Ivor and Olive Lewis on wed 19 nov 08
Dear Lili,
There should be no barrier to making a high potash frit from freely
available materials using methods widely disseminated in several of
the standard texts on glazing published over the past half century or
so.
I could see this task being given to senior undergrad students as a
way of developing their skills and knowledge.
There are several avenues by which the task could be approached. At
its simplest, obtaining the formulae for commercial frits and
substituting Potash monoxide for Sodium monoxide would be a good place
to start but I would favour a return to basic principles, selecting
substances commonly found on the shelves of Ceramic Supply Houses.
I think I may do a trial run, having most of the needed ingredients on
the shelves.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Paul Herman on wed 19 nov 08
Ivor,
There is a description of a high potash frit made from pearl ash,
feldspar and kaolin in Michael Cardew's "Pioneer Pottery", page 144 to
148. He writes that it "breaks all the rules of frit making" and uses
it to make a bright iron red glaze.
best,
Paul Herman
Great Basin Pottery
Doyle, California US
www.greatbasinpottery.com/
On Nov 18, 2008, at 8:55 PM, Ivor and Olive Lewis wrote:
> There are several avenues by which the task could be approached. At
> its simplest, obtaining the formulae for commercial frits and
> substituting Potash monoxide for Sodium monoxide would be a good place
> to start but I would favour a return to basic principles, selecting
> substances commonly found on the shelves of Ceramic Supply Houses.
> I think I may do a trial run, having most of the needed ingredients on
> the shelves.
> Best regards,
> Ivor Lewis.
> Redhill,
> South Australia.
Ivor and Olive Lewis on thu 20 nov 08
Dear Paul Herman,
Yes, that is an interesting discussion but where does Mr. Cardew
mention the firing temperature ? These ideas need testing.
Our discussion related to the absence of Potash rich frits available
in the market place and working in the Orton Cone 6 genre.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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