Sharon31 on tue 11 apr 00
O.K.
I see that we start a new friendship!
I do mix the borax with hot water,
but it is a limited help.
After finding these 2 recipes, of Crystalline glaze, not aventurine glazes!
I
bought the book, Crystalline Glazes by Diane Creber, read it and only than
tested!
I cannot be too deep into crystalline because it is too expensive for
me.Also because don,t work very clean and also because I started ceramics
late, and if I want to be good I cannot do everything.
That is why it is easier for me to limit myself to two "subjects" Raku and
^6 electric! a very wide "limitation"!
I add here two recipes.
Crystal^6 1222C 1
=================
FRIT 3110........... 42.00 41.79%
QUARTZ.............. 28.00 27.86%
CMC GUM............. 0.50 0.50%
ZINC OXIDE.......... 28.00 27.86%
LITHIUM CARBONATE... 2.00 1.99%
========
100.50
CaO 0.09* 2.68%
Li2O 0.05* 0.82%
K2O 0.02* 0.98%
Na2O 0.19* 6.50%
ZnO 0.65* 28.33%
Al2O3 0.03 1.58%
B2O3 0.03 1.10%
SiO2 1.79 58.00%
Si:Al 62.33
SiB:Al 63.35
Expan 8.12
Notes:
Cool to1055C and leave there an hour.drop the temp. and repeat several
times.FromJeane Richter,Lana Wilson' book. More details in the book. I did
not succeed with this recipe!
Crystal ^6/2
============
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%
========
99.20
CaO 0.11* 3.12%
K2O 0.02* 1.19%
Na2O 0.24* 7.56%
ZnO 0.63* 26.25%
TiO2 0.14 5.76%
Al2O3 0.04 2.34%
B2O3 0.04 1.28%
SiO2 1.70 52.49%
Fe2O3 0.00 0.01%
Cost/kg 16.32
Si:Al 38.02
SiB:Al 38.83
Expan 9.10
Notes:
>From Lana Wilson's book page 50
Good base: fire to 1222C then cool to 1055C to soak 1 hour then cool
normally. some people do it different see in the book!
This is "my" basic recipe, from this I try to develop more recipes by
changing frits and other materials.
I did not try all the recipes, I use Conard engob as my regular one.
* * * * * * * *
There is another interesting experiment there, "Look like wood fire in ^6
electric. I don't have any woodfire piece, and I cannot work in this firing.
I coated according to Lana Wilson advises, and got very good results.
That is all for now!
Ababi
sharon@shoval.org.il
http://www.israelceramics.org/main.asp?what=gallery.htm
http://clay.justnet.com/cgallery/asharon.htm
iandol on thu 13 apr 00
------------------
I am wondering why the person who invented this cooling programme to create =
a
crystalline glaze chooses to hold a steady temperature then cool and reheat =
back
to 1055 C several times, as was put in the following extract
Cool to 1055C and leave there an hour. drop the temp. and repeat several =
times.
>From Jeane Richter, Lana Wilson' book. More details in the book. I did not
succeed with this recipe=21
I think I can understand why it did not work but the following thoughts are =
pure
speculation. The glaze as it cools is a vitreous solution. When a compound
reaches its saturation point, as the fluid cools, it begins to crystallise. =
If
the temperature is held constant, crystallisation can continue if there has =
been
a degree of supercooling. When the temperature remains constant for a longer
period, several hours, other compounds may also crystallise. But if the
temperature rises, what has already solidified can remelt so crystals are =
lost.
It is also possible that the temperature of 1055 Celsius may be much too =
high.
Yes, Ok for Zinc crystalline, but not for Aventurines. It is certainly well
above the temperature at which crystallisation would be complete if the kiln
were cooled at say 10 degrees Celsius per hour down to 600 Celsius.
Could I have more information about the source material please. Book, =
Author,
ISBN, Date, Publisher so that I read it and get a better understanding.
Regards,
Ivor Lewis.
Sharon31 on fri 14 apr 00
Hello Ivor
In Lana Wilson's book, among many other things, there is a chapter about:
"Glazes we have tested".
There, were, two crystalline glazes.I tested them in all the coloring
possibilities,that Lana Wilson offered,When I enter a base glaze to Insight.
Sometimes I add the colorants and sometimes not.
For me, to copy all the text to the program is a big project, especially
that anyone can look, or buy the book and look at the recipes.
There were two recipes, as I wrote before, The first was a total failure,
and the other one, was a success, good enough to go on testing. This
crystalline, as well as another one or two variations, out of this glaze.My
good adviser at my supplier didn't believe, when I gave him the recipe, that
it can work.Only when I sent him a piece he realized that it can be. I
don't have a test kiln So I cannot make too many testing on this subject.
Why 1055.5C?I don't know.I know that one fired piece I added to a regular^6,
refired and turned out beautyfull and the next time tried the same and got
disaster. In general I fire to 1222C ,soak 30minuts,(once I did not soak at
the top and I got less beautifull works)than cool to 1055C ,
soak 1 hour go home and after 2 days open the kiln. I sent the two recipes,
because I wanted to hear about possible reasons why the first one did not
succeed.... Ababi
sharon@shoval.org.il
http://www.israelceramics.org/main.asp?what=gallery.htm
http://clay.justnet.com/cgallery/asharon.htm
-- Original Message -----
From: iandol
To:
Sent: Thursday, April 13, 2000 08:32
Subject: Re: re Lana's dry engobe+crystalline
----------------------------Original message----------------------------
------------------
I am wondering why the person who invented this cooling programme to create
a
crystalline glaze chooses to hold a steady temperature then cool and reheat
back
to 1055 C several times, as was put in the following extract
Cool to 1055C and leave there an hour. drop the temp. and repeat several
times.
>From Jeane Richter, Lana Wilson' book. More details in the book. I did not
succeed with this recipe!
I think I can understand why it did not work but the following thoughts are
pure
speculation. The glaze as it cools is a vitreous solution. When a compound
reaches its saturation point, as the fluid cools, it begins to crystallise.
If
the temperature is held constant, crystallisation can continue if there has
been
a degree of supercooling. When the temperature remains constant for a longer
period, several hours, other compounds may also crystallise. But if the
temperature rises, what has already solidified can remelt so crystals are
lost.
It is also possible that the temperature of 1055 Celsius may be much too
high.
Yes, Ok for Zinc crystalline, but not for Aventurines. It is certainly well
above the temperature at which crystallisation would be complete if the kiln
were cooled at say 10 degrees Celsius per hour down to 600 Celsius.
Could I have more information about the source material please. Book,
Author,
ISBN, Date, Publisher so that I read it and get a better understanding.
Regards,
Ivor Lewis.
Fabienne Cassman on fri 14 apr 00
At 01:32 PM 4/13/00 -0400, you wrote:
>Could I have more information about the source material please. Book, Author,
>ISBN, Date, Publisher so that I read it and get a better understanding.
Hello Ivor :)
I have made a list of some of what's available for macro-crystalline glazes
at http://www.milkywayceramics.com/toolbox/crystal.htm
The articles I've read have comments as to their content. There are a few
book titles and web sites relevant to this type of glaze.
Good luck!
Faye
--
Milky Way Ceramics http://www.milkywayceramics.com/
Yes, I have learned from my mistakes...
I can reproduce them exactly.
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