Vince Pitelka on fri 12 jan 07
Keith Arbogast asked:
> What are the specific reasons to use a ball mill? There seem to be
> two general cases; pulverizing large particles, and homogenizing the
> batch. I may be misinformed on that, but that is why I am asking the
> question.
> Why should we consider using a ball mill? What are the benefits, in
> glaze surface, or otherwise? Which glaze ingredients behave better
> in a glaze if the batch is milled? Since one cannot put a 5000 gram
> batch in a one gallon jar, what does one omit? Once you have milled
> the part, how do you uniformly mix that and the remainder of the
> ingredients back together?
Keith -
Some people ball-mill all their glazes, and I wonder why they would want to
reduce the particle sizes so uniformly? I'd rather leave a little more
variety in fusion and dispersion. But there are cases where ball milling is
a great advantage. Some glazes, like celadons, chuns, and temmokus, benifit
from greater uniformity in particle size, and ball milling can give better
results. Also, when adding colorants to terra sigillata, ball milling
reduces the particle size of the colorants, and thus they interfere less
with the degree of polish you can attain.
There are other cases where ball milling is an advantage. I'm sure that
other posts will illuminate them.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Keith Arbogast on fri 12 jan 07
What are the specific reasons to use a ball mill? There seem to be
two general cases; pulverizing large particles, and homogenizing the
batch. I may be misinformed on that, but that is why I am asking the
question.
Why should we consider using a ball mill? What are the benefits, in
glaze surface, or otherwise? Which glaze ingredients behave better
in a glaze if the batch is milled? Since one cannot put a 5000 gram
batch in a one gallon jar, what does one omit? Once you have milled
the part, how do you uniformly mix that and the remainder of the
ingredients back together?
This with my thanks and best wishes,
Keith Arbogast
Bloomington, Indiana
Richard Aerni on sat 13 jan 07
Keith,
I used to use one to ball mill some of my ash glazes. It was particularly
useful when incorporating cobalt, copper or other colorants into them, to
avoid speckling or uneven distribution. The colors came out with a silken
softness not seen in my other, non-milled glazes. The runs were different.
I still have the ball mill, but no longer take the time to run my glazes
through it as I'd be milling quite a bit, and it's pretty noisy in an open
studio setting, and well, there just seem to be plenty of other things to do
with my time. But, I keep the mill around because you just never know when
it will come in handy again.
I've got power tools that I rarely use, but when the right job comes up,
they are invaluable. I put the ball mill into the same category.
Best,
Richard Aerni
Rochester, NY
John Rodgers on sat 13 jan 07
In the world of casting slips, especially porclain casting slips, when
making up a colored slip using metallic oxides, the ball mill becomes an
essential piece of equipment in order to achieve a smooth uniform color
throughout the medium.
In the realm of glazes some require ball milling, others do not. It
depends of the effect one wishes to acheive. To find what works, what
doesn't, testing is the solution.
For throwing clays, I'm not so sure as I am not familiar. Most materials
that go into clay bodies are ground fine or other wise processed, dried
and then air floated to the point of dry bagging or mixing into a clay
body. Only once have I ever had the occasion to ball mill a prospective
clay body. In that case the ingredients were "found" outdoors in nature,
and after a lot of draining, straining, and settling it was decided to
ball mill then dry in plaster bowls.
Regards,
John Rodgers
Chelsea,
Keith Arbogast wrote:
> What are the specific reasons to use a ball mill? There seem to be
> two general cases; pulverizing large particles, and homogenizing the
> batch. I may be misinformed on that, but that is why I am asking the
> question.
>
> Why should we consider using a ball mill? What are the benefits, in
> glaze surface, or otherwise? Which glaze ingredients behave better
> in a glaze if the batch is milled? Since one cannot put a 5000 gram
> batch in a one gallon jar, what does one omit? Once you have milled
> the part, how do you uniformly mix that and the remainder of the
> ingredients back together?
>
> This with my thanks and best wishes,
> Keith Arbogast
> Bloomington, Indiana
>
> ______________________________________________________________________________
>
> 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.
>
>
claystevslat on sat 13 jan 07
Keith --
Partial answer -- ball milled glazes sometimes adhere differently
when applied to bisqued clay; and the final fired result often
differs from non-milled glaze. And if I've only got a quart of
milling capacity and a gallon of glaze, I mix the whole glaze, then
I do the glaze in multiple batches.
-- Steve Slatin
--- In clayart@yahoogroups.com, Keith Arbogast wrote:
>
> What are the specific reasons to use a ball mill? There seem to be
> two general cases; pulverizing large particles, and homogenizing
the
> batch. I may be misinformed on that, but that is why I am asking
the
> question.
>
> Why should we consider using a ball mill? What are the benefits, in
> glaze surface, or otherwise? Which glaze ingredients behave better
> in a glaze if the batch is milled? Since one cannot put a 5000
gram
> batch in a one gallon jar, what does one omit? Once you have milled
> the part, how do you uniformly mix that and the remainder of the
> ingredients back together?
Paul Herman on sat 13 jan 07
Keith,
It's an indispensable tool in my shop.
I gather a lot of local materials, and use the ball mill for grinding
granite, feldspar, rhyolite, volcanic ash, primary clay, etc.
I also use it for dispersion of pigment in my celadon glaze. It gets
iron speckles even when sieved to 80 mesh, but 15 minutes in the mill
and they are gone. Several other glazes benefit from it too. It's a
home made affair, with a stoneware jar I made about 30 years ago and
holds one gallon of glaze or 3 kilos of mineral. It rolls on rubber
rolls from a washing machine.
Best,
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Jan 12, 2007, at 11:14 AM, Keith Arbogast wrote:
> What are the specific reasons to use a ball mill? There seem to be
> two general cases; pulverizing large particles, and homogenizing the
> batch. I may be misinformed on that, but that is why I am asking the
> question.
>
> Why should we consider using a ball mill? What are the benefits, in
> glaze surface, or otherwise? Which glaze ingredients behave better
> in a glaze if the batch is milled? Since one cannot put a 5000 gram
> batch in a one gallon jar, what does one omit? Once you have milled
> the part, how do you uniformly mix that and the remainder of the
> ingredients back together?
>
> This with my thanks and best wishes,
> Keith Arbogast
> Bloomington, Indiana
>
> ______________________________________________________________________
> ________
> 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.
>
>
Ivor and Olive Lewis on sun 14 jan 07
Dear Keith Arbogast,=20
If materials being purchased are minus 200 mesh a ball mill is generally =
unnecessary.
Ball milling is an ideal was of eliminating blue spots when using Cobalt =
oxide. Mix the Cobalt Ox. with a portion of the Quartz fraction and wet =
mill for half an hour.
It is a useful tool for people who collect and prepare their own =
minerals and a good way to finish the reduction of stuff that has been =
put through the "Dolly Pot" to get > 200 #
It is inadvisable to wet mill any of the Felspars, Nepheline Syenite or =
Frits. The alkali fraction will dissolve into the water and change the =
glaze composition.
Best regards,=20
Ivor Lewis.
Redhill,
South Australia.
Paul Herman on sun 14 jan 07
Greetings Ivor,
I wish to take issue with your statement below discouraging the wet
milling of feldspar.
While I don't dispute that some of the alkali content will be
dissolved, I think it is an insignificant amount.
Three evidences I offer:
(#1) I wet mill my local feldspar for six hours to get glaze material
of 150-200 mesh. The resulting dried feldspars test out as containing
over 16% total alkali content. That's pretty close to theoretically
pure feldspar. So my conclusion is, there may be some alkali removed
when de-watering the material, but it's an insignificant amount.
(#2) Commercially available feldspars are wet milled in at least some
circumstances, and virtually all commercial feldspars are refined by
flotation, a wet process. If it's good enough for the "Feldspar
Corporation".......?
(#3) If a person could obtain some dry milled feldspar, wouldn't the
same amount of alkali be released into the glaze slop as soon as you
mixed it with water?
What say you Ivor, any flaws in my reasoning?
Best wishes,
Paul Herman
Great Basin Pottery
Doyle, California US
http://greatbasinpottery.com
On Jan 13, 2007, at 5:09 PM, Ivor and Olive Lewis wrote:
>
> It is inadvisable to wet mill any of the Felspars, Nepheline
> Syenite or Frits. The alkali fraction will dissolve into the water
> and change the glaze composition.
>
> Best regards,
>
> Ivor Lewis.
> Redhill,
> South Australia.
>
Tom Sawyer on wed 17 jan 07
I've used a ball mill for making terra sig out of a variety of different
types of clay.
Tom Sawyer
| |
|
