Jeff Lawrence on sun 22 dec 96
Hello Clayfolk!
Here are a couple of ^04 glazes I was given that may be a good start. Both
have a bit of zinc in them, which may be undesirable. I'm working myself on
de-zinc'ing them. The Ferro recipe (thanks to Dick Culver at Ferro) has a
delicious surface on my ^04 slipcast earthenware -- clean bluish frosty
white, slightly translucent so that dark engobes break through more or less
depending on thickness. The Ron Roy recipe (one that he generously cooked up
as a cheaper and barium-free alternative) is shinier but still a nice
off-gloss; a lovely slurry to work with. Too bad they both shiver off my
ware! This is a problem I haven't seen on thrown ware though.
I'm using variations myself, since my clay body and the large percentages of
colarants I add give me other problems. Tony Hansen's Insight helped me
twiddle up the expansion to make it fit (subbed in 3269 instead of 3134,
with a bit more Alumina to get mat back). Insight printouts follow:
Hope these are of use to others as they are to me.
Ferro 05-04 Barium Mat
======================
Frit 3289 - Leadless 590.00 59.00%
WOLLASTONITE........ 150.00 15.00%
EPK KAOLIN.......... 80.00 8.00%
ZINC OXIDE.......... 120.00 12.00%
ALUMINA CALCINED.... 60.00 6.00%
==========
1000.00
FORMULA & ANALYSIS
==================
*BaO .24 16.35%
*CaO .30 7.35%
*MgO .00 .01%
*K2O .00 .03%
*Na2O .12 3.28%
*ZnO .34 12.13%
*Fe2O3 .00 .04%
TiO2 .00 .03%
P2O5 .00 .02%
B2O3 .24 7.40%
Al2O3 .27 12.34%
SiO2 1.55 41.02%
RATIO 5.65
EXPAN 8.07
WEIGHT 227.03
Ron Roy ^04 Satin Mat
================
NEPHELINE SYENITE... 34.00 34.00%
FERRO FRIT 3134..... 26.00 26.00%
WOLLASTONITE........ 10.00 10.00%
ZINC OXIDE.......... 6.00 6.00%
EPK KAOLIN.......... 24.00 24.00%
==========
100.00
FORMULA & ANALYSIS
==================
*CaO .49 10.69%
*MgO .00 .07%
*K2O .05 1.73%
*Na2O .26 6.28%
*ZnO .20 6.21%
*Fe2O3 .00 .12%
TiO2 .00 .09%
P2O5 .00 .05%
B2O3 .23 6.18%
Al2O3 .45 17.72%
SiO2 2.18 50.85%
RATIO 4.88
EXPAN 8.29
WEIGHT 257.03
Jeff Lawrence
Sun Dagger Design
Rt 1 Box 394L
Espanola NM 87532
ph/fax 505-753-5913
AWM (Amused Wry Male)
Wendy Hampton on tue 24 dec 96
Hi Jeff,
Why are you trying to remove the zinc from your ^04 glazes?
Wendy from Bainbridge Island WA
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