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All the glazes listed below are currently in use and, in
the context of the bodies used and the firing cycles, are
stable. They are all fired to Orton Cone 9 well down with
a 20 minute soak over, typically, an 11 hour cycle. The
kiln atmosphere is reducing - reduction from around 950C to
cone 9 down - the soak is oxidising. Cooling is over 48 to
60 hours.
Where limestone appears in the recipe Wollastonite or whiting can be
subsituted in the same quantity; however, in my opinion
limestone dust (which can be sourced for almost nothing
from any limestone quarry) introduces more variegation
into the matrix making for a more lively surface. I also
use ball clay(s) in the recipes partly to introduce silica,
partly to act as a glaze-suspender and partly to increase
the mechanical strength of the glaze prior to firing.
All the glazes are mixed for about 20 minutes in my ball
mill and then sieved through a 40s mesh. I have never
used a hydrometer but rely on native wit to gauge the
viscosity, which is typically the consistency of cream
on the top of Jersey milk.
I have been developing these over a number of years to be
used in conjuction with a second glaze overlay, usually
with wax-resist decoration, so stability is important,
particularly on a tall vertical surface such as a 40cm
vase.
A number of my glazes are featured in Mike Bailey's
excellent "Oriental Glazes", published by A and C Black,
ISBN 0-7136-6214-X. A highly-recommended sourcebook.
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White over tenmoku
Wax resist
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Chestnut Tenmoku
Although I call this a tenmoku it is heading more towards
the hare's fur tenmokus rather than the classic black breaking
to rust on edges. The surface is slightly iridescent and
produces good results with the white and opal blue glazes
as overlays.
Cornish stone 33
Potash Felspar FFF 13
Limestone 12
Flint/quartz 17
China clay 5
Hymod AT ball clay 7
Standard borax fritt 3
Red Iron Oxide 7
Ilmenite 3
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100
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Opal blue over plum
(on shoulder of vase)
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Opal Blue
I got the scaffolding for this glaze off the net from
a US potter (I think) called Liz Dodge. After some
adjustment for my needs it is now in constant use.
Better on a white-firing body than a dark-firing body
and useful as an overlay. Good reduction is critical
for this as it is, in effect, a rutile CHUN.
Nepheline Syenite 35
Dolomite 15
Wood ash 3
Limestone 3
China clay 5
Hymod AT ball clay 5
Flint/quartz 29
Rutile 5
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100
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Opal over blue-black
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Blue-black
This is, effectively, a very versatile, stable glaze;
a superb base glaze for overlays, really well-behaved and
exceptionally forgiving. At the normal raw viscosity it
makes a classic black temoku, just breaking to rust on edges.
Even if thick it barely runs at temperature. If the mix is
thin it can produce a dirty rust colour on all surfaces.
Leavingout the cobalt and increasing the iron to 7% or 8%
generates a respectable tenmoku.
Cornish stone 30
FFF Felspar 20
Limestone 10
Flint/quartz 20
China clay 5
Hymod AT ball clay 5
Standard borax fritt 5
Cobalt carbonate 3
Iron oxide 3
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100
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Celadon box with pigment
brushwork
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Celadon
The yellow clay in this recipe is from my paddock. The clay fires
to a beautiful orange red at around 980C and contains sufficient
iron to produce the soft green/blue of a typical celadon. Best
on pale-firing bodies and ideal for brushwork.
Potash Felspar FFF 45
Limestone 10
Flint/quartz 20
China clay 10
Local yellow clay 5
Standard borax fritt 5
Barium carbonate 5
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100
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white over Tenmoku
Wax resist
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White
A white is a white is a white - but finding the right
one is not easy. I use this almost entirely as an
overlay glaze - very rarely solo.
Potash Felspar FFF 20
Cornish stone 30
Limestone 10
Flint/quartz 20
China clay 5
BBV ball clay 5
Standard borax fritt 5
Zircon silicate 5
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100
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GWB over blue-black
Wax resist
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GWB(uff) and Blue
Years ago a guy called George Weltner came over from
the US to stay with David Winkley and left me with the
bones of this useful glaze. Quite interesting on its
own but best as an overlay - as an overlay it is used
at about half the normal viscosity and can generate
rich variegation.
Potash Felspar FFF 40 |
Limestone 20 |
Flint/quartz 10 | base glaze add oxides
China clay 10 | to taste
Zircon silicate 6 |
Titanium dioxide 8 |
Barium carbonate 5 |
(Cobalt oxide 0.25 for a medium variegated blue)
(Manganese dioxide 1->2 for peachy/buff)
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100
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Turquoise/sea green
Semi-matt
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Turquoise/sea green semi-matt
There are a number of turquiose matt recipes around and
all are dependent on the firing cycle and the the amount of
reduction. This one works well both on its own and with the
opal blue as an overlay when very rich reds and blues can
result - although this combination is very fluid so care
must be taken to allow for glaze flow.
Potash Felspar FFF 47
Limestone 15
Barium carbonate 20
Hyplas 71 ball clay 10
China clay 5
Titanium dioxide 2
Copper carbonate 1 - 1.5
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100
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Dolomite matt over
blue-black
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Dolomite matt
I have been playing around with dolomite matt glazes
for years and have always sought a glaze which is not
only interesting in its own right but one which will
also prove stable and interesting when used as an overlay.
This version seems complicated because it is the result
of blending two glazes with similar properties. Many
dolomites use talc in the recipe - I do not as I find
talc in the raw glaze degrades the wax-resist properties
of the glaze.
Potash Felspar FFF 27
Limestone 16
Nepheline syenite 10
Mixed wood ash 6
China clay 25
Dolomite 8
Flint 5
Yellow ochre 3
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100
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