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crystalline glazes( long)

updated mon 8 jan 01


william schran on sat 6 jan 01

Ababi - I'm going to do some more testing with MFE crystal glaze and
cut back on amount of titanium dioxide. Titanium does help seed and
promote crystal growth but too much will hinder large crystals.
I'd suggest not soaking at cone 6 but dropping temperature 200=B0F and
holding there for at least 3 hours.
I like adding about 6% copper to my glazes. I also like the colors
from nickel compounds.

Ababi Sharon on sat 6 jan 01

Hello Bill! Hello Cheryl
Your article, in Clay Times helped me in my way, in ^6 crystalline glaze.
For a while, I am testing these glazes, starting from two similar glazes I
found at Lana Wilson's book.
I saw, that the recipe you sent called Helen's was very similar, to the one
recommended at Lana Wilson's book as Jeanne Richter 2 which I use. This
glaze, I succeeded with made me understand that there is life (for
crystalline) below ^9. I tested Helen's glaze, not exactly like you
recommended, as a compromise with the other glazes in the firing. I soaked
in the top1222C 30 minutes and than at 1055C for 90 minutes.Conclusion: To
be repeated + to read again your article.
Another thing I do, is by changing frits, and some materials, try to change
the glaze.There was one test that could not be repeated .
The Crystalline Glaze are one corner in my triangle of my art, So it takes
time to develop.
I would like to hear from you suggestion of coloring.

To Cheryl!
After finding these recipes at LanaWilson's book I bought Crystalline Glazes
by Diane Creber, very easy to understand, even to a none speaking English
person (except to my wife).After that I understood more what and why I had
to do.
Here is a good starting point:
Here are the two recipes
Crystal ^6/2 (Jeanne Richter)
FRIT 3110........... 49.00 49.40%
ZINC OXIDE.......... 26.00 26.21%
ENGLISH KAOLIN...... 1.40 1.41%
QUARTZ.............. 17.10 17.24%
TITANIUM DIOXIDE.... 5.70 5.75% Or 7 TiO2 in the second version

FRIT 3110........... 46.10 46.10%
ZINC OXIDE.......... 23.19 23.19%
ENGLISH KAOLIN...... 1.45 1.45%
QUARTZ.............. 17.10 17.10%
TITANIUM DIOXIDE.... 7.41 7.41%

I believe that The Li2O is softening the glaze, according to my test, and
to the one I did before I read your article and failed in repeating it as
the whole crystals flew away: I made that glaze side by side with ^6/2
(Jeanne Richter) through Insight. Here both recipe, Jeanne Richter's again,
and my deviation:
Crystal ^6/2
FRIT 3110........... 49.00 49.40%
ZINC OXIDE.......... 26.00 26.21%
ENGLISH KAOLIN(Puraf 1.40 1.41%
QUARTZ.............. 17.10 17.24%
TITANIUM DIOXIDE.... 5.70 5.75%

CaO 0.11* 3.11%w 3.71%m
K2O 0.02* 1.18%w 0.84%m
Na2O 0.24* 7.55%w 8.14%m
ZnO 0.63* 26.21%w 21.51%m
TiO2 0.14 5.75%w 4.80%m
Al2O3 0.04 2.34%w 1.53%m
B2O3 0.04 1.28%w 1.23%m
SiO2 1.70 52.41%w 58.24%m
Fe2O3 0.00 0.01%w 0.00%m

L.O.I. 0.16
Si:Al 38.02
SiB:Al 38.83
Expan 9.10

>From Lana Wilson's book pag 50

Good base: fire to 1222C then cool fast to 1055C live to soak 1 hour then
cool normally. some people do it different see in the book!

crystal^6 4
ZINC OXIDE.......... 26.00 25.31%
ENGLISH KAOLIN(Puraf 4.19 4.08%
QUARTZ.............. 29.86 29.07%
TITANIUM DIOXIDE.... 5.70 5.55%
FRIT 2120........... 30.44 29.63%
WOLLASTONITE........ 2.54 2.47%

CaO 0.10* 3.03%w 3.62%m
Li2O 0.10* 1.59%w 3.56%m
K2O 0.00* 0.12%w 0.09%m
Na2O 0.24* 8.18%w 8.83%m
ZnO 0.56* 25.31%w 20.82%m
TiO2 0.13 5.55%w 4.65%m
Al2O3 0.04 2.28%w 1.49%m
SiO2 1.54 51.10%w 56.93%m
Fe2O3 0.00 0.03%w 0.01%m

Cost/kg 12.76
L.O.I. 2.81
Si:Al 38.09
SiB:Al 38.09
Expan 9.13

Lithium instead of B2O3

6 lithium carbonate, makes

floating flowers. 5,or 4 still nice. The colorant I used 2copper
nickel ox.

I tested this glaze with 1-7 Lithium Carbonate.

Could not repeat.

Another question, I asked before.These two sub-recipes one with 5.7
titanium the other 7 Titanium. results are different. I was told the
titanium helps to seed the crystal. Can I play here? how much?
In my photo album you may see these glazes:The easy way is here
The password :clay

The first picture is of Richter' 2 with 5.7 titanium and 5 copper ox.
In the title "As glazed" the top, the two on the right, the same glaze on
Limoge the next one is my never repeated test on good Dutch stoneware
K-110. The one on the left is the second variation with 7 titanium + 4
manganese. I usually did it with the oxide, tried it the last time with the
carbonate and did not like the results.

Ababi Sharon

----- Original Message -----
From: "william schran"
Sent: Saturday, January 06, 2001 12:07 AM
Subject: Re: crystalline glazes

> Cheryl - I'd be happy to share whatever information I have. I've been
> working in crystalline glazes at cone 6 for a while and wrote an
> article for ClayTimes last Sept./Oct. issue. Please feel free to
> email me off line.
> Bill Schran
> Send postings to
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