To get the formula, we divide each material by its molecular
which we find listed in glaze books.
Whiting (calcium carbonate) has a molecular weight of 100.
Dividing our 32 gms of whiting by molecular weight of 100 we get .3200.
We divide the zinc we have-12 gms-by 81 and get .1481.
And we skip to the flint ( you will see why) and divide 17 by 60
Now we get to a bit more complicated stuff. The dolomite and the
Both have two components, two materials.
Dolomite has 1 calcium and 1 magnesium. And dividing the 15 gms in
recipe, we get .0815 of EACH.
With clay we get 24 divided by 258. Or .0930. But wait
a minute. Here we
have two parts of silica for one of alumina. So we multiply the
two, and get .1860
To finish our formula properly we add up all the fluxes and write them
in a column, all the stickers in their column, and the glass-formers in
Because we have more than one source of a specific ingredient-in this
calcium-- we put down what each material contributes, and add that up
the total we will be getting of that ingredient.
CaO .3200 + .0815 = .4015
SiO2 .2833 + .1860 = .4693
To tidy this up, we reduce it to unity. To see to it that the
flux/melter/RO column adds up to 1, and the other columns are adjusted
accordingly. We add up the RO column for a total of .6311, and
every ingredient in the whole formula by that number.
At this point you are all upset and in a small panic.
But look. If you need 24 ounces of chocolate chips, and you can
chips only in 7 oz packets, what do you do? You divide your
NEED (24 oz)
by your supply (7 oz packets) and learn you will need
Your cookie recipe includes flour, sugar, butter, eggs, milk. So
get to the fat/protein/carbohydrate part you actually follow the same
procedure as above.