Kanika Sircar on sat 26 nov 11
Here is the comparison between Pacer and our expectations.
Look at the silica % as well.
Kanika
=3D20
=3D20
Typical
Pacer Mine
=3D20
Silica (SiO2
68.50%
73.50%
=3D20
=3D20
Alumina (AI203)=3D20
17.00%
15.00%
=3D20
=3D20
Iron Oxide (Fe2o3
0.15%
0.15%
=3D20
=3D20
Lime (CaO)
0.30%
0.30%
=3D20
=3D20
Magnesia (MgO
Trace
trace
=3D20
=3D20
Soda (Na2O
3.00%
3.00%
=3D20
=3D20
Potash (K20)
10.00%
7.00%
=3D20
=3D20
=3D20
=3D20
=3D20
=3D20
=3D20
=3D20
--------------------------------------------------
From: "Paul Herman"
Sent: Saturday, November 26, 2011 10:50 AM
To:
Subject: Re: Custer changed?
> Greetings Ron,
>=3D20
> I think you may have provided an explanation as to why I am seeing
> some changes in my stoneware body, which includes 10% Custer feldspar.
> It seems to be not as vitreous as it should be. So yes, I am having a
> problem like what you describe, but in a clay body, not a glaze.
>=3D20
> Two questions: Can you share the analysis that shows Custer being low
> in potash?
>=3D20
> And, has anyone tried to talk to Pacer Minerals (Custer's owner) about
> the problem, and if so what did they say?
>=3D20
> Thanks,
>=3D20
> Paul Herman
>=3D20
> Great Basin Pottery
> Doyle, California US
> www.greatbasinpottery.com/
> On Nov 25, 2011, at 8:20 AM, Ron Roy wrote:
>=3D20
>> Those of you who use Custer spar - potter friend of mine who takes =3D
the
>> time to do it right has found the last batch of Custer he bought is
>> short of potassium.
Edouard Bastarache on sat 26 nov 11
Na2O 0.29 (KNaO .97) Al2O3 1.05 SiO2 7.11
K2O 0.68 Fe2O3 0.00
CaO 0.03
Alumina:Silica ratio is 1.00:6.75
Neutral:Acid ratio is 1.00:6.75
Alk:Neut:Acid ratio is 1.00:1.05:7.12
Expansion: 81.1 x 10e-7 per degree C
Na2O 0.38 (KNaO .96) Al2O3 1.15 SiO2 9.55
K2O 0.58 Fe2O3 0.01
CaO 0.04
Alumina:Silica ratio is 1.00:8.32
Neutral:Acid ratio is 1.00:8.32
Alk:Neut:Acid ratio is 1.00:1.15:9.56
Expansion: 71.4 x 10e-7 per degree C
----- Original Message -----
From: "Kanika Sircar"
To:
Sent: Saturday, November 26, 2011 1:02 PM
Subject: PACER MINE CUSTER FELDSPAR
Here is the comparison between Pacer and our expectations.
Look at the silica % as well.
Kanika
Typical
Pacer Mine
Silica (SiO2
68.50%
73.50%
Alumina (AI203)
17.00%
15.00%
Iron Oxide (Fe2o3
0.15%
0.15%
Lime (CaO)
0.30%
0.30%
Magnesia (MgO
Trace
trace
Soda (Na2O
3.00%
3.00%
Potash (K20)
10.00%
7.00%
--------------------------------------------------
From: "Paul Herman"
Sent: Saturday, November 26, 2011 10:50 AM
To:
Subject: Re: Custer changed?
> Greetings Ron,
>
> I think you may have provided an explanation as to why I am seeing
> some changes in my stoneware body, which includes 10% Custer feldspar.
> It seems to be not as vitreous as it should be. So yes, I am having a
> problem like what you describe, but in a clay body, not a glaze.
>
> Two questions: Can you share the analysis that shows Custer being low
> in potash?
>
> And, has anyone tried to talk to Pacer Minerals (Custer's owner) about
> the problem, and if so what did they say?
>
> Thanks,
>
> Paul Herman
>
> Great Basin Pottery
> Doyle, California US
> www.greatbasinpottery.com/
> On Nov 25, 2011, at 8:20 AM, Ron Roy wrote:
>
>> Those of you who use Custer spar - potter friend of mine who takes the
>> time to do it right has found the last batch of Custer he bought is
>> short of potassium.
Lee on sun 27 nov 11
This is why empirical testing is so important of each batch and why
you can't always depend upon analysis and glaze calculation programs.
(they make you lazy.)
When you use "natural" glaze materials, you expect to have to make
adjustments EVERY batch.
--
=3DA0Lee Love in Minneapolis
http://mingeisota.blogspot.com/
=3DA0"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D9=
7that is, =3D
"The
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
Ron Roy on sun 27 nov 11
Nothing wrong with testing - but the combination of testing and =3D20
calculation is greater than the parts - having more information makes =3D20
adjusting easier,
Why anyone would turn up their nose at getting a clearer picture of =3D20
what is going on is beyond my understanding.
RR
Quoting Lee :
> This is why empirical testing is so important of each batch and why
> you can't always depend upon analysis and glaze calculation programs.
> (they make you lazy.)
>
> When you use "natural" glaze materials, you expect to have to make
> adjustments EVERY batch.
>
> --
> =3DC2=3DA0Lee Love in Minneapolis
> http://mingeisota.blogspot.com/
>
> =3DC2=3DA0"Ta tIr na n-=3DC3=3DB3g ar chul an tI=3DE2=3D80=3D94tIr dlainn=
trina ch=3DC3=3DA9=3D
ile"=3DE2=3D80=3D94that is, "The
> land of eternal youth is behind the house, a beautiful land fluent
> within itself." -- John O'Donohue
>
Lee on sun 27 nov 11
On Sun, Nov 27, 2011 at 10:20 AM, wrote:
> Why anyone would turn up their nose at getting a clearer picture of what =
=3D
is
> going on is beyond my understanding.
Ron, there is more than one way to "get a clearer picture of what is
going on." Theoretical and empirical are two ways.
Folks who think WE know the best way (modern theoretical
practices) are the ones who are "turning up their noses" at
traditional empirical methods.
Traditional methods work in almost all studio situations. Modern
theoretical methods depend upon uniformed materials and precise
analysis of the materials. Because "garbage in =3D3D garbage out."
--
=3DA0Lee Love in Minneapolis
http://mingeisota.blogspot.com/
=3DA0"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D9=
7that is, =3D
"The
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
Ron Roy on wed 30 nov 11
Hi Lee,
I have never put down empirical testing - use it constantly in my work =3D2=
0
with clay bodies - to see when they need adjusting - but do the =3D20
adjusting using calculation - tremendous savings in time - problems =3D20
solved in much less time. Same with glazes - you are missing out on a =3D20
valuable tool that can only help solve your technical problems.
Anyone can get analysis of materials cheaply and accurately now - that =3D2=
0
is no longer a problem.
Your view that you need to have precise analysis for all our materials =3D2=
0
is simply not true - we have only had typical analysis and they work =3D20
just fine - you need to understand that there is lots of leeway in the =3D2=
0
clays and glazes we use - otherwise how could they work over the years =3D2=
0
using different batches of materials.
If you use calculation on a regular basis you would understand this.
No skin off my nose if you prefer to ignore progress but you do others =3D2=
0
a disservice with your closed mind.
RR
Quoting Lee :
> On Sun, Nov 27, 2011 at 10:20 AM, wrote:
>
>> Why anyone would turn up their nose at getting a clearer picture of what=
=3D
is
>> going on is beyond my understanding.
>
> Ron, there is more than one way to "get a clearer picture of what is
> going on." Theoretical and empirical are two ways.
>
> Folks who think WE know the best way (modern theoretical
> practices) are the ones who are "turning up their noses" at
> traditional empirical methods.
>
> Traditional methods work in almost all studio situations. Modern
> theoretical methods depend upon uniformed materials and precise
> analysis of the materials. Because "garbage in =3D3D garbage out."
>
> --
> Lee Love in Minneapolis
> http://mingeisota.blogspot.com/
>
> "Ta tIr na n-=3DC3=3DB3g ar chul an tI=3DE2=3D80=3D94tIr dlainn tri=
na ch=3DC3=3DA9=3D
ile"=3DE2=3D80=3D94that is, "The
> land of eternal youth is behind the house, a beautiful land fluent
> within itself." -- John O'Donohue
>
| |
|
