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blue celadon formulas?

updated fri 31 oct 97

 

Numo Jaeger and Michael Miller on wed 29 oct 97

Hello ClayArt Folks,

I was wondering if anyone has some formulas that they would be willing to
share for "Blue Celadons" that will work in an Alpine updraft kiln?

Numo Jaeger
Studio One Art Center
Oakland, CA

Dannon Rhudy on thu 30 oct 97

----------------------------Original
message----------------------------
Hello ClayArt Folks,

.... "Blue Celadons" that will work in an Alpine updraft kiln?...

Numo Jaeger

...................................

Hi, Numo. Let me recommend, first, that if you are really
interested in blue Celadons, you get Robert Tichane's book,
"Those Celadon Blues" (worth it just for the title, no?).
They had them at The Potter's Shop a while back.

Second, as long as you can achieve a reduction atmosphere, it
does not matter what kind of kiln you use, though if it cools
slowly that is to your advantage with celadons, in my opinion.

Here is a Choy Blue, Val Cushing's: (does contain barium) ^9-10

50 Custer Spar
6 Whiting
4 EPK
16 Barium
24 Flint

Add RIO 2%

And another without barium: ^9-10

44 K-200 Feldspar
20 Wollastonite
4 Dolomite
12 Grolleg (I substitute EPK here)
20 Flint

Add rio 2%

Dannon Rhudy

Rafael Molina-Rodriguez (Rafael Molina-Rodriguez) on thu 30 oct 97

Numo :

Try the following recipe :

Pinell's Blue Celadon ^ 10 Red. (from Sam Clarkson)

Potash Feldspar 25
Silica 35
Whiting 20
Grolleg Kaolin 20

Add :
Tin Oxide 1
Barium Carbonate 2
Barnard Slip 3

I achieved a somewhat nice blue color and no crazing from this glaze in
our Alpine 24 updraft. Sam Clarkson and John Britt achieve some
outstanding blue in Brookhaven's Geil downdraft. I don't believe the
difference came from the kiln design but rather the firing cycle.
According to John, they reduce heavily starting at ^ 012 - ^ 010. Of
course, the whole kiln load is Grolleg porcelain clay and they can do that
without fear of black core. I, on the other hand, have to contend with
many different clays from dark stonewares to grolleg porcelains in our
class firings and have to be careful with reduction to avoid that "Demon
Black Core." ;-D

Good luck!

Rafael

>>> Numo Jaeger and Michael Miller 10/29/97
06:51am >>>
----------------------------Original message----------------------------
Hello ClayArt Folks,

I was wondering if anyone has some formulas that they would be willing
to
share for "Blue Celadons" that will work in an Alpine updraft kiln?

Numo Jaeger
Studio One Art Center
Oakland, CA