Talbott on mon 13 jan 97
My husband and I have been firing together for about three years now and
have had varied success with copper red. We have one recipe that has
ranged from bright red, to a beautiful blue, a grayish red - all from the
same recipe. Our length of firing has ranged from 12 hours, up to 18-20.
Does anyone have suggestions on the length of the firing - long and slow,
medium to fast, etc. I'd also like to know about soaking at the end of the
firing. Is a soak worthwhile, if so how long and should it be in oxidation
or reduction? We fire to cone 9-10 in a reducing atmosphere. Soaking has
always been a bit of a mystery to me.
Thank you in advance for all info. on length of firing times, and soaking.
Celia
------------------------------------------------------------------------------
1ST ANNUAL CLAYARTERS' GALLERY-NAPLES, ME (Summmer 1997) {contact me
directly for more information}
Celia & Marshall Talbott
Pottery By Celia
Route 114
P.O. Box 4116
Naples, Maine 04055-4116
(207)693-6100 voice and fax
clupus@ime.net
Jon Pettyjohn on tue 14 jan 97
Hi Celia
recently I asked some similar questions and got some very good advice
from people here on clayart, especially Pete Pinnell (sp?) and Tom Buck.
In my question I was wondering whether very long firings were detrimental
to copper reds. It was pointed out to me that the Chinese kilns that
originally produced these glazes were very large and probably took
many days to fire. I'm sure there are people around today who are
firing in as few as 10 hours or even less, so time would probably not
be that critical a factor, assuming the glaze is fired to the right
degree of maturity. There is some opinion that overfiring can cause
the copper to volatize out of the glaze and lose the color. Pete
suggested that it is also possible to over-reduce, especially in the
later stages of firing and that this can ruin the color. He suggested
that reduction should begin as early as 900 deg. C. and that the
reduction can be cut back after reaching 1100 C. if I remember
correctly, (I lost his original post in a crashed hard drive). I
tried out these suggestions and got much better results right away,
this advice along with the recipe for Coleman's Red (which is in the data
bank) have been a big help to me. Thanks again to Mishy Lowe for
sending me that and other recipes.
The thread about whether to do an oxidation soaking has come up a
few times recently and there seem to be divided opinions. I think
the consensus might be in favor of a short 10-15 min. oxidation soak,
but many people point out that the moment you shut down the kiln it
re-oxidises anyway. My guess would be that if the firing is on the
short side, maybe less than 12 hours a short soak would help.
Jon Pettyjohn Manila jon@mozcom.com
>----------------------------Original message----------------------------
>My husband and I have been firing together for about three years now and
>have had varied success with copper red. We have one recipe that has
>ranged from bright red, to a beautiful blue, a grayish red - all from the
>same recipe. Our length of firing has ranged from 12 hours, up to 18-20.
>Does anyone have suggestions on the length of the firing - long and slow,
>medium to fast, etc. I'd also like to know about soaking at the end of the
>firing. Is a soak worthwhile, if so how long and should it be in oxidation
>or reduction? We fire to cone 9-10 in a reducing atmosphere. Soaking has
>always been a bit of a mystery to me.
>Thank you in advance for all info. on length of firing times, and soaking.
>Celia
LINDA BLOSSOM on wed 15 jan 97
Dear Celia,
Just to show that there are many theories and schedules for firing reds, I
start reduction at 1040 and maintain a 6 on the oxyprobe to cone 6 and shut
down without closing the damper or ports. I fire for about 12-13 hours at
about 90degrees Centigrade per hour and about 60 per hour after 1000. In
one firing a glaze I used was nearly apple red and in my last firing it
looked like blood. All you can say is sheez sometimes. That glaze is very
interesting when fired over a saturated iron glaze.
Linda Blossom
2366 Slaterville Rd.
Ithaca, NY 14850
blossom@lightlink.com
http://www.artscape.com
607-539-7912
Bob Hanlin on mon 20 jan 97
Well, I'm going to add my two cents worth to this thread. I've been firing
copper reds for 13 years now. My firing cycle goes like this
oxidation to c010
heavy reduction to c5
moderate reduction to c9
oxidation to a FLAT c10
Some times I leave the dampers open for about 3 hours (but close it before
the kiln goes dark (quartz inversions...))and sometimes I close it (I don't
plug anything, just close the damper). I find that the quality of the red
is not comprimised by the way the kiln cools. I know that the color
changes in the cooling but whether I soak or plug of vent. That's it, it
works.
Bob Hanlin
At 07:19 PM 1/13/97 EST, you wrote:
>----------------------------Original message----------------------------
>My husband and I have been firing together for about three years now and
>have had varied success with copper red. We have one recipe that has
>ranged from bright red, to a beautiful blue, a grayish red - all from the
>same recipe. Our length of firing has ranged from 12 hours, up to 18-20.
>Does anyone have suggestions on the length of the firing - long and slow,
>medium to fast, etc. I'd also like to know about soaking at the end of the
>firing. Is a soak worthwhile, if so how long and should it be in oxidation
>or reduction? We fire to cone 9-10 in a reducing atmosphere. Soaking has
>always been a bit of a mystery to me.
>
>Thank you in advance for all info. on length of firing times, and soaking.
>
>Celia
>
>---------------------------------------------------------------------------
---
>1ST ANNUAL CLAYARTERS' GALLERY-NAPLES, ME (Summmer 1997) {contact me
>directly for more information}
> Celia & Marshall Talbott
> Pottery By Celia
> Route 114
> P.O. Box 4116
> Naples, Maine 04055-4116
> (207)693-6100 voice and fax
> clupus@ime.net
>
>
Bob Hanlin
Oklahoma City, OK
bhanlin@ionet.net
LINDA BLOSSOM on tue 21 jan 97
Some times I leave the dampers open for about 3 hours (but close it before
the kiln goes dark (quartz inversions...))and sometimes I close it (I don't
plug anything, just close the damper). I find that the quality of the red
is not comprimised by the way the kiln cools. I know that the color
changes in the cooling but whether I soak or plug of vent. That's it, it
works.
Dear Bob,
I wonder if the cooling rates on both cooling methods you use both fall
within the range needed to produce the reds. I cannot get decent reds with
an oxidation at the end and prefer to leave the damper open at the end.
Leaving the damper open seems to scare folks. When I read Jeff Neely's
article it scared me and I was in and out of the kiln room checking the
cooling rate. But when I opened the kiln nothing had suffered the quicker
cool. I fire thicker items than any potter I know. A sink is about 3/4 of
an inch thick and I've had 2 1/2" sections on pedestals. Both of which
take the faster cool without cracking. It is a lot like single firing.
For so long there was so much information about why it would not work that
even with so many of us saying it works just fine, others just can't quite
buy it. Faster cooling seems to have the same resistance.
Linda Blossom
2366 Slaterville Rd.
Ithaca, NY 14850
blossom@lightlink.com
http://www.artscape.com
607-539-7912
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