Alisa Liskin Clausen on sat 13 jul 02
I can second this experience. I have a bag of G.B. that I bought, basically
because I could. I use my local frit as a sub for all G.B. in the glazes I
use, so it is about 2 years old. Admitedly not packed as it should be. It
was sort of damp in places and I used it anyway for a raku white crackle.
I knew in the back of my mind that this was going to be a problem, but I
could not remember why. Earl explained that well.
Of course this was the summer's first firing, everyone completely full with
anticipation. Claus finally left on the boat because the white crackle just
stood there, lumpy and gray. He was figuring the cost of the gas and
getting
very annoyed. I fired it so long the pots cracked. I kept thinking that I
must have grabbed
something other than G.B. when I mixed that glaze. After all, it is not
really a recipe that requires high concentration, 80 G.B. and 20 Neph. Sye
(or other). But the next times, I used my frit and things got shiny in the
kiln after the usual 15 minutes. Serves me right I guess for hoarding. Now
I have 24 lbs. of G.B. that is good for nothing. Didn't need it in the
first place.
regards from Alisa
william schran on sat 13 jul 02
Alisa - I had the same problem with the same raku glaze - 80% G.B. &
20% Neph Sy. All the other glazes that used G.B. as the flux seemed
to be fine, but the tried and true 80/20 glaze just didn't want to
melt. Even left a pot in through two raku firing cycles and still not
melted. Had 5000 grams of this glaze as clear and another 5000 grams
with opacifier as white.
I added approximately 10% lithium carb. to each glaze batch and that
did the trick - melts great now! Maybe even too much. Have to really
watch the glaze, otherwise it ends up looking like an ash glaze,
which I guess ain't all that bad.
Bill
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