porcelain

updated mon 27 jun 11

Rita Darling on sat 14 mar 98

Is it possible to reconstitute a bucket of trimmings into a casting slip?

Thank you all for the advice on crystalline firing - seems an electronic
controller is the only answer.

I.Lewis on thu 13 jan 00

------------------
I understand Porcelain to be a ceramic which has the following qualities=3B

1 It is Translucent, meaning that light which enters the substance from one =
side
passes through and out of the other. Any sense of a clear image is diffused =
or
obscured but an object held between the light and the porcelain will be seen=
as
a shadow.

2 It is white, or nearly so unless deliberately coloured.

These qualities can be achieved using a variety of compositions and firing
programmes.

Of these properties, Translucency is the most important. If not present the =
name
should be denied. I would call a ceramic which is not translucent white
stoneware.

Provided people can accept this as a definition I will continue forwarding
information to the group which may assist many people to understand some of =
the
problems.

Best regard to all,

Ivor Lewis. Who recorded a temperature of 45 Celsius in the studio. Are we
talking serious air conditioning=21=21=21 And Olive is preparing a Ripe =
Damson Ice
Cream Base

Carolyn Nygren Curran on fri 14 jan 00

Porcelain is porcelain if it is translucent WHERE THIN...of at least that's
been my understanding. There is a lot of wonderful antique traditional
Chinese porcelain which is not translucent. Or are we just splitting
hairs? It's a super clay body, whatever we call it and even if we can't
always see its translucency on a particular piece. I may be all wet, but
that's what I've read in books over the years. CNC

Iveragh Ceramics on fri 14 jan 00

Ivor,
What a load of pedantic crap.Porcelain is a clay body and people can
do whatever the hell they like with it and it remains porcelain.Who promoted
you to God.
Bob Hollis trying very hard to be non agressive.
is
----- Original Message -----
From: "I.Lewis"
To:
Sent: 13 January 2000 21:58
Subject: Porcelain


----------------------------Original message----------------------------
------------------
I understand Porcelain to be a ceramic which has the following qualities;

1 It is Translucent, meaning that light which enters the substance from one
side
passes through and out of the other. Any sense of a clear image is diffused
or
obscured but an object held between the light and the porcelain will be seen
as
a shadow.

2 It is white, or nearly so unless deliberately coloured.

These qualities can be achieved using a variety of compositions and firing
programmes.

Of these properties, Translucency is the most important. If not present the
name
should be denied. I would call a ceramic which is not translucent white
stoneware.

Provided people can accept this as a definition I will continue forwarding
information to the group which may assist many people to understand some of
the
problems.

Best regard to all,

Ivor Lewis. Who recorded a temperature of 45 Celsius in the studio. Are we
talking serious air conditioning!!! And Olive is preparing a Ripe Damson Ice
Cream Base

Earl Brunner on fri 14 jan 00

I think I would also include high firing temperature, and vitreous quality to th
fired work. Your definition may in fact encompass those elements ( i.e. you may
be able to get the translucency at lower temperatures, or the vitreousness witho
the translucency)

I.Lewis wrote:

> ----------------------------Original message----------------------------
> ------------------
> I understand Porcelain to be a ceramic which has the following qualities;
>
> 1 It is Translucent, meaning that light which enters the substance from one si
> passes through and out of the other. Any sense of a clear image is diffused or
> obscured but an object held between the light and the porcelain will be seen a
> a shadow.
>
> 2 It is white, or nearly so unless deliberately coloured.
>
> These qualities can be achieved using a variety of compositions and firing
> programmes.
>
> Of these properties, Translucency is the most important. If not present the na
> should be denied. I would call a ceramic which is not translucent white
> stoneware.
>
> Provided people can accept this as a definition I will continue forwarding
> information to the group which may assist many people to understand some of th
> problems.
>
> Best regard to all,
>
> Ivor Lewis. Who recorded a temperature of 45 Celsius in the studio. Are we
> talking serious air conditioning!!! And Olive is preparing a Ripe Damson Ice
> Cream Base

--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net

Ray Aldridge on fri 14 jan 00

At 04:58 PM 1/13/00 EST, you wrote:
>----------------------------Original message----------------------------
>------------------
>I understand Porcelain to be a ceramic which has the following qualities;
>
>1 It is Translucent, meaning that light which enters the substance from
one side
>passes through and out of the other. Any sense of a clear image is
diffused or
>obscured but an object held between the light and the porcelain will be
seen as
>a shadow.
>
>2 It is white, or nearly so unless deliberately coloured.
>
>These qualities can be achieved using a variety of compositions and firing
>programmes.
>
>Of these properties, Translucency is the most important. If not present
the name
>should be denied. I would call a ceramic which is not translucent white
>stoneware.

This strikes me as a problematic definition, because translucency is not
simply a matter of ceramic composition, but is also structural in nature--
in other words, porcelain must be thinly potted to be translucent. There
are many bodies which would fulfill the definition if thinly potted, but
would be classified as "white stoneware" if more robustly made, according
to Ivor's definition.

Further, there are many classic Chinese wares that we commonly call
porcelain which would fail this definition.

It seems to me that translucency is not the most singular aspect of
porcelain, since there are bone chinas which are translucent.

To me, porcelain is an artificial body fired to a high temperature, is
usually white, is very finegrained, and fractures in a conchoidal pattern.
To me, porcelain is a near-glass fired almost to the point of collapse,
with a glaze (if glazed) matured in the same firing that matures the body.
In many ways, the best and purest definition of porcelain would probably
involve the unusual intimacy between the glaze of a porcelain pot and the
near-glass of the body.

Just my opinion.

Ray


Aldridge Porcelain and Stoneware
http://www.goodpots.com

Nina Jones on fri 14 jan 00

------------------
CNC, you're absolutely right. Whether the piece you create or that is =
created
from the porcelain clay body is translucent or not, if the clay body is
porcelain, the pot is a porcelain pot even if you can't achieve that 1/8th =
of an
inch thinness. Porcelain is a type of clay, not a method of forming.

Nina D. Jones
Southside Chicago
=40 njones=40winston.com

=3E=3E=3E Carolyn Nygren Curran =3Ccncpots=40capital.net=3E 01/14/00 02:04PM=
=3E=3E=3E
----------------------------Original message----------------------------
Porcelain is porcelain if it is translucent WHERE THIN...of at least that's
been my understanding. There is a lot of wonderful antique traditional
Chinese porcelain which is not translucent. Or are we just splitting
hairs? It's a super clay body, whatever we call it and even if we can't
always see its translucency on a particular piece. I may be all wet, but
that's what I've read in books over the years. CNC

Janet Kaiser on sat 15 jan 00

------------------
I do not work in porcelain, but I can add my college notes if it helps =
anyone?
They give away their (and my) age by references to early editions of =
magazines
now either defunct or in their hundred-and-something edition=21 Anyway for =
what
they are worth here goes:

PORCELAIN

In China the definition of porcelain is wider than generally accepted in the
West. Known as T'zu it could be any fine pale body of primary clay with a
distinctive ring when struck, fired to vitrification but often too thick to =
show
the translucency which we expect today.

Essentially porcelain is kaolin and silica with a little flux, fired to
vitrification point. This is =22true=22 or hard-paste porcelain and requires
temperatures in the region of 1350 degrees Celsius.

An increase or multiplication of the bases (or of the acids, boron or =
fluorine)
can lower the melting point and it is possible that the Eastern kilns =
averaged
no more than 1270 to 1300 deg. C.

Richard Parkinson asserts that 1360 deg. C. is needed to fully develop the
=22felted mass of mullite needles bonded in a glassy cement=22 by which a =
true
porcelain is defined and that lower temperature mixtures such as David =
Leach's
1270 deg. C. body give a white stoneware.

To a degree this is a difference of words and preferences. Certainly the
bentionite porcelains lack the white purity of the harder types and one must
learn to counter what Harry Davis calls their =22evil properties=22, but =
they throw
pleasantly and thinly up to 9 inches/22 cm high or so. It can also be used =
for
pinching, but the joins tend to show in slab pots. The colour is better in
reduction.

BASIC PORCELAIN RECIPE:
50 =25 kaolin (china clay)
25 =25 flint or quartz
25 =25 feldspar

It is wise to leave the feldspar at 25=25 although this may be replaced in =
small
part by mepheline: silica can be reduced to a 15=25 minimum. English kaolins=
lack
plasticity, limiting the development of porcelains in England. By sapping a
proportion of kaolin ball clay the throwing qualities are improved but the
translucency diminished. Rhodes suggests up to 15=25 ball clay, 2-5=25 =
=22white=22
bentonite will make a body throwable but will increase shrinkage and =
impurities.
Bentonite will also greatly increase thixotropy so apparently stiff or even
leather hard clay may soften suddenly and alarmingly under pressure or when
turning. Practice can overcome the dangers here. More serious is the =
tendency to
warp in drying and firing.

Mixing the body needs to be thorough for complete fusion of the particles.
Parkinson recommends a 300 screen. For many potter the simple compounding of
already finely ground materials followed by efficient hand kneading and a =
week
or so of =22resting=22 will suffice.

DAVID LEACH PORCELAIN:
Grollegg china clay powder 53
Potash feldspar 25
Water-ground quartz 17
White bentonite 5
Firing to translucency 1260 to 1280 deg. Celsius Substitute some quartz for
china clay if crazing is persistently encountered.

PARKINSON PUBLISHED CERAMIC REVIEW NO. 3
EEC JM china clay 51
Potash feldspar 18
EEC BB ball clay 7
Fine (300 mesh) quartz 24

A traditional commercial earthenware body, fired to 1280 deg. C. or more can
also be used to produce a low translucency =22proto-porcelain=22. There are =
also
dolomite porcelains. The English porcelain equivalent is bone china.

Bernard Leach's recipe given in Pottery Quarterly 1 is near to the =
earthenware
body type:
China clay 25
Black ball clay 33
Feldspar 30
Quartz 12

END OF NOTES

If anyone would like my college notes on PORCELAIN GLAZES please mail me. =
But
here is the glaze given for the David Leach Porcelain body above:

Feldspar 12
Dolomite 12
Quartz 22
China clay 14
Ball clay 9
Petalite 28
Bentonite 3



Janet

The Chapel of Art: Home of The International Potters' Path
Criccieth LL52 0EA, GB-Wales, UK
WEBSITE: http://www.the-coa.org.uk
EMAIL: postbox=40the-coa.org.uk
See The Path=21 Tiles still needed: 4000+

John Rodgers on sat 15 jan 00

I have worked with porcelain for quite a number of years, and my reading and
research produces the definition of porcelain as a clay body that is vitreous
when fired to maturity, sonorous if thin, and translucent where thin, It
always worked for me!

John Rodgers
Birmingham, AL

Carolyn Nygren Curran wrote:

> ----------------------------Original message----------------------------
> Porcelain is porcelain if it is translucent WHERE THIN...of at least that's
> been my understanding. There is a lot of wonderful antique traditional
> Chinese porcelain which is not translucent. Or are we just splitting
> hairs? It's a super clay body, whatever we call it and even if we can't
> always see its translucency on a particular piece. I may be all wet, but
> that's what I've read in books over the years. CNC

Richard mahaffey on sun 16 jan 00

Hi,

The definition that we laerned in Grad School for porcelain specified: 0%
porosity, Reduction fired to cone 8 or above. The old defintiion of "true
Procelain" the clay color was blue white, this came for very slight
ammounts of Iron in the clay. Fiored in Oxidation this clay was a bit
creamy in color. The porcelain in China was a creammy yellow in
Jingdezhen, yellow or green in Japan when they were in the wet state.

0% porosity implies that the clay body is vitreous. By the way the German
(can't remember how to spell his name) who "invented" Porcelain (some
800-1,000 years after the Chinese, by the by.) came up
with a clay body that fired out red...go figure.

Since the Chinese invented it, poreclain should have the qualities of
their clay.

Well this will help stir the slip barrel a bit...
For what it is worth....this is what we were taught by F. Carlton Ball. I
also was gfiven a similar definition by Hebert Sanders at San Jose State.


Rick Mahaffey
Tacoma Washington, USA

Bill Williams on sun 16 jan 00

I made porcelain dolls for many years. Poured the molds, cleaned, fired,
painted..........the whole bit. My porcelain slip ranged in color from
white to brown. You can buy porcelain slip in a variety of colors and most
of the colors are not translucent, but it is still porcelain. It still
looks decidedly different than earthenware clay or stoneware clay when in
the bisque form. White porcelain does not become stoneware simply because
it is not translucent. Connie

Peter T. Wang on sun 16 jan 00

Because claybodies can have varying ingredients they are not always easy
to categorize; so it is difficult to define what "porcelain" means. One
can use a strict or loose interpretation of the term, but I do not agree
with the notion that porcelain has "very fine particle size." Since many
porcelains consist mainly of kaolin, a very pure, high-firing primary
clay, its particle size is actually larger than many stonewares, the
primary ingredient of which is fireclay (a secondary clay).

One can say translucency is a criterion for porcelain but this is also
misleading as mentioned. A more accurate description is the idea of how
vitreous the body is when fired to its maturing range.

Earthenware is not vitreous at maturity; nor will it become vitreous if
fired past its range. Hence it has a porosity greater than 2% (usually
5-20%).

Stoneware is vitreous at maturity, therefore it is generally non-porous
(1-2% porosity).

Porcelain is extremely vitreous at maturity, rendering it the most
glasslike and non-porous of bodies, with typical porosities ranging from 0
to 1%.

This classification is of course not quantitative. In particular the
line between stoneware and porcelain is sometimes so blurred that we call
some bodies "porcelaneous stoneware." Note that no mention of high- or
low-fire was made, because some bodies become quite vitreous at lower
cones and it would be misleading to classify them as earthenware bodies.

In any case, the best way to determine what a body is is to consider
various properties: What are the ingredients? Is it primarily composed
of a primary, or secondary clay? How vitreous is it when fired? How
dense or non-porous is the body?

Misleading properties may be: Is it white? High-fire, or low-fire?
Translucent when thin? Plastic, or non-plastic? How do other wares fit
the desired criteria? Glaze/body boundary well-defined? (This last one
is not applicable to unglazed fired porcelains!)

-Peter

> This strikes me as a problematic definition, because translucency is not
> simply a matter of ceramic composition, but is also structural in nature--
> in other words, porcelain must be thinly potted to be translucent. There
> are many bodies which would fulfill the definition if thinly potted, but
> would be classified as "white stoneware" if more robustly made, according
> to Ivor's definition.
>
> Further, there are many classic Chinese wares that we commonly call
> porcelain which would fail this definition.
>
> It seems to me that translucency is not the most singular aspect of
> porcelain, since there are bone chinas which are translucent.
>
> To me, porcelain is an artificial body fired to a high temperature, is
> usually white, is very finegrained, and fractures in a conchoidal pattern.
> To me, porcelain is a near-glass fired almost to the point of collapse,
> with a glaze (if glazed) matured in the same firing that matures the body.
> In many ways, the best and purest definition of porcelain would probably
> involve the unusual intimacy between the glaze of a porcelain pot and the
> near-glass of the body.
>
> Just my opinion.
>
> Ray
>
>
> Aldridge Porcelain and Stoneware
> http://www.goodpots.com

Richard Selfridge on sun 16 jan 00

Bob,
It seems to me that maybe you just don't get the concept of porcelain.
Things don't take on their name until fully realized. We don't call cookie
dough cookies nor a small bright child with an interest in medicine a
doctor. Porcelain is one of those things that is teleological in the way
Aristotle saw the world as "becoming".
The clay body you speak of can, (if free from opacifiers such as titanium
or talc or colorants such as iron), sometimes "become" porcelain. This is
only after it is fired to vitrification. One does not demand transclucency
that you can read a newspaper through but at least the transmission of
light, or the kind of refraction or reflection we call luminosity. Often
quite thick pots can have this quality.
Once you have tried to make transclucent porcelain you realize how
inadequate opaque "whitewares" are at imitating this demanding standard.
People can call things what they wish; that is the nature of language, but
when someone says "pit fired porcelain" it makes me wince. Like the
cookies, they are not realized until they are properly baked.
For a great discussion of what porcelain really is, see John Reeve, "More
Notes on Porcelain" in Studio Potter. Vol. 6 No. 2. This whole issue is
like a bible for those who seek the special quality called porcelain.
Hope this helps to clear things up, a very ungod like Richard Selfridge
Http://www.compusmart.ab.ca/selfridge

At 01:06 PM 1/14/00 -0700, you wrote:
>----------------------------Original message----------------------------
>Ivor,
> What a load of pedantic crap.Porcelain is a clay body and people can
>do whatever the hell they like with it and it remains porcelain.Who promoted
>you to God.
> Bob Hollis trying very hard to be non agressive.
> is
>----- Original Message -----
>From: "I.Lewis"
>To:
>Sent: 13 January 2000 21:58
>Subject: Porcelain
>
>
>----------------------------Original message----------------------------
>------------------
>I understand Porcelain to be a ceramic which has the following qualities;
>
>1 It is Translucent, meaning that light which enters the substance from one
>side
>passes through and out of the other. Any sense of a clear image is diffused
>or
>obscured but an object held between the light and the porcelain will be seen
>as
>a shadow.
>
>2 It is white, or nearly so unless deliberately coloured.
>
>These qualities can be achieved using a variety of compositions and firing
>programmes.
>
>Of these properties, Translucency is the most important. If not present the
>name
>should be denied. I would call a ceramic which is not translucent white
>stoneware.
>
>Provided people can accept this as a definition I will continue forwarding
>information to the group which may assist many people to understand some of
>the
>problems.
>
>Best regard to all,
>
>Ivor Lewis. Who recorded a temperature of 45 Celsius in the studio. Are we
>talking serious air conditioning!!! And Olive is preparing a Ripe Damson Ice
>Cream Base
>
>

george koller on mon 17 jan 00

Hello,

I have studied the Arne Ase book "Water Colour on Porcelain".
We are working with the soluable salts on stoneware - a nice
variety readily available to me. I think I may know how to transfer
complex images to flat Porcelain. Shading would be possible
within bodies on a color.

The process I have in mind would not make sense for small
pieces, but would be marvelously economical for many tile
pieces - as in larger murals. One of a kinds no particular
problem.

Would this be exciting to anybody?


George Koller
Sturgeon Bay, WI - Door County


*the programmer formerly known as the artist formerly known
as georgio*

Ray Aldridge on mon 17 jan 00

At 09:26 PM 1/16/00 EST, you wrote:
>----------------------------Original message----------------------------
>Because claybodies can have varying ingredients they are not always easy
>to categorize; so it is difficult to define what "porcelain" means. One
>can use a strict or loose interpretation of the term, but I do not agree
>with the notion that porcelain has "very fine particle size." Since many
>porcelains consist mainly of kaolin, a very pure, high-firing primary
>clay, its particle size is actually larger than many stonewares, the
>primary ingredient of which is fireclay (a secondary clay).

You've misinterpreted what I wrote, I think. The term I used was
"finegrained" and I used it in the sense that in earthenware and to a
lesser extent stoneware, microscopic examination of fired ware reveals a
more granular structure than that of fired porcelain.

I also must disagree with the implication that low-fired translucent wares
might be properly called porcelain, though perhaps here I'm
misunderstanding you.

Ray

Aldridge Porcelain and Stoneware
http://www.goodpots.com

Ray Aldridge on mon 17 jan 00

At 09:32 PM 1/16/00 EST, you wrote:
>----------------------------Original message----------------------------
>Bob,
> It seems to me that maybe you just don't get the concept of
porcelain.
>Things don't take on their name until fully realized. We don't call cookie
>dough cookies nor a small bright child with an interest in medicine a
>doctor. Porcelain is one of those things that is teleological in the way
>Aristotle saw the world as "becoming".
> The clay body you speak of can, (if free from opacifiers such as
titanium
>or talc or colorants such as iron), sometimes "become" porcelain. This is
>only after it is fired to vitrification. One does not demand transclucency
>that you can read a newspaper through but at least the transmission of
>light, or the kind of refraction or reflection we call luminosity. Often
>quite thick pots can have this quality.

This last quality would seem to be pretty subjective. But if Ivor had
defined porcelain as a white highfired body, translucent when potted
thinly, I wouldn't have quibbled with him.

> Once you have tried to make transclucent porcelain you realize how
>inadequate opaque "whitewares" are at imitating this demanding standard.
>People can call things what they wish; that is the nature of language, but
>when someone says "pit fired porcelain" it makes me wince.

Me too. I was in a gallery in Taos some years ago, without my "Been a
Potter for Years and Years" T-shirt. There were some very pretty thrown
whiteware pieces in the gallery, skillfully-done brushwork songbirds. They
were labeled porcelain but they were obviously not-- the body was a chalky
lowfire you could practically scratch with a fingernail. I mentioned to my
companion that they were not actually porcelain, and the gallery owner
descended on me like a silver-and-turquoise-bedizened harpy. She had, she
said, been a gallery owner for years more than I had been a potter, and she
knew all about pottery. I retreated in horror.

Ray


Aldridge Porcelain and Stoneware
http://www.goodpots.com

Iveragh Ceramics on mon 17 jan 00

Ray,
I certainly do get the concept of porcelain,the name comes from the
Italian name for a shellfish "porcellana"and this shell is translucent,I
have been told that the body used for this in Italy was a pure white
earthenware but I do not know this to be true. Most potters order a
porcelain body from their suppliers and over the course of time,the potters
being in general an imaginative lot,have done all kinds of things with this
type of body and every other body for that matter.For me,using porcelain
gives me an additional glaze spectrum without having to make new glazes as
my glazes come out completely different on my stoneware,I also throw
porcelain thin and thick and I raku and pit-fire it.To me it is still
porcelain.
My imagination does not allow me to subscribe to the doctrine of teleology.
Regards,
Bob
-----Original Message-----
From: Richard Selfridge
To: CLAYART@LSV.UKY.EDU
Date: 17 January 2000 02:34
Subject: Re: Porcelain


----------------------------Original message----------------------------
Bob,
It seems to me that maybe you just don't get the concept of
porcelain.
Things don't take on their name until fully realized. We don't call cookie
dough cookies nor a small bright child with an interest in medicine a
doctor. Porcelain is one of those things that is teleological in the way
Aristotle saw the world as "becoming".

>
>Provided people can accept this as a definition I will continue forwarding
>information to the group which may assist many people to understand some of
>the
>problems.
>
>Best regard to all,
>
>Ivor Lewis. Who recorded a temperature of 45 Celsius in the studio. Are we
>talking serious air conditioning!!! And Olive is preparing a Ripe Damson
Ice
>Cream Base
>
>

ababy sharon on mon 17 jan 00

Hallo Fellows!
Lately I try sometimes, to "play" with Porcelain, I like to direct you to
V.C. Hand book with many recipes of claybodies include Porcelain,&
translucent bodies.
What is Porcelain? Yes, it is a claybody like a donkey or horse are animals!
But to "drive" the on an-unplastic Porcelain, is like to drive a beautifull
wild horse!
(Donkey has his good sides too) And the fragillnes of thePorcelain
remains me the story of "The Princess On The Pea" .
Here is a recipe of raku resist Porcelain the way I make it. V.C. recommends
of
using two different kinds of kaolin, but I have only one kind. Last firing I
applied it above my excellent Dutch raku claybody K-129 burnished with my
fingers. After the bisque, I applied the 80/20 raku glaze and got BEAUTIFULL
CRACKLE! Also can be by itself.


V.C. Raku Porcelain Body ^04
==========================
ENGLISH KAOLIN(Puraf .....40.00 39.22%
BALL CLAY........... .............. 20.00 19.61%
ALUMINA HYDRATE......... 12.00 11.76%
molochite.............................. 10.00 9.80%
BENTOLITE ....................... 2.00 1.96%
TALC................................... 18.00 17.65%
==========
102.00

CaO 0.00* 0.06%
MgO 0.91* 7.63%
K2O 0.09* 1.73%
TiO2 0.00 0.08%
Al2O3 1.71 36.45%
SiO2 4.25 53.31%
Fe2O3 0.02 0.74%

Cost/kg 13.66
Si:Al 2.48
SiB:Al 2.48
Expan 5.05

Ababi
sharon@shoval.org.il
http://www.israelceramics.org/main.asp?what=gallery
http://clay.justnet.com/cgallery/asharon.htm

madwa on tue 18 jan 00

Yes George, yes! Start the ball rolling - I saw a fellow student using
soluble salts on porcelain last year and was fascinated - some very
beautiful staining of the clay.

Yours in Clay
Sharry Madden
from Sweet New Zealand

Hank Murrow on wed 19 jan 00

>----------------------------Original message----------------------------
>Bob,
Snip.. Once you have tried to make transclucent porcelain you realize how
>inadequate opaque "whitewares" are at imitating this demanding standard.
>People can call things what they wish; that is the nature of language, but
>when someone says "pit fired porcelain" it makes me wince. Like the
>cookies, they are not realized until they are properly baked.
For a great discussion of what porcelain really is, see John Reeve,
"More
>Notes on Porcelain" in Studio Potter. Vol. 6 No. 2. This whole issue is
>like a bible for those who seek the special quality called porcelain.
> Hope this helps to clear things up, a very ungod like Richard
>Selfridge

Dear Richard; I appreciate your posting and the reference to Reeve's
article. I would further suggest looking for Nigel Wood's article published
in Pottery Quarterly #47 titled, "Chinese Porcelain". Reeve describes Wood
as one of his 'brilliant' students, and the article is seminal. It was
Nigel Wood's article which in 1979 sent David Stannard on his search for
Petuntse, which took him to Jing-de-jhen for an international porcelain
conference.He also prosoected along the west coast part of the Pacific Rim,
culminating (to date) in several finds here of petuntse-like stones which
have made translucent (count your fingers through them) white bodies at
c/8-9; and which, when modified by the addtion of 15-20% limestone, make
wonderful celadons. David also prospected some sericitic stones in which
the hydrothermal alteration carried along some iron and titania
contamination; though contamination is a pejorative word for bodies which
carry the glaze so incredibly beautifully, and even self-glaze to an extent
because of remaining solubles. I find they are exquisite when fired in the
anagama. Hoping this contributes something to the discussion, Hank in Eugene

Hank Murrow on wed 19 jan 00

>----------------------------Original message----------------------------
>Hi,
SNIP__ The porcelain in China was a creammy yellow in
>Jingdezhen, yellow or green in Japan when they were in the wet state.
>0% porosity implies that the clay body is vitreous. By the way the German
>(can't remember how to spell his name) who "invented" Porcelain (some
>800-1,000 years after the Chinese, by the by.) came up
>with a clay body that fired out red...go figure. Snip___
>Rick Mahaffey
>Tacoma Washington, USA

Dear Rick; That German gent was Bottger, whose sad (self delusional) story
is told in Janet Gleeson's book, "The Arcanum"; though Janet did not get
the story of Chinese porcelain right at all. He finally ,more or less, got
the white translucent clay that the king of Prussia kept him locked up in
anticipation of.
Hank in Eugene

Hank Murrow on wed 19 jan 00

>----------------------------Original message----------------------------
>From Janet Kaiser
snip__
>Essentially porcelain is kaolin and silica with a little flux,
fired to
>vitrification point. This is "true" or hard-paste porcelain and requires
>temperatures in the region of 1350 degrees Celsius.
>
>An increase or multiplication of the bases (or of the acids, boron or
>fluorine)
>can lower the melting point and it is possible that the Eastern kilns averaged
>no more than 1270 to 1300 deg. C.
>
>Richard Parkinson asserts that 1360 deg. C. is needed to fully develop the
>"felted mass of mullite needles bonded in a glassy cement" by which a true
>porcelain is defined and that lower temperature mixtures such as David Leach's
>1270 deg. C. body give a white stoneware.
another snip___ Janet Kaiser

Dear Janet; Your college notes naturally reflect a Western bias concerning
the composition of Chinese porcelain. Even Janet Gleeson's recent book,
"The Arcanum" makes a similar assumption. The present day researchers in
China and in the West consider wares from the Sung period to have been
constituted of Petuntse 60% to 80%, Kaolin10% to 15%, and Silica 20% to
30%. Petuntse is an extrusive rock showing fine grained crystalline
structure and having around 7% to 8% Alkaline content. The critical
difference is that the fluxes are present IN the clay lattice at the ATOMIC
level, where they cause early vitrification at around C/8. This is with
full transparency at that temperature. In contrast, Western porcelains used
Kaolin, Silica, Feldspar, and limestone to achieve the vitrification. A
sense of scale is essential to understanding the difference. If an average
clay particle were the size of your fingernail, the comparable smallest 400
mesh particle of feldspar or limestone would be that of a very large home.
As one of these relatively huge particles melts, it takes everything into
solution around it; altering the clay lattice. Most of these European
porcelains were bisque fired, often on supports to C/10-12 to develop
translucency, then glost fired to C/5-7 where the addition of glaze would
not cause them to slump or warp. The Chinese pots were able to develop
their translucency at the lower temperatures and the glazes they used were
the same Petuntse with about 15% to 20% limestone (or wood ash) added; and
those marvelous celadons consisted of just these two ingredients!
Incidently, the glaze fit of such glazes on their bodies must be
experienced to be believed. You can virtually crack two together without
breaking, and they ring like tuning forks. The sad thing is that China is
now turning to the western model of Kaolin/Feldspar/Silica to satisfy the
demand for replicas of 'old' wares by the presentday Chinese 'nouveau
riche'. Following David Stannard's lead, I have begun prospecting volcanic
tuffs which have undergone alteration to a sericitic form in an attempt to
more closly follow the original Chinese model of Petuntse-based bodies.
Living along the Very Volcanic Pacific Rim (Eugene, OR) was viewed as a
liability in my youth(1958+) because there weren't any fireclays to speak
of; but now the petuntse future looks bright indeed, with volcanos on every
horizon. Stannard has been very successful in producing classic translucent
porcelains from such material in Alaska at the northeastern part of the
Rim. I have many of his natural porcelain bowls and can report that you can
count your fingers through them and they are lovely soft celadons. They are
not unusually thin either. Hoping you don't mind my two cents and best
regards, Hank in Eugene

Janet kindly suggested that I post this private reply from me to her for
everyone on the Clayart List.......Hank

James L Bowen on fri 21 jan 00

------------------
Once more from the old Sevres kilnmaster. =22Porcelains to be worth =
cosideration
must have many qualities. The paste must be translucent, hard, impossible =
to
scratch with steel, homogeneous, very sonorous, completely vitrified, and =
when
broken, must show a sharp angular break with a very fine and brilliant =
grain.
In this condition it will be impervious to water and proof against injuries =
by
frost, and will resist climates like ours in which humidity is a great
disintegrating agent. These characteristics, especially translucency and
vitrification, constitute the definition of porcelain. If one of them is
missing, we have another kind of ware. If the paste keeps all of these
properties except translucency, we have a gres: if it is not vitrified, we =
have
terra cotta, faience or pipe clay.=22 Taxile Doat
Says it all for this westerner.

Solveig Stegen on fri 21 jan 00

Dear Potters,
I would like to work with porcelain during my final semester of Craft
School and am interested in obtaining recipes. I plan to be throwing and
adding some sculptural, handbuilt pieces. I will be focusing on
oxidation firings, but will also be experimental with other techniques
such as wood, soda, reduction, and raku. If you'd like to know how your
claybody handles any of these techniques, I'd be happy to let you know
if I use your recipe. Oh, I'll probably be in the cone 9-11 range.
That's probably most important!
Thanks a lot!
Solveig

Jim Brooks on sat 22 jan 00

I have read.. don' t remember where ..that Porcelain is high fired with high
fire glaze . (often one firing) to high temp..cone 10-12 for example..
and China is fired (bisque) to high fire and then glazed with a low fire (
low temp) glaze..That is one reason you can scratch some dinner ware of
China. but cannot do the same with Porcelain.. If this is true., then the
clay body could be the same,.. only the glaze would differ and the
temperature to which the glaze is fired.. Any comments.?

Hank Murrow on sat 22 jan 00

------------------
=3E----------------------------Original message----------------------------

=3EOnce more from the old Sevres kilnmaster. =22Porcelains to be worth
=3Ecosideration
=3Emust have many qualities. The paste must be translucent, hard, =
impossible to
=3Escratch with steel, homogeneous, very sonorous, completely vitrified, and=
when
=3Ebroken, must show a sharp angular break with a very fine and brilliant =
grain.
=3EIn this condition it will be impervious to water and proof against =
injuries by
=3Efrost, and will resist climates like ours in which humidity is a great
=3Edisintegrating agent. These characteristics, especially translucency and
=3Evitrification, constitute the definition of porcelain. If one of them is
=3Emissing, we have another kind of ware. If the paste keeps all of these
=3Eproperties except translucency, we have a gres: if it is not vitrified, =
we
=3Ehave
=3Eterra cotta, faience or pipe clay.=22 Taxile Doat
=3ESays it all for this westerner.

Dear Taxile(in absentia) =26 James=3B
Look, I don't have any quibble about the specific qualities of
western Kaolinite-based bodies. In fact, I absolutely covet a few wares
made by a French family of potters near Chantilly, just before S=E8vres took
off. You may see these wares in the Ch=E2teau at Saumur, on the Loire, SW of
Paris. What I DO have issue with is the stubborn western insistence that
kaolin is necessary for true translucent and vitreous porcelain. The fact
that the Chinese were making translucent wares hundreds of years earlier of
transcendent quality from volcanic-based rocks is after all what induced in
the European nobility the idea that there was something to profit from, as
they were bankrupting themselves collecting this Chinese ware. So, they
bankrolled the search for 'porcelain' and Bottger came up(eventually) with
kaolin, feldspar, silica, and limestone to create =22hard-paste =
porcelain=22=3B
upon which the western world promptly seemed to develop amnesia concerning
the poorly understood eastern model in favor of the upstart. Now, three
centuries later, we have the benefit of several conferences and voluminous
papers concerning the true origins of the Chinese porcelain, which would
enable western potters to broaden their search for suitable materials to
include these volcanics which seem to occur wherever there have been
eruptions. So many of us live within range of these materials that it would
be shortsighted to continue 'importing' Grolleg to the US and Avery to
Britain=3B when the makings of a real tasty translucent body at C/8 may be
nearby, in many locations around the world. I think of Michael in New
Zealand, Jon in the Philippines, myself in Oregon, and David (who along
with Nigel, started this search) in Fairbanks=3B and I imagine it would be
worthwhile to have a look around to see if 'Petuntse' may be nearby.
Another related point concerns the consequences of using nearby
materials. I recognize an increasing proclivity among potters during the
last century to try to be seen as novel and original. I think that much of
the impetus for this comes from the use of standard materials now available
nearly worldwide, to the exclusion of those having local origin. Our wares
made from nearby resources (in contrast) might have unforced intrinsic
novelty and originality when seen in distant contexts=3B and when the fossil
fuels (which at present bring us those tasty distant materials) begin to
run out=3B we might have already developed choice stuff nearby. Mother earth
has been generous, prodigal, and inventive in creating the stuff we make
our wares from=3B I think we owe it to Her to respond with equal creativity
in recognizing and answering Her.

ps: I'd like to think that some potter from Jingdezhen might
someday hold a piece of my ware and be as moved by it as I have been by
theirs in the basement. Anyway, thanks to James for provoking the response
and bearing with me.
Hank in Eugene, digging, drying, making, and hoping to continue
another 43 years much the same.

Solveig Stegen on mon 24 jan 00

I think I just read something in Tichane's Clay Bodies book about your
China porcleain question. You're right- Porcelain is hi-gired clay and
glazes and China is hi-fired clay with low fire glazes. China wear is
supported by stilts and various other supports so that it doesn't warp,
then low fire glazes (I think lead-borsilicate or something like that)
are used to glaze that at low temperatures, where there is no fear of
warping.
Hope that helps.
Solveig

I.Lewis on mon 24 jan 00

------------------
I think we should all thank James Bowen for his contribution 01.20.00. Nice =
to
know homework is being done. Has any one got a translation of Brongniart's
contribution to our understanding. Call it what you will, the qualities are
pretty unambiguous

Well done James

Ivor. Inquisitive and appreciative.

Malcolm Cooke on mon 24 jan 00

> ----------------------------Original message----------------------------
> I have read.. don' t remember where ..that Porcelain is high fired with high
> fire glaze . (often one firing) to high temp..cone 10-12 for example..
> and China is fired (bisque) to high fire and then glazed with a low fire (
> low temp) glaze..That is one reason you can scratch some dinner ware of
> China. but cannot do the same with Porcelain.. If this is true., then the
> clay body could be the same,.. only the glaze would differ and the
> temperature to which the glaze is fired.. Any comments.?

Hi All

Digging back into some of my old books from 35 years ago and some from
people studying ceramics in china the requirements for porcelain in china
are a hard white body which is generally fired over about 1280c.
Translucency is not necessary to classify the work as porcelain. However
many pieces where very thin show some translucency. I have old pieces from
china classified as porcelain which are not translucent. Most museums you go
into with a comphrensive collection of ceramics from china will have
porcelain pieces which do not fall into the "WESTERN" notion of porcelain.


Regards


Mal Cooke
mcooke@tyndale.apana.org.au
http://www.spirit.com.au/~mcooke

Timakia@AOL.COM on tue 19 sep 00

Chris I paint a mixture of aluminia and cmc on my shelves. On heavier pieces
also paint this mixture on the bottom of the pot. This also works when I fire
pots with lids to keep them seperate. The mixture brushes of easily
afterwards.

Antoinette Badenhorst
PO Box 552
Saltillo,MS
38866
http://hometown.aol.com/timakia

Chris Clarke on tue 19 sep 00

I've tried out porcelain and my problem is about when I fired it to =
glaze temp (it looked great). I reached into that kiln and left half =
the pot stuck to the shelf. What did I do wrong? Do I fire it in a bed =
of alumina? =20

chris clarke
Temecula, CA
chris@ccpots.com
www.ccpots.com
look again

iandol on wed 20 sep 00

Chris,

I suppose that by now you will have had a hundred answers to your query. =
I hope this one is useful.

Porcelain has a high proportion of fluxing materials and is well on =
it=92s way to becoming an opalescent glass. So it is able wet the =
surface of any ceramic material it comes in contact with. This causes a =
weld to develop and an adhesion. Also, be very certain to make sure you =
have no suspicion of glaze near the feet of your pots.

The solution is to use a good kiln wash which is low in silica and high =
in alumina. 50/50 kaolin and aluminium hydrate on your shelves. As a =
second line of defence, sprinkle a light dusting of alumina sand, =
+100mesh, on the shelf. This allows your porcelain to move as it =
shrinks.

All the best,

Ivor Lewis. Redhill, South Australia.

Earl Brunner on wed 20 sep 00

Mix a little alumina into some wax resist. YOur porcelain
is getting too tacky at peak temp. (can be a good thing with
porcelain) causing the pieces to adhere to the shelves. Just
don't get your alumina wax mixed up with the regular stuff.
It's good to use between lids and the pot as well.

Timakia@AOL.COM wrote:
>
> Chris I paint a mixture of aluminia and cmc on my shelves. On heavier pieces
> also paint this mixture on the bottom of the pot. This also works when I fire
> pots with lids to keep them seperate. The mixture brushes of easily
> afterwards.
>
> Antoinette Badenhorst
> PO Box 552
> Saltillo,MS
> 38866
> http://hometown.aol.com/timakia
>
> ______________________________________________________________________________
> 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.

--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net

Lynne at The Pottery Web on wed 20 sep 00

> mixture of aluminia and cmc


What are the percentages of each? When using on lidded pots in firing, do
you use this in place of wax or as a wad?

Lynne in Atlanta


>______________________________________________________________________________

Lee Marshall on wed 20 sep 00

In a message dated 9/19/00 8:22:07 PM Central Daylight Time, chris@CCPOTS.COM
writes:

<< ve tried out porcelain and my problem is about when I fired it to glaze
temp (it looked great). I reached into that kiln and left half the pot stuck
to the shelf. What did I do wrong? >>
i use a kiln wash
40 epk
40 silica
20 alumina hydrate
it's not great for glaze release especially on mullite shelves. but it does
wonders for releasing porcelain
lee marshall
lmarsh1220@aol.com

Stephen Capelli on thu 21 sep 00

I have had the problem of my porcelain sticking to the shelves from time to
time and not always but sometimes (depending on how I am feeling about the
glazing process) I will add a some alumina to the wax (like in cooking, I
add enough, but not too much). I will was all my lids first without the
alumina, (where does the alumina go when the wax melts from the lids) and
than add the alumina and wax the bottoms.... I make sure I clean out the
hot wax pan when I am finished so as not to mess with anyone else in the
studio (I work in a community studio at a University) and keep the alumina
wax till the next time I feel like using it....
CIAO Stephen from the still muggy Montgomery
----- Original Message -----
From: Lynne at The Pottery Web
To:
Sent: Wednesday, September 20, 2000 2:42 PM
Subject: Re: porcelain


> > mixture of aluminia and cmc
>
>
> What are the percentages of each? When using on lidded pots in firing, do
> you use this in place of wax or as a wad?
>
> Lynne in Atlanta
>
>
>
>___________________________________________________________________________
___
>
>
____________________________________________________________________________
__
> 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.

Timakia@AOL.COM on thu 21 sep 00

CMC acts like a glue. I only estimate about 1 spoon full of CMC and about
a 100g of aluminia. Mix with water to become a creamy paste. After I glazed I
put this on the clean area where the porcelain may touch, eg. on the footrim
or where lid and pot touches. This prevent fragile rims to break after or
during firing. since Aluminia is still fire resistant at
1260 C it almost acts like a roler. The pot can move on it as it shrinks.
Fluxing agents become active in the porcelain clay at a high temperature.
Between the lid and pot aluminia simply resist the two from sticking
together. i also use it on my stoneware clay at a high temperature. Take care
not to let it get on the glaze. That will result in a ugly coarse surface.

Antoinette Badenhorst
PO Box 552
Saltillo,MS
38866
http://hometown.aol.com/timakia

w miller on sun 18 mar 01

I'm sort of sidling up to my first venture into handbuilding porcelain. Any
suggestions? Caveats? Success stories

Willi


--
Willi Miller (Ms.)
Member: Florida Freelance Writers Association
Contributing Editor- Bahamas, USVI, BVI - for Wcities.com
The premier provider of location-based information services for World Cities

Ababi on sun 18 mar 01

If you can buy the Limoge, sorry for misspelling. it is quite plastic
Ababi Sharon
ababisha@shoval.ardom.co.il
http://members4.clubphoto.com/ababi306910/

----- Original Message -----
From: "w miller"
To:
Sent: Sunday, March 18, 2001 7:26 PM
Subject: porcelain


> I'm sort of sidling up to my first venture into handbuilding porcelain.
Any
> suggestions? Caveats? Success stories
>
> Willi
>
>
> --
> Willi Miller (Ms.)
> Member: Florida Freelance Writers Association
> Contributing Editor- Bahamas, USVI, BVI - for Wcities.com
> The premier provider of location-based information services for World
Cities
>
>
____________________________________________________________________________
__
> 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.
>

Christina Zola on sun 18 mar 01

Limoge, definitely! Best thing to do with porcelain is plan plan plan. Know
exactly what you want to make, how you're going to make it, before you
begin. Keep it covered to dry slowly. Don't fall in love with anything til
it's sitting, glazed, on your favorite shelf.

Porcelain is so much fun to texture and alter! and it blends so well.
Reinforce your joins with coil where you can, and wax the joins to keep
everything drying slowly, evenly.

Have fun!

Bosworth on thu 25 apr 02

Yes I have searched the archives... I still did not find the answer to =
the "perfect" porcelain question, I guess this is because it just does =
not exist. I am having trouble with Helios from highwater cracking. I'm =
sure it is mostly my bad skill (ugh). If so I welcome technique advise, =
but I am also looking for suggestions to a good all-round throwing body =
that can withstand throwing and altering big forms, cone 10, soda =
firing, no glaze on the outside, oxidation, of course as white as =
possible (will sacrifice the whitest of whites for workability and =
ability to attach with minimal trouble). Someone suggested Laguna's Dave =
Porcelain and Laguna's 550. Anyone agree? or disagree? The place I'm =
getting cracks is in the handles (which I am going to try the vinegar =
trick and the wax trick) the harder one to solve is the crack I am =
getting at the point of application of clay buttons at the junction of =
the lip. I am making pitchers with a cut out exaggerated lip and at the =
base of the cut out I apply a button of clay on either side. I am =
getting cracks at the spot of the buttons. I attach before leather hard =
and support the inside of the pot during application of the button. Any =
help will be greatly appreciated!

Heather Bosworth
Coastal Clay Co
St. Helena Island, SC

*** looking out my window to the most lovely high tide!!! Must go get in =
the boat with my son and off the computer (smile)

David Binch on sat 15 feb 03

I read a great book about the quest for a true porcelain body in Europe. =
The Arcanum: The Extraordinary True Story of the Invention of European =
Porcelain, by Janet Gleeson.

Amazon.co.uk Review
Since the middle ages, Western Europeans have practised alchemy, a =
primitive form of chemistry, in the great hope of transforming base =
metal into gold. In the early 18th century, a second great secret =
puzzled Western Europe's early scientists: how to make porcelain. =
Recently arrived from the Orient, porcelain quickly became a symbol of =
power, prestige and good taste. In The Arcanum, Janet Gleeson presents =
an entertaining and informative account of the invention of European =
porcelain and the founding of the Meissen Porcelain Manufacture outside =
Dresden, Germany. Her narrative focuses on three individuals: alchemist =
Johann Frederick B=F6ttger inadvertently discovered the arcanum, or =
secret formula, for making porcelain; Johan Gregor Herold, an ambitious =
artist, developed colours and patterns of unparalleled brilliance at the =
newly established Meissen Porcelain Manufacture; Johann Joachim =
Kaendler, a virtuoso sculptor, used the Meissen porcelain to invent a =
new art form. Interwoven with the story of Augustus the Strong, the =
greedy and ambitious king of the Kingdom of Saxony, who held B=F6ttger =
captive until he discovered the formula, Gleeson's tale reads easily and =
maintains a high level of suspense and intrigue throughout. --Bertina =
Loeffler, Amazon.com=20

Gave me a perspective of how fortunate we are to have all the pasts =
advances in materials and techniques at our disposal. For example =
refractories that Bottger could never imagine were possible.=20
May not clear up the definition of porcelain that is being discussed, =
but certainly will give a new perspective and appreciation of the =
material.

David Binch

Jim Tabor on sun 16 feb 03

Go to the site listed below for "The Great Potters - Palissy, Bottgher,
Wedgwood. This is from the Samuel Smiles book, "Self Help" published in
1859. The entire book can also be found at The Universal Library site. I
used to have a copy from the first edition. The stories of the potters
is to illustrate perseverance.

http://www.ulib.org/webRoot/Books/CMU_Classics/Browse_By_Title/S/Self_Help/3Struct.html

Volume I, Ceramics And Civilization: Ancient Technology, edited by W.D.
Kingery (MIT) has great info on development of soft paste
porcelain(1673). Phase equalibrium diagrams, microstructure photos at
x800 and x1000, and compositions determined by electron microprobe
analysis of examples. An example of Medici porcelain from 1582 is also
discussed.

In Volume II: Technology and Style includes the development of Chinese
white porcelain(A.D. 575) with more science and history as noted above.

The article in Volume II on The Innovation in European Porcelain cotains
the comparison of the earliest porcelains with contemporary porcelain
quality and explanns what make the earliest hard paste porcelains
produced in Europe better than current production.

Both of the books cover the science and history of many different
ceramic development. Another book I may submit later (it's at school)
includes the science and history of Bottgher's porcelains. His earliest
porcelains were not white. The group's discussion appears to be focused
on white porcelain that is translucent and high fired. My perspective is
that examples from history do not always fit such a narrow definition.

I would like anyone with info on a Japanese porcelain "Samurai China" to
email me off list. I am puzzled by how it is made. I have an enameled
cup and saucer the thickness of a credit card that is more translucent
than any porcelain I've seen.

Jim Tabor

David Binch wrote:

>.....
>Gave me a perspective of how fortunate we are to have all the pasts advances in materials and techniques at our disposal. For example refractories that Bottger could never imagine were possible.
>May not clear up the definition of porcelain that is being discussed, but certainly will give a new perspective and appreciation of the material.
>
>David Binch
>
>______________________________________________________________________________
>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.
>
>
>

Brenda on fri 20 jan 06

I own a small business hand painting tile. Most of my exterior work has
been in South Florida. I have a client in southern Georgia who would like
to use my designs in their pool. I need to produce a frost proof tile.
Does anyone have a source for porcelain bisque and or tips for a successful
completion?
Brenda

Fredrick Paget on tue 26 dec 06

Hi,
The clay is great. I like it so much I think it is precious and am
afraid to run out! I want to get more . Can you send another 5 boxes?
What is the price now?
Fred Paget
--
Twin Dragon Studio
Mill Valley, CA, USA

Michael Wendt on tue 26 dec 06

Fred,
We are expecting a shipment of Neph
Sye, Silica and other needed ingredients
to make 12,000 lbs of the porcelain.
The cost is almost the same except I found that
38 lbs is all that will fit in one of the USPS
flat rate boxes so the 38 lb box costs $17.50..
Most of you already know that priority
mail boxes cost $8.10 no matter how
much you put in them.

Marcia Selsor asked what is so unusual
about this porcelain.

It throws like nothing you have ever seen.
It dries in free air in the room with little
trouble.
It fires reasonably white in clean kilns
and it flashes characteristically Helmer
in wood.
In thin sections, it is translucent.
On top of that, it is being made for use
in my studio so it is the only clay mixed
in the equipment during a particular run.
When we change bodies, we tear the pug
mill apart completely and clean it to bare
metal before we mix a different body.
Result: no cross contamination of the clay.

Thanks for the interest and please give open
feedback on clayart if you don't mind. I want
to address concerns as they happen.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, Idaho 83501
USA
wendtpot@lewiston.com
www.wendtpottery.com

joyce lee on thu 28 dec 06

Michael, I'd like to order 5 boxes of your porcelain
also. If it works well for handbuilding I'm sure I'll
order more soon if it's available.

Thank you.
Joyce
In the Mojave Desert of California where our road is
the windiest ever ....... a few short miles away... maybe
5..... almost no wind today! =20

Elizabeth Priddy on sat 19 may 07

Every clay has a beautiful, purposeful application.

Earthenware is just as good as stoneware as porcelain.

It is a lateral comparison.

But some people think that porcelaian is better than the
others. And they are mistaken. They say it is harder, but
not even in the sense of tensile strength, as it is only harder
when it is truly vitrified.

Every clay you don't understand yet is harder to use than one
you do. A simple statement, but rich with meaning.

What I am getting at with porcelain envy, is that it ought to
be used when it is the best clay for the job. And I have seen
a lot of it used for the ego. Thick, stoneware forms, no
exploitation of the resource to take it to new heights, just
using it to say you are.

And this is not a slam on anyone, just an observation that
people often use things they don't need just to feel a certain
way, and potters are not immune. It is like a $400 haircut,
when you are a dude with 3 inches of hair at any given time.

So don't take anything I said as a particular remark about your
use of porcelain, but as a remark about using the right thing for
the right job.

If I go to a craft fair and I see some vendor with a sign saying,
"Hand thrown porcelain", I take a look. My experience has
been most often to be nonplussed, and definitely not to open
my wallet and buy it.

And that is all that I meant, nothing more.

E

Elizabeth Priddy
Beaufort, NC - USA

Natural Instincts Conference Registration Information:

http://www.ceramics.org/potterscouncil/naturalinstincts/registrationinfo.asp

http://www.elizabethpriddy.com
http://www.flickr.com/photos/7973282@N03/


----- Original Message ----
From: Lois Ruben Aronow misslo@NYC.RR.COM


This post is insulting on so many levels.



____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games.
http://sims.yahoo.com/

Meg Smeal on mon 16 jun 08

Here is my super simple way of placing porcelain in the clay spectrum:

There are deposits of earthenware and stoneware that can be dug up.
Porcelain has to be blended. This is why the pre early 19th century european and
american potters went out of their minds trying to discover the secret formula
for making it.

Now of course we blend all types of clay so the differences are more obscure.




**************Vote for your city's best dining and nightlife. City's Best
2008. (http://citysbest.aol.com?ncid=aolacg00050000000102)

Lee Love on mon 16 jun 08

On Mon, Jun 16, 2008 at 6:29 AM, Meg Smeal wrote:

> Now of course we blend all types of clay so the differences are more obscure.
>

Ahh. So porcelain corrupted us? ;^)

--
Lee Love in Minneapolis
http://mashikopots.blogspot.com/
http://claycraft.blogspot.com/

"We are such stuff as dreams are made on, and our little life is
rounded with a sleep." --PROSPERO Tempest Shakespeare

Curtis Benzle on mon 16 jun 08

And..... this helps explain how Geoge Ohr became the Mad Potter from Biloxi....

On 6/16/08, Meg Smeal wrote:
> Here is my super simple way of placing porcelain in the clay spectrum:
>
> There are deposits of earthenware and stoneware that can be dug up.
> Porcelain has to be blended. This is why the pre early 19th century
> european and
> american potters went out of their minds trying to discover the secret
> formula
> for making it.
>
> Now of course we blend all types of clay so the differences are more
> obscure.
>
>
>
>
> **************Vote for your city's best dining and nightlife. City's Best
> 2008. (http://citysbest.aol.com?ncid=aolacg00050000000102)
>

Antoinette Badenhorst on tue 17 jun 08

Meg is it possible that your "super simple way of placing porcelain in the clay spectrum" may be too simple?

--
Antoinette Badenhorst
www.clayandcanvas.com
www.studiopottery.co.uk


-------------- Original message ----------------------
From: Meg Smeal
> Here is my super simple way of placing porcelain in the clay spectrum:
>
> There are deposits of earthenware and stoneware that can be dug up.
> Porcelain has to be blended. This is why the pre early 19th century european
> and
> american potters went out of their minds trying to discover the secret formula
> for making it.
>
> Now of course we blend all types of clay so the differences are more obscure.
>
>
>
>
> **************Vote for your city's best dining and nightlife. City's Best
> 2008. (http://citysbest.aol.com?ncid=aolacg00050000000102)

Marty Morgan on tue 11 may 10

I'm searching for a porcelain claybody which doesn't warp like crazy at con=
e
ten. I've tried the old Miller 550 and currently use Standard 257, both of
which warp unless the walls are extremely thick- not how I like to throw.
Just unloaded the kiln with big gorgeous shino cappuchino cups that came ou=
t
basically oval shaped, pulled out of round by the handles. Any suggestions
greatly appreciated.

Marty Morgan, Gloucester, MA

Getting ready for our 10th Empty Bowl dinner this Thursday, expecting 1,000
people!

Michael Wendt on tue 11 may 10

Ask any of the people who use my clay.
See if they have warping issues.
Click on Helmer Kaolin link on
www.wendtpottery.com
Regards,
Michael Wendt

Mary Morgan wrote:

I'm searching for a porcelain claybody which doesn't warp
like crazy at cone
ten. I've tried the old Miller 550 and currently use
Standard 257, both of
which warp unless the walls are extremely thick- not how I
like to throw.
Just unloaded the kiln with big gorgeous shino cappuchino
cups that came out
basically oval shaped, pulled out of round by the handles.
Any suggestions
greatly appreciated.

Marty Morgan, Gloucester, MA

Getting ready for our 10th Empty Bowl dinner this Thursday,
expecting 1,000
people!

mel jacobson on tue 17 aug 10

i am not a pure white clay guy at all. i have some strong opinions
on making sure white clay used for large pieces is treated
like any other clay. sand, grog and opening the body helps a
great deal. same for ball clay. it just makes the body throwable.

there is always a trade off if you want a clay to do what it
was not intended to do. you can't throw a casting body very well.
same for size....you have to adjust the body. `every clay that is compound=
ed
as a very specific use. there is no such thing as `broad range`.`
(J.T. Abernathy, into my tape recorder.)

often people get obsessed with whiteness and that means you
may give up structure.

i love the old alfred 25x4 recipe.
it throws like a stoneware and i can add grog and sand and it fires
`rather` white.

i know this is blasphemy for many that love porcelain...but, it
is just another clay body. it must be treated as such.
it is not sacred.

some potters/artists think they have a higher moral standing
if they fire pure white clay. (scream, yell, call me names.)
you know..."Well, I fire Porcelain". good, i fire high iron stoneware with
sand and fine grog.
and my loss factor is under 1%.
mel
as i have stated very clearly in my new book on kilns and firing.
`loss is the big eco enemy. if you are wasting fuel on pots that do
not fire well, or your loss factor is at 40%, or your kiln fires
poorly, you are wasting your own
money, and you are not being a steward of the earth. and, think in terms
of your own bottom line first. that will lead to good stewardship.`
from: minnetonka, mn
website: http://www.visi.com/~melpots/
clayart link: http://www.visi.com/~melpots/clayart.html
new book: http://www.21stcenturykilns.com
alternate: melpots7575@gmail.com

Randall Moody on tue 17 aug 10

On Tue, Aug 17, 2010 at 9:05 AM, mel jacobson wrote:

> i am not a pure white clay guy at all. i have some strong opinions
> on making sure white clay used for large pieces is treated
> like any other clay. sand, grog and opening the body helps a
> great deal. same for ball clay. it just makes the body throwable.
>
> there is always a trade off if you want a clay to do what it
> was not intended to do. you can't throw a casting body very well.
> same for size....you have to adjust the body. `every clay that is
> compounded
> as a very specific use. there is no such thing as `broad range`.`
> (J.T. Abernathy, into my tape recorder.)
>
> often people get obsessed with whiteness and that means you
> may give up structure.
>
> i love the old alfred 25x4 recipe.
> it throws like a stoneware and i can add grog and sand and it fires
> `rather` white.
>
> i know this is blasphemy for many that love porcelain...but, it
> is just another clay body. it must be treated as such.
> it is not sacred.
>
> some potters/artists think they have a higher moral standing
> if they fire pure white clay. (scream, yell, call me names.)
> you know..."Well, I fire Porcelain". good, i fire high iron stoneware wi=
th
> sand and fine grog.
> and my loss factor is under 1%.
> mel
> as i have stated very clearly in my new book on kilns and firing.
> `loss is the big eco enemy. if you are wasting fuel on pots that do
> not fire well, or your loss factor is at 40%, or your kiln fires
> poorly, you are wasting your own
> money, and you are not being a steward of the earth. and, think in terms
> of your own bottom line first. that will lead to good stewardship.`
> from: minnetonka, mn
> website: http://www.visi.com/~melpots/
> clayart link: http://www.visi.com/~melpots/clayart.html.com/%7Emelpots/clayart.html>
> new book: http://www.21stcenturykilns.com
> alternate: melpots7575@gmail.com
>

I agree with everything that you have said. I do not hold any moral
superiority due to the clay I choose to throw. I am simply a better person
than most. :) (That was a joke people.) Although there is a perceived
preciousness historically present in porcelain wares. I am also looking int=
o
putting in a bit of molochite rather than grog.

--
Randall in Atlanta
http://wrandallmoody.com/home.html

Antoinette Badenhorst on tue 17 aug 10

Mel, my dear Friend, are you picking a fight with me now or what :-) ! Imag=
=3D
ine my pretty moving leaves swinging off one of your=3DC2=3DA0 iron claypot=
s ! =3D
( okay you know I am just messing with you right?)=3D20



Back to seriousness: I have recently wrote=3DC2=3DA0some articles about por=
cela=3D
in that you might want to look at.=3D20

Every claybody had its own place in this ceramics world of us.Stoneware, ea=
=3D
rthenware and ..............porcelain is just another one of them. What mak=
=3D
es "true porcelain" different from other claybodies is it's high glass form=
=3D
ing abilities. That very glass forming is porcelain's biggest friend, but a=
=3D
lso its biggest enemy. So for us working in porcelain, we made a choice to =
=3D
make our enemy our best friend.=3D20



It is important=3DC2=3DA0NOT to use porcelain just for the sake of using po=
rcel=3D
ain and then work with it like you are working with stoneware. That would b=
=3D
e like driving with a 4 x 4 truck on smooth roads just for the sake of driv=
=3D
ing 4 x 4. =3DC2=3DA0If you are=3DC2=3DA0 looking for a white clay to get t=
he best =3D
out of your glazes, white stoneware would be good and it would really be =
=3D
=3DC2=3DA0a big waste to use porcelain UNLESS you are looking for a marblel=
ike =3D
apearence and the smooth glasslike feel and ring of porcelain. Of cause if =
=3D
all the other qualities of porcelain becomes important, the ball game chang=
=3D
es.=3D20



Just as Mel has his passion for his irom based claybody and the woodfirers =
=3D
have their passion for their firing processes, so one should have a passion=
=3D
to work with porcelain. One learn it's character and form a relationship w=
=3D
ith the claybody, just as one do with other claybodies.=3D20



Porcelain is not superior to other claybodies, but it is expensive and requ=
=3D
iers a spesific kind of personality that is willing to adjust its way of wo=
=3D
rking and their studio environment to accomodate the tediousness of porcela=
=3D
in. When everybody else do not even notice the bugs in their studios, I cur=
=3D
se them dying in my claybucket! When everybody else is counting their bucks=
=3D
while the kiln is cooling down, I am keeping my fingers crossed that there=
=3D
will be at least a few workable pots coming from the batch.=3D20



Randy, while you are looking into additives for your clay ( which I persona=
=3D
lly think would be unnessesary) consider using a coarser( sandlike)=3DC2=3D=
A0si=3D
lica rather than the fine ones. The person to talk to about that is Robin H=
=3D
opper, since that is what he does to give some tooth to his porcelain. I wo=
=3D
uld not add sand on top of the silica, that=3DC2=3DA0might put too much fli=
nt i=3D
n the claybody. The equil parts recipe is what most porcelain aritst use. L=
=3D
ook at the recipes available in Peter Lane's book "studio porcelain"=3D20



Mel, I trust that the white pot I gave you some years back, is sitting in t=
=3D
he most important spot of your collection! Grin............................=
=3D
....=3D20



Nice day, guys.=3D20

Antoinette Badenhorst=3D20
www.porcelainbyAntoinette.com =3DC2=3DA0=3D20

----- Original Message -----=3D20
From: "mel jacobson" =3D20
To: Clayart@LSV.CERAMICS.ORG=3D20
Sent: Tuesday, August 17, 2010 8:05:39 AM=3D20
Subject: porcelain=3D20

i am not a pure white clay guy at all. =3DC2=3DA0i have some strong opinion=
s=3D20
on making sure white clay used for large pieces is treated=3D20
like any other clay. =3DC2=3DA0sand, grog and opening the body helps a=3D20
great deal. =3DC2=3DA0same for ball clay. =3DC2=3DA0it just makes the body =
throwabl=3D
e.=3D20

there is always a trade off if you want a clay to do what it=3D20
was not intended to do. =3DC2=3DA0you can't throw a casting body very well.=
=3D20
same for size....you have to adjust the body. =3DC2=3DA0`every clay that is=
com=3D
pounded=3D20
as a very specific use. =3DC2=3DA0there is no such thing as `broad range`.`=
=3D20
(J.T. Abernathy, into my tape recorder.)=3D20

often people get obsessed with whiteness and that means you=3D20
may give up structure.=3D20

i love the old alfred 25x4 recipe.=3D20
it throws like a stoneware and i can add grog and sand and it fires=3D20
`rather` white.=3D20

i know this is blasphemy for many that love porcelain...but, it=3D20
is just another clay body. =3DC2=3DA0it must be treated as such.=3D20
it is not sacred.=3D20

some potters/artists think they have a higher moral standing=3D20
if they fire pure white clay. =3DC2=3DA0(scream, yell, call me names.)=3D20
you know..."Well, I fire Porcelain". =3DC2=3DA0good, i fire high iron stone=
ware=3D
with=3D20
sand and fine grog.=3D20
and my loss factor is under 1%.=3D20
mel=3D20
as i have stated very clearly in my new book on kilns and firing.=3D20
`loss is the big eco enemy. =3DC2=3DA0if you are wasting fuel on pots that =
do=3D
=3D20
not fire well, or your loss factor is at 40%, or your kiln fires=3D20
poorly, you are wasting your own=3D20
money, and you are not being a steward of the earth. and, think in terms=3D=
20
of your own bottom line first. =3DC2=3DA0that will lead to good stewardship=
.`=3D
=3D20
from: minnetonka, mn=3D20
website: http://www.visi.com/~melpots/=3D20
=3DC2=3DA0=3DC2=3DA0clayart link: =3DC2=3DA0http://www.visi.com/~melpots/cl=
ayart.html=3D
=3D20
new book: http://www.21stcenturykilns.com=3D20
alternate: melpots7575@gmail.com=3D20


Nice day, guys.=3D20

Antoinette Badenhorst=3D20
www.porcelainbyAntoinette.com =3DC2=3DA0=3D20

----- Original Message -----=3D20
From: "mel jacobson" =3D20
To: Clayart@LSV.CERAMICS.ORG=3D20
Sent: Tuesday, August 17, 2010 8:05:39 AM=3D20
Subject: porcelain=3D20

i am not a pure white clay guy at all. =3DC2=3DA0i have some strong opinion=
s=3D20
on making sure white clay used for large pieces is treated=3D20
like any other clay. =3DC2=3DA0sand, grog and opening the body helps a=3D20
great deal. =3DC2=3DA0same for ball clay. =3DC2=3DA0it just makes the body =
throwabl=3D
e.=3D20

there is always a trade off if you want a clay to do what it=3D20
was not intended to do. =3DC2=3DA0you can't throw a casting body very well.=
=3D20
same for size....you have to adjust the body. =3DC2=3DA0`every clay that is=
com=3D
pounded=3D20
as a very specific use. =3DC2=3DA0there is no such thing as `broad range`.`=
=3D20
(J.T. Abernathy, into my tape recorder.)=3D20

often people get obsessed with whiteness and that means you=3D20
may give up structure.=3D20

i love the old alfred 25x4 recipe.=3D20
it throws like a stoneware and i can add grog and sand and it fires=3D20
`rather` white.=3D20

i know this is blasphemy for many that love porcelain...but, it=3D20
is just another clay body. =3DC2=3DA0it must be treated as such.=3D20
it is not sacred.=3D20

some potters/artists think they have a higher moral standing=3D20
if they fire pure white clay. =3DC2=3DA0(scream, yell, call me names.)=3D20
you know..."Well, I fire Porcelain". =3DC2=3DA0good, i fire high iron stone=
ware=3D
with=3D20
sand and fine grog.=3D20
and my loss factor is under 1%.=3D20
mel=3D20
as i have stated very clearly in my new book on kilns and firing.=3D20
`loss is the big eco enemy. =3DC2=3DA0if you are wasting fuel on pots that =
do=3D
=3D20
not fire well, or your loss factor is at 40%, or your kiln fires=3D20
poorly, you are wasting your own=3D20
money, and you are not being a steward of the earth. and, think in terms=3D=
20
of your own bottom line first. =3DC2=3DA0that will lead to good stewardship=
.`=3D
=3D20
from: minnetonka, mn=3D20
website: http://www.visi.com/~melpots/=3D20
=3DC2=3DA0=3DC2=3DA0clayart link: =3DC2=3DA0http://www.visi.com/~melpots/cl=
ayart.html=3D
=3D20
new book: http://www.21stcenturykilns.com=3D20
alternate: melpots7575@gmail.com=3D20

Larry Kruzan on tue 17 aug 10

I know that she uses STONEWARE for her personal, fun things. Just not her =
=3D
art work. And a very fine mix of stoneware it is too=3D21 LOL

Best to you and the best studio help I've ever seen,
Larry Kruzan
Lost Creek Pottery
www.lostcreekpottery.com

=3D20

-----Original Message-----
From: Clayart =3D5Bmailto:Clayart=3D40LSV.CERAMICS.ORG=3D5D On Behalf Of =
=3D
Antoinette Badenhorst
Sent: Tuesday, August 17, 2010 11:51 AM
To: Clayart=3D40LSV.CERAMICS.ORG
Subject: Re: porcelain

Mel, my dear Friend, are you picking a fight with me now or what :-) =3D21 =
=3D
Imagine my pretty moving leaves swinging off one of your iron claypots =3D
=3D21 ( okay you know I am just messing with you right?)=3D20



Back to seriousness: I have recently wrote some articles about porcelain =
=3D
that you might want to look at.=3D20

Every claybody had its own place in this ceramics world of us.Stoneware, =
=3D
earthenware and ..............porcelain is just another one of them. What =
=3D
makes =3D22true porcelain=3D22 different from other claybodies is it's high=
=3D
glass forming abilities. That very glass forming is porcelain's biggest =3D
friend, but also its biggest enemy. So for us working in porcelain, we =3D
made a choice to make our enemy our best friend.=3D20



It is important NOT to use porcelain just for the sake of using porcelain =
=3D
and then work with it like you are working with stoneware. That would be =
=3D
like driving with a 4 x 4 truck on smooth roads just for the sake of =3D
driving 4 x 4. If you are looking for a white clay to get the best out =
=3D
of your glazes, white stoneware would be good and it would really be a =3D
big waste to use porcelain UNLESS you are looking for a marblelike =3D
apearence and the smooth glasslike feel and ring of porcelain. Of cause if =
=3D
all the other qualities of porcelain becomes important, the ball game =3D
changes.=3D20



Just as Mel has his passion for his irom based claybody and the woodfirers =
=3D
have their passion for their firing processes, so one should have a =3D
passion to work with porcelain. One learn it's character and form a =3D
relationship with the claybody, just as one do with other claybodies.=3D20



Porcelain is not superior to other claybodies, but it is expensive and =3D
requiers a spesific kind of personality that is willing to adjust its way =
=3D
of working and their studio environment to accomodate the tediousness of =
=3D
porcelain. When everybody else do not even notice the bugs in their =3D
studios, I curse them dying in my claybucket=3D21 When everybody else is =
=3D
counting their bucks while the kiln is cooling down, I am keeping my =3D
fingers crossed that there will be at least a few workable pots coming =3D
from the batch.=3D20




Randy, while you are looking into additives for your clay ( which I =3D
personally think would be unnessesary) consider using a coarser( sandlike) =
=3D
silica rather than the fine ones. The person to talk to about that is =3D
Robin Hopper, since that is what he does to give some tooth to his =3D
porcelain. I would not add sand on top of the silica, that might put too =
=3D
much flint in the claybody. The equil parts recipe is what most porcelain =
=3D
aritst use. Look at the recipes available in Peter Lane's book =3D22studio =
=3D
porcelain=3D22=3D20



Mel, I trust that the white pot I gave you some years back, is sitting in =
=3D
the most important spot of your collection=3D21 =3D
Grin................................=3D20



Nice day, guys.=3D20

Antoinette Badenhorst=3D20
www.porcelainbyAntoinette.com =3D20

----- Original Message -----=3D20
From: =3D22mel jacobson=3D22 =3D20
To: Clayart=3D40LSV.CERAMICS.ORG=3D20
Sent: Tuesday, August 17, 2010 8:05:39 AM=3D20
Subject: porcelain=3D20

i am not a pure white clay guy at all. i have some strong opinions=3D20
on making sure white clay used for large pieces is treated=3D20
like any other clay. sand, grog and opening the body helps a=3D20
great deal. same for ball clay. it just makes the body throwable.=3D20

there is always a trade off if you want a clay to do what it=3D20
was not intended to do. you can't throw a casting body very well.=3D20
same for size....you have to adjust the body. =3D60every clay that is =3D
compounded=3D20
as a very specific use. there is no such thing as =3D60broad range=3D60.=
=3D60=3D20
(J.T. Abernathy, into my tape recorder.)=3D20

often people get obsessed with whiteness and that means you=3D20
may give up structure.=3D20

i love the old alfred 25x4 recipe.=3D20
it throws like a stoneware and i can add grog and sand and it fires=3D20
=3D60rather=3D60 white.=3D20

i know this is blasphemy for many that love porcelain...but, it=3D20
is just another clay body. it must be treated as such.=3D20
it is not sacred.=3D20

some potters/artists think they have a higher moral standing=3D20
if they fire pure white clay. (scream, yell, call me names.)=3D20
you know...=3D22Well, I fire Porcelain=3D22. good, i fire high iron stonew=
are =3D
with=3D20
sand and fine grog.=3D20
and my loss factor is under 1%.=3D20
mel=3D20
as i have stated very clearly in my new book on kilns and firing.=3D20
=3D60loss is the big eco enemy. if you are wasting fuel on pots that do=3D=
20
not fire well, or your loss factor is at 40%, or your kiln fires=3D20
poorly, you are wasting your own=3D20
money, and you are not being a steward of the earth. and, think in terms=3D=
20
of your own bottom line first. that will lead to good stewardship.=3D60=3D=
20
from: minnetonka, mn=3D20
website: http://www.visi.com/=3D7Emelpots/=3D20
clayart link: http://www.visi.com/=3D7Emelpots/clayart.html=3D20
new book: http://www.21stcenturykilns.com=3D20
alternate: melpots7575=3D40gmail.com=3D20


Nice day, guys.=3D20

Antoinette Badenhorst=3D20
www.porcelainbyAntoinette.com =3D20

----- Original Message -----=3D20
From: =3D22mel jacobson=3D22 =3D20
To: Clayart=3D40LSV.CERAMICS.ORG=3D20
Sent: Tuesday, August 17, 2010 8:05:39 AM=3D20
Subject: porcelain=3D20

i am not a pure white clay guy at all. i have some strong opinions=3D20
on making sure white clay used for large pieces is treated=3D20
like any other clay. sand, grog and opening the body helps a=3D20
great deal. same for ball clay. it just makes the body throwable.=3D20

there is always a trade off if you want a clay to do what it=3D20
was not intended to do. you can't throw a casting body very well.=3D20
same for size....you have to adjust the body. =3D60every clay that is =3D
compounded=3D20
as a very specific use. there is no such thing as =3D60broad range=3D60.=
=3D60=3D20
(J.T. Abernathy, into my tape recorder.)=3D20

often people get obsessed with whiteness and that means you=3D20
may give up structure.=3D20

i love the old alfred 25x4 recipe.=3D20
it throws like a stoneware and i can add grog and sand and it fires=3D20
=3D60rather=3D60 white.=3D20

i know this is blasphemy for many that love porcelain...but, it=3D20
is just another clay body. it must be treated as such.=3D20
it is not sacred.=3D20

some potters/artists think they have a higher moral standing=3D20
if they fire pure white clay. (scream, yell, call me names.)=3D20
you know...=3D22Well, I fire Porcelain=3D22. good, i fire high iron stonew=
are =3D
with=3D20
sand and fine grog.=3D20
and my loss factor is under 1%.=3D20
mel=3D20
as i have stated very clearly in my new book on kilns and firing.=3D20
=3D60loss is the big eco enemy. if you are wasting fuel on pots that do=3D=
20
not fire well, or your loss factor is at 40%, or your kiln fires=3D20
poorly, you are wasting your own=3D20
money, and you are not being a steward of the earth. and, think in terms=3D=
20
of your own bottom line first. that will lead to good stewardship.=3D60=3D=
20
from: minnetonka, mn=3D20
website: http://www.visi.com/=3D7Emelpots/=3D20
clayart link: http://www.visi.com/=3D7Emelpots/clayart.html=3D20
new book: http://www.21stcenturykilns.com=3D20
alternate: melpots7575=3D40gmail.com=3D20





=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D
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Patty on tue 17 aug 10

Antoinette,

Well said.

Patty Kaliher

Martin Rice on tue 17 aug 10

Wondering whether the fact that Mel is not a "pure white clay guy at all" h=
as anything to do with the fact that while he was an apprentice at Mr. Uchi=
da's pottery in Japan, that's all they worked with? :-) I read that in Mel'=
s fantastic Pottery: A Life, A Lifetime.

Martin
Signal Mountain, TN
>
> ----- Original Message -----
> From: "mel jacobson"
> To: Clayart@LSV.CERAMICS.ORG
> Sent: Tuesday, August 17, 2010 8:05:39 AM
> Subject: porcelain
>
> i am not a pure white clay guy at all.

David Finkelnburg on wed 18 aug 10

Mel,
You wrote, in part,
"i love the old alfred 25x4 recipe.
it throws like a stoneware and i can add grog and sand and it fires
`rather` white.
i know this is blasphemy for many that love porcelain...but, it
is just another clay body. it must be treated as such.
it is not sacred."

There is so much truth in what you say. Porcelain is not something
magic. It can be made, changed, managed for your purpose if you only
understand it.
However, as Ron Roy has pointed out many times, few ingredients may make
a recipe simple but those few ingredients also make the recipe very
vulnerable to failure if any one ingredient changes. In the case of
porcelain, using a single clay also pretty much guarantees the recipe will
not achieve optimum particle packing and the resulting body won't have the
plasticity it could with a proper blend of clay particle sizes produced by =
a
mix of different clays.
Good potting!
Dave Finkelnburg
http://www.mattanddavesclays.com

Neon-Cat on thu 19 aug 10

Here=3D92s an industrial historical porcelain from 1912 =3D96 looks pretty
much like some of our recipes. This clay body was used for outdoor
high tension electrical insulators =3D96 its white, tough, durable, takes
glaze or an Albany-type slip glaze well, and you can jolt it with
100,000 volts. This clay body vitrifies at Cone 12 =3D96 12 =3DBD. Source:
ACS, vol. XIV, March 1912.

Tenn. ball clay No. 1 =3D96 15
North Carolina kaolin =3D96 20
English china clay =3D96 25
spar (Brandywine Summit) =3D96 20
Flint (Ohio, 8 hr. grind) =3D96 20

I like all kinds of clay but I=3D92m still partial to my long-range native
white and red calcareous clays and my high iron stoneware greensand
clay body. I=3D92ve tried many versions of clay, found, made and bought
(haven=3D92t yet tried Porcelain for the People) and find it odd to read
that clay bodies might be =3D93vulnerable to failure if any one ingredient
changes=3D94. If one learns the particular clay body, with or without
change of ingredients (it doesn=3D92t take long to =3D93know=3D94) and what=
it ca=3D
n
and cannot do, how can there be failure?

Marian
Neon-Cat

Rimas VisGirda on thu 23 jun 11

I've been using the 25/25/25/25 by weight porcelain formula since the late =
60's. Came from a colleague at Wash State Univ. Has worked fine for me. Tem=
pted to try the coffee can version just to check it out... So many things, =
so little time... -Rimas

Rimas VisGirda on thu 23 jun 11

Hi John,
As David H said, equal parts by weight (what I use):
Kaolin (EPK)
Ball clay (OM-4)
Silica (flint, I don't recall if it's 200 or 325 mesh)
Feldspar (Custer, Kingman back in the day)
-Rimas

--- On Thu, 6/23/11, John Rodgers wrote:

Rimas,
Would you please send me a copy of that porcelain formula. I would
love to give it a try.
Thanks,
John


On 6/23/2011 9:07 AM, Rimas VisGirda wrote:

I've been using the 25/25/25/25 by weight porcelain formula since the=
late 60's. Came from a colleague at Wash State Univ. Has worked fine for m=
e. Tempted to try the coffee can version just to check it out... So many th=
ings, so little time... -Rimas

Eric Hansen on sun 26 jun 11

This comes from The Nelson Book, and is mentioned in Rhodes, also
Glick uses it for his slurry he paints with on pots -
25 Ball Clay
25 kaolin
25 potash feldspar
25 silica
- e -

On Thu, Jun 23, 2011 at 3:07 PM, Rimas VisGirda wrote:
> Hi John,
> As David H said, equal parts by weight (what I use):
> Kaolin (EPK)
> Ball clay (OM-4)
> Silica (flint, I don't recall if it's 200 or 325 mesh)
> Feldspar (Custer, Kingman back in the day)
> -Rimas
>
> --- On Thu, 6/23/11, John Rodgers wrote:
>
> Rimas,
> =3DA0 =3DA0 =3DA0Would you please send me a copy of that porcelain formul=
a. I w=3D
ould
> =3DA0 =3DA0 =3DA0love to give it a try.
> =3DA0 =3DA0 =3DA0Thanks,
> John
>
>
> =3DA0 =3DA0On 6/23/2011 9:07 AM, Rimas VisGirda wrote:
>
> =3DA0 =3DA0 =3DA0I've been using the 25/25/25/25 by weight porcelain form=
ula si=3D
nce the late 60's. Came from a colleague at Wash State Univ. Has worked fin=
=3D
e for me. Tempted to try the coffee can version just to check it out... So =
=3D
many things, so little time... -Rimas
>



--=3D20
Eric Alan Hansen
Stonehouse Studio Pottery
Alexandria, Virginia
americanpotter.blogspot.com
thesuddenschool.blogspot.com
hansencookbook.blogspot.com
"Simplify, simplify, simplify" - Thoreau