Ivor and Olive Lewis on tue 28 feb 06
Dear Friends,
At the beginning of February I recall asking if anyone would help me to =
develop a recipe or a series of recipes for an ancient ceramic colourant =
called Egyptian Blue or Pompeian Blue.
John Hesselberth gave it a go but seemed to not understand what I was on =
about. Possibly I did not make things crystal clear. Apart from that =
there was silence.
I offered a Seger Formula for this ancient pigment, as being =
CaO.CuO.4SiO2 ( K. Wehlte, "The Materials and Techniques of Painting" =
p.143. ISBN 0971217602. 1982.
I reached the following recipe. Perhaps someone might like to test this =
for accuracy using their computer glaze program.
Copper Oxide 21.28%
Wollastonite 30.85%
Silica 47.87%
Note: This is not a glaze formulation and will require prolonged =
sintering to develop its colour.
If it is ground up it may behave a stable pigment without dissolving =
into a glaze melt and also be resistant to leaching.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
=2
Des & Jan Howard on wed 1 mar 06
Ivor
Sorry about that. I was so interested in the artist's pigments site I
forgot why I went there.
Using GlazeChem I get:
black copper oxide 21.14
wollastonite 30.88
silica 47.98
CaO 16.7%
CuO 16.7%
SiO2 66.7%
Des
Ivor and Olive Lewis wrote:
>I offered a Seger Formula for this ancient pigment, as being CaO.CuO.4SiO2 ( K. Wehlte, "The Materials and Techniques of Painting" p.143. ISBN 0971217602. 1982.
>I reached the following recipe. Perhaps someone might like to test this for accuracy using their computer glaze program.
>
>Copper Oxide 21.28%
>Wollastonite 30.85%
>Silica 47.87%
>
>
--
Des & Jan Howard
Lue Pottery
LUE NSW 2850
Australia
Ph/Fax 02 6373 6419
http://www.luepottery.hwy.com.a
Ivor and Olive Lewis on thu 2 mar 06
Dear Des=20
Thank you for confirming my mental attributes are still able to cut the =
mustard.
We seem to be in pretty close agreement.
Notices the sign on the highway telling me I can start firing out doors =
after April 26th Will have to get my hands back in the slops again.
Must make some of this stuff. I will fire at cone 8 and use Soda ash as =
a flux.
Best regards,
Ivor.
| |
|
