Fonda Hancock on fri 22 dec 06
In my quest for a green that I like (not olivey) I would like to try one
of the alumina matts of Michael Bailey's Glazes cone 6 book. I have custer
feldspar but do not have soda feldspar. Are these two interchangeable?
Merry Christmas, Happy Hanukah, or Jolly Soltice to one and all.
Fonda in Tennessee..soon to be in Kansas with my beautiful grand-daughter
Marcia Selsor on fri 22 dec 06
Fonda,
Custer is a pot ash feldspar and a soda ash spar is kona-f4. There
are others.
Marcia
On Dec 22, 2006, at 3:21 PM, Fonda Hancock wrote:
> In my quest for a green that I like (not olivey) I would like to
> try one
> of the alumina matts of Michael Bailey's Glazes cone 6 book. I have
> custer
> feldspar but do not have soda feldspar. Are these two interchangeable?
> Merry Christmas, Happy Hanukah, or Jolly Soltice to one and all.
> Fonda in Tennessee..soon to be in Kansas with my beautiful grand-
> daughter
>
> ______________________________________________________________________
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> Send postings to clayart@lsv.ceramics.org
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>
Marcia Selsor
http://marciaselsor.com
Bobbruch1@AOL.COM on sat 23 dec 06
<<<
<<<
<<<I would like to try one of the alumina matts of
Michael Bailey's Glazes cone 6 book. I have custer
feldspar but do not have soda feldspar. Are these
two interchangeable?
They "can" be interchangeable in that you can use
a custer spar where a soda spar is called for .... but
you may well get different results. One of
these would be that soda spars often have a lower
melting point than do custer spars, and they are often
substituted when you want to achieve that. There
are possibly other factors that would change as well.
Bob Bruch
Craig Martell on sat 23 dec 06
Hello Spar melters:
My personal feeling is that nothing we use, in terms of raw materials, is
directly interchangeable. Although some things are more successful with
direct substitution than others. If you sub Custer spar for G-200, for
example, there will be fewer differences than subbing Custer for Nepheline
Syenite.
Custer is much less fusible than Soda spar because of the flux percentage
and contents of the mineral fluxes but also because of the higher amount of
silica in Custer. The ideal flux/silica ratio of a potash feldspar (Custer
is a Potash spar) is about 1/6. Custer is a bit above 1/7 and Kona F-4
(soda spar) is about 1/5.74. The silica/alumina ratios are different
too. The more spar in the glaze the greater the difference when making
subs. G-200 Potash Spar is very close to the ideal.
For a good visual reference you can do fusion buttons of all the spars you
use at your usual firing temp.
regards, Craig Martell Hopewell, Oregon
Lisa E on sun 24 dec 06
Hi Fonda;
I just did a bunch of test glazes for Michael Bailey's alumina matts. They
actually came out almost identical to the pictures.
A couple things to note, they are quite matt so not good for functional ware
(unless you are just using it on the outside) and they are also quite opaque
so they cover up most accents and marks. But if you are looking for some
natural matt colors, these are beautiful.
If you are looking for a nice sage (not olivey at all), the AM1 plus 6%
nickel oxide is gorgeous!
As far as the soda vs custer, I am a newbie to glaze making and would have
to test it to see the results. Hopefully someone will be able to shed some
light on that for you.
Regards,
Lisa E
Squamish, BC
On 12/22/06, Fonda Hancock wrote:
>
> In my quest for a green that I like (not olivey) I would like to try one
> of the alumina matts of Michael Bailey's Glazes cone 6 book. I have custer
> feldspar but do not have soda feldspar. Are these two interchangeable?
> Merry Christmas, Happy Hanukah, or Jolly Soltice to one and all.
> Fonda in Tennessee..soon to be in Kansas with my beautiful grand-daughter
>
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
--
Lisa E
Sunny Daze Design Pottery Studio
Squamish, BC
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