John Rodgers on sat 11 nov 06
Tim,
Chappells book on Glaze and Clay has a number of porcelain recipes -
cone 6 to cone 10 - and mixing instructions. You might want to check it
out.
Regards,
John Rodgers
Chelsea, AL
Timothy Joko-Veltman wrote:
> I want to make my own porcelain body, but before I do, I wanted to ask
> the list for any tips or tricks, or things that I should keep in mind.
>
> Regards,
>
>
> Tim
>
> ______________________________________________________________________________
>
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>
>
Timothy Joko-Veltman on sat 11 nov 06
I want to make my own porcelain body, but before I do, I wanted to ask
the list for any tips or tricks, or things that I should keep in mind.
Regards,
Tim
Ivor and Olive Lewis on sun 12 nov 06
Dear Tim,
I would always select materials that have the minimum amount of Iron =
oxides in their published compositions
Best regards,
Ivor Lewis.
Redhill,
South Australia.
John Britt on sun 12 nov 06
Start with a small batch, like 1000g. (Around two pounds)
Take this cone 10 porcelain recipe or any other:
550 Grolleg Kaolin
250 Silica
250 Custer feldspar
20 Bentonite
Mix the 'plastic' materials first, or put the bentonite in about 1/2 cup
of water the night before. (You could do it immediately with the hand
blender by sprinkling it in to the water while stirring>)
Then add the grolleg and mix with a hand blender. (Add enough water to
make it like a wet slip. Maybe about 2 cups??) Then add the Custer and
then the silica.
Then pour the wet clay/slip on to a plaster bat and let it dry to a
useable form.
Throw or handbuild a piece.
Now you can easily test as many bodies as you want.
Hope it helps,
John Britt
www.johnbrittpottery.com
WJ Seidl on sun 12 nov 06
Tim:
You're going to get flooded with "recipes" no doubt. But I have a simple
tip. Porcelain gets a lot of its plasticity from ball clay, which isn't very
white. The whiter the porcelain, the less plastic, unless you "add"
something.
If you can, if you have the storage space; make up a batch or two. Add some
type of liquid "aging" like beer or urine (I know, I know, ewwwwwww, but it
works) and put the clay aside for at least 90 days. A year is better. Let
it get all green with algae, then rework it all. Then try to throw it.
Compare it to "new" porcelain of the same "recipe".
It will make all the difference.
Best,
Wayne Seidl
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Timothy
Joko-Veltman
Sent: Saturday, November 11, 2006 8:14 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: mixing your own porcelain
I want to make my own porcelain body, but before I do, I wanted to ask
the list for any tips or tricks, or things that I should keep in mind.
Regards,
Tim
____________________________________________________________________________
__
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.
Craig Martell on mon 13 nov 06
Tim wanted to know:
>I want to make my own porcelain body, but before I do, I wanted to ask
>the list for any tips or tricks, or things that I should keep in mind.
Hello Tim:
There's a lot to formulating any kind of claybody and there are myriads of
things you can do to move things ahead. I'm not sure what it is you want
to know but I'll start at the beginning and see if it's at all
helpful. I've been working in porcelain bodies for the last two years or so.
I don't know what temp you are working at so I'll just assume it's high fire.
You can start by looking at a standard guideline for cone 10 or so
porcelain body compositions. 50 clay, 25 feldspar, 25 quartz or
flint. The first thing to do is work with and test various types of these
materials that might be appropriate for what you want. Do you have a broad
range of what's acceptable as the finished product or is it narrow as in: "
I want a totally white, vitreous translucent body? Test some
kaolins. Test for plasticity and color. Just wet some clay and make test
mice and shrinkage bars for the kiln and fire to your usual temp. Test
some spars for fusion and also color. For porcelain you probably want a
nice white glassy test button. I use g-200 potash spar which is mined here
in the US in North Carolina. When I test spars for fusion and color I use
a 000 porcelain crucible which is basically a one half inch crucible that
has the shape and size of a sewing thimble. The spar is just dry packed
into the crucible and then tapped out onto a tile and fired. This gives a
good visual comparison of as many spars as you can stand to
test. Periodically I do all the potash spars, soda spars and that I use,
and two types of nepheline syenite. You can do fusions and comparisons
every time you buy new batches of materials and compare with what's worked
well in the past. I don't do any testing with the quartz other than a
screen analysis which usually turns out the same. I use a 200 mesh quartz
for claybodies and I just run it thru a 200 mesh sieve. It all goes right
thru. I also sieve the clays and spars too in order to determine the level
of purity and quality control done by the company mining and milling the
material. If there's a component that consistently contains a lot of crap
you can elect not to use it or just factor in that you have to screen it
before mixing. I use a 30 mesh sieve to screen the clays. There's only
one clay I use that needs to be screened all the time and it's Old Hickory
#5 Ball clay.
Once you've found some clays and other stuff you think will work you can
blend some tests for throwing and further testing. I usually do 2000 gram
batches for a test. I mix the 2000 gram dry batch into 1000 ml of
water. This will give you enough to make some small pieces as well as test
mice and shrinkage bars. I usually make some small test mice to try my
glazes on and see what the differences are between bodies. I dewater the
clay so it's in a workable state and set it aside for about 3 days before I
throw little pots and make test bars. I don't worry about optimum aging
time at first because I want to get things rolling along. The clay should
throw fine after 3 days. After firing I look at vitrification and glaze
fit and make necessary adjustments. Adjust the spar for vitrification and
adjust the quartz or flint if you use flint, for glaze fit. One thing to
think about too is particle size. Finer particles require less heatwork.
Aside from the kaolins, spar, and quartz, I usually use a small amount of
light burning ball clay and some vee gum T which is a montmorillonite
material that is called "smectite". It's a very fine montmorillonite clay
that is mainly a magnesium alumino silicate. Like bentonite, which is also
a montmorillonite it increases the "slide factor" of the clay platelets and
greatly improves workability. Don't use too much though because it can
greatly retard drying time and increase warpage if you use too much. I
normally use one to one and a half percent.
If you mix a body and it feels weak and flabby when you work with it try
about a quarter percent Epsom Salt. This will help flocculate the clay and
make it stronger during forming. I add Epsom Salt to a body made with two
English China Clays because they are mined by water jet and are
deflocculated during mining. If I don't focculate this body it isn't worth
mixing at all.
that's about it, Craig Martell Hopewell, Oregon
Timothy Joko-Veltman on tue 14 nov 06
On 11/12/06, WJ Seidl wrote:
> Tim:
> You're going to get flooded with "recipes" no doubt. But I have a simple
> tip. Porcelain gets a lot of its plasticity from ball clay, which isn't very
> white. The whiter the porcelain, the less plastic, unless you "add"
> something.
Tips are what I'm looking for. Thanks.
> If you can, if you have the storage space; make up a batch or two. Add some
> type of liquid "aging" like beer or urine (I know, I know, ewwwwwww, but it
> works) and put the clay aside for at least 90 days. A year is better. Let
> it get all green with algae, then rework it all. Then try to throw it.
> Compare it to "new" porcelain of the same "recipe".
> It will make all the difference.
Don't know if I'm ready to urinate in my mix (I'm probably not going
to be the only person using it), but will definitely keep the
aging/curing factor in mind.
Regards,
Tim
Timothy Joko-Veltman on tue 14 nov 06
On 11/13/06, Craig Martell wrote:
> Tim wanted to know:
> >I want to make my own porcelain body, but before I do, I wanted to ask
> >the list for any tips or tricks, or things that I should keep in mind.
>
> Hello Tim:
>
> There's a lot to formulating any kind of claybody and there are myriads of
> things you can do to move things ahead. I'm not sure what it is you want
> to know but I'll start at the beginning and see if it's at all
> helpful. I've been working in porcelain bodies for the last two years or so.
>
> I don't know what temp you are working at so I'll just assume it's high fire.
>
> You can start by looking at a standard guideline for cone 10 or so
> porcelain body compositions. 50 clay, 25 feldspar, 25 quartz or
> flint. The first thing to do is work with and test various types of these
> materials that might be appropriate for what you want. Do you have a broad
> range of what's acceptable as the finished product or is it narrow as in: "
> I want a totally white, vitreous translucent body? Test some
> kaolins. Test for plasticity and color. Just wet some clay and make test
> mice and shrinkage bars for the kiln and fire to your usual temp. Test
> some spars for fusion and also color. For porcelain you probably want a
> nice white glassy test button. I use g-200 potash spar which is mined here
> in the US in North Carolina. When I test spars for fusion and color I use
> a 000 porcelain crucible which is basically a one half inch crucible that
> has the shape and size of a sewing thimble. The spar is just dry packed
> into the crucible and then tapped out onto a tile and fired. This gives a
> good visual comparison of as many spars as you can stand to
> test. Periodically I do all the potash spars, soda spars and that I use,
> and two types of nepheline syenite. You can do fusions and comparisons
> every time you buy new batches of materials and compare with what's worked
> well in the past. I don't do any testing with the quartz other than a
> screen analysis which usually turns out the same. I use a 200 mesh quartz
> for claybodies and I just run it thru a 200 mesh sieve. It all goes right
> thru. I also sieve the clays and spars too in order to determine the level
> of purity and quality control done by the company mining and milling the
> material. If there's a component that consistently contains a lot of crap
> you can elect not to use it or just factor in that you have to screen it
> before mixing. I use a 30 mesh sieve to screen the clays. There's only
> one clay I use that needs to be screened all the time and it's Old Hickory
> #5 Ball clay.
>
> Once you've found some clays and other stuff you think will work you can
> blend some tests for throwing and further testing. I usually do 2000 gram
> batches for a test. I mix the 2000 gram dry batch into 1000 ml of
> water. This will give you enough to make some small pieces as well as test
> mice and shrinkage bars. I usually make some small test mice to try my
> glazes on and see what the differences are between bodies. I dewater the
> clay so it's in a workable state and set it aside for about 3 days before I
> throw little pots and make test bars. I don't worry about optimum aging
> time at first because I want to get things rolling along. The clay should
> throw fine after 3 days. After firing I look at vitrification and glaze
> fit and make necessary adjustments. Adjust the spar for vitrification and
> adjust the quartz or flint if you use flint, for glaze fit. One thing to
> think about too is particle size. Finer particles require less heatwork.
>
> Aside from the kaolins, spar, and quartz, I usually use a small amount of
> light burning ball clay and some vee gum T which is a montmorillonite
> material that is called "smectite". It's a very fine montmorillonite clay
> that is mainly a magnesium alumino silicate. Like bentonite, which is also
> a montmorillonite it increases the "slide factor" of the clay platelets and
> greatly improves workability. Don't use too much though because it can
> greatly retard drying time and increase warpage if you use too much. I
> normally use one to one and a half percent.
>
> If you mix a body and it feels weak and flabby when you work with it try
> about a quarter percent Epsom Salt. This will help flocculate the clay and
> make it stronger during forming. I add Epsom Salt to a body made with two
> English China Clays because they are mined by water jet and are
> deflocculated during mining. If I don't focculate this body it isn't worth
> mixing at all.
>
> that's about it, Craig Martell Hopewell, Oregon
Craig,
Dude! That is exactly the kind of info I was looking for. Thanks a
million. I am actually on a book fast (promised my wife I wouldn't by
a new one until I've read everything I've got - still about 50 to go)
- and I am working in a relative vacuum, down here (in Brazil).
Thanks so much for your input, and know that it will definitely be put
to good use.
Best regards,
Tim
Michael Wendt on tue 14 nov 06
Tim,
One thing not yet mentioned is something
you want removed from all clay bodies
to get the maximum forming ability:
air
Before I had deairing equipment,
pulling a handle with non-deaired
porcelain was very difficult. Once
I built a deairing mixer, I could
not only pull a handle with the
same clay, I could tie it in a knot!
Air is often the hidden culprit
in cracking and warping since it
is a discontinuity that offers no
mechanical strength.
Good Luck,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, Idaho 83501
USA
wendtpot@lewiston.com
www.wendtpottery.com
WJ Seidl on wed 15 nov 06
For the record, (oh I can hear it coming ) I don't urinate in my clay
either, nor does the cat (that I know of).
I find that a handful of baking yeast in a 500 pound batch of clay does me
just fine. Any "organic liquid" will work as well.
Sorry for the misconception, all.
Best,
Wayne Seidl
(quit snickering, Lisa...see how you are?)
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Timothy
Joko-Veltman
Sent: Tuesday, November 14, 2006 5:51 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: mixing your own porcelain
On 11/12/06, WJ Seidl wrote:
> Tim:
> You're going to get flooded with "recipes" no doubt. But I have a simple
> tip. Porcelain gets a lot of its plasticity from ball clay, which isn't
very
> white. The whiter the porcelain, the less plastic, unless you "add"
> something.
Tips are what I'm looking for. Thanks.
> If you can, if you have the storage space; make up a batch or two. Add
some
> type of liquid "aging" like beer or urine (I know, I know, ewwwwwww, but
it
> works) and put the clay aside for at least 90 days. A year is better.
Let
> it get all green with algae, then rework it all. Then try to throw it.
> Compare it to "new" porcelain of the same "recipe".
> It will make all the difference.
Don't know if I'm ready to urinate in my mix (I'm probably not going
to be the only person using it), but will definitely keep the
aging/curing factor in mind.
Regards,
Tim
Craig Martell on wed 15 nov 06
Tim responded:
>That is exactly the kind of info I was looking for.
Hello Tim:
Thanks for the response. I wasn't sure what would be most useful so I'm
glad to know that the post helped. Good luck with your porcelain testing
and let us know if there are other things you'd like to hear about.
regards, Craig Martell Hopewell, Oregon
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