search  current discussion  categories  materials - clay 

porcelain formulas

updated sat 30 nov 96

 

marcie on mon 28 oct 96


Please, if anyone has formulas --tested--for porcelain, cone 8-10,
oxidation or reduction, could you share them with me.

I am a student at Ga State Un. and I am testing hopefully as many as 100.
This is my course of study this qtr. The qtr. is over in 4 weeks. EEK!
Help.

I appreciate your support!!

Marcie Blizzard
E-mail address: gs01rbs@panther.gsu.edu

"Rafael Molina-Rodriguez (Rafael Molina-Rodriguez)" on mon 28 oct 96

Marcie:

Try the following:

David Leach Porcelain Cone 10 reduction

Grolleg Kaolin 55
Potash Feldspar 25
Flint 15
Bentonite 5

I use this recipe in deflocculated slip form to decorate with (hakeme,
trailing, etc.,...) A local supplier, John Logan at Texas Pottery, uses this
recipe with #6 Tile clay instead of Grolleg for a commercial body he sells.
Nice claybody not as white as with grolleg.

>>> marcie 10/28/96 07:57am >>>
----------------------------Original message----------------------------

Please, if anyone has formulas --tested--for porcelain, cone 8-10,
oxidation or reduction, could you share them with me.

I am a student at Ga State Un. and I am testing hopefully as many as 100.
This is my course of study this qtr. The qtr. is over in 4 weeks. EEK!
Help.

I appreciate your support!!

Marcie Blizzard
E-mail address: gs01rbs@panther.gsu.edu

Bob Howell on mon 28 oct 96

Try this porcelain recipe. It's nice & white, throws well, and fires well.
It's transluscent at cone 10, but works OK as low as cone 6.

#6 tile kaolin 30
kaopaque 20 kaolin 15
OM#4 ball clay 7
custer feldspar 24
flint 24
macaloid or Vee gum T 1.6
epsom salts 1.6


Bob Howell
Alexandria, LA
bobhowell@linknet.net

At 08:57 AM 10/28/96 EST, you wrote:
>----------------------------Original message----------------------------
>
>Please, if anyone has formulas --tested--for porcelain, cone 8-10,
>oxidation or reduction, could you share them with me.

Craig Martell on tue 29 oct 96

Marcie: Here is the formula for the porcelain body that I use. It is an
excellent throwing body and handbuilds as well. It is very white and most
glazes will fit it they are not extremely high expansion. This porcelain was
formulated by Tom Turner and he gave it to me in 1989. He should be given
credit as the originator if this body is passed on to others. I might also
mention that in order for large bowls and flatware to survive the Quartz
inversion on the way DOWN, I bisque fire this clay to cone 03. If I don't,
it's crack city for platters and big bowls. At cone 03 glazes still apply
well, as the body is still quite porous.

Turner Porcelain-cone 9-10 Red. or Ox.

vee gum "t" 1.5%(do not substitute bentonite for this
material)
om4 ball clay 4.5%
#6-tile clay 29.0%
kaopaque 20 14.5%
custer feldspar 23.5%
200 mesh silica 27.0%

Good luck, Craig Martell-Oregon

Jeanne Otis on wed 30 oct 96


>Please, if anyone has formulas --tested--for porcelain, cone 8-10,
>oxidation or reduction, could you share them with me.
>
>I am a student at Ga State Un. and I am testing hopefully as many as 100.
>This is my course of study this qtr. The qtr. is over in 4 weeks. EEK!
>Help.
>
>I appreciate your support!!
>
>Marcie Blizzard

Marcie, here is a recipe I used in graduate school at Ohio State in 1974
and I still use occassionally. My students like it. Columbus Clay Company
has been selling it as a prepared clay for several years. Hope it works for
you!

Porcelain - Cone 8-10

Grolleg 45
Sgp Ball 15
Silica 10
Nepheline syenite 10
Kona F-4 Feldspar 15
Macaloid 2

Jeanne Otis e-mail: Jeanne.Otis@asu.edu

Karen Gringhuis on wed 30 oct 96

A Cushing (AU) revision of a Jean Otis (ASU) body is what I use firing to
c/9 flat C/10 well over (hopefully). Grolleg 45% Tenn. Ball Clay
(#9) 15% Kona F-4 20% Flint 20% Total 100% Plus macaloid 2%
Can be translucent but not really designed for that, just to throw well.
Jean's orig. recipe is avail. commercially from Columbus Clay Co in
Ohio - one reservation. When mixing a BODY w/ macaloid, it's best to
blunge it in water & let stand overnight before mixing into the clay.
Otherwise micro air bubbles occur throughout which don't really come
out with wedging. Col Clay says they don't do this &"no one ever complained."
(I just never bought it again.) If you can deal with this, their store
bought body is quick & easy. My version has 15% total shrinkage.

John Britt on fri 1 nov 96

Karen Gringhuis wrote:
>
> ----------------------------Original message----------------------------
> A Cushing (AU) revision of a Jean Otis (ASU) body is what I use firing to
> c/9 flat C/10 well over (hopefully). Grolleg 45% Tenn. Ball Clay
> (#9) 15% Kona F-4 20% Flint 20% Total 100% Plus macaloid 2%
> Can be translucent but not really designed for that, just to throw well.
> Jean's orig. recipe is avail. commercially from Columbus Clay Co in
> Ohio - one reservation. When mixing a BODY w/ macaloid, it's best to
> blunge it in water & let stand overnight before mixing into the clay.
> Otherwise micro air bubbles occur throughout which don't really come
> out with wedging. Col Clay says they don't do this &"no one ever complained."
> (I just never bought it again.) If you can deal with this, their store
> bought body is quick & easy. My version has 15% total shrinkage.

Since we are on the subject of Porcelain and Columbus Clay Co., I am
interested in getting the recipe for "Mather Porcelain" that Columbus
Clay sells.

Does anyone know it. Do you think I could get it from them directly or
is it a commercial secret?

I have used this clay for many years but am moving to Dallas, TX soon
and don't necessarily want to ship it there. It is a fantastic throwing
body.

Thanks for your help!
--
Bye, Bye,


John Britt
Dys-Functional Pottery
http://www.erinet.com/claydude/britt1.html

Sally Bowen Prange on sat 2 nov 96

Here is my favorite, all-time and constantly used formula for porcelain. I
demand a lot from my clay body, in elasticity and pushing the edge:

Grolleg --------50
Potash spar------25
silica (200)--------25
BENTONITE-----------2%

I prefer bentonite to V-gum anytime. I have very little cracking--and that
includes firing in a luster kiln several times.----This is from someone else,
but I am not sure who.>>>>>>>>good luck>*__*<

Lisa on sat 2 nov 96

Karen Gringhuis wrote:
>
> ----------------------------Original message----------------------------
> A Cushing (AU) revision of a Jean Otis (ASU) body is what I use firing to
> c/9 flat C/10 well over (hopefully). Grolleg 45% Tenn. Ball Clay
> (#9) 15% Kona F-4 20% Flint 20% Total 100% Plus macaloid 2%
> Can be translucent but not really designed for that, just to throw well.
> Jean's orig. recipe is avail. commercially from Columbus Clay Co in
> Ohio - one reservation. When mixing a BODY w/ macaloid, it's best to
> blunge it in water & let stand overnight before mixing into the clay.
> Otherwise micro air bubbles occur throughout which don't really come
> out with wedging. Col Clay says they don't do this &"no one ever complained."
> (I just never bought it again.) If you can deal with this, their store
> bought body is quick & easy. My version has 15% total shrinkage.


What is this macaloid stuff? I never heard of it before.

Russel Fouts on sun 3 nov 96

John,

>> Formula for "Mather Porcelain" <<

Even if it is a trade secret, couldn't one glaze analysis programs be used to
figure out a reasonable imitation?

Russel (enjoying John's wacky pots)

!^NavFont02F00A00007NGHHGA26034

Karen Gringhuis on mon 4 nov 96

Dear Lisa - Apparently in m sleepless state, I threw your post into the
MAIL folder w/out reading it. Sorry. Am not sure if your qn. is
"what on earth is macaloid?" or "why blunge it the night before?" so
will attempt to answer both. Macaloid comes from refining hectorite ore
and in a clay body adds plasticity. (It's also a glaze suspension
agent.) It's better for porcelain bodies than bentonite because
it's cleaner, less iron ox. It absorbs SO MUCH WATER (Put a bit in a little
water, & watch as you keep adding more & more water.) that to get it
evenly distributed throughout the glaze or body it should be blunged 1st.
I once saw a body with it in which this had NOT been done & even Cushing
wedging & throwing could not get rid of the micro-porous foamy texture which
still remained in cross section when cut. I once re-pugged (after paying freigh
really fix it. So I am still blending it in bit by bit w/ other clay.

Now that I've told you more than you wanted to know, if you have more
qns., just write. Karen Gringhuis

Tony Hansen on mon 4 nov 96

> What is this macaloid stuff? I never heard of it before.

Macaloid is an off-white flaky powder used primarily as a glaze suspender made
from hectorite montmorillonitic ore. It tends to suspend and harden the dried
glaze while not extending the glazes drying time as is the case with CMC gum. Th
it is common to use Macaloid and CMC together to control drying time, suspension
and glaze hardness.

Macaloid is valued for its long-time suspending properties which helps prevent
uneven settling of material particles which have differing specific gravities
(i.e. stain particles tend to be much heavier and settle first).

Macaloid is lower in iron than bentonite and thus is valued as a plasticizer in
porcelain bodies. Like bentonite, it increases water requirements and can be use
in similar amounts.

To get maximum benefit from Macaloid, it should be mixed thoroughly into the wat
with a power blunger (for hours if possible) before adding the other dry
ingredients.

--
Tony Hansen, IMC
134 Upland Dr., Medicine Hat, Alta T1A 3N7 Canada
Phone:403-527-2826 FAX:527-7441 email: thansen@mlc.awinc.com
web: http://digitalfire.com/imc.html

Andy Roth on tue 12 nov 96

marcie wrote:
>
> ----------------------------Original message----------------------------
>
> Please, if anyone has formulas --tested--for porcelain, cone 8-10,
> oxidation or reduction, could you share them with me.
>
> I am a student at Ga State Un. and I am testing hopefully as many as 100.
> This is my course of study this qtr. The qtr. is over in 4 weeks. EEK!
> Help.
>
> I appreciate your support!!
>
> Marcie Blizzard
> E-mail address: gs01rbs@panther.gsu.edu


Dear Marcie;

This is my formula which has worked well for me. I modified a formula
used at Skidmore college in Saratoga Springs, NY.

#6 Tile clay 50
Custer Feldspar 25
Silica 23
Alumina hydrate 2
Talc 2
Bentonite 2

It is reasonably plastic, Matures at Cone 8-10 (it might bloat at 11),
and is somewhat translucent When thin. I modified the original formula to
alow it to vitrify in my electric kiln when I switched to Oxidation.
The original formula Fired well in reduction but was not really mature
under cone 10 and best at cone 11.

The Original formula:
Epk 50
Custer spar 25
silica 25
Bentonite 2


Good Luck

Andy Roth
Saratoga Pottery
rotha@crisny.org