Leon Popik on fri 21 feb 97
I have always had the understanding that if you need to reduce in an
electric kiln, that silicon carbide would be the best for glazes. Has
anyone experimented with using silicon carbide for Copper Reds in electric
kilns yet?
I read that you need between 1-4% silicon carbide that is preferably
powdered, if you have larger particles it says that it boils. I am going to
try some test, anyone else interested?
Bill Aycock on sat 22 feb 97
At 09:07 AM 2/21/97 EST, you *** (Leon) *** wrote:
>----------------------------Original message----------------------------
>I have always had the understanding that if you need to reduce in an
>electric kiln, that silicon carbide would be the best for glazes. Has
>anyone experimented with using silicon carbide for Copper Reds in electric
>kilns yet?
>I read that you need between 1-4% silicon carbide that is preferably
>powdered, if you have larger particles it says that it boils. I am going to
>try some test, anyone else interested?
>
Leon- SiC does offer a means of reduction in an Electric Kiln. The Carbon in
the SiC attaches to the Oxygen in other ingredients, making CO2, usually,
and thereby reducing the glaze.
You mentioned Boiling- Yes it does, but it would more properly be called
foaming, in most cases. The problem is that the CO2 has to go somewhere, and
, since it is pretty evenly distributed, it collects into small bubbles. In
fact, depending on the fluidity of your glaze, the foam ( or froth, in some
cases), persists even after cooling. I have made some tests that would
"sing" to me, if I touched them,as the bubbles on the surface broke.
One answer is to hold at a fluid condition, to let the bubbles clear. The
down side is that the time you hold it there gives the glaze time to
re-oxidize.
Test-test-test-have fun!
PS- a simple source of SiC is valve grinding compound at your local auto
parts store- it usually comes in either water base or oil base; get the
water base stuff. It comes in two particle sizes, in a two sided container.
Bill Aycock --- Persimmon Hill --- Woodville, Alabama, USA
--- (in the N.E. corner of the State)
also-- W4BSG -- Grid EM64vr
Marcia Kindlmann on sat 22 feb 97
Subject: oxidation to reduction
Amy, I've been doing reduction in an electric kiln for 14 years, but
it's a kiln built for the purpose, has heavy-duty Kanthal elements
which last longer than people would expect, and a special chamber
below the main body of the kiln for putting in the reducing agent: charcoal.
I had to modify the original design of the kiln to get
reduction throughout instead of just near the bottom. With the
charcoal, and a longer firing cycle than is typical for electric
firings, I do get those glazes I liked so much from working
in a gas kiln studio.
But please, please VENTILATE if you try any kind of reduction
indoors. Have a hood with a serious exhaust fan over the kiln
(hood larger than kiln diameter) that's ducted up a chimney, and
HAVE A WINDOW OPEN for so fresh replacement air can get in. Get
a CO detector. You would not have a barbecue indoors or run your
car in a closed garage.
In Japan (hi, Mel) we saw potters using electric kilns designed
with ports to take in propane. They introduced the burner(s) when
kiln was hot enough to ignite the gas immediately, thus avoiding
explosion. Of course they got those reduction glazes they were after.
These electric kilns for gas reduction were widely used and potters
seemed to consider them perfectly normal.
There is a strong mythology in this country against the idea of
electric reduction. I'm beginning to suspect my elements take more
of a beating from bisqueing in that kiln than from reducing in it.
Mel--I'm curious what Nils is working on. You wrote, referring to
some reserach,
> nils is working on some new ideas that will be very interesting.
> but it will have very specific uses.
Marcia
Clay on sat 22 feb 97
2 Cases here
My instructor bought a eletric reduction kiln,which is an antique built in
England.It have a little drawer underneath the kiln which you put oil in
when it go up to the reduction temperature.More info might come from
England.NOTE: I never seen her work on it.
Eric Jackson, Kiln manufacturer from Ottawa, said his kiln,the elements is
so thick that you can fire reduction.He suggest that we fire once oxidation
& one reduction,as a cycle.
Good luck with all this information.
Best regard Ian Chung
At 09:07 AM 2/21/97 EST, you wrote:
>----------------------------Original message----------------------------
>I have always had the understanding that if you need to reduce in an
>electric kiln, that silicon carbide would be the best for glazes. Has
>anyone experimented with using silicon carbide for Copper Reds in electric
>kilns yet?
>I read that you need between 1-4% silicon carbide that is preferably
>powdered, if you have larger particles it says that it boils. I am going to
>try some test, anyone else interested?
>
Susan Leise on wed 27 jan 10
For the last several years I have been experimenting with the glazes =3D
from "Mastering cone 6 Glazes" by John Hesselberth and Ron Roy. I have =3D
enjoyed it very much and combined with Tony Hansens 5 x 20 Glaze and =3D
also Alisa Clausen's Wodo Glaze have come up with some very nice glazes. =
=3D
Now..my situation has changed. I have moved to a new town and have no =3D
place to set up my equipment..so, taking a class at the local =3D
college...which should really expand my horizons..but ...and this is a =3D
big "but" for me, they fire cone 6 reduction. =3D20
My question to you all...has anyone had any luck with the above glazes =3D
in reduction and been successful? I also would like to have some food =3D
safe glazes for my functional pieces!!! Any tips , any help, or point =3D
me in the right direction, I would most certainly appreciate it!!!
Even though I am finding it difficult to change my mindset for the =3D
glazing, I am really enjoying the slab roller, pug mill and will learn =3D
to spray on glazes..instead of dipping. Watching the other students =3D
work is also very interesting and inspiring! Should be a very =3D
interesting experience in many ways!
Susan
William & Susan Schran User on thu 28 jan 10
On 1/27/10 10:48 PM, "Susan Leise" wrote:
> For the last several years I have been experimenting with the glazes from
> "Mastering cone 6 Glazes" by John Hesselberth and Ron Roy. I have enjoye=
d it
> very much and combined with Tony Hansens 5 x 20 Glaze and also Alisa Clau=
sen's
> Wodo Glaze have come up with some very nice glazes. Now..my situation ha=
s
> changed. I have moved to a new town and have no place to set up my
> equipment..so, taking a class at the local college...which should really
> expand my horizons..but ...and this is a big "but" for me, they fire con=
e 6
> reduction.
> My question to you all...has anyone had any luck with the above glazes in
> reduction and been successful? I also would like to have some food safe
> glazes for my functional pieces!!! Any tips , any help, or point me in t=
he
> right direction, I would most certainly appreciate it!!!
From what you write, can I assume firings will be ^6 reduction?
If so, we have transitioned from ^10 to ^6 reduction at school.
Changed both to save on gas and allow more color options at the lower
temperature.
I held a class last summer where students participated in entering glazes
into Glaze Master calculation software program, mix glazes and test fire in
reduction and oxidation.
We are continuing to test various glazes, but have developed a palette so
far that seems to be working well. One glaze that is working well is the
Variegated Blue from MCSG. A medium slate blue, semi mat and glossy, depend=
s
on thickness.
We are also using a couple of Diana Pancioli's glazes. Here's her article:
http://www.dianapancioli.com/downloads/GlazeForward.pdf.
We also use the raw sienna glaze from John Britt's article some time back i=
n
Ceramics Monthly on ^6 reduction.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
David Beumee on thu 28 jan 10
I see no reason to fear firing successful oxidation cone 6 glazes in
reduction. You may well find greater richness of color and depth in
reduction, partly because the reduced clay body will influence the glaze
outcome.
David Beumee
Lafayette, CO
On Wed, Jan 27, 2010 at 8:48 PM, Susan Leise wrote:
> For the last several years I have been experimenting with the glazes from
> "Mastering cone 6 Glazes" by John Hesselberth and Ron Roy. I have enjoye=
d
> it very much and combined with Tony Hansens 5 x 20 Glaze and also Alisa
> Clausen's Wodo Glaze have come up with some very nice glazes. Now..my
> situation has changed. I have moved to a new town and have no place to se=
t
> up my equipment..so, taking a class at the local college...which should
> really expand my horizons..but ...and this is a big "but" for me, they f=
ire
> cone 6 reduction.
> My question to you all...has anyone had any luck with the above glazes in
> reduction and been successful? I also would like to have some food safe
> glazes for my functional pieces!!! Any tips , any help, or point me in t=
he
> right direction, I would most certainly appreciate it!!!
> Even though I am finding it difficult to change my mindset for the glazin=
g,
> I am really enjoying the slab roller, pug mill and will learn to spray on
> glazes..instead of dipping. Watching the other students work is also ver=
y
> interesting and inspiring! Should be a very interesting experience in ma=
ny
> ways!
> Susan
>
Marcia Selsor on thu 28 jan 10
I think John's article was Oct or Nov of 2008. I posted a bunch of ^6 =3D
reduction glazes on Clayart in the 90s.
Diana has used them and John tweeked one. They are in the archives.
Marcia=3D20
On Jan 28, 2010, at 8:10 AM, William & Susan Schran User wrote:
> On 1/27/10 10:48 PM, "Susan Leise" wrote:
>=3D20
>> For the last several years I have been experimenting with the glazes =3D
from
>> "Mastering cone 6 Glazes" by John Hesselberth and Ron Roy. I have =3D
enjoyed it
>> very much and combined with Tony Hansens 5 x 20 Glaze and also Alisa =3D
Clausen's
>> Wodo Glaze have come up with some very nice glazes. Now..my =3D
situation has
>> changed. I have moved to a new town and have no place to set up my
>> equipment..so, taking a class at the local college...which should =3D
really
>> expand my horizons..but ...and this is a big "but" for me, they fire =
=3D
cone 6
>> reduction.
>> My question to you all...has anyone had any luck with the above =3D
glazes in
>> reduction and been successful? I also would like to have some food =3D
safe
>> glazes for my functional pieces!!! Any tips , any help, or point me =3D
in the
>> right direction, I would most certainly appreciate it!!!
>=3D20
>> =3D46rom what you write, can I assume firings will be ^6 reduction?
> If so, we have transitioned from ^10 to ^6 reduction at school.
> Changed both to save on gas and allow more color options at the lower
> temperature.
>=3D20
> I held a class last summer where students participated in entering =3D
glazes
> into Glaze Master calculation software program, mix glazes and test =3D
fire in
> reduction and oxidation.
>=3D20
> We are continuing to test various glazes, but have developed a palette =
=3D
so
> far that seems to be working well. One glaze that is working well is =3D
the
> Variegated Blue from MCSG. A medium slate blue, semi mat and glossy, =3D
depends
> on thickness.
>=3D20
> We are also using a couple of Diana Pancioli's glazes. Here's her =3D
article:
> http://www.dianapancioli.com/downloads/GlazeForward.pdf.
>=3D20
> We also use the raw sienna glaze from John Britt's article some time =3D
back in
> Ceramics Monthly on ^6 reduction.
>=3D20
> Bill
>=3D20
> --
> William "Bill" Schran
> wschran@cox.net
> wschran@nvcc.edu
> http://www.creativecreekartisans.com
>=3D20
Marcia Selsor
http://www.marciaselsor.com
Marcia Selsor on thu 28 jan 10
Usually Oxidation glazes contain higher % of oxides because the =3D
reduction isn't pulling them out. Oxidation is a little more passive =3D
unless you play around with the slow cooling and holding as it cools to =3D
develop micro crystals on the surface. . That would be my only =3D
concern...excessively high oxides could boil in reduction. Really =3D
depends on the glaze.
Marcia
On Jan 28, 2010, at 7:49 AM, David Beumee wrote:
> I see no reason to fear firing successful oxidation cone 6 glazes in
> reduction. You may well find greater richness of color and depth in
> reduction, partly because the reduced clay body will influence the =3D
glaze
> outcome.
>=3D20
> David Beumee
> Lafayette, CO
>=3D20
>=3D20
>=3D20
Marcia Selsor
http://www.marciaselsor.com
Lee Love on thu 28 jan 10
Copper glazes will change as well as fake celadons.
On Thu, Jan 28, 2010 at 7:49 AM, David Beumee wrote=
=3D
:
> I see no reason to fear firing successful oxidation cone 6 glazes in
> reduction. You may well find greater richness of color and depth in
> reduction, partly because the reduced clay body will influence the glaze
> outcome.
>
> David Beumee
> Lafayette, CO
>
>
>
>
>
>
>
>
>
>
>
> On Wed, Jan 27, 2010 at 8:48 PM, Susan Leise wrote:
>
>> For the last several years I have been experimenting with the glazes fro=
=3D
m
>> "Mastering cone 6 Glazes" by John Hesselberth and Ron Roy. =3DA0I have e=
nj=3D
oyed
>> it very much and combined with Tony Hansens 5 x 20 Glaze and also Alisa
>> Clausen's Wodo Glaze have come up with some very nice glazes. =3DA0Now..=
my
>> situation has changed. I have moved to a new town and have no place to s=
=3D
et
>> up my equipment..so, =3DA0taking a class at the local college...which sh=
ou=3D
ld
>> really expand my horizons..but ...and this is a big "but" for me, =3DA0t=
he=3D
y fire
>> cone 6 reduction.
>> My question to you all...has anyone had any luck with the above glazes i=
=3D
n
>> reduction and been successful? =3DA0I also would like to have some food =
sa=3D
fe
>> glazes for my functional pieces!!! =3DA0Any tips , any help, or point me=
i=3D
n the
>> right direction, I would most certainly appreciate it!!!
>> Even though I am finding it difficult to change my mindset for the glazi=
=3D
ng,
>> I am really enjoying the slab roller, pug mill and will learn to spray o=
=3D
n
>> glazes..instead of dipping. =3DA0Watching the other students work is als=
o =3D
very
>> interesting and inspiring! =3DA0Should be a very interesting experience =
in=3D
many
>> ways!
>> Susan
>>
>
--=3D20
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
William & Susan Schran User on thu 28 jan 10
On 1/28/10 8:49 AM, "David Beumee" wrote:
> I see no reason to fear firing successful oxidation cone 6 glazes in
> reduction. You may well find greater richness of color and depth in
> reduction, partly because the reduced clay body will influence the glaze
> outcome.
Hey David,
I agree the clays that come out buff or light brown in oxidation do warm up
in reduction, but some of the dark brown and red bodies used in oxidation
can become very dark in reduction because of the added iron. This will
certainly make many of the glazes appear much darker also. There are a
couple dark red bodies that have turned nearly black in our ^6 reduction
glazes.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
David Woof on fri 29 jan 10
David=3D2C=3D20
if your clay body was formulated as a true ^ cone 6 dark oxidation body you=
=3D
will most likely get black coring=3D2C and worst case=3D3B fluxing=3D2C bl=
oating=3D
=3D2C and possible deformation of form.
=3D20
Black coring causes handles to come off when filled with hot liquids and du=
=3D
nting failure of the body's core strength and integrity.
=3D20
Do it anyway!!! Test=3D2CTest=3D2C Test=3D2C fire and break some. The bl=
ack co=3D
re will appear as such thru-out the body. It may even appear as a matrix of=
=3D
tiny blackened bubbles.
=3D20
David Woof =3D20
=3D20
where Spring is bursting forth in Northern Arizona and south of that arbitr=
=3D
ary line some drunken Generals scribbled on a map from Texas to California =
=3D
way back when we were a free territory. OOPs am I bad or what? So come a=
=3D
n have at it cowboy=3D2C as usual I'm feeling feisty this AM.
=3D20
=3D20
=3D20
=3D20
________________________________________________________________________
2a. Re: Oxidation to Reduction
Posted by: "William & Susan Schran User" wschran@COX.NET=3D20
Date: Thu Jan 28=3D2C 2010 11:33 am ((PST))
=3D20
On 1/28/10 8:49 AM=3D2C "David Beumee" wrote:
=3D20
> I see no reason to fear firing successful oxidation cone 6 glazes in
> reduction. You may well find greater richness of color and depth in
> reduction=3D2C partly because the reduced clay body will influence the gl=
az=3D
e
> outcome.
=3D20
Hey David=3D2C
I agree the clays that come out buff or light brown in oxidation do warm up
in reduction=3D2C but some of the dark brown and red bodies used in oxidati=
on
can become very dark in reduction because of the added iron. This will
certainly make many of the glazes appear much darker also. There are a
couple dark red bodies that have turned nearly black in our ^6 reduction
glazes.
=3D20
Bill
=3D20
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
=3D20
=3D20
=3D20
_________________________________________________________________
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