mel jacobson on thu 26 aug 10
would you please lead us to, or give us a basic recipe
for cone 10 cones.
and, some basic inform on making them.
molds, drying.
or, tell us where to look.
thanks.
mel
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
Lee Love on thu 26 aug 10
From the archives:
David Hendley on thu 30 dec 99
By trail and error, I have worked out cone formulations
that work for ME (read this as a big disclaimer; be sure
to rigorously test your homemade cones for accuracy
before you depend on them).
I made my mold for the cones by using Orton cones
to make a plaster gang mold for 6 cones. Do this by
laying the cones on a smooth flat surface, surrounding
them with a 1 X 4 'fence' and pouring in a few inches
of plaster.
My cones were sacrificed in the process. Perhaps you
could bisque-fire the cones first so they could be
used after being cast around.
Interestingly, in "The Potter's Alternative", by Harry
Davis, he says NOT to make a pyrometric cone mold
this way. He suggests sheet metal molds.
To make my cones, I mix up a recipe to plastic-clay
consistency, slightly over-fill each space in the mold,
and then tamp down and remove the excess with a
putty knife. It's important that you don't remove too
much material; an undersized cone will bend at a lower
work-heat point.
Since the recipes don't have much clay in them, they
mixtures are pretty short, but still fine to work with.
I used ball clay, with it's inherent impurities, to
improve the workability, so this throws my formulas
a little off from the theoretical cone formulas.
A 100 gram batch makes LOTS of cones.
CONE 10
Custer feldspar 17
Whiting 7
OM#4 ball clay 37
flint 31
(this adds up to 92)
CaO .67
MgO .03
K2O .21
Na2O .08
Fe2O3 .02
TiO2 .08
Al2O3 1.26
SiO2 10.02
CONE 8 1/2
I like this cone because it gives me a little earlier
warning than cone 9 for my cone 10 firings.
Custer feldspar 22.5
whiting 9
OM#4 ball clay 29
flint 39.5
(100 total)
CaO .69
MgO .02
K2O .21
Na2O .08
Fe2O3 .02
TiO2 .05
Al2O3 .90
SiO 8.96
John Britt on sun 2 jan 00
David Green wrote the best book I have ever read on cones and it is a
must read for those interested in Glaze chemistry! "Handbook of Pottery
Glazes" ISBN: 0-8230-2181-5 I believe it is out of print although it
is available through inter-library loan. (precursor to the internet) He
has devoted the first 60 pages to cones. Although the first 38 pages
are the most outstanding. He discusses Seger's paper in 1886 and the
theory that he used. It is a must read!
The discussion of the thinking process itself makes it important. He
began by choosing materials that were in use in the
porcelain industry on a large scale. (i.e. feldspar, whiting, silica
and kaolin.) He tried to use the purest ingredients , Zettlitz Kaolin,
Norwegian quartz, etc.. You can read it for yourself.
The making of cones is not really a concern for me. It is the knowledge
gained in the process that is important. Orton and other cone
manufacturers provide a product of amazing consistency, accuracy and
at a price that is unbeatable. The time you would spend thinking about
making cones
would far exceed the price they charge and that is not even counting,
making the molds, making the cones or the material cost, etc.
The first cone Seger made was cone 4 and he called
it "4" because of the amount of Silica. K20 -0.3, Ca0-0.7 Al203-0.5
and
silica 4.0. From cone 5 upwards the ratio of silica to alumina was
fixed at 1:10 , i.e. Al203-0.5 Si20-5.0 for cone 5 or Al203-0.6 Si02
-6.0 for cone 6 etc. (The flux column remains the same 0.3 K20 and 0.7
Ca0)
The illustrative part is the Silica/Alumina ratio. And when you
understand this, Ian Currie's "Stoneware Glazes" is much more
readable.
So using Insight, I formulated several cone recipes directly from
Seger's
theory, only using current materials. (Green gives recipes that Seger
used but since the materials are unavailable they are not very
accurate.)
For example Cone 9
Custer Feldspar-23.06g
EPK - 20.45g
Whiting - 9.66g
Silica (200m)- 46.82g
The Al/Si ratio is 0.9/9.0
Or cone 8:
Custer Feldspar-22.21g
EPK - 16.65g
Whiting - 9.30g
Silica (200m)-38.84g
The Al/Si ratio is 0.8/8.0.
From John Britt:
For example Cone 9
Custer Feldspar-23.06g
EPK - 20.45g
Whiting - 9.66g
Silica (200m)- 46.82g
The Al/Si ratio is 0.9/9.0
Or cone 8:
Custer Feldspar-22.21g
EPK - 16.65g
Whiting - 9.30g
Silica (200m)-38.84g
The Al/Si ratio is 0.8/8.0.
David again:
CONE 06
Redart clay 48.5
Custer feldspar 9.0
Gerstley borate 28.0
whititng 10.5
CaO .65
MgO .07
K2O .11
Na2O .17
Fe2O3 .08
TiO2 .02
B2O3 .72
Al2O3 .31
SiO2 2.22
--
=3DA0Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
Paul Herman on thu 26 aug 10
Hi Mel,
I've read all about making cones in a book by Harry Davis "The
Potter's Alternative." It's from page 36 to 41 in my copy (1987.)
ISBN 0 454 01113 X
This is one of the best potter's books I've got. He tells you how to
do almost everything from scratch. You can build a pugmill out of
concrete, from Harry's plans.
best wishes,
Paul Herman
Great Basin Pottery
Doyle, California US
www.greatbasinpottery.com/
On Aug 26, 2010, at 6:06 PM, mel jacobson wrote:
> would you please lead us to, or give us a basic recipe
> for cone 10 cones.
> and, some basic inform on making them.
> molds, drying.
> or, tell us where to look.
> thanks.
> mel
> 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
jonathan byler on thu 26 aug 10
thank you mel for asking this, and to the others who responded. this
is all going into my "necessary knowledge for post apocalyptic
survival" file.
On Aug 26, 2010, at 8:51 PM, Paul Herman wrote:
> Hi Mel,
>
> I've read all about making cones in a book by Harry Davis "The
> Potter's Alternative." It's from page 36 to 41 in my copy (1987.)
>
> ISBN 0 454 01113 X
>
> This is one of the best potter's books I've got. He tells you how to
> do almost everything from scratch. You can build a pugmill out of
> concrete, from Harry's plans.
>
> best wishes,
>
> Paul Herman
>
> Great Basin Pottery
> Doyle, California US
> www.greatbasinpottery.com/
>
>
>
>
> On Aug 26, 2010, at 6:06 PM, mel jacobson wrote:
>
>> would you please lead us to, or give us a basic recipe
>> for cone 10 cones.
>> and, some basic inform on making them.
>> molds, drying.
>> or, tell us where to look.
>> thanks.
>> mel
>> 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
Lee Love on fri 27 aug 10
On Thu, Aug 26, 2010 at 9:52 PM, jonathan byler wrote:
> thank you mel for asking this, and to the others who responded. =3DA0this
> is all going into my "necessary knowledge for post apocalyptic
> survival" file.
Welcome! But for "post apocalyptic survival", firing by eye and
draw tiles are probably the best way to go.
--
=3DA0Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
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