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addendum to glaze questions

updated thu 8 mar 01

 

Andie Carpenter on wed 7 mar 01


Ones I forgot to ask:

If a glaze has been tested for food safety after being fired in
reduction, would it remain food safe if instead fired in oxidation?
Doesn't the atmosphere change the chemical composition of the glaze,
changing the leaching possibilities?

If a glaze is food safe at cone 6, and is refired to 04, as has been
discussed recently, is it still food safe?


Again, thanks for any insight -

: ) Andie

John Hesselberth on wed 7 mar 01


Andie Carpenter wrote:

>Ones I forgot to ask:
>
>If a glaze has been tested for food safety after being fired in
>reduction, would it remain food safe if instead fired in oxidation?
>Doesn't the atmosphere change the chemical composition of the glaze,
>changing the leaching possibilities?
>
>If a glaze is food safe at cone 6, and is refired to 04, as has been
>discussed recently, is it still food safe?

Hi Andie,

I don't know the answer to either of these questions. My guess is that
there will be little difference in leaching between reduction and
oxidation firings, but it would have to be tested. I would also guess
that refiring to 04 would not change much but, again, you'd have to test.
I have never tested either of these scenarios.

Regards, John

"The life so short, the craft so long to learn." Chaucer's translation of
Hippocrates, 5th cent. B.C.