Lee Love on sun 22 nov 09
One thing every one is overlooking: with natural materials like
Albany Slip, you are dealing with a material of variable composition.
You calculations are only good as your access to accurate analysis
of your materials. Calculations don't work so well with natural,
variable, unrefined materials. That is why empirical testing is the
best method with natural materials.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
Lee Love on sun 22 nov 09
I suppose we could "angels on a pinhead" a single material, but I
have never heard of eutectics used in that way. I think it is an
example of how absurd we can take theoretical analysis.
Eutectic point
From Wikipedia, the free encyclopedia
(Redirected from Eutectic)
"The melting point of a mixture of two or more solids (such as an
alloy) depends on the relative proportions of its ingredients. A
eutectic or eutectic mixture is a mixture at such proportions that the
melting point is a local temperature minimum, which means that all the
constituents crystallize simultaneously at this temperature from
molten liquid solution."
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
Ron Roy on sun 29 nov 09
Hi Lee,
Not true - you can always deal with the materials you do have =3D20
reasonable analysis for to adjust clays and glazes with variable =3D20
materials using calculation.
For instance - if you have a recipe of 50 Albany and 50 spar - you can =3D2=
0
replace some of the spar with spodumene to lower expansion.
I have reformulated many Gerstley Borate recipes replacing it with =3D20
frit and they work fine.
I'm not sure why you seem qualified to comment this way when you don't =3D2=
0
use calculation software - where are you getting this information?
RR
Quoting Lee Love :
> One thing every one is overlooking: with natural materials like
> Albany Slip, you are dealing with a material of variable composition.
> You calculations are only good as your access to accurate analysis
> of your materials. Calculations don't work so well with natural,
> variable, unrefined materials. That is why empirical testing is the
> best method with natural materials.
>
> --
> Lee, a Mashiko potter in Minneapolis
> http://mashikopots.blogspot.com/
>
> "Ta tIr na n-=3DC3=3DB3g ar chul an tI=3DE2=3D80=3D94tIr dlainn trina ch=
=3DC3=3DA9ile"=3D
=3DE2=3D80=3D94that is, "The
> land of eternal youth is behind the house, a beautiful land fluent
> within itself." -- John O'Donohue
>
Lee Love on sun 29 nov 09
On Sun, Nov 29, 2009 at 12:30 PM, wrote:
> Hi Lee,
>
> Not true - you can always deal with the materials you do have reasonable
> analysis for to adjust clays and glazes with variable materials using
> calculation.
No, you can't always have a "reasonable" analysis of your
materials. You point out the main limitation of theoretical analysis.
If you deal in a glaze or clay that is totally made of natural
materials, and the effects, and usually the best effects, happen on
the edges of the the matrix limits, you are better off doing empirical
testing
If you only know industrial methods and don't know the
traditional methods of working with natural, unrefined materials, then
it is difficult to understand.
--=3D20
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
John Britt on mon 30 nov 09
Ron,
I have to side with Lee on this one.=3D20
If you don't have an accurate analysis of local natural materials then=3D20=
=3D
your software doesn't work very well. You would then have to guess on=3D20
the formula or you would have to test it empirically.
But, as a matter of fact, either way you have to test it empirically. The=
=3D
=3D20
software is just an aid to get you closer on the testing.=3D20
John Britt
On Sun, 29 Nov 2009 13:30:54 -0500, Ron Roy=3D20
wrote:
>Hi Lee,
>
>Not true - you can always deal with the materials you do have=3D20=3D20
>reasonable analysis for to adjust clays and glazes with variable=3D20=3D20
>materials using calculation.
>
>For instance - if you have a recipe of 50 Albany and 50 spar - you can=3D2=
0=3D
=3D20
>replace some of the spar with spodumene to lower expansion.
>
>I have reformulated many Gerstley Borate recipes replacing it with=3D20=3D=
20=3D
>frit and they work fine.
>
>I'm not sure why you seem qualified to comment this way when you=3D20
don't=3D20=3D20
>use calculation software - where are you getting this information?
>
>RR
>
>Quoting Lee Love :
>
>> One thing every one is overlooking: with natural materials like
>> Albany Slip, you are dealing with a material of variable composition.=
=3D
>> You calculations are only good as your access to accurate analysis
>> of your materials. Calculations don't work so well with natural,
>> variable, unrefined materials. That is why empirical testing is the=
=3D
>> best method with natural materials.
>>
>> --
>> Lee, a Mashiko potter in Minneapolis
>> http://mashikopots.blogspot.com/
>>
>> "Ta tIr na n-=3DC3=3DB3g ar chul an tI=3DE2=3D80=3D94tIr dlainn trina c=
h=3DC3=3DA9i=3D
le"=3DE2=3D80=3D94that=3D20
is, "The
>> land of eternal youth is behind the house, a beautiful land fluent
>> within itself." -- John O'Donohue
>>
Lee Love on mon 30 nov 09
On Mon, Nov 30, 2009 at 2:16 PM, John Britt wr=
=3D
ote:
>
> But, as a matter of fact, either way you have to test it empirically. The
> software is just an aid to get you closer on the testing.
When all you have is a hammer, then all problems look
like a nail. If you have both theoretical (hammer) and empirical
(drill) methods in your bag of tricks, you are able to deal with both
nails and screws.
I have used analysis when only one ingredient is unknown.
But it is always best to only deal with one variable at a time, so
you know what causes the changes.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
Steve Slatin on tue 1 dec 09
Read it again, John. The example
was Albany slip -- true, a natural
material, but a relatively consistent
one. But you not only don't have to
guess at the constituent materials,
you don't have to start from ground
zero on testing, either.
Knowing more is always better than
knowing less. Calc software is just
a tool. It helps you know more. =3D20
A few minutes spent
"ranging in" a recipe with calc
software -- even for a new recipe
with a natural material -- makes
the process easier.=3D20
Steve Slatin --=3D20
La confiance sur les signatures pr=3DC3=3DA9tentieuses est le signe le plus=
s=3D
=3DC3=3DBBr de faiblesse intellectuelle.=3D20
--- On Mon, 11/30/09, John Britt wrote:
> Ron,
>=3D20
> I have to side with Lee on this one.=3D20
>=3D20
> If you don't have an accurate analysis of local natural
> materials then=3D20
> your software doesn't work very well. You would then have
> to guess on=3D20
> the formula or you would have to test it empirically.
>=3D20
> But, as a matter of fact, either way you have to test it
> empirically. The=3D20
> software is just an aid to get you closer on the testing.=3D20
>=3D20
> John Britt
>=3D20
>=3D20
>=3D20
> On Sun, 29 Nov 2009 13:30:54 -0500, Ron Roy=3D20
>
> wrote:
>=3D20
> >Hi Lee,
> >
> >Not true - you can always deal with the materials you
> do have=3DC2=3DA0=3D20
> >reasonable analysis for to adjust clays and glazes with
> variable=3DC2=3DA0=3D20
> >materials using calculation.
> >
> >For instance - if you have a recipe of 50 Albany and 50
> spar - you can=3DC2=3DA0=3D20
> >replace some of the spar with spodumene to lower
> expansion.
> >
> >I have reformulated many Gerstley Borate recipes
> replacing it with=3DC2=3DA0=3D20
> >frit and they work fine.
> >
> >I'm not sure why you seem qualified to comment this way
> when you=3D20
> don't=3DC2=3DA0=3D20
> >use calculation software - where are you getting this
> information?
> >
> >RR
> >
> >Quoting Lee Love :
> >
> >> One thing every one is
> overlooking:=3DC2=3DA0=3DC2=3DA0=3DC2=3DA0with natural materials like
> >> Albany Slip, you are=3DC2=3DA0 dealing with a material
> of variable composition.
> >>=3DC2=3DA0=3DC2=3DA0=3DC2=3DA0You calculations are only good as
> your access to accurate analysis
> >> of your materials.=3DC2=3DA0=3DC2=3DA0=3DC2=3DA0Calculations
> don't work so well with natural,
> >> variable, unrefined
> materials.=3DC2=3DA0=3DC2=3DA0=3DC2=3DA0That is why empirical
> testing=3DC2=3DA0 is the
> >> best method with natural materials.
> >>
> >> --
> >>=3DC2=3DA0 Lee, a Mashiko potter in Minneapolis
> >> http://mashikopots.blogspot.com/
> >>
> >>=3DC2=3DA0 "Ta tIr na n-=3DC3=3D83=3DC2=3DB3g ar chul an tI=3DC3=3DA2=
=3DE2=3D82=3DAC=3DE2=3D80=3D9D=3D
tIr
> dlainn trina ch=3DC3=3D83=3DC2=3DA9ile"=3DC3=3DA2=3DE2=3D82=3DAC=3DE2=3D8=
0=3D9Dthat=3D20
> is, "The
> >> land of eternal youth is behind the house, a
> beautiful land fluent
> >> within itself." -- John O'Donohue
> >>
> =3D0A=3D0A=3D0A
John Britt on wed 2 dec 09
Steve,
Guess I misread it. I thought it was referring to local materials, like=3D=
20=3D
Albany Slip, that you don't have analysis of. Then, empirical testing is=3D=
20=3D
needed. (Of course the analysis of Albany Slip is well known but many=3D20
other local materials, like the stuff from the creek down yonder, aren't.=
=3D
)
I have nothing against glaze software but realize, as you say, it is one=3D=
20=3D
=3D20
tool and it has limitations.
Thanks,
John Britt
www.johnbrittpottery.com
Ron Roy on sat 5 dec 09
Hi Lee,
You can always have local materials analyzed - not that expensive anymore -
the value of calculation goes way beyond what empirical testing tells you b=
=3D
y
the way. You have information on expansion, silica alumina ratio which is
useful for maintaining the same surface qualities of glazes when adjusting
them, information on glaze solubility and durability. For clays you can
substitute other materials when they change or are no longer available. The
list goes on.
As you know - I am charged with maintaining the clays to strict standards
for Tuckers - I also deal with customers clay and glaze problems - I use
calculation just about every day - I can't imagine doing this job without
calculation. If I had to use empirical methods only it would take months
instead of hours and days.
The results must be proven in the kiln of course - and line blends get you
there even faster - so I have always advocated a combination of the two
methods.
It is clear that you don't use calculation Lee - and not all who try it fin=
=3D
d
it enjoyable enough to learn how to use this valuable tool - and like most
tools it is not fool proof - but those who do use it see just how valuable
it can be.
You like quotes - here is one from Michael Cardew.
"It is sometimes held by artist potters, especially in England, that it is =
=3D
a
waste of time to calculate glazes according to the Seger formula....In spit=
=3D
e
of these objections, the pioneer potter would be unwise to deprive
themselves of this useful tool... which only involves simple arithmetic...
There are so many possible causes of failure in a potters life that it woul=
=3D
d
be a mistake for them to to reject a method which saves valuable time, whic=
=3D
h
is certainly capable of enhancing both the technical and artistic merits of
their glazes, and which in the process may possibly also enlarge the
confines of their wits."
An this was written before computers when you had to spend hours
calculating by hand - now our programs do it all in a blink of an eye.
RR
On Sun, Nov 29, 2009 at 1:40 PM, Lee Love wrote:
> On Sun, Nov 29, 2009 at 12:30 PM, wrote:
> > Hi Lee,
> >
> > Not true - you can always deal with the materials you do have reasonabl=
=3D
e
> > analysis for to adjust clays and glazes with variable materials using
> > calculation.
>
> No, you can't always have a "reasonable" analysis of your
> materials. You point out the main limitation of theoretical analysis.
> If you deal in a glaze or clay that is totally made of natural
> materials, and the effects, and usually the best effects, happen on
> the edges of the the matrix limits, you are better off doing empirical
> testing
>
> If you only know industrial methods and don't know the
> traditional methods of working with natural, unrefined materials, then
> it is difficult to understand.
>
> --
> --
> Lee, a Mashiko potter in Minneapolis
> http://mashikopots.blogspot.com/
>
> "Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97t=
hat is, =3D
"The
> land of eternal youth is behind the house, a beautiful land fluent
> within itself." -- John O'Donohue
>
--=3D20
Ron Roy
15084 Little Lake Road
Brighton, Ontario, Canada
K0K 1H0
Lee Love on sat 5 dec 09
On Sat, Dec 5, 2009 at 6:06 PM, Ron Roy wrote:
> It is clear that you don't use calculation Lee -
I use calculation all the time Ron. When it is useful. I
had to convert American materials into Japanese materials to test my
old glazes in Japan. I am doing the same here to convert clay
bodies and glazes from Japanese materials into USA ones.
But analysis is just one tool in the bag of tricks that a rounded
craftsman uses.
It is obvious that you have no experience or respect for
traditional empirical methods and technologies.
Ian Currie is someone who does and is not totally dependent on
industrial methods. He took what he learned in Kyoto, working with
Masataro Onishi and created an empirical method that works well along
side our industrial analytical method.
I have no idea why you are unable to see the compatibility of both
methods. That is the problem with folks who follow "one true way."
Anyone interested in working with natural materials is encourage
to explore Ian Currie's work:
http://ian.currie.to/
http://www.glazes.org/
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D97tha=
t is, "T=3D
he
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
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