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firing - refiring reduction glazes in oxidation

updated thu 20 nov 03

 

Ron Roy on sun 16 nov 03


Hi Laurie,

I am having trouble remembering - I disliked it that much.

Very dramatic - no black left at all - a very acid green - made me feel
sick to look at it - making me feel uncomfortable just thinking about it -
just refired to cone 04 with some bisque.

RR

>Hi Ron,
>You've got me curious now - what does the tenmoku look like after it's
>been re-fired?
>
>Laurie
>Sacramento, CA
>
>
>On Friday, November 14, 2003, at 11:28 AM, Ron Roy wrote:
>
>> My limited experience is with a tenmoku glaze - black when fired to
>> 10R and
>> a remarkable difference when bisque fired again. I"m not sure if it's
>> the
>> iron reoxidizing or crystals growing or maybe both.

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

Laurie Kneppel on mon 17 nov 03


Hi Ron,
Acid green? Eeeewww! Doesn't sound very appetizing. But thanks for the
warning against refiring tenmoku like that. I certainly won't even
think about it!

On another note, a potter I know just ordered her first kiln and plans
to fire ^6 oxidation so I recommended Mastering ^6 Glazes book as one
she "must have".

Laurie
Sacramento,CA
On Sunday, November 16, 2003, at 03:30 PM, Ron Roy wrote:

> Hi Laurie,
>
> I am having trouble remembering - I disliked it that much.
>
> Very dramatic - no black left at all - a very acid green - made me feel
> sick to look at it - making me feel uncomfortable just thinking about
> it -
> just refired to cone 04 with some bisque.
>
> RR

Craig Martell on wed 19 nov 03


RR commented:
>Very dramatic - no black left at all - a very acid green - made me feel
>sick to look at it - making me feel uncomfortable just thinking about it -
>just refired to cone 04 with some bisque.

Hello Ron:

I hope you're feeling better. 8>)

I've refired your tenmoku and two others that I've made at about 1988F in
the electric. When the glazes are thick I've seen this acid green in yours
and the others are a yellow-green where thicker and red where
thinner. Most of us apply tenmokus fairly thick to get the nice deep black
in reduction. When refiring in oxidation a lighter application will give
reds on edges and raised areas with the yellow/green in the recessed,
thicker parts. Depending on what you like for color, this can be nice or
it can be not so nice. When I hold the peak temp for even a half hour
there are some nice crystals that develop in these refires. I've refired a
higher magnesia celadon at the same temp and there are more crystals with
that too.

regards, Craig Martell Hopewell, Oregon