Maurice Weitman on thu 11 may 06
At 21:41 -0400 on 5/11/06, Eleanora Eden wrote:
>Hi again,
>
>I just realized I have two very different recipes for this glaze.
>The first one below is from clayart circa 1995 in my files.
>The second was given over clayart the other day.
Hello, Eleanora,
The first one you quoted as being from 1995 is the one that I found
in an article in Ceramics Monthly (3/2003 page 88), and I've seen
referenced in many places. I use it quite often and find it reliable.
The second one (posted by Donna Kat this past Monday) I've not seen
before, and I'm not sure it's actually supposed to be Weathered
Bronze Green; Donna stated the name in another paragraph, but it
might be one of the variations she mentions there.
Regards,
Maurice
Eleanora Eden on thu 11 may 06
Hi again,
I just realized I have two very different recipes for this glaze.
The first one below is from clayart circa 1995 in my files.
The second was given over clayart the other day.
Any observations?
Eleanora
PINNELL STRONTIUM
MATTE GLAZE (cone 6 oxidation)
Pottery Making Illustrated-pg31
WEATHERED BRONZE GREEN
Lithium Carbonate 1%
Strontium Carbonate 20%
Nepheline Syenite 60%
Ball Clay 10%
Flint 9%
Total 100%
Weathered bronze green:
titanium dioxide 5%
copper carbonate 5%
>
>Pinnell's
>
>Nepheline Syenite 4920
>Strontium Carbonate 1990
>Ball Clay-Old Mine #4 1790
>Flint 800
>Lithium Carbonate 500
>Titanium Dioxide 130
>
>Copper Carbonate 670
>
--
Bellows Falls Vermont
www.eleanoraeden.com
John Hesselberth on fri 12 may 06
Hi Eleanora,
The first one is correct. It is certainly the one I have mixed and
tested many times. The second one has been adjusted significantly and
in an unsatisfactory way. Among other things, lithium carbonate has
been increased from 1 to 5%. This can cause strange things to happen
on a glaze like crazing and shivering on the same piece. Also copper
has been increased to from 5 up to 6.7%. I've not yet seen a glaze
that can hold that much copper without leaching significantly.
I suggest you purge the 2nd one from your files unless you make only
decorative/sculptural work and are will to deal with any crazing/
shivering problems you may encounter. Pete's Weathered Bronze Green
is an excellent glaze, but it is right on the edge at cone 6 and it
is probably best to use it as it is unless you know what you are
doing with glaze chemistry. For example, I am fairly sure it would be
substantially less stable if fired only to cone 5--it is barely fully
melted at cone 6 and was originally considered to be a cone 9 glaze.
It just happens to work very well at cone 6 also.
Regards,
John
On May 11, 2006, at 9:41 PM, Eleanora Eden wrote:
> PINNELL STRONTIUM
> MATTE GLAZE (cone 6 oxidation)
> Pottery Making Illustrated-pg31
>
> WEATHERED BRONZE GREEN
> Lithium Carbonate 1%
> Strontium Carbonate 20%
> Nepheline Syenite 60%
> Ball Clay 10%
> Flint 9%
> Total 100%
>
> Weathered bronze green:
> titanium dioxide 5%
> copper carbonate 5%
>
>
>>
>> Pinnell's
>>
>> Nepheline Syenite 4920
>> Strontium Carbonate 1990
>> Ball Clay-Old Mine #4 1790
>> Flint 800
>> Lithium Carbonate 500
>> Titanium Dioxide 130
>>
>> Copper Carbonate 670
Don Whitehouse on sun 14 may 06
Elenora,
I use a recipe like your first one, but substitute EPK for the ball clay.
Have had good results from Cone 6 electric to Cone 10 Soda.
Don
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