From cone 10 to cone 6

I read that you can substitute potash feldspar for NephSy feldspar (maybe add 10% Gerstley) and this will allow you to turn almost any cone 10 recipe into a cone 6 recipe. Has anyone tried this or have comment?

Comments

Lori Watts said…
I have replaced half the feldspar in some Cone 10 glazes to bring the firing temp down to Cone 8. That worked fine.
John Britt said…
The nepheline syenite for Custer will sometimes work but... that and ....adding 10 % frit or GB will work, usually. Still have to test and it isn't the same glaze anymore because of more sodium and more boron.
Melissa Rohrer said…
I have a recipe written for both cones 8-10 reduction and cone 6 oxidation. To change to cone 6 it makes a direct substitution of Neph Sy for Custer feldspar.
Diane Puckett said…
My concern with making substitutions is that I may transform a food-safe glaze into one that is not. I am sure Britt covered that in Glaze Boot Camp For Masochists, but my brain had shut down by then.