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crystal glaze

updated fri 11 aug 00


Cobus Potgieter on tue 8 aug 00

Dear List,
Can anyone help me with recipes for crystal glazes for Orton Cone 2 as =
well as Cone 5?
Cobus Potgieter.

NAMIBIA CERAMICS Tel: +264-61-264526
PO Box 6742 Fax: +264-61-261590

Sharon31 on wed 9 aug 00

Hello Cobus!
I do not know what you know about crystal glazing so, I will tell you as
much as I can.First go to
Than buy the book Crystalline Glazes by Diane Creber. We are talking about
"low fire" crystalline, not the real thing, but it is very good to know, The
why before you do any instructions.Actually, I repeat a earlier letter of
mine, but I will add Some details. From Lana Wilson's book:Ceramics:

Jeany Richter 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%

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%

Si:Al 38.02
SiB:Al 38.83
Expan 9.10

>From Lana Wilson's book page 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!

There were some offers, I succeeded with two:
(A) add 5%black copper oxide

And, use a version with 7 titanium, (B) 4% manganese dioxide.

You might succeed with the other offers, so order the book!

About (A)5%black copper oxide:In my "photo album"
I have left 3 pictures:glaze (a) on brown mottled body Amaco 140, above
white engob.
On Dutch , Vingeling K-110,
almost white mottled body.
And on ^6 porcelain.
> If that doesn't work, go to, and log in to my albums
with the following information:
> Log-in ID:
> Guest Password: local potter

I also added to dry Limouze plastic porcelain 10% nephline seynite to make
lower maturing.
the results, besides very weak body before firing was, with the same
glaze,VERY VERY special! "use a version with 7 titanium, (B) 4% manganese
dioxide". beautifull too.
If T will repeat the "Limouze business" I will add 8% nephaline and CMC.
Good luck
four years old(in ceramics)

----- Original Message -----

From: Cobus Potgieter
Sent: Tuesday, August 08, 2000 06:17
Subject: Crystal glaze

Dear List,
Can anyone help me with recipes for crystal glazes for Orton Cone 2 as well
as Cone 5?
Cobus Potgieter.

NAMIBIA CERAMICS Tel: +264-61-264526
PO Box 6742 Fax: +264-61-261590

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Janet Kaiser on thu 10 aug 00

Hi Cobus

See Ceramic Review Number 174, November/December
Article by Annet Hamster a potter in the

I cannot type out the whole article for you, but
here are the salient points:

Glazes for Special Effects, Herbert H. Saunders
Keramische Glasuren, Wolff E. Matthes
Draai en Glazuurtechniken K. Kurstjens
Ceramic Review Nos. 126, 128, 137, 164

Robbelien, Reubenweg 12, 6071 Swalmen, NL
Ve-Ka, POBox 23, 6620 Dreumel, NL
Potterycrafts, Campbell Road, Stoke-on-Trent ST4
TOMA, Heuvelstraat 10, 5408 Volkel, NL


Crystal Glaze
Ferro frit 3110 25.55g (Potterycraft and
Potash feldspar 15.75 g
Barium carbonate 3.0 g
Whiting 4.0 g
Colemanite 1.5 g
Ball clay 0.2 g
Quartz 25.8 g
Zinc oxide 20.9 g
Aluminium oxide 0.15 g
Titanium oxide 1.8 g

A. Soft blue
Cobalt carbonate 0.7 g
Copper carbonate 0.5 g

B. Soft green
Copper carbonate 1.0 g

This is a simple crystal glaze recipe which forms
large crystals and usually requires only one layer
of glazing and firing.

Frit 15.10 (Ve-Ka) 17.3 g
Titanium oxide 3.0 g
Quartz 4.2 g
Lithium oxide 1.15 g
Zinc oxide 14.9 g
G5794 (Robbelien) 59.5 g

A standard ready to use glaze

The crystal glaze is fired in six hours to 1000
deg. C. The temperature is subsequently changed as
quickly as possible to 1260 deg. C., 1050 deg. C
and finally 1150 deg. C. From 1150 deg. C the
temperature is dropped slowly: in 180 minutes to
1130 deg. C, in 120 minutes to 1100 deg C, in 120
minutes to 1070 deg. C, in 120 minutes to 1040
deg. C. and finally in 60 minutes to 1010 deg. C.

Hope this helps!

Janet Kaiser
The Chapel of Art . Capel Celfyddyd
Criccieth LL52 0EA, GB-Wales Tel: (01766) 523570