Michelle H. Lowe on mon 4 nov 96
I saw a woman firing raku, five years ago or so, using this glaze and it
came out a lovely burgundy matt. I just recently got my raku kiln up and
running and my first try with this recipe yielded a glossy green :-? It
was suggested to me to fire it to a lower temp and to reduce it in a
smaller chamber. At any rate, this is the recipe and any other suggestions
to make it "work" would be welcome.
Very dry matt burgundy red
Gerstley borate 50
Neph Sy 20
Talc 30
Copper carb 3
Michelle Lowe, potter in the Phoenix desert \|/ |
mishlowe@indirect.com -O- | |
mishlowe@aztec.asu.edu /|\ | | |
|_|_|
http://www.amug.org/~mishlowe ____ |
-\ /-----|-----
( )
<__>
Craig Martell on wed 6 nov 96
I have to start by saying that I don't do Raku and haven't fired any Raku
pots for about 8yrs. I used to use a Raku red glaze very similar to yours,
that was very reliable when it came to burgundy colors. The one difference I
see in your glaze that could be a problem is that it does not contain any tin
oxide. Most copper reds will have small amounts of tin to aid in the
formation of reds. Try 1 to 2% tin oxide, it should help. Anyway, I HOPE
that it does!
Kind Regards,
Craig Martell-Oregon
Harvey Sadow on fri 15 nov 96
Michelle H. Lowe wrote:
>
> ----------------------------Original message----------------------------
> I saw a woman firing raku, five years ago or so, using this glaze and it
> came out a lovely burgundy matt. I just recently got my raku kiln up and
> running and my first try with this recipe yielded a glossy green :-? It
> was suggested to me to fire it to a lower temp and to reduce it in a
> smaller chamber. At any rate, this is the recipe and any other suggestions
> to make it "work" would be welcome.
>
> Very dry matt burgundy red
>
> Gerstley borate 50
> Neph Sy 20
> Talc 30
> Copper carb 3
>
> Michelle Lowe, potter in the Phoenix desert \|/ |
> mishlowe@indirect.com -O- | |
> mishlowe@aztec.asu.edu /|\ | | |
> |_|_|
> http://www.amug.org/~mishlowe ____ |
> -\ /-----|-----
> ( )
> <__>
Hi,
I am intimately familiar with this glaze, having used it extensively in
the early 1970's, though I haven't thought about it in almost 20 years.
You really have to fire it cool to keep it from glossing up. It was
formulated as a gloss glaze. It will matt out, however. For
consistency, you will need to fire with a pyrometer, and fire the first
piece till it begins to show gloss in the kiln. Check the pyrometer.
Fire the next piece down about 10 degrees, assuming you go at more or
less the same speed. Keep dropping the temperature down till you get
the desired matt effect, or start adding clay to the stew, till you get
where you want to be.
As far as the color goes, you are getting the oxidation effect
of the copper (green). For the reduction effect, get the pot out of the
open air and into the reduction chamber or barrel as quickly as possible
and let it cool completely before you peek. Next time, try to give
yourself a minute to breathe, think a nice thought, then get the piece
into the reduction chamber and leave it there until it's cool. Don't
peek. Next time, take a deep breath, click your heels together three
times, think a nice thought....etc. Keep adding a piece to the dance
till you get the color that you want. Relative to each glaze, each
colorant, each type of combustible, each atmospheric condition, there is
a perfect moment of action for each potential effect. This is the
beauty of flash firing.
| |
|
