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glaze calculation: old potter loses cool - use the magic button

updated wed 15 mar 06


John Post on tue 14 mar 06

I agree with Lili. I too think that glaze calculation is not hard at
all. You don't even need to know the math that she wrote about to learn it.

I will tell you what I think is the easiest way to learn about glaze
Download the program called Glazchem by Robert Wilt.

Enter your recipes into the program.
Then click on the button that says batch calculation (It is on the
recipe screen.)
Then you will see a button that labeled "Make Suggestion".
This is the magic button.
Say you have a recipe that has clay, a feldspar, a little gerstley
borate and some flint, you then click the Make Suggestion button and the
program will go through the list of possible ingredients that you could
use to reformulate the glaze.
It will show you all of the feldspars that are possibilities, then the
frits, clays etc.
What glazchem does is look at the oxides in the glaze and then suggest
the materials that you can use to supply the oxides in the glaze. There
are lots of choices you can make, and as you make the choices, you end
up learning about the oxides and the materials that supply them in your
glaze. The magic "make suggestion" button guides you through the
process of choosing materials that will work in your glaze. I don't
know why all glaze programs don't have this feature.

It is a great learning experiment to try and make some of your own
glazes using different materials.
There is no math involved in this. If you can press the "make
suggestion" button and then look at the unity formula at the end to make
sure that both your original glaze and your new glaze are close in terms
of their unity formula, you are on your way to becoming a glaze
expert... (well an expert about your glazes anyway.)

Glazchem costs about $35 but has a free 90 day trial. It runs on
Windows. (I have an old laptop I run my copy on).

John Post
Sterling Heights, Michigan