David Beumee on sun 17 apr 05
I'm researching for a porcelain clay body recipe that fits Hamer's definition of porcelain (white, translucent and vitrified) that has good green strength, good to excellent workability, relatively low shrinkage, an acceptable absorption rate, no warping, cracking or excessive slumping, a fine texture and excellent glaze fit.
The clays used for a porcelain bodies are highly refractory, low in silica and relatively non plastic by nature, meaning that a relatively high proportion of non plastic feldspar and silica must be added tp a porcelain clay body mixture, plus some sort of plasticizer to correct the short kinds of (kaolin) clays used.
I want to maximize the amount of clay in the recipe for greater workability, and I want to cut down on the amount of spar nneded to give an acceptable absorption rate for a potential porcelain body. I wonder about the use of non traditional fluxes in combination with feldspar, and having looked at the potter's periodic table,(table 37b, page 415, The Potters Dictionary),I've decided on the following fluxes to use in combination with a small proportion of feldspar (perhaps 5%); Wollastonite, Petalite, Dolomite and Whiting. Are there any suggestions as to additions or subtractions to this list that I should be thinking about?
David Beumee
Porcelain by David Beumee
Earth Alchemy Pottery
Lafayette, CO
www.davidbeumee.com
Jonathan Kaplan on sun 17 apr 05
David:
Pyrophyllite, dude! I have used this material fro a long time. What can
I help you with?
Depending on the ratios of plastics to non-plastics, you can easily add
pyrophyllite for some of the flint and spar and really work on the
vitrification and absorption.
Post me your clay body, off list if you wish, and I'll be happy to look
it over for you.
Best
Jonathan
Jonathan Kaplan
Ceramic Design Group
PO Box 775112
Steamboat Springs CO 80477
(970) 879-9139
(please use this address for all USPS deliveries)
Plant Location:
1280 13th Street Suite K
Steamboat Springs CO 80487
(please use this address for all UPS, courier, and common carrier
deliveries only!!)
info@ceramicdesigngroup.net
www.ceramicdesigngroup.net
On Apr 17, 2005, at 2:22 PM, David Beumee wrote:
> I'm researching for a porcelain clay body recipe that fits Hamer's
> definition of porcelain (white, translucent and vitrified) that has
> good green strength, good to excellent workability, relatively low
> shrinkage, an acceptable absorption rate, no warping, cracking or
> excessive slumping, a fine texture and excellent glaze fit.
> The clays used for a porcelain bodies are highly refractory, low in
> silica and relatively non plastic by nature, meaning that a relatively
> high proportion of non plastic feldspar and silica must be added tp a
> porcelain clay body mixture, plus some sort of plasticizer to correct
> the short kinds of (kaolin) clays used.
> I want to maximize the amount of clay in the recipe for greater
> workability, and I want to cut down on the amount of spar nneded to
> give an acceptable absorption rate for a potential porcelain body. I
> wonder about the use of non traditional fluxes in combination with
> feldspar, and having looked at the potter's periodic table,(table 37b,
> page 415, The Potters Dictionary),I've decided on the following fluxes
> to use in combination with a small proportion of feldspar (perhaps
> 5%); Wollastonite, Petalite, Dolomite and Whiting. Are there any
> suggestions as to additions or subtractions to this list that I should
> be thinking about?
>
> David Beumee
> Porcelain by David Beumee
> Earth Alchemy Pottery
> Lafayette, CO
> www.davidbeumee.com
>
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URL Krueger on sun 17 apr 05
On Sunday 17 April 2005 01:22 pm, David Beumee wrote:
> I'm researching for a porcelain ... (white, translucent
> and vitrified) ... I've decided on the
> following fluxes ... Wollastonite,
> Petalite, Dolomite and Whiting. Are there any suggestions
> as to additions ... to this list
David,
What about ground glass (frit)?
It is not colored, transparent and melts at a low temp.
Seems to me this meets your requirements.
Just my thought to tweak your thinking.
--
Earl K...
Bothell WA, USA
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