Lili Krakowski on sat 3 dec 05
It needs to be said first: liking a book does not mean one is =
"knocking" another.
I plug Fraser's "Glazes for the Craft Potter", as well as Bailey's =
"Glazes Cone 6" . Which does not imply any lesser love for RonJohn's =
"Mastering Cone 6 Glazes". It is like the Prophets. There are days =
one needs Jeremiah, others when one needs Micah. One learns from each =
book, and, as Hobart Cowles used to say, even if you only learn one =
thing from a book, that is worth it...
One of Bailey's gracious aspects is that, like Cooper, he tells you =
where the recipe came from. This recipe, G23 is attributed to Judy =
Musicant, and "....was developed by Val Cushing and Pam Fredericks." =
Additions of 1-2% copper carb, 1% cobalt OXIDE (u.c. mine) 35 red iron =
oxide are suggested. He adds that this can be a rather tricky glaze to =
get to work right.
Now, looking at the recipe, it includes Neph Sy and Gerstley Borate. =
Neph Sy is mined in a number of places, and even in the same place, same =
mine, mine runs vary over the years. GB is known for its fickleness..it =
must be a character flaw, because I think--am I wrong?--it is mined only =
in one place. EPK also may have changed its actual content over the =
years, and, in my limited experience, not all whitings are identical. =20
Are these changes Falling Off Your Chair types? No. They are =
Go-With-the-Flow -That-Is-Life Changes.
Earl writes the glaze runs too much. Too fluid. Like that. This is =
interesting in itself because addition of Copper Carb is "allowed" and =
Copper Carb fluxes. I would expect the maturation of this glaze would =
vary a bit from plain to copper to iron and cobalt additions.
1. The most forgotten factor in glaze success is THE BODY UNDERNEATH. =
Need I point out that it is absurd for me to complain that a dress that =
looks fabulous on Julia Roberts looks unspeakable on me? (Believe =
me....And no need to say it would not be made in my size) Cure #1: =
Always have at last three different clay bodies of your firing temp on =
hand, and have test tiles for these. Try each new glaze on the =
different tiles so that you KNOW whether 'tis the glaze proper, or the =
body underneath. Failing that: always stripe your test tiles with white =
slip. Yes, even a white body. Be sure the slip does NOT contain =
magnesium, as in talc or dolomite. Also no boron.
2. Make straight line blends. People who have been my students will =
tell you these are my favorite things. At one end have the "normal" =
amount of each flux, at the other 1/2. You do not in this case need to =
do such a blend for the clay, nor the silica. Check out the most =
promising of your results and start blending again. I do not know how =
to do Currie blends, but someone who does know may be helpful.
3. This is an interesting glaze because the alkaline and earth fluxes =
are just about equal. You may not want to unbalance that too far. =20
Now as to the nice person who bought a clay body from one producer and =
glaze from another. I KNOW you had the honesty to say you do this as a =
hobby, but this may be of use to others as well.
I learned this from a friend, who had no room for glaze supplies in his =
small shop, and also was not a glaze pro. He DRIED commercial glazes =
and then blended them. In the asked-about case, talking to the producer =
is the best answer...if it works out. Otherwise consider laying in a =
small amount of clay and of silica and making tests on the dried out =
troublemaker, by putting in small additions of clay and--separate =
tests--silica. This would be a nice intro into glaze anyway. DO =
REMEMBER: Using dry glazes and ingredients makes wearing a mask even =
more imperative.
=20
'....
Lili Krakowski
Be of good courage
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