Jim Larkin on sat 4 aug 01
John,
I do a 1 1/2 hour oxidation soak at the end of C10 Reduction firings to
improve the orange of shinos, but also derive benefit of smoothing out ash
rivulet glazes which might tend to pit. Iron crystal glazes also really
benefit. And I find no detrimental effects on copper reds. They stay red. My
glazes don't seem to benefit from longer soaks, but that certainly doesn't
mean that other glazes wouldn't. I've always done an oxidation "clean-up"
soak at the end of a firing, but Hank's posts have prompted me to experiment
with longer soaks, and they've been beneficial.
Jim Larkin
Fox Pass Pottery
379 Fox Pass
Hot Springs, Arkansas
71901
foxpass@aristotle.net
----- Original Message -----
From: John Weber
To:
Sent: Saturday, August 04, 2001 11:07 AM
Subject: Long Oxidation Soak after Reduction
> Earlier on the list we were discussing a long (3 Hour) soak after letting
> the kiln cool from Cone 10 down to 2000 F and then soak to slow the
cooling.
> I would like to know if anyone who had done this has done it following a
> firing in Reduction and were the effects of Reduction reversed in any way?
> Or, stated another way, does a long oxidation soak after a reduction
firing
> reverse the reduction process?
>
> John Weber
> Manakin-Sabot, VA
>
>
____________________________________________________________________________
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> Send postings to clayart@lsv.ceramics.org
>
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>
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>
John Weber on sat 4 aug 01
Earlier on the list we were discussing a long (3 Hour) soak after letting
the kiln cool from Cone 10 down to 2000 F and then soak to slow the cooling.
I would like to know if anyone who had done this has done it following a
firing in Reduction and were the effects of Reduction reversed in any way?
Or, stated another way, does a long oxidation soak after a reduction firing
reverse the reduction process?
John Weber
Manakin-Sabot, VA
Hank Murrow on sat 4 aug 01
>Earlier on the list we were discussing a long (3 Hour) soak after letting
>the kiln cool from Cone 10 down to 2000 F and then soak to slow the cooling.
>I would like to know if anyone who had done this has done it following a
>firing in Reduction and were the effects of Reduction reversed in any way?
>Or, stated another way, does a long oxidation soak after a reduction firing
>reverse the reduction process?
>
>John Weber
>Manakin-Sabot, VA
>
Dear John;
The long oxidation soak during the cooling cycle is an idea I have
promoted based upon the outstanding results with Shino glazes. These are
glazes which derive their intense color from microcrystalline growth after
the firing. Reduction early and throughout the firing brings the iron into
solution, and slow cooling allows the crystalline growth. Then the color of
rusty iron develops down around 1900F during cooling, and only on the
surface (20 microns or so).
Glazes such as celadons, which derive their color from iron in
solution will likely not benefit (in color intensity) from a soak in
Oxidation. However, I am getting a fantastic range of colors firing in
oxidation to C/10 cooling normally down to 1900F, and soaking in oxidation
for from 4-8 hours. Copper yellows, blues, and greens; jet blacks,
rutile/cobalt greens, all benefit from this soak.
The rule seems to be, "If the color comes from microcrystalline
growth, SOAK." Otherwise, "Maybe."
Hoping this helps, Hank in Eugene
Jan Cannon on sun 5 aug 01
John,
I do a six or so hour oxidation soak at cone 10, after reduction firing, and
then turn off the kiln and relight later around 1800 or 1900 deg. and put
the kiln in an oxidation soak for a couple of hours. I don't know if that
is what is being discussed here but when I fire that way (for Shino alone)
it has a terrible effect on my celadon. Maybe the negative effect on the
celadon is because of the six-hour cone 10 soak and not a result of the
lower temperature soak.
Jan
Jan Cannon Pottery
19 Garen Road
Charlotte, VT 05445
Tel: 802-425-6320
jan@jancannonpottery.com
www.jancannonpottery.com
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Hank Murrow
Sent: Saturday, August 04, 2001 3:33 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Long Oxidation Soak after Reduction
>Earlier on the list we were discussing a long (3 Hour) soak after letting
>the kiln cool from Cone 10 down to 2000 F and then soak to slow the
cooling.
>I would like to know if anyone who had done this has done it following a
>firing in Reduction and were the effects of Reduction reversed in any way?
>Or, stated another way, does a long oxidation soak after a reduction firing
>reverse the reduction process?
>
>John Weber
>Manakin-Sabot, VA
>
Dear John;
The long oxidation soak during the cooling cycle is an idea I have
promoted based upon the outstanding results with Shino glazes. These are
glazes which derive their intense color from microcrystalline growth after
the firing. Reduction early and throughout the firing brings the iron into
solution, and slow cooling allows the crystalline growth. Then the color of
rusty iron develops down around 1900F during cooling, and only on the
surface (20 microns or so).
Glazes such as celadons, which derive their color from iron in
solution will likely not benefit (in color intensity) from a soak in
Oxidation. However, I am getting a fantastic range of colors firing in
oxidation to C/10 cooling normally down to 1900F, and soaking in oxidation
for from 4-8 hours. Copper yellows, blues, and greens; jet blacks,
rutile/cobalt greens, all benefit from this soak.
The rule seems to be, "If the color comes from microcrystalline
growth, SOAK." Otherwise, "Maybe."
Hoping this helps, Hank in Eugene
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
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