Ken Chin-Purcell on tue 18 dec 01
Hmmm, I'm not sure about the oxidation theory vis a vis tea dust.
I've been testing lately the tea dust recipes that Bret Hinsch
posted in February: http://www.potters.org/subject37674.htm
In that post he quotes from a well researched Taiwanese magazine
article by Wu Peng-fei. The recommended firing was cone 9 oxidation.
These traditional Chinese glazes look great, IMHO, when fired
in my ever-so-humble electric kiln. I fire to 1250C, soak at
1210C and cool at 70C/hr down to 700C. This bends cone 9 for me.
So Brett, if you're still reading, THANKS! It was a great post.
BTW, the glaze formulas were:
Teadust #1
KNaO 0.15
CaO 0.55
MgO 0.3
Al203 0.25
SiO2 2.5
Teadust #2
KNaO 0.2
CaO 0.62
MgO 0.18
Al2O3 0.3
SiO2 3.0
Teadust #3
KNaO 0.3
CaO 0.5
MgO 0.2
Al2O3 0.35
SiO2 3.5
To all add 10% iron, 1% titanium and 2% nickel.
In terms of the ingredients I like to use (total batch size of 100):
Teadust 1
CUSTER FELDSPAR 31.5
DOLOMITE 18.5
WOLLASTONITE 8
EPK KAOLIN 8
FLINT 22
TITANIUM DIOXIDE 1
IRON OXIDE RED 9
Nickel Oxide 2
Teadust 2
CUSTER FELDSPAR 38
DOLOMITE 10
WOLLASTONITE 13.5
EPK KAOLIN 7
FLINT 19.5
TITANIUM DIOXIDE 1
IRON OXIDE RED 9
Nickel Oxide 2
Teadust 3
CUSTER FELDSPAR 52
DOLOMITE 10
WOLLASTONITE 7.5
EPK KAOLIN 1.5
FLINT 17
TITANIUM DIOXIDE 1
IRON OXIDE RED 9
Nickel Oxide 2
Tea Dust #2 was especially popular with non-potter friends.
#1 is glossier and pretty in sunlight. #3 is stonier.
All very nice glazes and well worth trying if you are high
firing in oxidation.
-- Ken Chin-Purcell
Wesley Rolley on wed 19 dec 01
Ken Chin-Purcell wrote:
>These traditional Chinese glazes look great, IMHO, when fired
>in my ever-so-humble electric kiln. I fire to 1250C, soak at
>1210C and cool at 70C/hr down to 700C. This bends cone 9 for me.
This is not very much different from my firing schedule. How long do yo=
u=20
soak at 1210C?
Also, the recipe's that you gave include nickel oxide.
Teadust 1
CUSTER FELDSPAR 31.5
DOLOMITE 18.5
WOLLASTONITE 8
EPK KAOLIN 8
FLINT 22
TITANIUM DIOXIDE 1
IRON OXIDE RED 9
Nickel Oxide 2
What is the purpose of the nickel oxide? How does this contribute to th=
e=20
"tea dust" effect?
--=20
Wesley C. Rolley
wrolley@refpub.com
"I find I have a great lot to learn =96 or unlearn. I seem to know far =
too=20
much and this knowledge obscures the really significant facts, but I am =
getting on." -- Charles Rennie Mackintosh=20
Paul Taylor on wed 19 dec 01
Dear Ken
How is it to be back home.
I will try these glazes thanks for including the formulas and the firing
cycle - recipes are useless with out them.
any idea what the nickel oxide does ?
Regards from Paul T
http://www.anu.ie/westportpottery
> From: Ken Chin-Purcell
> Reply-To: Ken Chin-Purcell
> Date: Tue, 18 Dec 2001 10:55:32 -0600
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Mo' Betta' Tea Dust
>
> Hmmm, I'm not sure about the oxidation theory vis a vis tea dust.
> I've been testing lately the tea dust recipes that Bret Hinsch
> posted in February: http://www.potters.org/subject37674.htm
> In that post he quotes from a well researched Taiwanese magazine
> article by Wu Peng-fei. The recommended firing was cone 9 oxidation.
>
> These traditional Chinese glazes look great, IMHO, when fired
> in my ever-so-humble electric kiln. I fire to 1250C, soak at
> 1210C and cool at 70C/hr down to 700C. This bends cone 9 for me.
>
> So Brett, if you're still reading, THANKS! It was a great post.
>
> BTW, the glaze formulas were:
>
> Teadust #1
> KNaO 0.15
> CaO 0.55
> MgO 0.3
> Al203 0.25
> SiO2 2.5
>
> Teadust #2
> KNaO 0.2
> CaO 0.62
> MgO 0.18
> Al2O3 0.3
> SiO2 3.0
>
> Teadust #3
> KNaO 0.3
> CaO 0.5
> MgO 0.2
> Al2O3 0.35
> SiO2 3.5
>
> To all add 10% iron, 1% titanium and 2% nickel.
>
> In terms of the ingredients I like to use (total batch size of 100):
>
> Teadust 1
> CUSTER FELDSPAR 31.5
> DOLOMITE 18.5
> WOLLASTONITE 8
> EPK KAOLIN 8
> FLINT 22
> TITANIUM DIOXIDE 1
> IRON OXIDE RED 9
> Nickel Oxide 2
>
> Teadust 2
> CUSTER FELDSPAR 38
> DOLOMITE 10
> WOLLASTONITE 13.5
> EPK KAOLIN 7
> FLINT 19.5
> TITANIUM DIOXIDE 1
> IRON OXIDE RED 9
> Nickel Oxide 2
>
> Teadust 3
> CUSTER FELDSPAR 52
> DOLOMITE 10
> WOLLASTONITE 7.5
> EPK KAOLIN 1.5
> FLINT 17
> TITANIUM DIOXIDE 1
> IRON OXIDE RED 9
> Nickel Oxide 2
>
> Tea Dust #2 was especially popular with non-potter friends.
> #1 is glossier and pretty in sunlight. #3 is stonier.
> All very nice glazes and well worth trying if you are high
> firing in oxidation.
>
> -- Ken Chin-Purcell
>
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