Scott Hunnicutt on sun 17 sep 06
hey all,
correction: the raku clay I am using is rated from 06-8 not to cone 10. I
was planning on bisque the piece to 010. and then glaze to cone 6.
Don suggested I use a clear glaze recipe and add a colorant. he said it
would be better to have a Al:Si ratio of 1:10. Does anyone have a recipe
that can fit that?
thanks,
Scott Hunnicutt
Scott Hunnicutt on sun 17 sep 06
what do people on the list mean when they are keep refering to stable Vs.
unstable glazes?
thanks,
Scott Hunnicutt
John Hesselberth on sun 17 sep 06
On Sep 17, 2006, at 9:35 AM, Scott Hunnicutt wrote:
> what do people on the list mean when they are keep refering to
> stable Vs.
> unstable glazes?
Hi Scott,
Stable glazes are ones that will hold up in use, particularly when
exposed to acidic foods and basic dishwasher detergents.
Unfortunately there are lots of glazes floating around potterland
(including some commercial ones) that won't pass a test of soaking in
vinegar for three days. They fade or the surface becomes eroded and
the sheen of the glaze changes. Stable glazes will show no change
after three days in vinegar. I have some mugs purchased from another
potter that are faded and pitted inside from a year or two regular
use with coffee. I have other mugs that have been in regular use for
nearly 30 years that still look as good as the day I bought them.
Regards,
John
Don Goodrich on sun 17 sep 06
Hi Scott,
The clear glaze I use is closer to what I suggested.
It's
Clear ^6
43.7 Gerstley borate
21.3 EPK
35 Flint
Alumina:Silica ratio is 1:9.86.
Calculated expansion is 59.5; adding 3% cobalt carb increases
it to 61.4. This is considerably less than the expansion of
77.4 that I get for the Wayne's Blue recipe.
Might be worth a try.
Don Goodrich
>Don suggested I use a clear glaze recipe and add a colorant. he said it
>would be better to have a Al:Si ratio of 1:10. Does anyone have a recipe
>that can fit that?
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