Sharon Miranda on wed 12 may 99
Clayarters: Here is a recipe for floating red that is really beautiful. Or
at least I THINK it could be beautiful. I used it over Miller 610 white
clay.
Ger. Borate: 54.88
Talc 14.63
flint 30.49
RIO 21.95
It is a dark chocolate brown with streaks of red, floating red pools.
It is definitely overfired at cone 6, probably more of a cone 4 glaze.
At cone 6 it runs off the pot and bubbles.
Can anyone suggest how to reformulate this for cone 6?
Any help greatly appreciated.
Thanks
Sharon Miranda
Fabienne Cassman on thu 13 may 99
------------------
Hi Sharon,
I was wondering if you had any ingredients missing here. I entered this
formula in Insight to give it a shot and found out that there isn't a shred
of alumina. Also there is not enough silica to fire it beyond c05 without
a catastrophy.
Can anyone confirm or explain why it is? Thank you,
Faye
=3EGer. Borate: 54.88
=3ETalc 14.63
=3Eflint 30.49
=3ERIO 21.95
=A4=BA=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=
=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=B0=60
Faye http://clay.justnet.com
Yes, I have learned from my mistakes...
I can reproduce them exactly.
Ian Macmillan on thu 13 may 99
Your glaze seems to contain far too much boron for cone 6.. Remember also
that in higher amounts, iron is flux at cone6. You are over-fluxed.(do not
try to say this fast!) Just as first guess without doing the calcs yet -
try substituting about half of the gb with feldspar.
Ian
>----------------------------Original message----------------------------
>Clayarters: Here is a recipe for floating red that is really beautiful. Or
>at least I THINK it could be beautiful. I used it over Miller 610 white
>clay.
>
>Ger. Borate: 54.88
>Talc 14.63
>flint 30.49
>RIO 21.95
>
>It is a dark chocolate brown with streaks of red, floating red pools.
>It is definitely overfired at cone 6, probably more of a cone 4 glaze.
>At cone 6 it runs off the pot and bubbles.
>
>
>Can anyone suggest how to reformulate this for cone 6?
>
>Any help greatly appreciated.
>Thanks
>Sharon Miranda
Marty Anderson on fri 14 may 99
One of our students uses this as an accent glaze over other glazes. Never
on the outside as it runssssssssssssssssss.
The RIO glaze I use does not run and is red if used thickly. It is the Jo's
Red I have previously posted. It has these ingredients in different amounts
and EPK added. the RIO is 22%
marty
-----Original Message-----
From: Fabienne Cassman
To: CLAYART@LSV.UKY.EDU
Date: Thursday, May 13, 1999 9:28 AM
Subject: Re: cone 6 floating red
----------------------------Original message----------------------------
------------------
Hi Sharon,
I was wondering if you had any ingredients missing here. I entered this
formula in Insight to give it a shot and found out that there isn't a shred
of alumina. Also there is not enough silica to fire it beyond c05 without
a catastrophy.
Can anyone confirm or explain why it is? Thank you,
Faye
>Ger. Borate: 54.88
>Talc 14.63
>flint 30.49
>RIO 21.95
$:0`0:$x,88,x$:0`0:$x,88,x$:0`0:$x,88,x$:0`0:$x,88,x$:0`
Faye http://clay.justnet.com
Yes, I have learned from my mistakes...
I can reproduce them exactly.
Paul Lewing on fri 14 may 99
Fabienne Cassman wrote:
>
> ----------------------------Original message----------------------------
> ------------------
> Hi Sharon,
>
> I was wondering if you had any ingredients missing here. I entered this
> formula in Insight to give it a shot and found out that there isn't a shred
> of alumina. Also there is not enough silica to fire it beyond c05 without
> a catastrophy.
>
> Can anyone confirm or explain why it is? Thank you,
>
> Faye
>
> >Ger. Borate: 54.88
> >Talc 14.63
> >flint 30.49
> >RIO 21.95
Hi, Fabienne,
I also ran this glaze through my version of Insight (an older Mac
version 4). Whether there is zero alumina in there or not depends on
what analysis you have for the Gerstley Borate. The one I'm using has a
little, but not much. You evidently have an analysis for GB that is
jsut calcium and boron, which I think is a little too simple.
But the fact remains that whether the SiO2/Al2O3 ratio is infinite (as
in your case) or 107 (as in mine) there is incredibly little alumina and
not much silica in there. There is, however, a lot of boron, which may
be acting as a glass-former in this case.
I've tested and used dozens of versions of this iron red glaze, and
they're all pretty similar. They have a lot of calcium, almost as much
(but not more) magnesium, lots of boron, not much silica and almost no
alumina. They are all runny and matte, very sensitive to temperature
and even more to rate of cooling, and are very affected by the brand of
iron you use. And they won't be red if the Si/Al ratio is under about
18:1, or if there's more MG than Ca. Food-safe? Maybe. Durable? No
way.
As I said in my slide show at NCECA, I've given up on them in favor of a
lead glaze I call Drop Dead Red, which has all the same post-firing
problems but does at least come out consistently iron red and glossy.
Paul Lewing, Seattle, where the April showers have brought the May
rains.
>
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