will edwards on tue 20 feb 01
Hello,
While this doesn't follow traditionals Shino styles and glaze, I have fou=
nd
one that simulates a nice shino effect in electric on various clay bodies=
=2E I
have tested it on #205 and B-mix as well as several other clays.
The tests ran in digital Skutt kilns on a medium cycle with envirovents
running. When writing my easy bases such as 1234 base I wanted a glossy a=
nd a
nice matte from those numbers. Here is the matte version and I believe Al=
isa
is testing it if I can remember correctly?
A good many of my posts aren't getting through so maybe this recipe will?=
Maybe my contributions are winding up in Egypt or in limbo in Bombay?? Th=
is
will conclude any more for a while anyways. Its time to let you get on wi=
th
your work. (Break-Time) Please know I will lurk or answer private replies=
as I
get the chance.
Glaze Name:Edwards 1234 Matte Base #3 =A9 2001
Cone: 6 Ox. (Shocking Shino)
Recipe:
Ferro Frit 3124 40.00
Epk Kaolin 30.00
Wollastonite 20.00
Ball Clay 10.00
0.016 K2O 0.584 Al2O3 2.707 SiO2
0.133 Na2O 0.249 B2O3 0.009 TiO2
0.822 CaO 0.006 Fe2O3
0.029 MgO
0.000 MnO
Add 4% Spanish Red Iron Oxide + 4% Light Rutile to above for (Shocking Sh=
ino)
The glaze breaks to a nice rust on high edges and has a very unique
off-white/greyish white background color. This is on B-mix which is witho=
ut
iron in the claybody and it deepens where iron is present in the clay bod=
y.
Fired to ^6 in oxidation.
Glaze Name: Edward's 1234 Matte with Dolomite =A9 2001
Cone: 6 ox (Dolomite Version)
Recipe:
Ferro Frit 3124 40.00
Epk Kaolin 30.00
Dolomite 20.00
Flint ( Quartz Silica ) 10.00
0.012 K2O 0.411 Al2O3 2.109 SiO2
0.111 Na2O 0.216 B2O3 0.003 TiO2
0.590 CaO 0.003 Fe2O3
0.287 MgO
As with any matte glaze these should be considered for exterior applicati=
on or
as a decorative glaze. Iron and Rutile when added have been included with=
figures for that below. Should you experiment with additional coloring ox=
ides
please advise me. I have many other examples of this glaze already with m=
any
coloring oxides used. I always like to add discoveries to them. "I" would=
consider this a low order for toxic release. Dust is always a hazard so w=
ear a
mask (NIOSH AP)! =
For those who wondered about Rutile pinks in the past. I would look at th=
e
trace amount of Chromium in the rutile and consider it as the culprit for=
Rutile Pinks. However that is highly debateable in some circles.
(Reduction/oxidation)? Try upping the chromium level (O.10%) a little and=
add
rutile in @ 5% and Tin ox @ 5%. The last time I did this I got a very pre=
tty
Matte Pink with variegations.
Rutile - 0.81 % SiO2
96.76 % TiO2
0.20 % Cr2O3
0.62 % Fe2O3
0.70 % V2O5
0.91 % ZrO
William Edwards
Alchemy 101 - Many thanks to those who have allowed me to swap with them =
back
and forth. I will see ya in a month or so. I got to get some time for oth=
er
things. (Gone Lurking) P.S. Artimator - Hang tight till I get back or get=
out
the big snakes.
____________________________________________________________________
Get free email and a permanent address at http://www.netaddress.com/?N=3D=
1
Mo Cain on wed 21 feb 01
Will Edwards. Not having your email address to ask my questions directly I
replied to the list.I trust that this is Ok
The following molecular formula has me baffled. It is the formula for
shocking Shino.
0.016 K2O 0.584 Al2O3 2.707 SiO2
0.133 Na2O 0.249 B2O3 0.009 TiO2
0.822 CaO 0.006 Fe2O3
0.029 MgO
0.000 MnO
The recipe is Frit3124 40% EPK 30% Wollast 20% Ball clay 10% and is a cone
6 glaze.
After much testing and falsestarting I have arrived at a firing schedule
that suits my definition of a cone 6 firing
That is to say the tips of the witness cones in the kiln just touch the
shelf. I have several cone 6 glazes some
of which run like heck with this firing schedule. Generally the amount of
alumina in the unity formula fall somewhere
between 0.35 and 0.45. The AL2O3:SiO2 ratio is generally in the order of 8
( not too shiney).
This formula has alumina at 0.584 which I have always equated to very high
cone glazes. Yet the alumina
to silica ratio is in the order of 4.8 which would tell me that the
finished glaze surface is as dry as old boots.
UNLESS that boron from the 3124 has thrown all my assumptions out of the
window.
Here's my real question that hopefully will get my glazes back to
consistency.
I assume that witness cones are formulated from materials that resemble
glazes. That is to say that they have
consistent specific unity formulae for each cone. 1 mole of flux for 0.X
moles of alumina and 0.Y moles
of silica. Can anyone point me to the literature where I can find X
particularly for cone 6 ? Also, where in
the literature can I get specific details about the effect of boron on this
whole subject.
kindest regards mo cain ExPat Brit now firmly rooted in Ga
John Hesselberth on wed 21 feb 01
Mo Cain wrote:
>Here's my real question that hopefully will get my glazes back to
>consistency.
>I assume that witness cones are formulated from materials that resemble
>glazes. That is to say that they have
>consistent specific unity formulae for each cone. 1 mole of flux for 0.X
>moles of alumina and 0.Y moles
>of silica. Can anyone point me to the literature where I can find X
>particularly for cone 6 ? Also, where in
>the literature can I get specific details about the effect of boron on this
>whole subject.
Hi Mo,
The original Seger Cone 6 was 0.3 K2O, 0.7 CaO, 0.6 Al2O3 and 6 SiO2 (The
Collected Writings of Hermann A. Seger, Vol. 1, p. 224). Don't forget,
though, that cones are just deforming. You really need for a glaze to be
thoroughly melted but still viscous enough to stay on the pot. So, if
there were such a thing, a "standard" cone 6 well-melted glaze would be
very different from the cone recipe.
I think you are also hoping for a simple answer to a complex system.
There are lots of ways to get glazes to melt. You can go to somewhat
higher levels of alumina and/or silica than "normal" if you use more
boron and/or use more powerful fluxes. Will used more boron in his
shocking shino glaze (I'm assuming it is well melted--I haven't tried it
myself). Another example, though, would be Pete Pinnell's strontium matte
glaze. It has 0.575 Al2O3, 2.98 SiO2 and NO boron. It still melts very
well (and is very stable) because he uses 0.44 K/Na plus a tiny bit of
lithium in the fluxing system. Also strontia is a pretty good flux in its
own right above 2000 deg F and it makes up most of the rest of the flux
system in Pete's glaze. That glaze is a true matte that is well melted at
cone 6 and partially crystallizes on cooling vs. lots of the mattes
floating around potter-land that just aren't very well melted.
Unfortunatey, you won't find much on fluxing power that is of a
quantitative nature in the literature--or if it is there is deeply buried
in research that was mostly aimed at lead-based glazes and was done
50-100 years ago. Lots of books talk about fluxes in a general,
qualitative or semi-quantitative way. I think Hamer and Hamer's
discussion of the various fluxes is one of the best.
Regards, John
"The life so short, the craft so long to learn." Hippocrates, 5th cent.
B.C.
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