Jim Kassebaum on fri 20 mar 98
B-Mix - Questions & Answers Revisited
As with any product, if we can't make it work to our personal
satisfaction, we become frustrated. If a simply answer is not
forthcoming to solve our problem, our level of frustration increases.
And yet for all of us involved in ceramics as a livelihood, we know
that the number of pot holes in the road to ceramic success is
virtually unlimited; and the ability to truly sort out and solve our
problems may well determine our ultimate success.
During a recent Steven Hill workshop I was fascinated in how Steven
would prepare and work the clay at the joining of the attached spouts
on his pitchers as well as at the point of attachment of the long,
graceful handles on his large and spectacular ewer vessels. The
capacity audience - mostly experienced potters - left the 2 day
workshop understanding more than ever before, that technique separates
truly fine potters from the rest of the field, and that technique is
not acquired only through the classroom, books, videos, workshops and
even years of experience but through a combination of all of the
above. A veteran, full time potter from Northern California commented
that after over 20 years as a potter he was amazed at how much he had
learned from the workshop; we never stop learning. When asked if he
experienced cracking or joining problems, Steven responded, "no; but
I've been doing this for over 25 years, and I learn new techniques all
the time." By the way, the only clay Steven Hill uses is B-Mix.
Last August I posted a few comments about B-Mix on ClayArt. Several
recent postings lead me to believe that not everyone saw that message,
so I have included it below. B-Mix is not a white stoneware; it is
not a porcelain; it is a highly plastic "porcelain-like" clay which
will throw as well as any clay you can find, but that same plasticity
which makes it a potter's dream to throw also creates in it a body
with a high shrinkage as it dries. Joining a thin attachment to a
thick vessel, or drying a piece in such a manner that the attachment
dries at a very different rate than the main body of the piece will
dramatically increase the potential for cracks at the joining point.
Is there a single, clear cut answer as to how to avoid ever having
problems with B-Mix or any other clay body? I don't believe there is.
In mathematics we are blessed with most questions being answered by a
definitive, numerical response. In ceramics, as with numerous other
disciplines, that definitive response usually comes only after an
exchange of a multitude of questions and intermediate and progressive
answers. By working together with potters and exchanging ideas and
information, our technicians solve hundreds of challenges each week,
but the essential element of those solutions is a goal of solving not
finding fault.
Reprint of August '97 B-Mix posting:
Several thoughts on B-Mix.
Over the past week there have been several comments regarding either
cracking or joining problems when using B-Mix. Of the 155 clay bodies
we sell, B-Mix is near the top of the list in popularity. Millions of
pounds of B-Mix are shipped each year primarily because it is a very
plastic, throwable, "potter friendly" clay. The trade off is that the
same materials which create its plasticity also make B-Mix prone to
cracking if it is not dried in a slow, even and controlled manner.
The most satisfactory drying method we have found is to cover your
B-Mix greenware with the plastic bags used by most dry cleaners. This
thin plastic will conform well to the shapes of your ware while still
breathing enough to allow controlled circulation. Even if you dry in
a cabinet, the level of humidity in the cabinet must be fairly
constant to properly dry greenware. The key is that all portions of
your ware dry at an even pace, and this can only happen if the drying
process is slow.
Other references to cracking in the glaze firing most likely do not
relate to the raw clay body but rather from thermal shock created when
the bisque firing was at too low a temperature. We recommend a
minimum of cone 06 for white and porcelain type clays. If these clays
are bisqued any lower, they are prone to thermal shock in the cooling
of the bisque or in the heating of the glaze firing.
As we all know, the art form in which we work is driven by a fairly
complex science. Nothing is quite as simple as it appears, and for
that reason we welcome and encourage your questions and comments to
our tech support group - either by phone [(800 452-4862 - Joe at ext.
216, or Steve at ext. 216] or to info@lagunaclay.com.
Jim Kassebaum
Laguna Clay
the cat lady on sat 21 mar 98
snip
>
>During a recent Steven Hill workshop I was fascinated in how Steven
>would prepare and work the clay at the joining of the attached spouts
>on his pitchers as well as at the point of attachment of the long,
>graceful handles on his large and spectacular ewer vessels. The
>capacity audience - mostly experienced potters - left the 2 day
>workshop understanding more than ever before, that technique separates
>truly fine potters from the rest of the field, and that technique is
>not acquired only through the classroom, books, videos, workshops and
>even years of experience but through a combination of all of the
>above. A veteran, full time potter from Northern California commented
>that after over 20 years as a potter he was amazed at how much he had
>learned from the workshop; we never stop learning. When asked if he
>experienced cracking or joining problems, Steven responded, "no; but
>I've been doing this for over 25 years, and I learn new techniques all
>the time." By the way, the only clay Steven Hill uses is B-Mix.
>
snip
Took a workshop in Ontario Canada with Steven Hill last July. Yes,
he does use and love B-mix...ordered it for the class.
HOWEVER
Ask him about it - it wasn't from his usual supplier and he went
crazy with it - cracking at joins, etc. B-mix isn't always the
same, depending on the source.
Just my $0.02
sam - alias the cat lady
Melbourne, Ontario
SW Ontario CANADA
http://www.geocities.com/paris/3110
Stuart Ridgway on sat 21 mar 98
Jim Kassenbaum of Laguna clay company tells us in his very interesting
and useful post on March 20th that B-mix is very plastic, but as a result
comes with a lot of shrinkage in drying that may lead to potters
difficulties with cracking, particularly in the bottom.
I use cone 5 B-mix extensively, and have some, but not much trouble
with cracking. I also notice that when I use rollers in the centering of
the clay, and twin rollers in the early stages of forming the pot, the final
product is quite a bit drier than when I do all the fabrication using hands,
fingers, and lubricating water. About rollers see my post on Feb 14 "Twin
Rollers for throwing pots without lubricating water."
Stuart Ridgway
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