Tom Buck on wed 7 aug 96
The other day a matt turquoise glaze was posted on Clayart. I am
suggesting that midfire potters not use this "Maryland" glaze for food
containers. It doesn't have enough silica to keep the copper properly
bound when faced with food acids. Adapting the same Seger formula, here are
two that are "balanced":
C5 ox. Turquoise matt C5 ox. Green matt
60 Neph sy. 40 Neph sy.
25 Strontium carb. 25 Wollastonite
2 Lithium carb. 12 Spodumene
4 EPK 12 EPK
9 Flint 11 Flint
4 Copper carb. 4 Copper carb.
2 Bentonite 2 Bentonite
Only tests will show if these yield an acceptable colour and surface on
your claybody.
Cheers TomB Hamilton ON Canada URL http://digitalfire.com/magic/tombuck.htm
CP Dunbar on sun 11 aug 96
Tom Buck wrote:
>
> ----------------------------Original message----------------------------
> The other day a matt turquoise glaze was posted on Clayart. I am
> suggesting that midfire potters not use this "Maryland" glaze for food
> containers. It doesn't have enough silica to keep the copper properly
> bound when faced with food acids. Adapting the same Seger formula, here are
> two that are "balanced":
> C5 ox. Turquoise matt C5 ox. Green matt
> 60 Neph sy. 40 Neph sy.
> 25 Strontium carb. 25 Wollastonite
> 2 Lithium carb. 12 Spodumene
> 4 EPK 12 EPK
> 9 Flint 11 Flint
> 4 Copper carb. 4 Copper carb.
> 2 Bentonite 2 Bentonite
> Only tests will show if these yield an acceptable colour and surface on
> your claybody.
>
> Cheers TomB Hamilton ON Canada URL http://digitalfire.com/magic/tombuck.htm
Can you say whether these glazess are food safe ?
cp dunbar
blfp@concentric.net
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