Steve Slatin on tue 24 jan 12
Phyllis -- The short answer is no, you can't generally substitute one-for-o=
=3D
ne=3D0Anepheline syenite for a soda feldspar.=3D0A=3DA0=3D0AThe slightly lo=
nger ans=3D
wer is you can't because the formulation of Neph Syenite=3D0Ais different -=
- =3D
a soda spar should be sodium oxide (Na2O), Alumina (Al2O3) and=3D0ASilica (=
Si=3D
O2), with about 12 percent sodium oxide, 19% alumina and the rest silica.=
=3D
=3D0ANepheline Syenite is a more complex material, with (typically) iron, c=
al=3D
cium, and =3D0Aother materials, but also with less silica than a soda spar =
an=3D
d possibly less sodium=3D0Aas well ... though it depends on the sourcing of=
y=3D
our nepheline syenite.=3D0A=3DA0=3D0AIf you have a glaze calc program and w=
ant to=3D
try, it's an interesting exercise to=3D0Asubstitute materials, but often y=
ou=3D
find that you just "can't get there from here."=3D0A=3DA0=3D0AOTOH, if you=
're no=3D
t wedded to that glaze there're plenty of good glazes that use=3D0Anephelin=
e =3D
syenite to source its melters.=3D0A=3DA0=3D0A=3DA0=3D0ASteve Slatin -- N48.=
0886450 W1=3D
23.1420482=3D0A=3D0A=3D0A________________________________=3D0A=3D0AHello Cl=
ayart Worl=3D
d=3D0A=3D0ACan soda feldspar be used interchangeably in glazes?=3DA0 Have a=
recip=3D
e for=3D0AAlbany Slip substitute which lists soda feldspar but I would like=
t=3D
o use=3D0ANeph Sy instead (because I have a lot of it).=3DA0 Any downside?=
=3D0A=3D
=3D0AThank you.=3D0APhyllis Canupp=3D0AVirginia Beach, Va
pe canupp on tue 24 jan 12
Hello Clayart World
Can soda feldspar be used interchangeably in glazes? Have a recipe for
Albany Slip substitute which lists soda feldspar but I would like to use
Neph Sy instead (because I have a lot of it). Any downside?
Thank you.
Phyllis Canupp
Virginia Beach, Va
Edouard Bastarache on tue 24 jan 12
Nope
Gis,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://smart2000.pagesperso-orange.fr/bloggs_edouard.htm
http://www.facebook.com/edouard.bastarache
----- Original Message -----
From: "pe canupp"
To:
Sent: Tuesday, January 24, 2012 2:05 PM
Subject: Soda feldspar/nepheline syenite
> Hello Clayart World
>
> Can soda feldspar be used interchangeably in glazes? Have a recipe for
> Albany Slip substitute which lists soda feldspar but I would like to use
> Neph Sy instead (because I have a lot of it). Any downside?
>
> Thank you.
> Phyllis Canupp
> Virginia Beach, Va
>
KATHI LESUEUR on tue 24 jan 12
On Jan 24, 2012, at 2:05 PM, pe canupp wrote:
> Hello Clayart World
>=3D20
> Can soda feldspar be used interchangeably in glazes? Have a recipe =3D
for
> Albany Slip substitute which lists soda feldspar but I would like to =3D
use
> Neph Sy instead (because I have a lot of it). Any downside?
>=3D20
>=3D20
I tried using neph sy instead of Minspar (a soda spar) in a favorite =3D
glaze. The result was a much drier surface. I would expect the reverse =3D
change would have a significant effect on the surface of your glaze. If =3D
you try a test, make sure you leave plenty of room for the glaze to run =3D
or fire it on a piece of flat bisque to save your kiln shelf.
KATHI LESUEUR
http://www.lesueurclaywork.com
John Post on tue 24 jan 12
The soda feldspar/albany slip substitutes I have tried tend to settle
into a hardpan at the bottom. The neph. sy will make it more likely
to do so. You could try adding some epsom salts to the mix to get it
to flocculate and keep it from settling.
John Post
Sterling Heights, Michigan
http://www.johnpost.us
Follow me on Twitter
https://twitter.com/UCSArtTeacher
On Jan 24, 2012, at 2:05 PM, pe canupp wrote:
> Hello Clayart World
>
> Can soda feldspar be used interchangeably in glazes? Have a recipe
> for
> Albany Slip substitute which lists soda feldspar but I would like to
> use
> Neph Sy instead (because I have a lot of it). Any downside?
>
> Thank you.
> Phyllis Canupp
> Virginia Beach, Va
pe canupp on wed 25 jan 12
Thank you to all responded to my soda feldspar/neph sy question. Will
stick with the soda feldspar and devote the time I could spend in testing
neph sy to more creative ventures!
Phyllis Canupp
On Tue, Jan 24, 2012 at 2:05 PM, pe canupp wrote:
> Hello Clayart World
>
> Can soda feldspar be used interchangeably in glazes? Have a recipe for
> Albany Slip substitute which lists soda feldspar but I would like to use
> Neph Sy instead (because I have a lot of it). Any downside?
>
> Thank you.
> Phyllis Canupp
> Virginia Beach, Va
>
ivor and olive lewis on thu 26 jan 12
Dear Phyllis Canupp,
The melting behaviour of these compounds is remarkably different though thi=
s
is not explained in many of the popular text books for ceramic artists.
When heated Potash felspar passes through a Peritectic Reaction in the
region of 1150 deg Celsius. This means that Potash Felspar decomposes to
become a fluid and a solid phase that has a very high melting point, almost
1700 deg Celsius. This explains the high viscosity, mentioned by Frank Hame=
r
in his description of that mineral.
Soda felspar melts in the region of 1104 deg Celsius.
Nepheline Syenite is not a single pure mineral compound but an intimate
mixture of two minerals. Depending on the composition of the magma from
which they form they can present us with natural eutectic mixtures which
solidified at a temperatures lower than those of the solitary pure
compounds. Some samples of Nepheline Syenite may remelt as low as 1020 deg
Celsius making this substance a flux with highly desired properties.
Regards,
Ivor Lewis,
REDHILL,
South Australia
ronroy@CA.INTER.NET on fri 27 jan 12
Hi Phyllis,
Send me the original recipe (with the soda spar) and I'll send it back
reformulated with Neph Sy - it will work exactly the same.
RR
Quoting pe canupp :
> Hello Clayart World
>
> Can soda feldspar be used interchangeably in glazes? Have a recipe for
> Albany Slip substitute which lists soda feldspar but I would like to use
> Neph Sy instead (because I have a lot of it). Any downside?
>
> Thank you.
> Phyllis Canupp
> Virginia Beach, Va
>
ronroy@CA.INTER.NET on fri 27 jan 12
It is true that sodium does leach out of Neph Sy in water and can
deflocculate a glaze. Depends on how much clay there is in the glaze
and what kind.
Subbing in ball clay for kaolin and adding some bentonite will
sometimes be enough - if not 1 or 2 % epsom salts will most likely work.
RR
Quoting John Post :
> The soda feldspar/albany slip substitutes I have tried tend to settle
> into a hardpan at the bottom. The neph. sy will make it more likely
> to do so. You could try adding some epsom salts to the mix to get it
> to flocculate and keep it from settling.
>
> John Post
> Sterling Heights, Michigan
>
> http://www.johnpost.us
>
> Follow me on Twitter
> https://twitter.com/UCSArtTeacher
>
>
>
>
>
>
>
>
>
>
> On Jan 24, 2012, at 2:05 PM, pe canupp wrote:
>
>> Hello Clayart World
>>
>> Can soda feldspar be used interchangeably in glazes? Have a recipe
>> for
>> Albany Slip substitute which lists soda feldspar but I would like to
>> use
>> Neph Sy instead (because I have a lot of it). Any downside?
>>
>> Thank you.
>> Phyllis Canupp
>> Virginia Beach, Va
>
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