Ababi Sharon on sun 18 apr 04
The Fluor Issue Food for thought.
If I understood correctly Rhodes's about the fluor; it is a melting
catalyze and in the same time, sometimes, attached to the SiO2 chain
instead of the O2. Please do not catch me for miss interrupting some of
the places of the numbers. It might be funny for you but I never write
the SiO2 before I see how it is written on the software window! (I can
easily write Si2O).
Back to the main story:
Out of my tests with crystal glazes at ^6 I came to this limit table
(based on three main recipes. One is mine and two of Bill Schran based
on David Shaner (I hope I am not misspelling his name).
KNO 0.2-0.35
ZnO 0.5-0.58
Li2O 0.05-0.1
Al2O3-0.04-0.06
SiO2-1.5
Out of recent tests I can tell I should add some CaO annd MgO but this
is the general key line to this glaze in this cone!
When my knowledge was minimal I had learnt that in low fire high zinc
(raw of course) gave me a crwaling glaze.
When I was trying it again at ^6 that time I chose the most expensive
clay (at that time) Amaco 48 or 480 I got "unexpected results".
http://members4.clubphoto.com/ababi306910/2056968/
second and third slide.
OK
I took the recipe I made some years ago and tested it in crystal firing
^6 soaking three hours in 1050C.
I added 2% nickel oxide.
The third slide is the best answer to the people that say that a glaze
software is an unnessery tool.
It is not the same porcelain but the recipes are as follow:
SIMPLE CRYSTALLINE GLAZE
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1210 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cryolite 20.00
Quartz 30.00
Ferro 3195 20.00
zinc oxide 15.00
kaolin CC31 15.00
Nickel Oxide 2.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.471 13.22%
CaO 0.097 2.44%
ZnO 0.432 15.76%
Al2O3 0.319 14.56%
B2O3 0.154 4.80%
SiO2 1.827 49.19%
TiO2 0.000 0.02%
K2O 0.010 0.44%
Na2O 0.460 12.78%
Al:Si 5.73
Expan. 10.21
ST 334.62
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
ABABI'S SIMPLE CRYSTALLINE GLAZE
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1210 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cryolite 17.70
Quartz 28.83
SOFTBORAX FRIT (BATH) 14.41
zinc oxide 14.77
EPK Kaolin 22.15
fluorspar 2.11
Nickel Oxide 2.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.465 12.88%
CaO 0.099 2.47%
MgO 0.001 0.02%
ZnO 0.435 15.80%
Al2O3 0.322 14.65%
P2O5 0.001 0.06%
B2O3 0.155 4.81%
SiO2 1.836 49.21%
TiO2 0.002 0.09%
K2O 0.003 0.11%
Na2O 0.462 12.77%
Al:Si 5.69
Expan. 10.13
ST 335.63
You can see very easy that this is an "abnormal crystal glaze".
There is no way that a recipe with such a high alumina will develop
any crystals at all. At least not in ^6.
The conclution: ( actualy of Denis- smart ) was that the fluor made
this crystal glaze possible.
I must warn you that fluor is a high poinous material both in cryolite
and fluorspar. I would not jump to follow this test I have made unless
you know what you deo and you know when care must be taken. (by the way:
that is why I never brush my teeth).
http://perso.wanadoo.fr/smart2000/cryolite.htm
Both good software that I use Matrix 2000 and Insight5x consider the
fluor as LOI.
I do not know what the others software do with this "L.O.I. flux".
In away it reminds me somehow of the embivalent look at the B2O3.
By the way. I am sure that if I have been replacing the criolite into a
sodium frit the crystals would not work.
Ababi Sharon
Glaze wizard
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://ababi.active.co.il
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
A fast link Ceramics forum in Hebrew:
http://www.botzpottery.co.il/kishurim.html
Ababi Sharon
Glaze wizard
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://ababi.active.co.il
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
A fast link Ceramics forum in Hebrew:
http://www.botzpottery.co.il/kishurim.html
Ivor and Olive Lewis on mon 19 apr 04
Dear Ababi,
For some peculiar reason I am having serious and strangely irreverent
thoughts about your inclusion of Zinc oxide and a proportion of the
Silica in the Unity formulae you have calculated.
Something in my mind is saying to me that these are not part of the
glaze. For the glaze to work they have to be removed from the melt. It
is what remains when Zinc Oxide and Silica are excluded which makes
the glaze. Zinc Oxide and Silica are just there for the ride, for the
convenience of dissolving, having a chemical reaction and then
crystallising as soon as possible.
Of course this a heresy and does not fit in with current religious
glaze dogma. Wondering if the Devil has taken me to a High Place
Best regards,
Ivor Lewis. Redhill, South Australia
at melpots@pclink.com.
Ababi on tue 20 apr 04
dear Ivor
I am glad it happens to you too, reading half letter and replying...
...Some years ago ( I started ceramics in 96 so each year of mine is 5 of a
"normal potter")
Some years ago using the glaze simulator I thought to myself: If This
Canadian guy could make that 5/20 glaze Why cannot I?
I made glaze, I do not remember exactly what I have wrote there among the
materials was 20 zinc. Yes zinc. the powder you put in kids rect...
Oxide? Maybe?
Yes.
Why did I choose zinc? Maybe the name reminded me the ring of the school
Bell! I added more materials. Which? Why? I do not know. The education I
got was something between mixed facts and memory of my teacher that
considered herself as a glaze guru + my daring to test and try and learn!
I got in 1020-1060 - an old pyrometer ( I did not know about the possibility
to measure with cones ( in my old kiln I had in Shoval).
So I got a crackled glaze. I believe it can explain you the need we
crystaliers are finding to calcine the zinc.
When I repeated the test in ^6 I made the glaze I had sent: I knew much more
but not enough.
Still I do not know enough:
To finish this letter. First Thank you for your excellent English, you force
me to lean new words.
The second point: please re read my letter and see the main point. I know it
is full of mistakes. My home computer is horrible ignores the speller: It is
being punished now and sent to be replaced.
You will give me 2 weeks to complain about the new one and after that I
will try to be a "good Boy" again!
Ababi Sharon
Glaze addict
Kibbutz Shoval -Israel
http://ababi.active.co.il
in my studio in front of my model 95 computer that wait to "eat the
leftovers" of my home computer...
----- Original Message -----
From: "Ivor and Olive Lewis"
To:
Sent: Monday, April 19, 2004 7:46 AM
Subject: Re: The Fluor Issue Food for thought
> Dear Ababi,
> For some peculiar reason I am having serious and strangely irreverent
> thoughts about your inclusion of Zinc oxide and a proportion of the
> Silica in the Unity formulae you have calculated.
> Something in my mind is saying to me that these are not part of the
> glaze. For the glaze to work they have to be removed from the melt. It
> is what remains when Zinc Oxide and Silica are excluded which makes
> the glaze. Zinc Oxide and Silica are just there for the ride, for the
> convenience of dissolving, having a chemical reaction and then
> crystallising as soon as possible.
> Of course this a heresy and does not fit in with current religious
> glaze dogma. Wondering if the Devil has taken me to a High Place
> Best regards,
> Ivor Lewis. Redhill, South Australia
>
> at melpots@pclink.com.
>
>
____________________________________________________________________________
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melpots@pclink.com.
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