ccpottery@BELLSOUTH.NET on sat 5 feb 05
I fire colored porcelain in an electric kiln
to a full Cone 8, almost 9.
I love the feel of the unglazed, sanded
porcelain ... dislike the slick feel of regular
glazes ... feels like I'm touching glaze, not
the clay.
But I have noticed some glazed porcelain
still feels like the clay ... the glaze lies in
such a thin coat you almost cannot feel it.
These pieces are usually matte and fired in
gas.
Does this mean I need a gas kiln or can such
a result be achieved in electric?
Chris Campbell - in North Carolina - looking out at a true
Carolina blue sky today as the thermostat creeps back up
to normal temps. Yummm !!
Chris Campbell Pottery, llc
9417 Koupela Drive
Raleigh, NC 27615
1-800-652-1008
1-919-676-2172
FAX : 919-676-2062
E Mail : chris@ccpottery.com
Website : www.ccpottery.com
Wholesale : www.wholesalecrafts.com
Ivor and Olive Lewis on sun 6 feb 05
Dear Chris Campbell,
I think you may be seeking a "Satin Mat" a glaze with a slight amount
of "Tooth" that does not have the characteristic shine or reflectivity
and slick smoothness of raw glass.
This is possible in an electric firing if you can slow the cooling
rate of your kiln . Reduction is not needed.
One suggestion would be to look for a Calcium Matt but my own
preference would be to include an equal proportion of Magnesia.
Incorporating either Dolomite or a mixture of Wollastonite and Talc in
the clear glaze you are currently using might provide an answer.Though
Talc may have its problems because it is difficult to wet, I like the
surface it gives when matched with Wollastonite
As is usual, test, test, test !
Best regards,
Ivor Lewis.
Redhill,
S. Australia.
----- Original Message -----
From:
To:
Sent: Sunday, 6 February 2005 2:18
Subject: Question for the Glaze Geniuses
> I fire colored porcelain in an electric kiln
> to a full Cone 8, almost 9.
>
> I love the feel of the unglazed, sanded
> porcelain ... dislike the slick feel of regular
> glazes ... feels like I'm touching glaze, not
> the clay.
>
> But I have noticed some glazed porcelain
> still feels like the clay ... the glaze lies in
> such a thin coat you almost cannot feel it.
>
> These pieces are usually matte and fired in
> gas.
>
> Does this mean I need a gas kiln or can such
> a result be achieved in electric?
>
> Chris Campbell - in North Carolina - looking out at a true
> Carolina blue sky today as the thermostat creeps back up
> to normal temps. Yummm !!
>
> Chris Campbell Pottery, llc
> 9417 Koupela Drive
> Raleigh, NC 27615
> 1-800-652-1008
> 1-919-676-2172
> FAX : 919-676-2062
> E Mail : chris@ccpottery.com
> Website : www.ccpottery.com
> Wholesale : www.wholesalecrafts.com
>
>
______________________________________________________________________
________
> 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.
John Rodgers on sun 6 feb 05
Chris,
I really like that smooth feeling of unglazed porcelain, myself!
Am I correct in assuming you are using a colored throwing porcelain?? Or
are you using a colored slip-casting porcelain??
Regards slip casting bodies:
In my own shop years ago in Alaska, we used colored slip-casting
porcelain bodies. Those bodies were thoroughly ball millled before
casting. And they were very smooth. Even so, however, they WERE NOT so
smooth as to accept a glaze without further surface preparation before
glazing.
After the initial firing of the porcelain pieces, they were preped by
scrubbing with a rubber-backed scrubbie, sort of like sandpaper. At that
point, the pieces would be as smooth as a baby's bottom. The surface was
damp wiped to remove sanding dust, then glazed. Due to the nature of the
work, most pieces were sprayed with a clear glaze rather than dipped.
Then they were fired.
We never fired to "Bisque". The porcelain was always fired to Cone 6,
scrubbed, wiped, glazed with a LOWER temperature glaze, and refired.
This gave a very smooth glaze finish.
I don't know if any of these procedures will work on throwing bodies of
porcelain or not. Might be worth a try. Food for thought anyway.
Good luck.
John Rodgers
Chelsea, AL
ccpottery@BELLSOUTH.NET wrote:
>I fire colored porcelain in an electric kiln
> to a full Cone 8, almost 9.
>
>I love the feel of the unglazed, sanded
>porcelain ... dislike the slick feel of regular
>glazes ... feels like I'm touching glaze, not
>the clay.
>
>But I have noticed some glazed porcelain
>still feels like the clay ... the glaze lies in
>such a thin coat you almost cannot feel it.
>
>These pieces are usually matte and fired in
>gas.
>
>Does this mean I need a gas kiln or can such
>a result be achieved in electric?
>
>Chris Campbell - in North Carolina - looking out at a true
>Carolina blue sky today as the thermostat creeps back up
>to normal temps. Yummm !!
>
>Chris Campbell Pottery, llc
>9417 Koupela Drive
>Raleigh, NC 27615
>1-800-652-1008
>1-919-676-2172
>FAX : 919-676-2062
>E Mail : chris@ccpottery.com
>Website : www.ccpottery.com
>Wholesale : www.wholesalecrafts.com
>
>______________________________________________________________________________
>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.
>
>
>
>
May Luk on sun 6 feb 05
Hi Chris;
I had wiped off glaze from porcelain [cone 8 ox] and it gives a sheen. I
reckon you can get similar effect by thinning out the glaze,. Or if you dip
the pot in water before you dip the glaze, then the pot would take less
glaze.
I just read something interesting. On page 176 - 177 in 'Out of the Earth,
Into the Fire' by Mimi Obstler. It says:"A thin coat of bone ash creates a
surface sheen on the claybody.....Hence, it is common practice to spray a
thin coat of bone ash on an unglazed claybody. This is especially effective
on sculptural forms."
Another paragraph; " Despite the dry stiff surface of bone ash, a
professional potter reports that a thin spray of bone ash and water will
produce a faint sheen on a white, fine-grained claybody, at the cone 5/6
temperatures." [oxidation]
Just something new to try.
Kung Hai Fai Choi!!
May
London, UK
Lee Love on sun 6 feb 05
ccpottery@BELLSOUTH.NET wrote:
>Does this mean I need a gas kiln or can such
>a result be achieved in electric?
>
>
>
Chris, Never say never!
Hey, I heard the author Victor Villaseñor (wrote Burro
Genius) say today that the original usage of genius had nothing to do
with intelligence or a superior ability or attribute, but rather: "The
deity, the guardian angel, that each of us begin with at birth."
I work with porcelain -like, unglazed clay. You can
see here: http://potters.blogspot.com/
You should experiment. You might have to flux your clay to
get the surface you want, but I am sure it is possible.
I have experimented with dipping porcelain in a saturated
soda ash solution and have developed some nice blushed surfaces on
porcelain. That was in gas, but it would be worth trying in
electric. There is an article in CM from a few years back. If you
need the recipe for soda ash water, let me know and I will dig it up.
--
Lee in Mashiko, Japan http://mashiko.org
http://potters.blogspot.com/ WEB LOG
http://claycraft.blogspot.com/ Photos!
Lee Love on mon 7 feb 05
May Luk wrote:
>Another paragraph; " Despite the dry stiff surface of bone ash, a
>professional potter reports that a thin spray of bone ash and water will
>produce a faint sheen on a white, fine-grained claybody, at the cone 5/6
>temperatures." [oxidation]
>
>
I'd hesitate about spraying real boneash in the air, especially
in England. Maybe synthetic could be a substitution.
Here in Japan, we've just had a first case of
Creutzfeldt-Jacob Disease diagnosed, from a guy who visited England for
a month many years ago. This disease has an incubation period of
possibly up to 30 years.. They are checking to see if this person made
any blood donations, because it has recently been discovered that
Creutzfeldt-Jacob Disease can be transmitted through blood transfusion.
The latest news is that they found a Goat infected with Mad
Cows in France. Maybe we will learn that you don't feed herbivore's
their own brains.....
Sorry Cowpokes, I am giving up beef. "*Chup, Chup!*"
--
Lee in Mashiko, Japan http://mashiko.org
http://potters.blogspot.com/ WEB LOG
http://claycraft.blogspot.com/ Photos!
Bob Masta on tue 8 feb 05
Lee Love writes:
> I'd hesitate about spraying real boneash in the air,
> especially
> in England. Maybe synthetic could be a substitution.
>
> Here in Japan, we've just had a first case
> of
> Creutzfeldt-Jacob Disease diagnosed, from a guy who visited
> England for a month many years ago. This disease has an
> incubation period of possibly up to 30 years.. They are
> checking to see if this person made any blood donations,
> because it has recently been discovered that
> Creutzfeldt-Jacob Disease can be transmitted through blood
> transfusion.
>
Lee, Creutzfeldt-Jacob and Mad Cow disease are caused
by prions, which are tiny mis-folded proteins. It is true
that prions are not destroyed by conventional sterilization
such as boiling, but real bone ash should have been
calcined at much higher temperatures such that no
organics remain. I'd say bone ash should definitely safe
to use, with no worry at all about prion diseases. However,
I sure wouldn't want to try *making* bone ash, and having
to deal with ground bones!
Best regards,
Bob Masta
potsATdaqartaDOTcom
mailtoandrew@FSMAIL.NET on tue 8 feb 05
Hello Lee,
Just a few points in response to your warning to May:
1. Bone ash has never been linked with CJD
2. To produce bone ash the bone is calcined at well over 1000oC, and all
organic material is therefore lost
3. Bone ash made and sold in England is not made from English cows
I could not agree more with your statement ... =94Maybe we will learn that
you don't feed herbivore's their own brains ...=94
Kind regards,
Andrew
Lee Love on wed 9 feb 05
mailtoandrew@FSMAIL.NET wrote:
>Hello Lee,
>
>Just a few points in response to your warning to May:
>
>1. Bone ash has never been linked with CJD
>2. To produce bone ash the bone is calcined at well over 1000oC, and all
>organic material is therefore lost
>3. Bone ash made and sold in England is not made from English cows
>
>
Yes, you are right. I posted the same data the last time we talked about
this. Just before I posted, I had just heard about the Japanese getting
Mad Cow's. and that was in front of my mind.
>I could not agree more with your statement ... ”Maybe we will learn that
>you don't feed herbivore's their own brains ...”
>
>
Yeah. Nature is a harsh schoolmaster. Maybe this is how "the meek" will
inherit the world? We will know more in 20 or 30 years.
--
Lee in Mashiko, Japan http://mashiko.org
http://potters.blogspot.com/ WEB LOG
http://claycraft.blogspot.com/ Photos!
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