tomsawyer on sun 12 aug 01
Some months ago there was mention of a power plant that was looking for =
a market for there ash. It was stated that this ash was very fine =
because of their method and temperature of firing. Axner's has started =
to sell this ash and I have been fooling around with it at Cone 6 =
oxidation. I've gotten three fairly nice ash glazes using this material =
as a 50/50 mix with alberta, redart and barnards clays. I used the ash =
directly as it is sold. I really like the barnard mix; it is nice dark =
brown on 2 separate test firings with lots of good runs. It did, =
however, show evidence of some clumping which may be because I didn't =
sieve it before use. As we speak, new tests are being fired - all =
sieved. The redart and alberta produce a nice golden brown ash.
I'm wanting to use some other additions such as oxides and stains. =
Another addition that I wanted to use - well just for the hell of it is =
cryolite; my question is what starting percentage should I use?
I'll report back as I do some additional testing.
Tom Sawyer
tsawyer@cfl.rr.com
Ababi on sun 12 aug 01
Hello Tom. I use cryolite like any other material for it's oxides.
From Hansen's Magic of Fire:
CRYOLITE
Description: FLUORIDE OF ALUMINUM AND SODIUM
A fluoride of aluminum and sodium associated with granite.
It is a valuable source of insoluble sodium used in
enameling and sometimes in frits and glazes.
Because cryolite lacks oxygen it is useful in creating
artificial reduction glazes for electric firing.
One source quotes melting temperature at 1020°C.
ANALYSIS & UNITY FORMULA
Na2O...... 29.45% [ 1.00]
Al2O3..... 16.13% 0.33
LOI....... 54.42%
In Behernse's book glaze Projects, there are some glazes with cryoilte.
As I wrote, I use it for what it has. Lana Wilson warns from damage to the
kiln it might make, I know we should not be around in firing time because of
it's LOI .
Ababi
----- Original Message -----
From: "tomsawyer"
To:
Sent: Sunday, August 12, 2001 10:50
Subject: Use of cryolite & ash glazes
Some months ago there was mention of a power plant that was looking for a
market for there ash. It was stated that this ash was very fine because of
their method and temperature of firing. Axner's has started to sell this ash
and I have been fooling around with it at Cone 6 oxidation. I've gotten
three fairly nice ash glazes using this material as a 50/50 mix with
alberta, redart and barnards clays. I used the ash directly as it is sold I
really like the barnard mix; it is nice dark brown on 2 separate test
firings with lots of good runs. It did, however, show evidence of some
clumping which may be because I didn't sieve it before use. As we speak, new
tests are being fired - all sieved. The redart and alberta produce a nice
golden brown ash.
I'm wanting to use some other additions such as oxides and stains. Another
addition that I wanted to use - well just for the hell of it is cryolite; my
question is what starting percentage should I use?
I'll report back as I do some additional testing.
Tom Sawyer
tsawyer@cfl.rr.com
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Hank Murrow on sun 12 aug 01
>Tom Sawyer wrote:
>Some months ago there was mention of a power plant that was looking for a
>market for there ash. It was stated that this ash was very fine because of
>their method and temperature of firing. Axner's has started to sell this
>ash and I have been fooling around with it at Cone 6 oxidation. I've
>gotten three fairly nice ash glazes using this material as a 50/50 mix
>with alberta, redart and barnards clays. I used the ash directly as it is
>sold. I really like the barnard mix; it is nice dark brown on 2 separate
>test firings with lots of good runs. It did, however, show evidence of
>some clumping which may be because I didn't sieve it before use. As we
>speak, new tests are being fired - all sieved. The redart and alberta
>produce a nice golden brown ash.
>I'm wanting to use some other additions such as oxides and stains. Another
>addition that I wanted to use - well just for the hell of it is cryolite;
>my question is what starting percentage should I use?
>I'll report back as I do some additional testing.
Gee, I love it when folks on this list report back;
And regards the Cryolite, start out about 1% and up it from there,
easy to do with successive additions of 1%. The main thing that you'll see
is the influence of Fluorine, which outgasses vigorously. You may need to
do a soak in Ox during the cooling, or soak after the cone goes down to
settle the bubbles. May be mor3e effective in glazes with less iron in them.
I ordered 50# of this superb unwashed ash from the powerplant
folks. That will get us through the testing and initial use phase. I expect
potters could get some nice carbon trapping because the solubl;e are left
in this ash.
Big thanks to Craig Martell and Jim Robinson for getting onto this
stuff right away and doing the intitial testing!
Cheers, Hank in Eugene
Ron Roy on mon 13 aug 01
Hi Tom,
Just a reminder - Barnard has a fair amount of Manganese - vent well,
breath as little as possible and understand what it is capable of doing to
your nervous system.
RR
>Some months ago there was mention of a power plant that was looking for a
>market for there ash. It was stated that this ash was very fine because of
>their method and temperature of firing. Axner's has started to sell this
>ash and I have been fooling around with it at Cone 6 oxidation. I've
>gotten three fairly nice ash glazes using this material as a 50/50 mix
>with alberta, redart and barnards clays. I used the ash directly as it is
>sold. I really like the barnard mix; it is nice dark brown on 2 separate
>test firings with lots of good runs. It did, however, show evidence of
>some clumping which may be because I didn't sieve it before use. As we
>speak, new tests are being fired - all sieved. The redart and alberta
>produce a nice golden brown ash.
>I'm wanting to use some other additions such as oxides and stains. Another
>addition that I wanted to use - well just for the hell of it is cryolite;
>my question is what starting percentage should I use?
>I'll report back as I do some additional testing.
>Tom Sawyer
>tsawyer@cfl.rr.com
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
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