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refiring cone 6 iron glaze

updated tue 31 dec 96

 

Fhelme@aol.com on sun 24 nov 96

There has been some previous discussion about refiring a cone 6 oxidation
glaze sometimes called "ketchup" in order to produce a better red. I did so
and did not get the results I had hoped for. As previoulsy posted, this
glaze is approximately: EPK 5, flint 30, Custer feldspar 20, Talc 14,
Gerstely borate 32, RIO 15. At cone 6, and with my red clay, Miller #75,
this glaze produces an interesting mixture of sort of brown, sometimes with
green spots, breaking to black as has been previously discussed. It is also
a hard glaze.

Postings had indicated that if this glaze were refired to cone 06 to 04 range
a redder color would develop. Well, that's not exactly what I got. I did
not get a redder color; what I did get was that the brown/red color on the
original piece became uniform and I lost the interesting brown breaking to
black. It did make sort of a slightly interesting uniform brown.

In an experiment, I arbitrarily modified the glaze to the following: EPK
10.2, flint 37.8, Custer 16.2, Magnesium Carb 9.2, Gerstley 12.3, RIO
15, bone ash 6.1, tin oxide 2.5, lithium carb 4.1, and wollastonite 4.1.
At cone 6 this glaze did give a redder brown, not quite as hard, and a more
uniform color without the green spots and the breaking to black. When
refired to the same temperature as the ketchup, the redder brown became the
same generally uniform brownish color as the ketchup.

I want to thank all the previous ClayArt people who have posted and written
to me. I would appreciate any new ideas on getting a redder iron glaze. You
people are great. Thanks.

frank helme in upstate NY

PJLewing@aol.com on thu 28 nov 96

Frank,
I've heard, too, that refiring an iron red^6 glaze to ^04 will make it
redder. Of course, I, too tried it, and it didn't work for me either. But
you gotta try it, right?
Good luck,
Paul Lewing, Seattle

Michelle H. Lowe on fri 29 nov 96

At 11:08 AM 11/28/96 -0500, PJLewing@aol.com wrote:
>----------------------------Original message----------------------------
>Frank,
>I've heard, too, that refiring an iron red^6 glaze to ^04 will make it
>redder. Of course, I, too tried it, and it didn't work for me either. But
>you gotta try it, right?
>Good luck,
>Paul Lewing, Seattle

It worked for me with three different glazes (maybe four) but I kind of
like the cone 6 version (before low-fire) better...go figure :-)

Mishy (who has recipes if anyone wants them-email me privately)




Michelle Lowe, potter in the Phoenix desert \|/ |
mishlowe@indirect.com -O- | |
mishlowe@aztec.asu.edu /|\ | | |
|_|_|
http://www.amug.org/~mishlowe ____ |
-\ /-----|-----
( )
<__>

"Rafael Molina-Rodriguez (Rafael Molina-Rodriguez)" on sat 30 nov 96

Paul :

On the subject of refiring, there is an interesting article by Lili Krakowski
in CM called "Hobart Cowles Albany Glazes". The article states "...a
range of rich tones for the Cone 4-6 repertory, what makes them
exceptional is their refiring capability. First fired to maturity at Cone 5,
they can be refired to Cone 04 for distinct color changes".

Supposedly the Albany browns turn to shades of yellow and gold. I
haven't tried them yet, but I hope to in the near future. I'll keep the list
posted.

Rafael
rmr3431@dcccd.edu

>>> 11/28/96 10:08am >>>
----------------------------Original message----------------------------
Frank,
I've heard, too, that refiring an iron red^6 glaze to ^04 will make it
redder. Of course, I, too tried it, and it didn't work for me either. But
you gotta try it, right?
Good luck,
Paul Lewing, Seattle

Lili Krakowski on mon 2 dec 96

Some years ago--I think 1985- I published a number of Albany Slip glazes
of Hobart Cowles's in Ceramics Monthly. All were to be fired at c. 5-6
and refired at c.04 to achieve a different--not necessarily
redder--look. I think--that is the operative word--think--that the
secret is a fairly runny glaze that really softens again at c.o4. Do
look up those glazes and checkem out. I know they work/ed. Also they
were quite high in iron--as I recall, there was extra iron along with
the Albany Slip. Furthermore: these were fired at true (senior cone)
c.6 and c.04. If you are relying on a kiln sitter junior cone reading
maybe maybe....

Lili Krakowski lkkrakow@edisto.cofc.edu

Iain Begg on mon 2 dec 96

Paul and Rafael:

I tried these glazes some time back. They indeed do change colour as you
refire at cone 06 (in my case) - some more than others. There are two
glazes
on the glazebase which develop dramatic changes to iron reds:
Super Fox Red and Persimmon. For the Hobart Cowles glazes
I used Alberta slip rather than Albany which resulted in some of the
glazes not being as well differentiated as the article suggested.
Definitely try them on different clay bodies as the results were quite
dramatic in some cases. An interesting range of galzes to be sure.

Iain
Iain Begg begg@mpr.ca
Bearsden Studio, Vancouver, BC

----------
> From: Ceramic Arts Discussion List
> To: Multiple recipients of list CLAYART
> Subject: Re: Refiring Cone 6 Iron Glaze -Reply
> Date: Saturday, November 30, 1996 9:51AM
>
> Subject: Re: Refiring Cone 6 Iron Glaze -Reply
> To: Multiple recipients of list CLAYART
>
>
> ----------------------------Original message----------------------------
> Paul :
>
> On the subject of refiring, there is an interesting article by Lili
Krakowski
> in CM called "Hobart Cowles Albany Glazes". The article states "...a
> range of rich tones for the Cone 4-6 repertory, what makes them
> exceptional is their refiring capability. First fired to maturity at
Cone 5,
> they can be refired to Cone 04 for distinct color changes".
>
> Supposedly the Albany browns turn to shades of yellow and gold. I
> haven't tried them yet, but I hope to in the near future. I'll keep the
list
> posted.
>
> Rafael
> rmr3431@dcccd.edu
>
> >>> 11/28/96 10:08am >>>
> ----------------------------Original message----------------------------
> Frank,
> I've heard, too, that refiring an iron red^6 glaze to ^04 will make it
> redder. Of course, I, too tried it, and it didn't work for me either.
But
> you gotta try it, right?
> Good luck,
> Paul Lewing, Seattle
>