June Perry on thu 14 nov 02
Linda, you asked "what methodology to people use to convert recipes
from one cone to another? Do you just calculate them with different
limit formulas?"
If the limits in the RO column can remain the same, because it is within the
limits suggested for that particular cone, I just alter the silica and
alumina amounts up or down.
If the RO column ingredients are such that they are not within limits for the
cone I want, I try to alter them just enough to bring the recipe into the
proper limit range; but then I might do another version keeping the RO the
same and only change the alumina and silica and fire both and mix each 1/2
and 1/2 (1-2T wet glaze each) to get a third test, just to see the
difference.
Often when you take a 6 glaze for instance, and up the silica and alumina to
a C10 for instance, you will get quite a different color to the glaze. The
added silica and/or alumina can alter the color in some formulas. You see
this a lot with celadons. You can keep the RO column the same but just upping
the silica/alumina will alter the color.
The Japanese glaze database site Nirin, shows some examples of this.
All you can do it test, test, test. :-)
Regards,
June Perry
http://www.angelfire.com/art2/shambhalapottery/index.html
Ababi on fri 15 nov 02
I would simplified your words June.
Perhaps because I can do it in Matrix, In Insight too, but in Insight you get rang of
cones in the limit table not the particular one.
Presume, I had the Al:Si high in ^10 I will make them high in ^6 About the other
material, if I can I leave as they are of course I will not use to much magnesium ,
might change the feldspar to Nepheline Syenite and in crystal glaze might add lithium
carbonate.
In Don Goodrich glazes list I found this:
>SUBSTITUTION ^6 FOR ^10
>Simply substitute the potash feldspar for Neph Sy feldspar. Most cone 10 glazes
can
>be lowered to cone 6 with this simple adjustment.
> MAYBE add 10% Gerstley Borate in addition to the substitution.
I used to do it, is too simple.
When ever you add flux, you must know what influence it has on the color you want to
archive
---------- Original Message ----------
>Linda, you asked "what methodology to people use to convert recipes
>from one cone to another? Do you just calculate them with different
>limit formulas?"
>If the limits in the RO column can remain the same, because it is within the
>limits suggested for that particular cone, I just alter the silica and
>alumina amounts up or down.
>If the RO column ingredients are such that they are not within limits for the
>cone I want, I try to alter them just enough to bring the recipe into the
>proper limit range; but then I might do another version keeping the RO the
>same and only change the alumina and silica and fire both and mix each 1/2
>and 1/2 (1-2T wet glaze each) to get a third test, just to see the
>difference.
>Often when you take a 6 glaze for instance, and up the silica and alumina to
>a C10 for instance, you will get quite a different color to the glaze. The
>added silica and/or alumina can alter the color in some formulas. You see
>this a lot with celadons. You can keep the RO column the same but just upping
>the silica/alumina will alter the color.
>The Japanese glaze database site Nirin, shows some examples of this.
>All you can do it test, test, test. :-)
>Regards,
>June Perry
>http://www.angelfire.com/art2/shambhalapottery/index.html
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