Tiggerbus on fri 21 feb 97
I am new to this mixing thing...I need information on what minerals and
chemicals to purchase to mix glazes for an electric kiln. I have always
worked with gas in college, which was years ago, but I understand the
whole concept of reduction and oxidation! I need to know about what types
of recipes will work in an electric kiln and where do I purchase them
from! Our professors always had the colors mixed together and we just
dipped out little hearts away. I only learned how to mix different types
of clays and I have plenty of knowledge in that area, just need help in
the glaze area!!'
If anyone has the time or can just point, I can follow!!!
Thanks,
amer
Evan Dresel on sun 23 feb 97
At 09:22 AM 2-21-97 EST, you wrote:
>----------------------------Original message----------------------------
>I am new to this mixing thing...I need information on what minerals and
>chemicals to purchase to mix glazes for an electric kiln. I have always
>worked with gas in college, which was years ago, but I understand the
>whole concept of reduction and oxidation! I need to know about what types
>of recipes will work in an electric kiln and where do I purchase them
>from! Our professors always had the colors mixed together and we just
>dipped out little hearts away. I only learned how to mix different types
>of clays and I have plenty of knowledge in that area, just need help in
>the glaze area!!'
>
>If anyone has the time or can just point, I can follow!!!
>
>Thanks,
>amer
>
I think there are a few strategies that you can take in developing a palette
of glazes. I'm maybe a step or two ahead of you in the process but am
still working on it.
The first thing I did was to buy some commercial cone 6 glaze so I could
fire some pots to go along with my test tiles. Had limited success with
that because at least one of them turned out kind of lousy and the others
are so-so. But that's why you want to make your own, right.
Anyway you can take the approach of finding some promising looking recipies
and buying enough of the glaze chemicals to make up some tests. You will
end up with a lot of bags of chemicals which you may or may not use again.
But soon you will get an idea of what are the basic ingredients that you
always seem to be running out of as you start to mix up bigger batches of
the best looking glazes.
You could take the pureist approach of trying to find the ultimate base glaze
for your clay and you firing temperature and then work through adding
colorants, opacifiers, matting agents, until you have the glazes you want.
You could do a lot of this using glaze calculation programs and judicious
tests.
You can take a kind of middle approach by looking at the recipies and
figuring out which ones use similar materials and then testing & adjusting
those. By looking at the recipies and a catalog from your supply house, you
will start to get a really good idea of what materials you will need a lot
of, what materials are really expensive but go a long way, and what materials
are pricey and make up a major portion of certain glazes. If you fire to cone
6ish, you will most probably need flint (or silica), a feldspar (either a soda
spar or a potash spar like Custer), nephalene syenite (a feldspathoid like a
feldspar but with less Si), gertley borate (unless you hate the stuff), kaolin
(such as EPK). You possibly will use whiting (calcium carbonate), dolomite
(calcium & magnesium carbonate) and frits like Ferro 3124 and 3134, maybe some
ball clay (eg Kentucky ball clay). Then there are things you will use less of
like strontium carbonate, zircopax (or other opacifier), and a whole bunch of
colorants.
I guess my point is that you don't need to start with a lot of materials.
Some things like flint, feldspar and whiting are so inexpensive in bulk that
it doesn't make sense IMO to buy less than a full bag. Other things may
end up being more in your way than anything if you buy too much before you
know you are going to need it -- things like my 5 lbs of manganese dioxide,
barium carbonate, or lead bearing anything. I would avoid even considering
glazes that use any of those things except if you substitute strontium carbonate
for barium carbonate or if it really is only a small percentage of manganese.
That being said, I kind of like minerals and chemicals so I have a little bit
of a number of things on hand. But don't be afraid to substitute different
materials for each other and see what happens. That's easier if you know how
to use glaze calculations, but can be done ad hoc.
I still think Clay and Glazes for the potter by Rhodes is a good place to start
learning about this stuff.
Test, test, test; have fun; and buy a good respirator for mixing those glazes.
-- Evan Dresel in Eastern Washington USA where the annual tumbleweed migration
is on.
Ron Roy on mon 24 feb 97
>----------------------------Original message----------------------------
>At 09:22 AM 2-21-97 EST, you wrote:
>>----------------------------Original message----------------------------
>>I am new to this mixing thing...I need information on what minerals and
>>chemicals to purchase to mix glazes for an electric kiln. I have always
>>worked with gas in college, which was years ago, but I understand the
>>whole concept of reduction and oxidation! I need to know about what types
>>of recipes will work in an electric kiln and where do I purchase them
>>from! Our professors always had the colors mixed together and we just
>>dipped out little hearts away. I only learned how to mix different types
>>of clays and I have plenty of knowledge in that area, just need help in
>>the glaze area!!'
>>
>>If anyone has the time or can just point, I can follow!!!
>>
>>Thanks,
>>amer
>>
Hi Amer,
I think Evan's answer is good basic advice. I was going to add to it but I
need to know at what temperature you plan to fire your glazes to.
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
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