use below compuserve address for direct communications... not
hotmail one above."
JBaymore@compuserve.com
http://www.JohnBaymore.com
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
John Hesselberth on tue 28 jun 05
On Jun 28, 2005, at 1:19 PM, John Baymore wrote:
> With the awful conversion factor of "centralized power" for creating
> electricity to generate heat out of burning fossil fuels, the typically
> poorly insulated electric kilns most potters use, and the inherent
> inefficieny of firing a small volume periodic kiln repeatedly versus a
> larger volume periodic kiln once, it makes more sense environmentally
> than
> using an electric kiln.
Hi John,
Do you have any references where this info is calculated. I can't
imagine the typical gas kiln is very efficient either--an awful lot of
heat goes up the stack. I do accept the inherent inefficiency of firing
multiple smaller volumes, but I would bet the conversion efficiency of
fossil fuel to useful heat is not much different between the two. Also
the cost of electricity is not moving up nearly as fast as natural gas
or propane because so much of it comes from coal and nuclear sources.
If you have any recent experimental comparisons I'd be interested in
knowing about them.
Regards,
John
John Hesselberth
http://www.frogpondpottery.com
http://www.masteringglazes.com
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