Clay Coordinator on fri 30 nov 01
Colin,
Potassium Feldspar (AKA Orthoclase), Calcium Feldspar (AKA Plagoclase )
Check out this web page:
http://www.theimage.com/mineral/feldspar/felds.html
There is too much to write to clarify your question fully, but microcline
refers to the crystal structure.
You can find a lot on the web if you search.
Hope it helps.
Thanks,
John Britt
Penland Clay
Gary Harvey on thu 22 apr 04
Clayarters, In the book "Mastering Cone 6 glazes" John and Ron have =
used the feldspar G 200 My material source as far as I know doesn't =
have it. What kind of feldspar is it and what can you substitute for it =
without messing up the recipies in the book. I am a newbie to making =
glazes so forgive the ignorance. GH
Lee Love on fri 23 apr 04
Gary Harvey wrote:
>Clayarters, In the book "Mastering Cone 6 glazes" John and Ron have used the feldspar G 200 My material source as far as I know doesn't have it. What kind of feldspar is it and what can you substitute for it without messing up the recipies in the book. I am a newbie to making glazes so forgive the ignorance. GH
>
>
>
Hi Gary,
In GlazeChem, under Edouard Bastarache's substitutions there are 14
different substitutions for G200. I provide one below:
Custer feldspar 0.984
Whiting 0.022
Kaolin 0.061
You might think about looking at Eudourd's book on
substitutions and also Robert Wilt's GlazeChem software. You can find
these here:
Book: http://sorel-tracy.qc.ca/~edouardb/menu_e.html
Software: http://www.dinoclay.com/software/glzchem.html
--
Lee in Mashiko, Japan http://mashiko.org
Ron Roy on fri 23 apr 04
Hi Gary,
Custer is very close - I don't think you will notice much difference. If
you do just ask me to make an adjustment - easy to do.
Just make sure you pay attention to the cooling cycle if you want yours to
look like those in the book - it is essential for most of the glazes.
RR
>Clayarters, In the book "Mastering Cone 6 glazes" John and Ron have used
>the feldspar G 200 My material source as far as I know doesn't have it.
>What kind of feldspar is it and what can you substitute for it without
>messing up the recipies in the book. I am a newbie to making glazes so
>forgive the ignorance. GH
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ron Roy on sat 24 apr 04
Hi Lee,
Maybe - with some glazes - but the KNaO is down and the alumina and silica
are up. And you are adding materials which are not premelted so that
compounds the problem.
The real problem here is that Custer has more SiO2 than G200 - you can't
take the SiO2 out. The only way to do it would be with a spar that has more
KNaO and that is not easy - G200 has more than most.
I tried it with Neph Sy but then you get more sodium and potassium and a
lower expansion.
The better way would be - using glaze calculation - satisfy the KNaO using
Custer then adjust the alumina and the silica keeping the silica/alumina
ratio and the expansion the same. You will get much closer.
RR
>In GlazeChem, under Edouard Bastarache's substitutions there are 14
>different substitutions for G200. I provide one below:
>
>Custer feldspar 0.984
>Whiting 0.022
>Kaolin 0.061
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Lee Love on sat 24 apr 04
Ron Roy wrote:
>Maybe
>
>
I am surprised you don't offer the substitutions in the book because
Custer is so much more common in the States. :-)
Edouard offers 13 other possibilities for G200 in his substitution list
used in GlazeChem. Maybe one of the others would work better.
You can find Wilt's program here:
http://www.dinoclay.com/software/glzchem.html
Download it and try it out for free for 45 days. If you like it, it
only costs $35.00 A very good value.
I just ordered Edouard's book on materials substitutions:
http://sorel-tracy.qc.ca/~edouardb/menu_e.html
Available in English, French, Spanish,
Portugese, German and Esperanto*. I ordered the English version ;^)***
--
Lee
in Mashiko, Japan http://mashiko.org
Gary Harvey on sat 24 apr 04
Dear Roy and Lee, thanks for your help but I did find a sourse for the G
200. So I will not need a substitue after all. I really appreciate both of
your help because I am DEFINATELY NEW AT GLAZES. Tell John that I got the
resirator that was p 100 rated as he suggested. And thanks to him to. By the
way, Good book guys. GH
----- Original Message -----
From: "Ron Roy"
To:
Sent: Friday, April 23, 2004 9:42 AM
Subject: Re: feldspar
> Hi Gary,
>
> Custer is very close - I don't think you will notice much difference. If
> you do just ask me to make an adjustment - easy to do.
>
> Just make sure you pay attention to the cooling cycle if you want yours to
> look like those in the book - it is essential for most of the glazes.
>
> RR
>
> >Clayarters, In the book "Mastering Cone 6 glazes" John and Ron have used
> >the feldspar G 200 My material source as far as I know doesn't have it.
> >What kind of feldspar is it and what can you substitute for it without
> >messing up the recipies in the book. I am a newbie to making glazes so
> >forgive the ignorance. GH
>
> Ron Roy
> RR#4
> 15084 Little Lake Road
> Brighton, Ontario
> Canada
> K0K 1H0
> Phone: 613-475-9544
> Fax: 613-475-3513
>
>
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Bill Merrill on thu 26 jul 07
Hi All,
Living in Wyoming on a ranch helped me develop a love of ceramic
materials. I still go home and dig a feldspar that melts opaque white
to a clear. I hammer mill it and use it in my clay body sometimes. I
also soak it in water, fire it the large pieces as fast as I can. The
spar seperates inti thin sheets and I layer these pieces over glazes. A
slip clay I dig looks similar to Albany slip, but has gold crystals on
the surface. This slip melts slightly more fluid than Albany and is
very high in calcium. I had it analyzed by a company in Vancouver B.C.
I still use Randall kick wheels. The bat head system is so well
designed. I use 8", 12", 16" and 20" plaster bats. Don't discount the
use of plaster bats.=20
Bill Merrill=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Lee Love
Sent: Thursday, July 26, 2007 3:47 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Fire Sale
Threw in the rain today, under the maple tree. Hey, a break in the
90F temps (dopped to 80F). Mixed Craig's feldspar granuales with
Wendt's Helmer porcelain. Excited to see how close it comes to
co-Shigaraki. I just wedged the feldspar in until it felt right.
Cut with wire to see what kind of stones to clay ratio I had.
Boy, the Leach wheel is easier than the Korean kickwheel.
Can't wait to see the tests!
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://mashikopots.blogspot.com/
"To affect the quality of the day, that is the highest of arts." -
Henry David Thoreau
"Let the beauty we love be what we do." - Rumi
________________________________________________________________________
______
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
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Moderator of the list is Mel Jacobson who may be reached at
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