iandol on wed 7 feb 01
Dear Paul Lewing,
You recently wrote
sides are the fluxes, the stabilisers, and the glassformers. It's just a =
pictorial representation of the Seger formula.>
Although there is a degree of truth in what you say, the simplicity of =
this assertion conceals a rather more complex story.
There are two styles of triangular diagram. One, from which a series of =
recipes can be deduced, is based on mineral and chemical compounds used =
to make the glazes. A compound is placed at each corner of the triangle. =
An example would be Potash felspar, Whiting and Quartz. Given six steps =
along each side of the triangle it is possible to develop twenty one =
recipes, where each compound is measured in twenty percent increments =
from zero to one hundred p/c. I would call this a triaxial blend =
diagram. See Cooper and Royle, "Glazes for the Studio Potter" pp 19-28 =
for a more detailed exposition..
The other form of triangular diagram charts the abstract relationships =
between the molecular oxides which are contained in the substances we =
chose to contribute to our recipes, for example, Calcium oxide, Silicon =
dioxide and Aluminium oxide would e represented at the the corners of =
the triangular diagram. This type of chart indicates the substances =
which will form when molten mixtures of various oxide content are cooled =
so that all of the material crystallises. I would call this a Phase =
Equilibrium Diagram. A search of the net will get you several excellent =
study programs on this topic.
Note that in the example I gave for the "recipe triangle" four oxides =
are involved. So the Phase Equilibrium diagram needs to have four =
corners. But it cannot be represented graphically as a square on a flat =
two dimensional surface as our other diagrams are because you have to =
cross reference six line blends of pure oxides.
To go further than this would take many of our colleagues into rather =
deep territory.
The rest of what you said, I agree wholeheartedly.
My best regards and thanks for your contributions to Clayart.
Ivor Lewis. Redhill, South Australia 5521
vince pitelka on fri 9 feb 01
> Four materials can be represented in a 3-D form of the triaxial diagram
.... a tetrahedron. Each corner of the tetrahedron represents 100% of one of
the four materials.
Could we please stay within the realm of physical reality? No one is going
to plot glaze tests on a tetrahedron. This is absurd.
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Logan Oplinger on fri 9 feb 01
Ivor,
You wrote
......Note that in the example I gave for the "recipe triangle" four oxides are involved. So the Phase Equilibrium diagram needs to have four corners. But it cannot be represented graphically as a square on a flat two dimensional surface as our other diagrams are because you have to cross reference six line blends of pure oxides.
Four materials can be represented in a 3-D form of the triaxial diagram ... a tetrahedron. Each corner of the tetrahedron represents 100% of one of the four materials.
Logan Oplinger
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David Hewitt on fri 9 feb 01
In message , iandol writes
>Dear Paul Lewing,
>
>You recently wrote
>
>>sides are the fluxes, the stabilisers, and the glassformers. It's just a =
>=3D
>pictorial representation of the Seger formula.>
>
>Although there is a degree of truth in what you say, the simplicity of =3D
>this assertion conceals a rather more complex story.
>
>There are two styles of triangular diagram. One,
> I would call this a triaxial blend =3D
>diagram. See Cooper and Royle, "Glazes for the Studio Potter" pp 19-28 =3D
>for a more detailed exposition..
>
>The other form of triangular diagram charts the abstract relationships =3D
>between the molecular oxides which are contained in the substances we =3D
>chose to contribute to our recipes,
> I would call this a Phase =3D
>Equilibrium Diagram. A search of the net will get you several excellent =3D
>study programs on this topic.
>
For those interested in further reading you might like to look at the
Matrix site, as the Matrix program enables you to visually see glaze
recipe analyses on a Triaxial phase diagram graph. A number of recipes
can be plotted on the same graph so you can see the difference a change
in recipe has made.
http://matrix2000.co.nz
Also if you wish you can read more on my site under 'Eutectics & Phase
Equilibrium Diagrams'. This way of presenting glazes can be useful and
this article is aimed at making this meaningful.
http://www.dhpot.demon.co.uk
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP18 3DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Web site http://www.dhpot.demon.co.uk
evan on sat 10 feb 01
What's so absurd about it? I've seen phase diagrams drawn as
perspective drawings of tetrahedra. You can represent hidden lines with
dashes. Granted this takes a fair bit of skill but it can be done. You
can also draw slices through the tetrahedron to show particular planes
of interest.
-- Evan in W. Richland where the snow isn't sticking much.
vince pitelka wrote:
>
> > Four materials can be represented in a 3-D form of the triaxial diagram
> ... a tetrahedron. Each corner of the tetrahedron represents 100% of one of
> the four materials.
>
> Could we please stay within the realm of physical reality? No one is going
> to plot glaze tests on a tetrahedron. This is absurd.
> - Vince
vince pitelka on sun 11 feb 01
> What's so absurd about it? I've seen phase diagrams drawn as
> perspective drawings of tetrahedra. You can represent hidden lines with
> dashes. Granted this takes a fair bit of skill but it can be done. You
> can also draw slices through the tetrahedron to show particular planes
> of interest.
Evan -
Okay, those of you inclinded towards the more esoteric approach to the
chemistry and physics of clay sand glazes may enjoy plotting your test
charts on tetrahedrons. Have fun with it. Seems to me an unnecessarily
complicated way of going about what ought to be a fairly simple task.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
David Hewitt on sun 11 feb 01
In message , David Hewitt writes
>For those interested in further reading you might like to look at the
>Matrix site, as the Matrix program enables you to visually see glaze
>recipe analyses on a Triaxial phase diagram graph. A number of recipes
>can be plotted on the same graph so you can see the difference a change
>in recipe has made.
>http://matrix2000.co.nz
This URL should have been
http://www.Matrix2000.co.nz
Please accept my apologies for this silly mistake.
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP18 3DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Web site http://www.dhpot.demon.co.uk
iandol on sun 11 feb 01
Dear Vince Pitelka,
You comment No one is going to plot glaze tests on a tetrahedron. This is absurd.>
No Vince, it is not absurd. It may not be important, but it is a valid =
way to view information. It is a valuable way of putting those abstract =
figures given in unity formulae in a form which is comprehensible. This =
may be irrelevant to many artists, but it is a nice way to illustrate =
some of the points made by Ian Currie, Ron Roy, Michael Banks and other =
technician who teach Glaze and Clay Technology.
If you want to see it done I will send you a look at one.
Best regards,
Ivor Lewis, Redhill, South Australia
Logan Oplinger on wed 14 feb 01
Ivor & Others
I thank you.
Although different oxide, or chemical components of glazes (and other materials) can be ploted graphically (sp), w/in a tetrahedral form, I use it for a more immediate, practical purpose which is important to me in terms of conserving time, work, and test kiln space.
When I want to investigate the interactions of four materials in glaze tests, I use the tetrhedron to organize my test recipies into a series of triaxial charts. When these charts are superimposed over one another in a specific order, a tetrahedral arrangement is generated. The resultant test tiles are also laid out in this manner, and the progression of effects of the four different materials working together can be seen.
Logan Oplinger
---- Ivor wrote:
> Dear Vince Pitelka,
>
> You comment
>
> No Vince, it is not absurd. It may not be important, but it is a valid way to view information. It is a valuable way of putting those abstract figures given in unity formulae in a form which is comprehensible. This may be irrelevant to many artists, but it is a nice way to illustrate some of the points made by Ian Currie, Ron Roy, Michael Banks and other technician who teach Glaze and Clay Technology.
>
> If you want to see it done I will send you a look at one.
>
> Best regards,
>
> Ivor Lewis, Redhill, South Australia
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