Roxanne Hunnicutt on thu 18 jan 07
All: =0A=0AI took a glaze calculation class in 1970 but have forgottem much=
of what I then learned!=0A=0AIs the placement of an element on the Periodi=
c Table and the molecular weight of an element important in the development=
of a stable glaze, one which will not degrade with time? For example, a g=
laze containing 16 atoms of Calcium, 8 atoms of Aluminium and 66 atoms of s=
ilica would be a "stable" glaze, right?=0A=0AIf ANYONE wants to send me off=
to read something on line or in a book, PLEASE TELL ME WHERE TO GO? Kindly=
?=0A=0ARoxanne in OR where the snow is melting slowly!
claystevslat on sat 20 jan 07
Roxanne --
The position of an element in the periodic table and
the molecular weight are not fundamentally important to glaze
stability. Molecular weight is important in calculating
substitutions, though, so the oxide concentration is right
and the glaze 'molecule' functions as predicted after a sub.
As for a good place to start, that depends on where you want
to end up. It's much easier to start with an existing recipe
and alter it than to begin with nothing and try to land on
a good stable recipe by dead reckoning.
And as for that proposed glaze recipe, one Clayarter recently
posited that you cannot petition the Lord with prayer -- oops,
I mean that you cannot get a stable glaze with group II or group
I melters alone, but that a mix of the two does the trick.
That said, there is a ^10 Val Cushing glaze (AA Base) that
comes close to being 16 calcium, 8 alumina and 32 silica, for
a matte result. I have very little experience with ^10 glazes,
and can't say what would happen with 2x as much silica, but it'd
give you a ratio well into the glossy range.
Best wishes -- Steve Slatin
--- In clayart@yahoogroups.com, Roxanne Hunnicutt
wrote:
>
> All:
>
> I took a glaze calculation class in 1970 but have forgottem much
of what I then learned!
>
> Is the placement of an element on the Periodic Table and the
molecular weight of an element important in the development of a
stable glaze, one which will not degrade with time? For example, a
glaze containing 16 atoms of Calcium, 8 atoms of Aluminium and 66
atoms of silica would be a "stable" glaze, right?
>
> If ANYONE wants to send me off to read something on line or in a
book, PLEASE TELL ME WHERE TO GO? Kindly?
>
> Roxanne in OR where the snow is melting slowly!
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