mel jacobson on thu 14 feb 02
just a reminder:
this is a long term project. testing, idea gathering
and a great deal more.
this is a tiny foot in the door. please do not start
thinking this is a done deal...by no means. just the
start. much to consider.
mel
Mel's laptop, someplace one the go.
http://www.pclink.com/melpots website
L. P. Skeen on thu 14 feb 02
hey mel, and Howard, I'm asking again: Will this be a ^6 or a ^10 clay
body?
Count me in on the testing if it's a ^6 body. :)
Thanks
Lisa
----- Original Message -----
From: "mel jacobson"
To:
Sent: Thursday, February 14, 2002 3:03 PM
Subject: clayart clay body
> just a reminder:
> this is a long term project. testing, idea gathering
> and a great deal more.
> this is a tiny foot in the door. please do not start
> thinking this is a done deal...by no means. just the
> start. much to consider.
> mel
>
> Mel's laptop, someplace one the go.
> http://www.pclink.com/melpots website
>
>
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> Send postings to clayart@lsv.ceramics.org
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>
mel jacobson on fri 15 feb 02
again, to clear the air.
this is how the conversation went with howard axner.
mel
`if clayart, as a group, came up with a standard stoneware
and white body, would you make it and print the recipe on
the box so that anyone in the world could make it?`
howard
yes.
end of conversation.
no body or clay formula has been established.
this is a long way down the track.
people like ron roy, john and david b. with the help of about
100 clayarters would have to test, discuss and establish clear ideas,
if this is possible.
i have said three times now...this is a baby step towards
some standardization in a claybody.
this is not reality that we are talking about...it is a theory.
it may never happen.
yes carla, care, concern for manufacture's rights and secrets
are critical. we are not trying to steal or step on toes. this is not
a vendetta against clay companies. i would hope that others
would embrace this.
ron is very clear about testing, standards, screening...and many
more concepts in making clay. (i have no expertise in this area.)
a formula on a box does nothing if standard testing is not done,
or poor materials are used to make the clay.
it is just like a glaze recipe. it does not often translate to
someone else.
carla knows of what she speaks. she is at that front line.
testing, knowing, adjusting...then understanding. that is how
quality potters are made. it does not come from a box or a
jar. it comes from hard work in the studio and years of study.
thank you carla for your insightful post.
this is not a rock throwing contest. this is about moving forward
in testing, quality control. the best companies should be doing
it without asking.
but, i do believe that we know very little, as potters, about our
most important asset...CLAY.
mel
From:
Minnetonka, Minnesota, U.S.A.
web site: http://www.pclink.com/melpots
Cindy Strnad on fri 15 feb 02
Yes, you are right, Mel.
Because you are right, in particular, concerning me, I would really, really like
to be involved in helping with this if we do it. I can't contribute a lot of
knowledge, but I can test, etc. and, I hope, learn a lot.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
L. P. Skeen on fri 15 feb 02
> no body or clay formula has been established.
> this is a long way down the track.
Ok, so whadda we do next? If there is voting involved, remember that I have
set up a Clayart Voting group that we can use. :)
L
iandol on sun 17 feb 02
L. P. Skeen comments
<< I STILL want to know if this clayart clay will be ^6 or ^10. >>
This is where the discussion starts to get interesting. Who gets to =
choose? Is it a numbers game? Will we have to count the "chads"
Ivor.
Dave Evans on thu 21 feb 02
Let's see if we can get the ball poised for a bit of a push. So we =
want a recipe (or several) that can be made out of ingredients that are =
readily available, preferably for as wide a group as possible. I've =
spent a few minutes wandering through some catalogs and websites to see =
what ingredients seem common through most of the US and Canada.
We will need silica, feldspar and clay at the least. Let's say we go =
for 200 mesh silica - available from just about any supplier. If we =
want a mid-range body we might want some nepheline syenite, being aware =
of some possible solubility - also just about universally available. My =
thought is that some wollastonite would be a good choice. I understand =
it helps with thermal shock resistance, and if we can cut down on free =
silica, so much the better. Just about everybody has got this too.
Feldspar availability varies around the region a bit, but there are =
a couple just about everybody can get their hands on. I'm thinking =
about Custer and G-200. Of the twelve places I glanced at only one =
doesn't seem to carry Custer, and two don't have G-200.
Now we get into clays. My thinking is that a mix of different types =
of clays would probably be suitable - kaolin (china clay), fireclay and =
ball clay. It's probably not a bad idea to have a couple of each type to =
give a variety of particle sizes and characteristics (melt and =
plasticity as well as color). Using more ingredients will probably also =
help insure against variability and lack of availability. Earthenwares =
as well for low-fire, though I didn't look into this. =20
Two kaolins seem to be the most widely available - EPK (Edgar =
Plastic Kaolin) and Tile #6. Only one of the twelve I looked at did not =
have EPK, and only two did not have Tile #6. Use them both?
Fireclay availability is similar, with only one outlet each not =
having the two I looked into. The two most common seem to be Missouri =
Hawthorn Bond Fireclay and Goldart. Both as well?
Ball clays seem not to be quite as universal, but almost everyone I =
looked at (with the exception of one) carried at least two of the three =
seemingly most common. Everyone seemed to have Kentucky (Old Mine) #4 =
ball clay, but I have some reservations on using this ( I hear it's a =
bit dirty and variable - correct me if I'm wrong). Nine of the twelve =
carried Tennessee #1 (SPG) ball clay and eight of the twelve carried =
Foundry Hill Cream. Try two out of three?
The places I looked at were from all over the US and one place in =
Canada. Axner, Laguna, Bracker's and Sheffield Pottery all seemed to =
carry everything I looked at. The others carried almost every item, and =
they were - New Mexico, Minnesota, Standard, Tucker's, Clayart Center, =
Georgies, Great Lakes and Clayworks Supplies.
=20
So just to mull over, I'm thinking a body with silica, wollastonite, =
Custer and G-200 with maybe some Neph Sy, EPK and Tile #6, Hawthorn Bond =
and Goldart, Kentucky Old Mine #4 and either Foundry Hill Cream or =
Tennessee #1 (SPG), add sand and/or grog to taste. So do I have too much =
or not enough, and what am I missing? Then the proportions and testing =
start to get interesting!!! Plastics to non plastics ratio? Cone 5 =
unity analysis anyone?=20
John Evans in San Diego
Dave Evans on mon 25 feb 02
Hawthorn Bond Missouri Fireclay is available in at lest two mesh =
sizes, but the 35 mesh seems the most common.
=20
Redart seems by far the most universally available of the iron =
bearing clays. Several outlets have Roseville, several have Lizella and =
some have Newman.
The Ione series of grogs is available at a number of locations, =
probably more than other types. Still, less than half of the places I =
looked at carried that. Molochite has similar availability. Similarity =
in grogs used throughout North America, let alone to other points, may =
be difficult to achieve. Silica sand is always an option, though not my =
personal preference.
Ron Roy asked about some information on the clays I looked at. What =
little I could find follows:
Kaolins:
EPK (Edgar Plastic Kaolin) - fires cream white and not particularly =
plastic (claymaker.com)
Tile #6 - very white, very plastic with small particle size =
(claymaker.com)
Fireclays:
Goldart - highly plastic (digitalfire)
Hawthorne Bond Missouri Fireclay - variable [composition], buff =
firing, plastic (digitalfire)
Ball Clays:
Foundry Hill Cream - creamy color (Sheffield Pottery)
Kentucky Ball Clay #4 (OM4) - fine grained (Kentucky - Tennessee =
Clay Company), lighter than OM4 (claymaker.com), seemingly most =
available
Tennessee #1 (SPG) - coarse grained (Kentucky - Tennessee Clay =
Company), lighter than OM-4 (claymaker.com)
=20
Red Clays:
Redart - dark red (claymaker.com), medium plasticity, clean, low =
shrinkage with long firing range (digitalfire) seemingly the most widely =
available
Newman - Red California clay, more orange than Laterite ( a high =
firing red plastic clay) (claymaker.com)
Lizella - tougher than redart, but not as dark as other red bodies =
(clayart archives)
John Evans in San Diego
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