Wayne & Camille Culp on sun 30 nov 97
------------------
Here are some glazes I got from Minnesota. The Metallic Glossy Black is =
very
black alone. It's a beautiful midnight blue with lighter blue breaks over =
other
glazes. It's one of the most interesting at this cone that I've used. The
ball's turquoise is matte and old looking, but not as nice as the one I used
when I could do cone 10. If someone thinks any of these recipes are not =
safe
for food, please tell me. It's not as much fun with these cone glazes in an
electric kiln, but better than nothing. I rent space from a nun whose very
generous with her studio.
Metallic Glossy Black
Oxidation Cone 6 - 8
(I use 7)
Feldspar 71.5
Whiting 4.9
Gerst B. 9.2
Kaolin 4.4
Copper C. 3.0
Mang D. 3.0
Cobalt C. 1.5
Ball's Turquoise
cone 6 - 8
Neph. Sy. 56.4
Barium 25.4
Ball Clay 5.8
Flint 6.6
Lithium 2.5
Copper C. 2.5
-----
Doesn't add 99.2
Camille
In Omaha where it's rained all day, sometimes really hard (when I was =
running to
the car)
Craig Martell on mon 1 dec 97
At 05:21 PM 11/30/97 EST, Camille wrote:
>----------------------------Original message----------------------------
>------------------
>Here are some glazes I got from Minnesota. If someone thinks any of these
>recipes are not safe for food, please tell me.
Hi Camille:
The metallic black is within limits for a durable glaze. I used custer spar
in the calculation which is the more silica rich of available potash spars.
Given the amounts of metal oxides used to color the glaze, I would test it
for leaching if it were used with food.
Ball's turquoise is not a food safe glaze. The silica is at the lower level
of the acceptable limit, but it is matt with an oversupply of Barium and
Alumina which would definitely call for more silica than is presently used.
I would wager heavily on this one leaching Barium. It also has copper as a
colorant which may increase the solubility of the glaze. I'd bag this one if
I were you, or use it on surfaces that don't contact food.
regards, Craig Martell-Oregon
Cindy Strnad on sat 6 oct 01
Dear Maggie,
This glaze works great for me. It's mirror shiny
with a quick (normal) cool, or satin matte with a
slow cool.
Ron Roy's Black #3
Cone 6, Oxidation
=====================================
CUSTER FELDSPAR..... 22.00 19.47%
WHITING............. 4.00 3.54%
TALC................ 5.00 4.42%
FRIT 3134........... 26.00 23.01%
EPK KAOLIN.......... 17.00 15.04%
FLINT............... 26.00 23.01%
BENTOLITE L......... 2.00 1.77%
IRON OXIDE RED...... 9.00 7.96%
*Cobalt Carbonate.... 2.00 1.77%
========
113.00
CaO 0.55* 8.05%
MgO 0.16* 1.67%
K2O 0.09* 2.20%
Na2O 0.20* 3.15%
TiO2 0.00 0.07%
Al2O3 0.38 9.99%
B2O3 0.32 5.68%
P2O5 0.00 0.04%
SiO2 3.89 60.65%
Fe2O3 0.21 8.51%
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
Cindy Strnad on sat 6 oct 01
Oops! I had Bentolite L in my last post--not sure
where that came from. I don't use the bentonite
anyway, because the glaze applies nicely for me
without it.
Ron Roy's Black #3
Cone 6, Oxidation
=====================================
CUSTER FELDSPAR..... 22.00 19.47%
WHITING............. 4.00 3.54%
TALC................ 5.00 4.42%
FRIT 3134........... 26.00 23.01%
EPK KAOLIN.......... 17.00 15.04%
FLINT............... 26.00 23.01%
BENTONITE......... 2.00 1.77%
IRON OXIDE RED...... 9.00 7.96%
*Cobalt Carbonate.... 2.00 1.77%
========
113.00
CaO 0.55* 8.05%
MgO 0.16* 1.67%
K2O 0.09* 2.20%
Na2O 0.20* 3.15%
TiO2 0.00 0.07%
Al2O3 0.38 9.99%
B2O3 0.32 5.68%
P2O5 0.00 0.04%
SiO2 3.89 60.65%
Fe2O3 0.21 8.51%
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
Paul Lewing on sun 7 oct 01
on 10/7/01 1:58 AM, Maggie Woodhead at maggiew@CLEAR.NET.NZ wrote:
> Talking to a friend at the Pottery today he
> commented that all the black glazes he has found in his search for a suitable
> black glaze for the electric kiln appear to have no magnesium in them. I have
> searched my home library and am beginning to think perhaps he is right.
> Is this really true and if so is there a reason?
No, it's not true. Many black glazes have no magnesium. However, many of
them do have manganese, and I'm sure that's what your friend meant to say.
Ron Roy's black is unusual in that it is a food-safe black and in that it
has no manganese. By the way, it also has very little magnesium, mostly
from the small amount of talc.
Here it is:
Ron Roy Black
Custer 22
Whiting 4
talc 5
Frit 3134 26
EPK 17
Silica 26
Bentonite 2
Iron Ox. 9
Cobalt Carb. 2
Paul Lewing, Seattle
Maggie Woodhead on sun 7 oct 01
Hello and Kia Ora Clayarters,
Talking to a friend at the Pottery today he
commented that all the black glazes he has found in his search for a suitable
black glaze for the electric kiln appear to have no magnesium in them. I have
searched my home library and am beginning to think perhaps he is right.
Is this really true and if so is there a reason? I had a copy of Ron Roy's black
glaze but can't find it. When I want a black shiny glaze my self I use my
Tessha 10% Fe in the electric but mostly these days fire reduction, then its
red. Have a nice matte from Tony Hansen's matte with oxides added but Richard
wants shiny.
----Best Wishes Maggie----
maggiew@clear.net.nz
A special hello to Tom Buck.
Ron Roy on mon 8 oct 01
Hi Maggie,
The only counter indication I know of MgO - for black glazes - is for
reduced iron tenmoku type glazes. You get green crystals - and some like em
- call em tea dust.
Must be spring or almost down there?
RR
>Hello and Kia Ora Clayarters,
> Talking to a friend at the Pottery today he
>commented that all the black glazes he has found in his search for a suitable
>black glaze for the electric kiln appear to have no magnesium in them. I have
>searched my home library and am beginning to think perhaps he is right.
>Is this really true and if so is there a reason? I had a copy of Ron Roy's
>black
>glaze but can't find it. When I want a black shiny glaze my self I use my
>Tessha 10% Fe in the electric but mostly these days fire reduction, then its
>red. Have a nice matte from Tony Hansen's matte with oxides added but Richard
>wants shiny.
>----Best Wishes Maggie----
> maggiew@clear.net.nz
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
Snail Scott on mon 8 oct 01
At 10:16 PM 10/7/01 +0000, you wrote:
>on 10/7/01 1:58 AM, Maggie Woodhead at maggiew@CLEAR.NET.NZ wrote:
>> ...all the black glazes he has found in his search for a suitable
>> black glaze for the electric kiln appear to have no magnesium in them...
Paul Lewing said:
>No, it's not true. Many black glazes have no magnesium. However, many of
>them do have manganese, and I'm sure that's what your friend meant to say.
Maybe that wasn't what he meant. Since most black glazes have
cobalt in fair quanities, and magnesium tends to do weird
things to cobalt glaze colors, one does seldom see magnesium
and cobalt together in glazes intended to be black or blue.
Good observation.
-Snail
Maggie Woodhead on mon 8 oct 01
Kia Ora,
I omitted to say the Cone we are working in is cone 9, sorry
about that and thanks Cindy for the recipe it is tucked away in the glaze file
for future reference,----Best Wishes Maggie----
maggiew@clear.net.nz
----- Original Message -----
From: "Cindy Strnad"
To:
Sent: Sunday, 7 October 2001 04:17
Subject: Re: Black Glazes
Oops! I had Bentolite L in my last post--not sure
where that came from. I don't use the bentonite
anyway, because the glaze applies nicely for me
without it.
Ron Roy's Black #3
Cone 6, Oxidation
=====================================
CUSTER FELDSPAR..... 22.00 19.47%
WHITING............. 4.00 3.54%
TALC................ 5.00 4.42%
FRIT 3134........... 26.00 23.01%
EPK KAOLIN.......... 17.00 15.04%
FLINT............... 26.00 23.01%
BENTONITE......... 2.00 1.77%
IRON OXIDE RED...... 9.00 7.96%
*Cobalt Carbonate.... 2.00 1.77%
========
113.00
CaO 0.55* 8.05%
MgO 0.16* 1.67%
K2O 0.09* 2.20%
Na2O 0.20* 3.15%
TiO2 0.00 0.07%
Al2O3 0.38 9.99%
B2O3 0.32 5.68%
P2O5 0.00 0.04%
SiO2 3.89 60.65%
Fe2O3 0.21 8.51%
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
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