iandol on wed 30 apr 03
Dear Fara Shimbo,
Some thirty five years ago I made a pot in a white clay and decorated it =
with a manganese wash as an underglaze pattern over wax resist. This was =
fired and glazed with the translucent white which was one of the art =
schools standard glazes. I had a magnificent violet colour. That is half =
a lifetime and half a world away. I do not recall any other details =
other than it was fired to Seger Cone 8 Electric.
From my reading into glass colour production I suspect that Manganese =
has to be kept in a strongly oxidising environment to achieve Purple or =
Violet. Reduce and you get yellow or brown. This is fairly easy to test =
with a Borax bead on Platinum wire.
There are other molten beads which can be used. Sodium Carbonate is one =
and another is a mixed salt of Phosphorus, Hydrogen-Sodium-Ammonium =
Phosphate (I might even try my new found Potassium Salt and Pearl Ash). =
Since Platinum is a bit beyond my pocket I will use Nichrome wire though =
if it oxidises the Ni and Cr oxides will contaminate the bead. An =
alternative might be to fire samples on small bisque white clay dished =
tiles.
Another thought is to inquire about the Purple colouring of a rare =
mineral called Blue John found in Derbyshire. This is form of Fluorite =
CaF. If the colour is caused by Manganese. This could be another clue =
directing further work.
Best of luck with your research,
Ivor Lewis.
OWLPOTTER@AOL.COM on thu 1 may 03
In a message dated 4/30/2003 6:56:50 PM, iandol@TELL.NET.AU writes:
<< Some thirty five years ago I made a pot in a white clay and decorated it
with a manganese wash as an underglaze pattern over wax resist. This was
fired and glazed with the translucent white which was one of the art schools
standard glazes. I had a magnificent violet colour. That is half a lifetime
and half a world away. I do not recall any other details other than it was
fired to Seger Cone 8 Electric. >>
This is like some alternate universe. This happened to me exactly! About
30-35 years ago -Got the most beautiful mottled purple/mauve accidentally at
cone 8 electric using manganese wash. This winter I happened to think about
that happy accident and spent 4 months trying to reproduce it without any
positive results!!!
I did it with the school's cone 6 glazes back then and even though I
revisited all of those recipes with no purple in the results, I did come up
with a few glazes I liked.
It made me wonder if some essential glaze ingredient had changed over the
years?
-Carolynn Palmer, Somerset Center, Michigan
Jocelyn McAuley on thu 1 may 03
Hi Fara...
I'm a little behind in posts (that darn spring!). Is this desired purple
for non-crystal glazes?
I just recently got the most gorgeous purple crystal glaze by reducing an
iron-co combo. If not for crystals, then I guess I'm just tooting my own
horn!
Good luck
Joc
--
Jocelyn McAuley ><<'> jocie@worlddomination.net
Eugene, Oregon http://www.ceramicism.com
Ilene Mahler on fri 2 may 03
You know Fa is the Queen of crystals and anybody can see her website and
drooool at the new reduction crystals...Ilene a worshiper
----- Original Message -----
From: "Jocelyn McAuley"
To:
Sent: Thursday, May 01, 2003 6:33 PM
Subject: Re: : Fara Shimbo and the Quest for Purple
> Hi Fara...
>
> I'm a little behind in posts (that darn spring!). Is this desired purple
> for non-crystal glazes?
>
> I just recently got the most gorgeous purple crystal glaze by reducing an
> iron-co combo. If not for crystals, then I guess I'm just tooting my own
> horn!
>
> Good luck
> Joc
>
> --
> Jocelyn McAuley ><<'> jocie@worlddomination.net
> Eugene, Oregon http://www.ceramicism.com
>
>
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