alilly6 on tue 1 sep 09
Hello,
I'm looking for a ^6 stoneware body. Ninety percent of the time it
will be used for throwing.
The first one I've tried is "Ash" sold by Mile Hi in Denver. It is
^5-7, close to white when fired in oxidation, has a shrinkage of
12.5%, absorption of 0.7%.
My questions concern the residue, which forms a very stiff layer, in
the bottom of the throwing water container: =3D20
=3D20
This material, over time, will form a greater percentage of the clay
body due to recycling -does this mean recycling is "out"?
Is this a characteristic of all (most?) mid fire stoneware clay
bodies?
Is the low absorption achieved by use of the material in question?
Any comment will be appreciated.
Adron
Mary Starosta on tue 1 sep 09
Hi Adron,
Depends on what kind of clay you want. I like a brown stone ware, so I am
not the norm here. B mix is popular at alot of the recreation centers, and
small community colleges. I would check with Mile high. They might be abl=
e
to work out a deal for you to try several different ones or at the least,
answer your questions about stoneware. I don't use ash, but I have heard i=
t
is good as well , though some folks have a problem with S cracks. Also
depends on what glazes you like, slips,etc. I like a earth'y' look and
feel, very rustic.
Happy potting!
Mary Starosta
Colorado Potter
http://marystarosta.wordpress.com/
On Tue, Sep 1, 2009 at 11:23 AM, alilly6 wrote:
> Hello,
>
> I'm looking for a ^6 stoneware body. Ninety percent of the time it
> will be used for throwing.
>
> The first one I've tried is "Ash" sold by Mile Hi in Denver. It is
> ^5-7, close to white when fired in oxidation, has a shrinkage of
> 12.5%, absorption of 0.7%.
>
> My questions concern the residue, which forms a very stiff layer, in
> the bottom of the throwing water container:
>
> This material, over time, will form a greater percentage of the clay
> body due to recycling -does this mean recycling is "out"?
>
> Is this a characteristic of all (most?) mid fire stoneware clay
> bodies?
>
> Is the low absorption achieved by use of the material in question?
>
> Any comment will be appreciated.
>
> Adron
>
--
Mary Starosta
http://www.homesincolorado.com/mstarosta
ReMax Alliance
mastarosta@gmail.com
Colorado Potter
http://marystarosta.wordpress.com/
720-271-7523
alilly6 on fri 4 sep 09
Eric,
Thanks for the information on Gold Art. Unfortunately it's not
available locally. 50 lbs (dry) is $16 + $34 for shipping.
I'm working my way through ^5 - 7 clays that Mile Hi sells in Denver.
Color is not a big issue so maybe I'll hit on something not too
expensive.
Mary,
My ideal clay would be light on grog, matures close to ^6, and tan or
light brown in color. I'm working with B Mix-5 to see how our glazes
look and fit. I'm in a ceramics class at Front Range Comm College but
it's too early to get any feedback on what people are using.
Thanks for the input,=3D20
Adron
On Fri, 4 Sep 2009 18:15:29 -0400, you wrote:
>Gold Art mixed with water and less than 5% medium grog. Let it cure =3D
after
>mixing for 24-48 hours then throw. About $15 for 75 lbs. of clay. =3D
Roseville
>is supposed to be better if you can get it. Ball clay can be added if =3D
you
>find this too hard to throw but then you are going to a slightly higher
>cone, either that or it will be slightly under-fired, which is not =3D
always
>bad. Clay mixes just like bread dough. See my blog site for pictures.
>americanpotter.blogspot.com
>
>On Tue, Sep 1, 2009 at 6:15 PM, Mary Starosta =3D
wrote:
>
>> Hi Adron,
>> Depends on what kind of clay you want. I like a brown stone ware, so =
=3D
I am
>> not the norm here. B mix is popular at alot of the recreation =3D
centers, and
>> small community colleges. I would check with Mile high. They might =3D
be
>> able
>> to work out a deal for you to try several different ones or at the =3D
least,
>> answer your questions about stoneware. I don't use ash, but I have =3D
heard
>> it
>> is good as well , though some folks have a problem with S cracks. =3D
Also
>> depends on what glazes you like, slips,etc. I like a earth'y' look =3D
and
>> feel, very rustic.
>> Happy potting!
>> Mary Starosta
>> Colorado Potter
>> http://marystarosta.wordpress.com/
>>
>>
>>
>>
>> On Tue, Sep 1, 2009 at 11:23 AM, alilly6 wrote:
>>
>> > Hello,
>> >
>> > I'm looking for a ^6 stoneware body. Ninety percent of the time it
>> > will be used for throwing.
>> >
>> > The first one I've tried is "Ash" sold by Mile Hi in Denver. It is
>> > ^5-7, close to white when fired in oxidation, has a shrinkage of
>> > 12.5%, absorption of 0.7%.
>> >
>> > My questions concern the residue, which forms a very stiff layer, =3D
in
>> > the bottom of the throwing water container:
>> >
>> > This material, over time, will form a greater percentage of the clay
>> > body due to recycling -does this mean recycling is "out"?
>> >
>> > Is this a characteristic of all (most?) mid fire stoneware clay
>> > bodies?
>> >
>> > Is the low absorption achieved by use of the material in question?
>> >
>> > Any comment will be appreciated.
>> >
>> > Adron
>> >
>>
>>
>>
>> --
>> Mary Starosta
>> http://www.homesincolorado.com/mstarosta
>> ReMax Alliance
>> mastarosta@gmail.com
>> Colorado Potter
>> http://marystarosta.wordpress.com/
>> 720-271-7523
>>
Eric Hansen on fri 4 sep 09
Gold Art mixed with water and less than 5% medium grog. Let it cure after
mixing for 24-48 hours then throw. About $15 for 75 lbs. of clay. Roseville
is supposed to be better if you can get it. Ball clay can be added if you
find this too hard to throw but then you are going to a slightly higher
cone, either that or it will be slightly under-fired, which is not always
bad. Clay mixes just like bread dough. See my blog site for pictures.
americanpotter.blogspot.com
On Tue, Sep 1, 2009 at 6:15 PM, Mary Starosta wrote:
> Hi Adron,
> Depends on what kind of clay you want. I like a brown stone ware, so I a=
m
> not the norm here. B mix is popular at alot of the recreation centers, a=
nd
> small community colleges. I would check with Mile high. They might be
> able
> to work out a deal for you to try several different ones or at the least,
> answer your questions about stoneware. I don't use ash, but I have heard
> it
> is good as well , though some folks have a problem with S cracks. Also
> depends on what glazes you like, slips,etc. I like a earth'y' look and
> feel, very rustic.
> Happy potting!
> Mary Starosta
> Colorado Potter
> http://marystarosta.wordpress.com/
>
>
>
>
> On Tue, Sep 1, 2009 at 11:23 AM, alilly6 wrote:
>
> > Hello,
> >
> > I'm looking for a ^6 stoneware body. Ninety percent of the time it
> > will be used for throwing.
> >
> > The first one I've tried is "Ash" sold by Mile Hi in Denver. It is
> > ^5-7, close to white when fired in oxidation, has a shrinkage of
> > 12.5%, absorption of 0.7%.
> >
> > My questions concern the residue, which forms a very stiff layer, in
> > the bottom of the throwing water container:
> >
> > This material, over time, will form a greater percentage of the clay
> > body due to recycling -does this mean recycling is "out"?
> >
> > Is this a characteristic of all (most?) mid fire stoneware clay
> > bodies?
> >
> > Is the low absorption achieved by use of the material in question?
> >
> > Any comment will be appreciated.
> >
> > Adron
> >
>
>
>
> --
> Mary Starosta
> http://www.homesincolorado.com/mstarosta
> ReMax Alliance
> mastarosta@gmail.com
> Colorado Potter
> http://marystarosta.wordpress.com/
> 720-271-7523
>
ivor & olive lewis on tue 8 sep 09
Dear Ron and Vince,
Ron's comment <<"Anyway - if your clay is working OK then don't worry about
it - if it seems hard in the box and you drop it and it becomes softer -
then it is probably deflocculated and will not throw as well as a properly
flocculated clay." >>.
and Vince's response <,
the water is redistributed, and the water layers restored, and the clay is
suddenly much softer and more plastic.>>
This issue has been raised several times over the past decade within
Clayart.
Possibly deflocculation is not implicated in this phenomenon.
Past responses usually lead to an opinion that the material is Thixotropic,
that is, viscosity of the plastic clay is reduced due to the additional
kinetic energy adsorbed when the motion of the falling mass is arrested. S=
o
called "Jelly Paints" set solid in the can but liquefy when vigorously
stirred. Bentonite clays (T-O-T structure) are noted for imparting this
property to pastes made with water.
If a clay exhibits this quality to and unwarranted degree then an excess of
bentonite may be suspected as an additive used to enhance plasticity to wha=
t
otherwise might be regarded as unresponsive ingredients. Ron may be able to
enlighten us on the degree to which Bentonite is used by clay body
manufacturers.
Best regards,
Ivor Lewis,
Redhill,
South Australia
Ron Roy on tue 8 sep 09
Hi Vince,
I suppose we have to entertain the thought that there can be different
degrees of deflocculation - small amounts will will give the result you
describe for instance.
As clay ages - becomes more acidic - surely some of the sodium comes out of
even a potash spar.
I do know you can have the effect to different degrees - and sometimes not
at all. It is usually present in older clay as opposed to newly mixed clay =
-
sometimes it happens quickly as in Neph Sy fluxed clay if it has not been
counter balanced with a flocculator.
I have not done any science to determine if my thinking is right Vince - it
just seems to make sense to me based on my experience - been making clays
for potters for 50 years - it's impossible not to come to some conclusions.
I would welcome seeing the results of some experiments - some clays with no
source of sodium compared with others with spars.
I don't find your idea of what is happening unreasonable - it just matches
what happens to deflocced clay so the question becomes - are there two kind=
s
of systems at work and how do we tell which is which?
How does one find out if a clay is slightly deflocced?
Good to hear from you - RR
On Mon, Sep 7, 2009 at 8:44 PM, Vince Pitelka wrote:
> Ron Roy wrote:
> "Anyway - if your clay is working OK then don't worry about it - if it
> seems
> hard in the box and you drop it and it becomes softer - then it is probab=
ly
> deflocculated and will not throw as well as a properly flocculated clay."
>
> Hi Ron -
> I wanted to get your opinion on something. I have seen the above
> phenomenon
> happen on clay that I am quite certain is not deflocculated, and I have
> always attributed it to simple gravity/settling - displacement of the wat=
er
> layer between particles and thus more friction, making the clay seem
> stiffer. When the clay is re-mobilized by wedging or dropping, the water
> is
> redistributed, and the water layers restored, and the clay is suddenly mu=
ch
> softer and more plastic.
>
> Does that make any sense to you? I ask this because I have seen this
> phenomenon in many different claybodies, including highfire claybodies wi=
th
> no soda spar that threw perfectly fine after they were re-mobilized. Whe=
n
> I
> teach workshops at Michael McDowell's we sometimes use boxed clay from th=
e
> Clay Art Center in Tacoma that has been sitting around stacked up in
> Michael's studio for a good long time. We drop the bags on the floor a f=
ew
> times and then the clay behaves just fine, and these are mostly cone 10
> stoneware bodies.
>
> As always, your opinion will be greatly appreciated -
> - Vince
>
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
>
--
Ron Roy
15084 Little Lake Road
Brighton, Ontario, Canada
K0K 1H0
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