Ryan Koechel on tue 4 mar 03
Hey all-
I'm looking for a ^04 porcelain throwing body...i haven't been able to put one
together...well atleast something i can throw with. Anyone have any recipes
or ideas....please let me know
Thanks Ryan
Vince Pitelka on tue 4 mar 03
Ryan -
There are lots of recipes out there for cone 04 whiteware bodies, but there
is no such thing as a cone 04 porcelain. It is an impossibility. A
porcelain body must be thoroughly vitrified and stonelike. At lowfire
temperatures you could approach vitrification by loading the body with
glassy frit, but the result would be extremely brittle. You could probably
achieve a fairly dense functional whiteware, but you couldn't call it a
porcelain. Some people misunderstand this. Porcelain is not just white
clay. And if you start with a higher temperature porcelain clay and fire it
to low-fire temperature or raku fire it, the product is not porcelain. In
order to have porcelain, you need a porcelain clay, and you need to fire it
to the appropriate midrange or highfire temperature to attain the necessary
density and durability.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
Paul Lewing on tue 4 mar 03
on 3/3/03 11:42 PM, Ryan Koechel at Ryan.Koechel@COLORADO.EDU wrote:
> I'm looking for a ^04 porcelain throwing body...i haven't been able to put one
> together.
And you won't either, Ryan. Porcelain is, by definition, a highfire clay.
You can get a cone 04 white clay, usually made from a combination of ball
clay and talc, but it will never have the density or the translucence of
porcelain. Many people even think that calling a mid-range (cone 5 or 6)
white clay porcelain is a misnomer.
Paul Lewing, Seattle
John Rodgers on tue 4 mar 03
Ryan, I've never heard of a porcelain body that vitrifies at such a low
temperature. Most porcelains vitrify at cone 6 or above. White
earthenwares are available for cone 04, but whatever body is used, if
it doesn't vitrify, there whill be porosity that can only be sealed by
glazing.
Is porcelain really what you are looking for?
John Rodgers
Birmingham, AL
Ryan Koechel wrote:
> Hey all-
>
>I'm looking for a ^04 porcelain throwing body...i haven't been able to put one
>together...well atleast something i can throw with. Anyone have any recipes
>or ideas....please let me know
>
>Thanks Ryan
>
>______________________________________________________________________________
>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.
>
>
>
Rick Hamelin on wed 5 mar 03
Another defining issue with porcelain is how the glaze and clay completely
integrate and fuse together, unlike lowfires where if you review the
crosssection of the the glaze and body the glaze layer is clearly a separate
layer.
> Ryan -
> There are lots of recipes out there for cone 04 whiteware bodies, but there
> is no such thing as a cone 04 porcelain. It is an impossibility. A
> porcelain body must be thoroughly vitrified and stonelike. At lowfire
> temperatures you could approach vitrification by loading the body with
> glassy frit, but the result would be extremely brittle. You could probably
> achieve a fairly dense functional whiteware, but you couldn't call it a
> porcelain. Some people misunderstand this. Porcelain is not just white
> clay. And if you start with a higher temperature porcelain clay and fire it
> to low-fire temperature or raku fire it, the product is not porcelain. In
> order to have porcelain, you need a porcelain clay, and you need to fire it
> to the appropriate midrange or highfire temperature to attain the necessary
> density and durability.
> Best wishes -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Technological University
> 1560 Craft Center Drive, Smithville TN 37166
> Home - vpitelka@dtccom.net
> 615/597-5376
> Office - wpitelka@tntech.edu
> 615/597-6801 x111, FAX 615/597-6803
> http://iweb.tntech.edu/wpitelka/
>
> ______________________________________________________________________________
> 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.
Sabine Wolf on wed 5 mar 03
> Ryan, I've never heard of a porcelain body that vitrifies at such a low
> temperature. Most porcelains vitrify at cone 6 or above. White
> earthenwares are available for cone 04, but whatever body is used, if
> it doesn't vitrify, there whill be porosity that can only be sealed by
> glazing.
I think a cone 04 porcelain body is possible with the right recipe. I would
try to mix a frit or a glaze with kaolin, but I don't know if this is
throwable. But I'm sure you get a lot of deformation together with the
vitrification.
Tschau,
Sabine
Tony Ferguson on wed 5 mar 03
Vince,
I thought porcelain was a kaolin, not a clay?
Thank you.
Tony Ferguson
On Lake Superior, where the sky meets the Lake
Stoneware, Porcelain, Raku and more
by Coleman, Ferguson, Winchester...
www.aquariusartgallery.com
218-727-6339
315 N. Lake Ave
Apt 312
Duluth, MN 55806
----- Original Message -----
From: "Vince Pitelka"
To:
Sent: Wednesday, March 05, 2003 9:54 PM
Subject: Re: ^04 porcelain
> > kept thinking about daniel rhodes...
> > from his & others' perspectives, porcelain isn't a clay body, it's a
> process that
> > requires 2 elements..
> > 1. porcelainous clay (ok, i can't spell)
> > 2. firing at cone 9 MINIMUM... up to ^14
>
> Sabra -
> Thanks for posting this. I am always bothered by the dilution and misuse
of
> language, and Daniel Rhodes is right in terms of the technical definintion
> of porcelain. But we went through all this recently, and in the
contemporary
> ceramics world it seems that people have accepted the definition that a
> dense, durable, vitreous, fine-grain, white claybody fired at cone 6 or
> above can be called a procelain. I guess we have to live with that, just
> like we have to live with the reality of so many otherwise intelligent
> people pronouncing the word "nuclear" like "nucular." How can anyone do
> that????
> Best wishes -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Technological University
> 1560 Craft Center Drive, Smithville TN 37166
> Home - vpitelka@dtccom.net
> 615/597-5376
> Office - wpitelka@tntech.edu
> 615/597-6801 x111, FAX 615/597-6803
> http://iweb.tntech.edu/wpitelka/
>
>
____________________________________________________________________________
__
> 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.
>
Ababi on wed 5 mar 03
In any case, porcelain or "Kaolain" there are such claybodies in Val Cushing's
handbook.
Ababi
---------- Original Message ----------
> Hey all-
>I'm looking for a ^04 porcelain throwing body...i haven't been able to put one
>together...well atleast something i can throw with. Anyone have any recipes
>or ideas....please let me know
>Thanks Ryan
>______________________________________________________________________________
>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.
Roger Korn on wed 5 mar 03
Paul Lewing wrote:
>on 3/3/03 11:42 PM, Ryan Koechel at Ryan.Koechel@COLORADO.EDU wrote:
>
>
>
>>I'm looking for a ^04 porcelain throwing body...i haven't been able to put one
>>together.
>>
>>
>
>And you won't either, Ryan. Porcelain is, by definition, a highfire clay.
>You can get a cone 04 white clay, usually made from a combination of ball
>clay and talc, but it will never have the density or the translucence of
>porcelain. Many people even think that calling a mid-range (cone 5 or 6)
>white clay porcelain is a misnomer.
>
Most of the mid-fire "porcelain" I've encountered is just a good ^10
porcelain with talc thrown at it. You can't get the trunslucency of the
original high-fire because by the time the mid-fire matures to that
point, it slumps. Or that's what happens to me.
Roger
>Paul Lewing, Seattle
>
>______________________________________________________________________________
>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.
>
>
>
--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464
clifton wood on wed 5 mar 03
i enjoyed reading all the past porcelain postings...
kept thinking about daniel rhodes...
from his & others' perspectives, porcelain isn't a clay body, it's a process that
requires 2 elements..
1. porcelainous clay (ok, i can't spell)
2. firing at cone 9 MINIMUM... up to ^14
me - i'm just a stoneware slob. it is what it is.
sabra
rochester ny
Vince Pitelka on wed 5 mar 03
> kept thinking about daniel rhodes...
> from his & others' perspectives, porcelain isn't a clay body, it's a
process that
> requires 2 elements..
> 1. porcelainous clay (ok, i can't spell)
> 2. firing at cone 9 MINIMUM... up to ^14
Sabra -
Thanks for posting this. I am always bothered by the dilution and misuse of
language, and Daniel Rhodes is right in terms of the technical definintion
of porcelain. But we went through all this recently, and in the contemporary
ceramics world it seems that people have accepted the definition that a
dense, durable, vitreous, fine-grain, white claybody fired at cone 6 or
above can be called a procelain. I guess we have to live with that, just
like we have to live with the reality of so many otherwise intelligent
people pronouncing the word "nuclear" like "nucular." How can anyone do
that????
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
Vince Pitelka on thu 6 mar 03
> I thought porcelain was a kaolin, not a clay?
Tony -
Kaolin is clay - either a pure residual primary clay mined from the original
location of the parent rock, or an almost pure "secondary kaolin" which has
been transported minimally (by wind or water) from the parent rock, and is
therefore still very pure but finer in particle size. The secondary kaolins
make the best throwing bodies.
Kaolinite is the basic clay crystal which results from the breakdown of
feldspathic minerals. So the primary clay content in kaolin, stoneware
clay, ball clay, and fireclay is all kaolinite.
Porcelain is generally a mix of kaolins and feldspar, usually with flint and
often with a white-burning ball clay as well.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Office - wpitelka@tntech.edu
615/597-6801 x111, FAX 615/597-6803
http://iweb.tntech.edu/wpitelka/
Craig Edwards on thu 6 mar 03
Tony:
I always thought porcelain as a claybody that contains Kaolin as an
ingredient. A porcelain claybody might contain a mix of Kaolin, ball clay,
silica and feldspar. This claybody is then fired hot enough to make it
translucent, ( cone 9-14).
Does this sound right?
Craig Edwards
New London MN
>
>Vince,
>
>I thought porcelain was a kaolin, not a clay?
>
>Thank you.
>
>Tony Ferguson
>
>
>----- Original Message -----
>From: "Vince Pitelka"
>To:
>Sent: Wednesday, March 05, 2003 9:54 PM
>Subject: Re: ^04 porcelain
>
>
> > > kept thinking about daniel rhodes...
> > > from his & others' perspectives, porcelain isn't a clay body, it's a
> > process that
> > > requires 2 elements..
> > > 1. porcelainous clay (ok, i can't spell)
> > > 2. firing at cone 9 MINIMUM... up to ^14
> >
>
_________________________________________________________________
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Janet Kaiser on fri 7 mar 03
WE Brits pronounce things differently?!?! Now just a minute all you young
whipper-snappers!! Who went off and decided to do everything differently?
Who decided NOT to speak the King's English? Hummm?? Then you went and
allowed a certain Mr. Webster to really screw it up even more! An early
example of unilateral US action... At least the German speaking nations get
together every now and then to "reform" German, so they all agree on the
same formal, academic language (which BTW accepts regional differences).
The most important part, it that we UNDERSTAND one another and that is
hardly going to be affected by mere pronunciation. Accents are becoming
more mid-Atlantic by the day... Even US English pronunciation and syntax on
the BBC! Horror of horrors!! There would have been hundreds of enraged
letters to The Times 20 years ago! Mind you, the jokes about COAL--IN
Powell are really funny and make it hard to take the man seriously...
(COLL--IN being a the pronunciation of this common name here).
As for the porcelain thing... I would be extremely angry if I were a
porcelain maker and someone came along claiming that their low-fired stuff
even approached my preferred medium. It is misrepresentation IMHO. The
skill levels needed to work in real porcelain successfully far exceed those
of other clays, the production costs are far higher and the results are so
much superior... How dare someone working in a white clay call it
porcelain??!!? How dare the clay makers claim it as such? Just to keep
their clients happy? Well, I'm sorry, that is not good enough.
Why claim something is, what it patently is not? It smacks of inverted clay
snobbery. There are laws against calling jewelry "gold" when made of base
metals or even gold below a certain carat content... And porcelain is just
as precious... It was even known as "White Gold" at one point. Why do we
have to reduce everything in this world to the lowest common denominator?
It makes me mad. No way will I accept this "change of language", just
because these cheats want it that way to suit their own dubious ends. They
devalue the work of others through their selfish actions.
AND furthermore, it confuses "the general public", which is inexcusable in
my book! There is so much whining about cheapo made-in-China Walmart
products affecting all clay people through their promotion of
cheap-and-cheerful, throw-away ware. Accepting low-fired clay as
"porcelain" is on a par with that IMO and it is really shooting ourselves
in the foot... We do not need that right now (especially) or at any time.
What we need are "precious", "extraordinary" and "rare" and therefore an
increase in awe and desirability. It is all a part of keeping those high
standards... Something which is apparently politically incorrect around
Clayart these days.
Sincerely
Janet Kaiser - speaking out for those who are afraid to say what they
think.
*** IN REPLY TO THE FOLLOWING MAIL:
Lili: >The Brits do pronounce things differently at times<
Earl: > And the word schedule, pronounced ssshhhedule, and school
pronounced
skool? What is that all about?<
**********************************************************************
TRUTH is too precious to tell every fool who asks for it...
****** This post was sent to you today by Janet Kaiser *******
The Chapel of Art / Capel Celfyddyd
8 Marine Crescent, Criccieth LL52 0EA, Wales, UK
Tel: ++44 (01766) 523570 URL: http://www.the-coa.org.uk
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Jon Pacini on fri 7 mar 03
Greetings all---- Now that we've collectively decided if you use the term
"Porcelain", you can only be referring to white firing kaolin based body
that must be fired to a specific temperature (yet to be specifically
defined, but may be restricted to higher than 2300*F, 1250*C for our Celsius
inclined members), Joanna wants to know what's going to happen when she
makes an object out of one of these fritted formulas yet to be named.
Well, the porcelain I grew up with was 25% kaolin 25% ball clay 25% silica
25% spar. If you sub frit for the 50% made up of silica and spar,(oddly
enough you end up with the body in S.Peterson's book), the frit isn't going
to impact the formability much. It will be a body with a fair workability,
at least as far as porcelains are concerned. Until the frit starts leaching
alkaline anyway, then it will get hard as a rock. Don't make any more of the
body than you plan on using within a few hours.
As for firing it and the end result, it depends on the frit you use. If you
use a frit that fluxes the body so it's vitreous at ^04, you're going to get
a very dense white object at ^04. Which the exact term for may be, 'low fire
fritted white ware'. 'China' is a common term sometimes applied,
'unadulterated bullshit' has also been submitted for this category, we'll
vote later. If you use a frit that fluxes the body so it's vitreous at ^5/6,
you are going to get an object that is white, very dense and may or may not
be porcelain, as this temperature range is still open for debate. If you use
a frit that fluxes the body so it's vitreous at ^10 or higher, you
apparently get a 'True' porcelain object.
I would like to add that no porcelain ware that was made in Asia during the
Chinese Dynastic period was ever formulated with the minerals we use in the
west nor likely fired in the manner that western kilns are fired. "True"
porcelain indeed.
I don't claim any of the above mentioned bodies are superior to non fritted
bodies or inferior to them. How you use the afore mentioned information is
up to your discretion.
Never fire a kiln without a test of some sort in it. Keep very good records,
you'll always learn something valuable!!
Best regards
Jon Pacini
Clay Manager
Laguna Clay Co.
John Rodgers on sat 8 mar 03
Janet Kaiser wrote:
> The
>skill levels needed to work in real porcelain successfully far exceed those
>of other clays, the production costs are far higher and the results are so
>much superior... How dare someone working in a white clay call it
>porcelain??!!? How dare the clay makers claim it as such? Just to keep
>their clients happy? Well, I'm sorry, that is not good enough.
>
Go Janet!!!
Porcelain has been my thang!! Is my thang, Will always by my thang!!!
It is the Kings claybody, whether thrown, slabbed, pinched, coiled or
slipcast. There is nothing like it In antiquity it was so valuable that
any who worked with it and gave away its secrets were put to death. That
was true in China at one time, and later even in France. The value of
porcelain was such that it has a terrible and violent history behind its
production over the centuries. Today it is still the "Best of the Best"
in claybodies for my purposes. Our own porcelain history here in America
began around 1750 with the digging of a pure white kaolin of the finest
quality near Savannah, Georgia. Georgia kaolins are still shipped all
over the country to this day.
John Rodgers
Birmingham, AL
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