search  current discussion  categories  glazes - misc 

building a glaze using the surface tension

updated sat 7 jun 03

 

Ababi on fri 6 jun 03


>Matrix calculates surface tension using Deitzel coefficients in dynes/cm -
>can't remember where I got these.

>Cheers,

>Lawrence Ewing
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

=========================Ababi======================

The well known waxy glazes are made with a lot of MgO. The problem with the MgO
appears when you want to use different colorants. Actually it was a combination of
using the ST (surface Tension) and calculating the flux oxides as pa part of the glaze..
Complicated ? Yes! Was very hard and took much longer than "playing" with a regular
recipe.

It is a bit hard to go back to history because I am not keeping too many old files.
You can see it in Carleton's waxy wares in his books or if you are lucky - the real
thing!
The result of one of my comprehensive test for crawling glaze was:

ABABISCRAWL__#3 (Decorative glaze)
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

SPODUMENE 21.75
RED CLAY (GRT) 21.75
FRIT A 2120 p 30.25
Magnesium Carb Light 16.75
ULTROX 9.50
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Seger Weight%
KNO 0.333 10.84%
CaO 0.077 2.19%
MgO 0.462 9.40%
Li2O 0.127 1.92%
Al2O3 0.237 12.18%
SiO2 1.854 56.20%
ZrO2 0.117 7.28%
K2O 0.025 1.20%
Na2O 0.308 9.64%
Al:Si 7.82
Expan. 8.11
ST 365.40
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Pretty ugly glaze with big potential.

Please note the Surface tension: To duplicate the effect I looked only at the surface
tension, neither ingredient nor the expansion!

The next movement was to remove the red clay to make it whiter
ABABI WAXY 2 (Decorative glaze)
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

SPODUMENE 29.00
BALL CLAY AK 12.00
FRIT A 2120 p 22.00
Dolomite 13.50
ULTROX 10.50
SILICA 15.00
Tin Oxide 10.00
Copper carbonate 5.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Seger Weight%
KNO 0.333 10.84%
CaO 0.077 2.19%
MgO 0.462 9.40%
Li2O 0.127 1.92%
Al2O3 0.237 12.18%
SiO2 1.854 56.20%
ZrO2 0.117 7.28%
K2O 0.025 1.20%
Na2O 0.308 9.64%
Al:Si 7.82
Expan. 8.11
ST 365.40
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
All the tests are here

http://members4.clubphoto.com/ababi306910/981929/

From now on I shall write only the recipe and the Al:Si Expansion and the ST.

Each colorant oxide effects the flowing of the glaze!
Each claybody effect the flowing of the glaze!

Waxy red:

ABABI WAXY RED NO 5 (Decorative glaze)
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

spodumen 10.50
kaolin CC31 26.50
frit A 2120 23.00
Wollastonite 27.80
Quartz 12.20
Tin Oxide 6.20
Chrome Oxide 0.35
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Al:Si 7.72
Expan. 8.33
ST 362.64
Increasing spodumen allows me to decrease the MgO.
I looked around for others materials to in order to have around the <364 > number of
the ST.
The picture is not the best it is mauve.

ABABI WAXY BROWN RED NO 4 (Decorative glaze)
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

SPODUMENE 31.30
BALL CLAY AK 11.10
FRIT A 2120 p 22.20
Dolomite 11.10
ULTROX 9.10
SILICA 15.20
Tin Oxide 5.05
Red Iron Oxide 5.05
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Al:Si 7.91
Expan. 7.07
ST 364.46


http://members4.clubphoto.com/ababi306910/894659/
down one before the end On English Porcelain of Laguna.
on Limoges was ugly- you will see it in the crystal tests.
You can see each recipe is different yet the result is similar:

Apply very thick!

To make it clearer I add the surface tension of my slightly conversion of J&R Gloss
liner:

ST 357.26

This is my regular Gloss liner glaze.


and Helen Crystal Bill Schran's version
HELEN'S CRYSTAL
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

frit 3110 49.80
zinc oxide calcined 25.00
Calcined Kaolin 1.60
silica 18.50
Lithium Carbonate 5.10
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Al:Si 35.73
Expan. 8.98
ST 341.82
This is a crystal glaze the kind you must put above a plat on small bricks to avoid
ruining your ware and having you shelf looked like after war!

I will add another one:
RAKU 80 320

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Gerstley Borate 80.00
Nepheline Syenite 20.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,


Al:Si 6.32
Expan. 9.42
ST 305.07

I don't think it matter the ST in raku just to show how it works
Did you understand it?
Does not matter: It is working!

Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.israel-ceramics.org/membersGallery/personalpage.asp?MID=507