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that fireclay thing...

updated fri 11 feb 00


Jonathan Kaplan on wed 9 feb 00


Why are potters still jeapordizing their work by including low grade and
low mesh fireclays?

Haven't we been through this before?

Our pottery paradigm is so rigid that we are willing to sacrifice our hard
work to inferior quality materials. I don't get it. We work too hard to
risk lime and coal contamination.

Briefly, to elaborate.

Fireclays are the weak link in a potters claybody. Especially APG Green. To
a lesser degree, the Hawthorne 50 mesh may be a bit better. These
materials will always be problematic. If you don't have any problems now,
trust me, you will in the future. Remember, you don't need to look for
problems in pottery, they will find you. And the problems associated with
low grade and low mesh fireclays always will.

If anyone cares to read more, go to (Tony's website for IMC
and Insight) and click on education. I authored and article "The Whining
Stops Here" about clays and what we can do to be more proactive.

BTW, we use Greenstripe 200 mesh fireclay in our stoneware casting body. At
this mesh size, there is not much bad juju that can happen. We have also
used Sutter from time to time with equally perfect results.

Really now, if you blend your own clay body, you don't need that 28 mesh
fireclay. Its just asking for trouble. If you buy clay in the box, ask the
right questions. Don't jeapordize your work.



Jonathan Kaplan
Ceramic Design Group LTd/Production Services
PO Box 775112
Steamboat Springs, CO 80477
(970) 879-9139 voice and fax

UPS: 1280 13th St. Unit13
Steamboat Springs, CO 80487

Dale A. Neese on thu 10 feb 00

Thanks to everyone who responded to questions about fireclay. For the most
part I only intended to use a fire clay body in a local wood fire workshop
coming in April so I wasn't planning to make a lot of this particular mix.
Really don't get any chances to fire with wood here, so admiring some of the
wood fired ware of some other folks and finding a recipe that was simple and
knew was really textural, different from my everyday stoneware production
pots, would be good enough to be put to the fire. The question was what
flavor of "Missouri Stoneware" was the recipe calling for. So I now know
there are more Missouri Fireclays than the A.P. Green which I happen to have
a couple of bags of taking up space. What I am working for is some large
jar forms which I will brush with some flashing and crackle slips. Bulbous,
Shigaraki clay like, ash covered jars. Fun. I may have to pull back from the
amount of the large mesh fireclay that the recipe is calling for just so I
can keep the skin on my fingers. Let you know how they come out.
Ya'll come to the James Watkins Wood fire workshop!! April 28th 29th, 30th.
And I do agree with Johnathan, Steve, David, and Tom on the use of fireclays
in claybody mixes and that one should use the best blends of clays for his
functional ware. Test and always test again.
I would be happy to see some exotic wood firing bodies from anyone.
Thanks again,
Dale Tex