Contents
INTRODUCTION
EARLY WORK
1966―1973
COLOURED
GLAZES 1971―73 & 1977 >
This
Notebook is intended to explain the context for my conceptual ideas, influences,
sources and processes; and provide technical information about my making and
glazing techniques. Facts are from the various notebooks I have kept over the
years and also from memory, which is dangerous, but as honestly accurate as I
can make it.
The
glaze formulas are replicated here exactly as they were recorded in my notes.
Because of ongoing modification, the quantities of materials are often no longer
percentages (that is, formulas may not add up to 100). Materials may also have
changed since the recipes were formulated with changes to supplier or mining
source. Gerstley borate for example is no longer available, neither are white
nor red lead.
As
with using all published formulas, it is imperative that you test the recipe
first. Glaze materials, clays, water source, application techniques and firing
methods vary from location to location and person to person. Each variable
produces its own flow-on effect. What worked for me, worked for me at the time I
did it.
All
glazes are sieved through 100 mesh sieves and are mostly sprayed on.
With
the exception of bisque or specialist firings, all my firings are standardised
at the climb rate of 150°C per hour because this is the rate at which the large
pyrometric cones are calibrated. (Cones measure heat work rather than specific
temperature, so the rate is crucial.) I never soak at top temperature except
with crystal glazes where soaking, while cooling down, at around 1000°C for a
number of hours can aid large crystal growth. This standardised rate originated
from a Middle Fire Glaze course I taught at the Auckland Studio Potters Centre,
where we all tested the same glazes in our individual kilns. The variations from
the same bucket were astronomic until we standardised the rate and soak time.
Bisque
firings—especially of my later, much thicker, grooved work—need to be of
absolutely bone-dry pieces to fire at 150°C per hour to 1000°C. Water can’t
boil inside solid clay. It just makes the clay explode. However, if desperate, I
can fire just turned leather-hard wet pieces by a slow climb of 15°C per hour
to 95°C, followed by a five-hour soak with all the spy holes open. The water
evaporates before it boils. Then I complete the firing at the usual 150°C per
hour up to the final temperature.
All
pre-London work was thrown on a home-made Leach kick wheel. After 1977 I have
used a couple of Talisman electric wheels. I currently fire in two Elecfurn
kilns: a 5.1 cubic foot top loader and a 15 cubic foot side door.
My
parents were ex-farming working class. My father drove petrol tankers for Mobil
and my mother made electric fence shock units. They indulged their only child.
The wood shed became my first studio. My wheel was a home-made version of the
Pantheon of Wheels—The Leach Kick. It had a galvanized tin, soldered drip
tray. My first kiln was an up-draught wood-fired raku affair. This was augmented
with the ubiquitous vacuum cleaner blower to actually achieve some sort of
melting temperature of 700―800°C.
The glazes I used were straight out of Bernard Leach’s A Potter’s Book.
Bernard
Leach Clear Raku (A
Potter’s Book, p.150)
White
lead 66
Quartz
30
China
clay
4
Bernard
Leach Kenzan Bright Apple Green (A
Potter’s Book, p.150)
White
lead 66
Quartz
30
China
clay
4
Copper
carbonate 16
This
produced the very new, reduced copper, metallic luster effect, which was to
haunt raku until Rick Rudd in the mid-seventies did something about taking it
seriously as a medium. Back then one had raku parties and drank tea out of hot
recently fired cups, raw lead and all.
My
favorite glaze was:
Bernard
Leach Grape Purple (A
Potter’s Book, p.154)
White
lead
42
Lead
bisilicate frit 42
Silica
8
Manganese
oxide
8
Cone
10 Reduction Fired Stoneware
I
built, with Grant Hudson, my first two-chamber down-draught kiln, in my
parents’ backyard. The kiln was designed after I stayed with Barry Brickell,
and it followed a sort of Roy Cowan plan. The aim was to fire natural-draught,
dribbling diesel down the front surface of a brick in the fire box, with all the
resulting smoke, smut and pollution. In
a residential area, that didn’t last
for long. Inevitably came the trusty Tellus vacuum cleaner motors as blowers,
and a much cleaner firing method. I first used Neil Grant’s burners, but
settled in the end for Teddy Twiss’ masterpieces. Firings took around twelve
hours and the quality of the clay and glaze was as you’d expect from a
reduction fuel kiln.
SN1
80
Crum
clay
80
Feldspar
20
White
ball clay
20
Silica
sand
10
SN1
was a white firing, dry powdered clay from Commercial Chemicals (which
eventually became C.C.G. Industries). Crum clay came as a plastic clay from Crum
Brick and Tile in New Lynn, Auckland, and was generally used for drainpipes and
flowerpots. When fired, this clay became quite creamy and pale like the
commercial Denby ware and it took oxides well. I often added 10% grog to the
clay to give a ripped texture as a result of the throwing process.
I
also used commercial white earthenware clay that was intended for jiggering and
jollying and consequently was not very plastic or wheel-friendly, but it fed my
interest in white clay.
Principal
Glazes
Bernard
Leach Cone 8 (modified
from A Potter’s Book, p.172)
Kaolin
30
Whiting
20
Silica
10
Feldspar
40
Daniel
Rhodes Cornwall Stone (Stoneware
and Porcelain, p.81)
Cornwall
stone
85
Whiting
15
This
is the basis for crackle glazes.
Carlton
F. Ball Turquoise (Making
Pottery Without a Wheel, p.142)
Barium
carbonate
60
Nepheline
syenite 130
Kaolin
14
Silica
16
Lithium
carbonate
4
Copper
carbonate
10
Pink-Purple
(modified
Daniel Rhodes High Clay Matt, Stoneware
and Porcelain, p.82)
Feldspar
56
Kaolin
28
Whiting
4
Dolomite
26
Cobalt
oxide
0.5 Pink
Cobalt
oxide
5 Purple
Chromium
oxide
44
Red
iron oxide
44
Manganese
dioxide
10
Cobalt
oxide
2
This
is not exactly a glaze, but rather a combination of oxides. The fluxing
properties of the iron and manganese react with the fluxes in the clay,
producing a graphite-like sheen similar to coke.
The
pieces were made following the Len Castle method of texturing a solid block of
clay and then cutting it in half, hollowing out and then rejoining the halves.
The necks were coiled and pinched around a thin paintbrush handle, then scraped
and shaved with metal kidneys, potato peelers and a special knife with a long
thin parallel blade made from an old hacksaw. After bisque firing the inside was
glazed, and then more glaze was brushed into the texture and wiped off where
desired. Then the rest of the piece was glazed.
These
bottles were textured by rolling them on the plaster cast of a printer’s mat
that included an item about Nixon and one about Laird. The mat (pre-word
processor) was the flexible mould taken from a flat composited page of metal
linotype, which was used to cast a zinc sheet that could be fixed around a
roller to print newspaper. (The Nixon Bottles were tall because the Nixon
reference came near the top of the page on the plaster slab, whereas the Laird
texture came nearer the bottom.) I guess they were political—it was 1971―72
after all. I wasn’t.
Love
Potion Bottles
I
discovered Wagnerian opera through an early interest in stereo equipment. A
friend, Bruce Graham, bought the Decca box set of records of Solti’s Seigfried, but had no turntable. The Love Potion Bottles refer to
Wagner’s Tristan und Isolde, where
the lovers think they are taking a death draught to end their impossible love in
a dual suicide pact. But the poison was replaced by a love potion. The words are
the German text of the famous Liebestod—the love duet climax Isolde achieves
on her own over the corpse of Tristan.
Morris
Bottles
The
texture of these bottles was made from directly pressing the clay onto Victorian
glass door windows. I was trying to create a version of William Morris
wallpaper. Smith and Caughey’s had a Sanderson wallpaper sample catalogue of
William Morris designs I used to drool over.
Here
the texture was made with a rubber rocker, intended for making artificial
wood-graining as a paint finish.
Coiled
Bottles 1973―77,
Royal College of Art
I
don’t draw well at all—most of my decoration has to do with the action of
the wheel. So agate is of particular interest to me because it has an
archaeological quality of showing you where the clay has travelled, like a
time-lapse photograph.
The
essence of agate is to take two or more different clays, wedged separately to
get the air bubbles out, and then to carefully place the clays together without
trapping air. The new combined lump is then placed on the wheel and thrown as
usual. There are a huge number of different possible effects. Firstly, the
proportions of the let’s say two colours, black and white, can give dominance
to one colour. Secondly, the placement on the wheel is important. Colours can be
placed side by side, on top of one another, or as spots around the side and so
on.
Throwing
agate usually produces spirals as the agate actually documents the rotation of
the top rim of the piece in relation to the clay at the bottom that is attached
to the wheel-head. It is important to throw as quickly as possible because the
two clays can get intermixed very quickly—although this can create another
effect. Tricks like deeply digging in your fingers and then smoothing out flat
can give zigzag lines. Sometimes you have to throw really badly at the beginning
to get the colour placements correct.
As
you throw, the piece gets covered in a combined slurry of the different clays.
When it is leather-hard, turning reveals the agate stratification—or
frequently the lack of it. You end up with a lot of clay turnings that are a
mixture of the differently coloured clays. In my case it was grey.
The
final stage is burnishing the piece on the wheel, using a metal kidney flexed
flat against the clay under pressure. Sometimes it is necessary to use a light
mist spray of water to help the burnishing.
The
bone-dry pieces were once-fired to 1220°C. In the firing the burnished clay
tended to roughen up again because of the activity of the body fluxes. The
pieces were then smoothed and polished with water using automotive wet and dry
carborundum paper.
Clays
The
basic clay was white firing David Leach/Podmore Porcelain. To this I added 10%
stain or an oxide like copper carbonate. It is easiest to mix the stain or oxide
with a little dry clay and water and then sieve it onto the weighed out balance
of clay before wedging. The clay needs to be of an even consistency.
The
exceptions to this include the addition of texturing materials like 2―5%
silicon carbide for volcanic agate, or 2―5%
brass key cuttings for reactive copper spotting on pieces that are intended to
be bisqued and glazed. The agate technique mixes the fortified clays in random
ways that are impossible to achieve with a brush. The clays disappear beneath
each other, resulting in subtle gradations of colour that affect the cover
glaze.
For
another series of work I added 10% molochite (refractory grog made from
vitrified kaolin which is used in non-slip paint for pedestrian crossings) that
Warren Tippett gave me. The result in different agate clays was a white
speckle—like a sandstone-concrete effect similar to Terrazzo benches.
When
the outside of a bowl, for example, had great agate and the inside had little, I
often inlaid pink, yellow or blue clay lines to balance the proportions.
Rodney
Fumpston introduced me to pink. In the mid-seventies in London he made a print
series, ‘Sky Marble Arch’, using embossing and graded colour rollups on the
zinc printing plate. The rectangular images were a response to the areas of sky
observed between tall buildings and the ever-present Northern Hemisphere jet
trails. I got involved with blue on blue agate with pink inlayed squiggles as 3D
versions of Rodney’s works on paper. They have been, I think, my only attempt
to suggest realism by painting pictures.
At
our Royal College of Art Degree Show, the Ceramics Department played Bryan
Ferry’s Hard rain’s gonna fall.
Auckland friends later referred to it as ‘fairy music’, so when the In Your Mind album was released, I made a defiant series of five
agate pieces on plinths based on lines from songs. I later made ten pieces based
on the Ken Russell film Valentino,
which were less successful because I was trying to be clever. There were five
good ideas spread thinly over ten works.
Rodney
had produced a ‘Learning Etching’
series of prints for teaching purposes as examples of every kind of etching
technique. The Bryan Ferry and Valentino pieces similarly told you ‘everything you ever wanted to
know about agate’—if you knew how to read the examples.
Throwing
is really simple and straightforward with practice. It helps if you prepare the
clay thoroughly. Bernard Leach said somewhere that you need to spiral wedge the
clay at least 100 turns to get an even consistency and to rid the clay of air
bubbles. I am a stickler for counting, and do 150 with the finer clays which
annoyingly love to retain their trapped air pockets.
I
am much better at turning than throwing, so I tend to make thick blanks. This is
especially so with my later grooved pieces, which can then be turned very deeply
into the surface.
It
helps to put the clay where you need it. For a bowl I centre the clay as a
mushroom, rather than the textbook cone shape so that I am using most of the
clay up in the bowl. I open out the piece using plenty of water, and then finish
it by stretching dry using the fine edge of a metal kidney to ensure absolutely
minimum contact with the clay.
When
the piece is leather-hard, I begin turning with the piece placed as it was
thrown and then invert it for the foot ring. I turn every surface.
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At
the Royal College of Art I had the opportunity to play around with ceramic
transfers for the first time. Commercially available sheets had everything you
had ever wanted, from Gainsborough figures to Liberty print forget-me-nots. My
favourite was the sheet of exotic butterflies. The large home-made butterfly on
the outside of a house is a New Zealand folk art icon that engendered homesick
connotations of the brick and tile quarter acre section with vegetable garden
and a rotary clothesline. I was being smart and clever, flaunting in
kitschiness, revelling in living in London and getting off on the outrage of it
all.
While
playing around with the industrial thing, I got into banding fine silver lines
on bone china, like a factory worker. My favourite film of all time, The Devils, was made by one of my great mentors and inspirations,
the British film-maker Ken Russell. Peter Maxwell-Davies wrote the score and
Derek Jarman was the production designer. Russell takes great risks. I admire an
epic disaster more than a mediocre safe success. The movie was shown here in a
modified version in 1972 so as not to affect the moral climate of New Zealand. I
saw the longer, but still heavily cut, print in London. I await the full length
Director’s Cut DVD.
The
‘Devil’s Food Cake Plates’ came out of this fusion of Wedgwood and Royal
Doulton with the silver screen. The decals were made in the Royal College of Art
printing workshop, using on-glaze enamel instead of black ink. The artwork came
from a set of production stills I had acquired in a movie flea market.
The
printed image was floated off in water (like a normal decal), applied carefully
with a rubber kidney to get out all the trapped water and air, and then fired to
900°C. The enamel fuses and sinks slightly into the glaze. The same
photographic process is used to put photographs on cemetery headstones,
especially in West Auckland.
I had worked on collaborative pieces with Terry Stringer before. The concept for a new show at Compendium Gallery was to photograph my hands as I made the work on the wheel, then make drawings and finally decals of the life-sized drawings. The blank pieces were then fired and glazed like white commercial ware. The decals were applied with my hands in the positions of throwing the pieces. ‘Works in Progress’ was in its own way a ‘How-to-be-a potter-in-ten-easy-lessons’ series. Manufacture and firing of the decals was similar to ‘The Devil’s’ images.
My
first copper/manganese metallic glaze effect came by accident at the Royal
College of Art in 1974. I had been trying to duplicate the 1300°C Reduction
Fired Matt Black glaze in the oxidised atmosphere of an electric kiln at 1220°C
with poor results. A test involved painting a copper carbonate spiral over
manganese dioxide. The edges of the brush stroke went gold—it was like
alchemy. It appealed to me because it was just a mixture of oxides like the old
Matt Black.
So
for years after that discovery I banded three layers of manganese and added
stationery Gum Arabic to make it flow and set. Then I floated a transparent wash
layer of copper carbonate which was also mixed with gum.
In
1987, Tony Birks’ book, Lucie Rie,
gave the following version of this glaze:
Manganese
dioxide
80
Copper
carbonate
20
I
still add gum and apply three or four layers of the mixture, grading it up from
the foot because it is very prone to running. It needs to be thick enough to
just obliterate the text when you brush it on newspaper. The glaze is tricky and
varies with no apparent reason. Applied too thickly it goes black silvery khaki.
But when it works it really works.
Mary
Hardwick-Smith Blue/Mauve Stain
Cobalt Oxide
40
Talc
50
Borax
frit
10
To
enhance the texture I sometimes used the stain like a standard wash—applied
thickly and then sponged off in gradations. This is similar to inking a
printer’s plate.
By
the time I returned to New Zealand from London, I had completely altered my
thinking to working exclusively with oxidised firings in an electric kiln to
1220―40°.
I
found the David Leach Porcelain I had used in Britain was now available. It was
very expensive, but I could continue with agate and get similar results to the
work I had made at the Royal College of Art. I used a Steve Rumsey mix for a
while for general work, which was very similar in fired quality to the old SN1
clay mix.
I
variously used Abbots’ Red, Terracotta, and then Abbots’ White, but have now
settled on Mac’s Mud manufactured by potter Royce MacGlashen. It is a middle
range white firing porcelainous clay that is relatively plastic for a pure clay.
In the long run I am willing to trade a degree of plasticity in favour of
whiteness.
VORTEX WARE 1976 >
The
following article was published in the New
Zealand Potter magazine (vol. 23, no. 2, Spring 1981, pp.24―25).
A
little known Auckland Pottery Factory, The
Vortex Works, was a rival to Crown Lynn
hand thrown ware in the mid nineteen-fifties.
The
Works, dating from around 1947, was a small owner operated business, sited first
in Mt Albert and later moving to the Waiatarua area.
All
the work was made by the owner from one clay source. The stylistic features of Vortex
Ware are a single shiny glaze on simple forms with most surfaces being a
heavily tooled ridging reminiscent of ‘coil’ pottery.
Vortex
Ware was purely
utilitarian, featuring ashtrays, cigarette boxes, planters, vases, flower
troughs, bowls and pineapple stands—all indispensable in the modern home.
The
work was relatively unnoticed in its day, as was the recent retrospective
exhibition at Alicat Gallery, which presented the pieces in their appropriate
lounge and sick room settings.
The
Vortex
Works had a limited output. Pieces are now
eagerly collected for their rarity, and may have found their way into at least
one important public or private collection somewhere in the world.
However,
would be collectors should be wary of fakes.
John Parker
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The Vortex phenomenon was a hoax. Most of the references in the New
Zealand Potter article have only some loose factual basis. For instance, I
was born in 1947, and I used Dianne White’s kiln in Mt Albert, Auckland prior
to moving to Bush Rd, Waitarua.
I
have always been interested in industrial wares. It comes from my chemistry set
background—the bone china evaporating dishes were my first fascination for
their translucency. I began collecting Crown Lynn around 1972, almost as a
reaction to the brown and green, truth to materials, cone 10 reduction tradition
I had evolved through. To a ‘real’ potter, Crown Lynn was at that time an
insult, implying moulding, casting and machine-like precision—everything
freedom of expression in clay was not. Yet they had ‘Hand Thrown’ printed on
their bases.
The
idea for a hoax exhibition at Peter Sinclair’s Alicat Gallery in Auckland came
from a scandal that had rocked the British penal and pottery systems. Prisoners
attending pottery classes as therapy had made fake Bernard Leach pots complete
with his ‘authentic’ seal. I think they were sold at Sotheby’s.
I
still get genuine calls wanting more information about the history of the Vortex
Works factory.
The
pieces were all hand thrown and turned. I use the usual wire and metal tools for
turning, but have made a notched third round profile to turn each of the coils
separately. In this way the pieces can be positioned with some tolerance as I
work, to compensate for the different shapes.
Original
Glaze
Kaolin
4.5
Feldspar
71.5
Whiting
5.0
Gerstley
borate
9.75
Copper
carbonate
3.75
Manganese
dioxide
3.75
Cobalt
oxide
2.0
Fired
to 1250°C in an electric kiln.
Revised
Glaze
Abbotts’
Clear glaze 90
Black
Stain 14E44
10
This
revised glaze is more mirror black than the original, which had more of an
opaque texture consistent with using a combination of chemical oxides to produce
black, rather than a commercially prepared stain.
These
vibrant technicolour glazes are commercially available. The pieces are high
bisque fired to 1150°C, as with traditional industrial earthenware, then glazed
and fired to 1060°C. Because they are virtually non-porous the glaze takes a
while to dry. Application is aided by the addition of a slurp of neutralised
acid (10% hydrochloric acid) which helps keep the glaze in suspension. The kiln
needs to be well ventilated.
There
was a Cadmium Selenium Lime Green that was very sexy, but it has been
discontinued.
(modified
from Studio Potter magazine)
Soda
feldspar
35
Stand
borax frit
23
Barium
carbonate
8
Whiting
8
Kaolin
8
Silica
18
Yellow
stain
10
Abbots’
Clear glaze 100
Yellow
stain
20
Abbots’
Clear glaze 100
Yellow
stain
10
Lime
stain
15
Abbots’
Clear glaze
100
Pink
HT stain
15
Frit
3124
50
(modified
from Glenn Nelson’s Cone 11 Zinc Crystal, Ceramics,
p.297)
Potash
feldspar
50.0
Whiting
17.5
Silica
17.5
Zinc
oxide
25.0
Cobalt
oxide
1.0
As
this is a classic crystalline glaze it is prone to running. I don’t subscribe
to the idea of firing on setters to catch the glaze runs, and then grinding the
stuck bases off. Gradations of spraying help prevent running, or you can mix
some of the glaze with 10% kaolin and spray the bases with a variation of the
same colour to act as a brake glaze. Soaking while cooling down at around 1000°C
for approximately four hours will aid large crystal growth. Substituting soda
feldspar for potash feldspar creates more glassy crystals.
Lead
bisilicate 40
Kaolin 4
Silica
16
Barium
carbonate
40
Zinc
oxide
16
Nickel
oxide
2
This
glaze is very fluid and is prone to running
John
Kenny Chrome Red Orange (The
Complete Art of Pottery Making, p.204)
White
lead
76.5
Kaolin
8.0
Silica
14.0
Chromium
oxide
1.5
Toxic
beyond belief.
Matt
Zinc Barium
Barium
carbonate
35―15
Zinc
oxide
15―35
Nepheline
syenite
25
Lithium
carbonate
5
Silica
15
Kaolin
3
Bentonite
2
Nickel
carbonate
0.5-3
The
combined total of barium and zinc should be 50%. Where barium predominates the
colour tends towards pink, and where zinc predominates it tends towards blue.
Josiah
Wedgwood’s advice: ‘Avoid nickel my son.’
True.
Nickel is the most totally frustrating and yet ultimately rewarding colouring
oxide there is. It exemplifies the adage: ‘When it is good it is very very
good, and when it is bad it is utterly rotten.’ You definitely need to employ
the crystalline glaze brake technique with these glazes.
I
first used silicon carbide between 1971―73 at 1300°C in a reduction
atmosphere stoneware kiln.
Modified
Daniel Rhodes Clear Porcelain (Stoneware
and Porcelain, p.82)
Silica
32
Whiting
20
Feldspar
33
Kaolin
15
Zinc
oxide
15
Silicon
carbide (600 mesh)
20
This
glaze contains a ridiculous amount of silicon carbide to produce the volcanic
effect, but I also used it for its greyness.
The
post-London pieces after 1977 initially had the following slip banded onto the
leather-hard turned piece:
Body
clay
100
Whiting
50
Silicon
carbide (400 mesh) 3
Using
a reactive slip means you can place it where the froth from the covering glaze
is not going to stick to the kiln shelf. The ultimate slip is achieved by
putting the additive directly into the clay. I use this technique for pitted
agate.
In
later work I cut out the slip stage and mixed two versions of the glaze, the
second with 3% silicon carbide added. Because I spray my glazes, I am able to
spray the foot and grade upwards with the non-reactive glaze and then do the
rest in the reactive. It achieves the same result as placing the slip and avoids
pitting near the base. Yet using a slip is more precise, as it produces a
definite cut off point.
The
following two glazes are oxidised to 1220°C.
Matt
Magnesia/Zinc
Potash
feldspar
31
Whiting
20
Talc
10
Kaolin
29
Silica
10
Zinc
oxide
10
This
was originally a Len Castle high temperature reduction glaze to which was added
10% zinc oxide to melt at a lower temperature
(from
Ceramics Monthly, July 1984, p.66)
Barium
carbonate
24.4
Dolomite
12.2
Petalite
12.2
Cornwall
stone
12.2
Nepheline
syenite
12.2
Kaolin
12.2
Silica
14.6
Tin
oxide
4.9
Copper
carbonate
3.5
The
reaction between the silicon carbide and the copper carbonate often produces
local artificial reduction resulting in copper reds. If the froth is ground off,
the red becomes more prominent.
I
took a Warren Tippett wood-fired, combed porcelain, lidded jar to a night school
class and, attempting to show off to the class, tried to make one. It was
addictive and became a passion, complete with its own silly technical jargon.
The
idea is basically simple. Make a cylinder, and texture it by combing vertically
using a notched tool. Then open out the cylinder and the combing will form a
spiral. The tricks we evolved were to make a thicker than normal cylinder, then
remove the slurry and throwing ridges from the outside of the cylinder. (The
throwing ridges conflict with the combing.) It is then important to clean all
the slurry from the inside. After texturing, you must have completely dry hands
as you want ‘to engage the drag’ by having as much frictional contact
between your flat hand and the clay. Bad throwing. As soon as you are happy with
the twist, use a metal kidney with only the edge making contact—‘disengaging
the drag’ to make the final shape. Then throw the neck, using conventional
throwing if it is a bottle. I use the larger ‘U’ shaped golf umbrella spines
inside narrow necks as a sixth finger. Once leather-hard, the neck is finely
turned upright on the wheel and the base is turned routinely in a clay chuck.
The
best effects come from cutting deeply into the clay with a needle rather than
just combing the surface. The cylinder needs to be thicker in order to cut
deeply. Cutting produces a more mechanical or industrial rather than organic
effect. Be prepared to lose a few pieces along the way.
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Bronwynne
Cornish first wet my appetite for low fire glazes. She came back from the United
States in the early ’70s with some Duncan Crystaltone glazes and used them on
her crashed butterflies and snakes. I went with Rosemarie McClay and Cecilia
Parkinson to a Hobby Ceramics class in the early ’80s. I wanted to learn how
to glaze like wood-grain.
Hobby
Ceramics® is a lucrative international business where you buy slip-cast green
ware and learn how to fettle and then glaze, paying for the item, glaze and
firing at each step along the way. The process was interesting and different to
my usual way of working. Adapting the technique to my own ends, I threw and
turned my own blanks and when dry, bisque fired them to their vitrification
point of 1200°C. The glaze was then painted on in layers with a fishtail brush.
The clay was no longer porous, but the bought containers of glaze had some glue
or suspension additive, which dried quite hard. Three or four layers need to be
applied, each in a different direction like using vinyl paint correctly.
The
crystal glazes have chunks of already fused glaze suspended in the wet glaze.
You need to sieve these out for the first coats and add the chunks only for the
final layer, which you can heap up a bit to seed larger growths of crystals.
I
haven’t yet made work using wood-grain glazes, but I have always planned a
dream ‘Fakes’ exhibition with work pretending to be made of other materials.
Richard Shaw, Richard Notkin and Peter Lange do the super-realistic, still life,
trompe l’oeil thing so well. I always get off on the deception when people
think my stuff is made out of glass, concrete or metal.
These
base glazes were originally formulated for a Middle Fire Glaze course I taught
at the Auckland Studio Potters Centre in 1980. The formulas result from
averaging the ingredients of many published recipes from various sources. The
idea was to find how many significantly different glazes there were by testing
their responses to different colouring oxides and stains. The following results
form the basis for all my recent glazes.
The
maturing temperature has been progressively lowered from 1250°C to 1220°C.
Potash
feldspar
43
Silica
24
Kaolin
2
Gerstley
borate
20
Whiting
2
Zinc oxide
3
Barium
carbonate
6
This
glaze was later replaced by the commercially available Abbots’ Clear.
Potash
feldspar
43
Silica
24
Kaolin
2
Gerstley
borate
20
Whiting
2
Zinc
oxide
3
Barium
carbonate
6
Tin
oxide
10
This
glaze was later replaced by the commercially available Abbots’ White.
Matt
Magnesia/Zinc
Potash
feldspar
31
Whiting
20
Talc
10
Kaolin
29
Silica
10
Zinc
oxide 10
This
was originally a Len Castle high temperature, reduction glaze to which was added
10% zinc oxide to melt at a lower temperature.
Barium
carbonate
27
Nepheline
syenite
58
Kaolin
6
Silica
7
Lithium
carbonate
2
Alkaline
frit
10
Barium
carbonate
35―15
Zinc
oxide
15―35
Nepheline
syenite
25
Lithium
carbonate
5
Silica
15
Kaolin
3
Bentonite
2
Daniel
Rhodes Cornwall Stone (Stoneware
and Porcelain, p.81)
Cornwall
stone
85
Whiting
15
This
is the basis for crackle glazes.
I
have always been keen on the graphic work of Swiss surrealist painter H.R. Giger
who collaborated on the production design of the movie Alien.
The idea of something growing out of another thing—of being the host of a much
larger entity—is behind the Penetrations, which are suggestive of something
nasty, toxic and lethal.
Despite
the sexual, shock-value titles, the pieces originated simply from accidentally
turning through the bases of bowls while inverted on the wheel-head. They are
the only instance where I made work outside the category of traditional,
functional, hand-thrown pottery. I was interested in playing around with all the
usual principles of positive and negative space, as well as the severely
contrasting elements of colour and form. It was also interesting to work with
two pieces, which are co-dependent and which ‘function’ through their
interaction.
The
pieces were thrown and turned as per normal and once-fired to the top
temperature of 1220°C. They were then electroplated with pure silver or copper,
by immersing them in chemicals with the appropriate electric charge. The
drawback was that electricity moves via the most direct path, so no deposits
really occurred on the insides of pieces. The resulting texture was a thin layer
of pure metal following every contour on the ceramic. Every vestige of the
making process was preserved.
The
first perforated ceramic piece I ever saw was an African pot in the Auckland
Museum. It was a kind of colander for separating curds from whey.
A
gobo is traditionally a metal stencil inserted into a theatre lamp which breaks
up the beam to project a textured light on the actors and set, creating, for
instance, shadows of sun through Venetian blinds or the illusion of being under
foliage. The holes I drilled into bowls allow a similar play of artificial
light, but they also create an infinite set of variations in natural light as
the sun shifts by day and alters its angle by season.
The
pieces are thrown as blanks and then turned evenly when leather–hard, testing
with a needle for thickness. The aim is to achieve an even wall thickness. The
piece is then marked up using a ruler and protractor, and the holes are pierced
with a tungsten-edged hole cutter in a portable electric drill. The rough edge
is then sponged into a rounded shape.
I
am interested in an even placement of perforations, as if the pieces were
stamped out of a sheet of uniformly perforated raw material, such as aluminium.
Where I have played around with patterning the perforations, they become pieces
about patterns, rather than something made out of stuff that has holes in it.
The
Stud Bowls and the Safe Sex Toys have brass, rubber and stainless steel marine
fittings filling in the holes.
The
first outing of Gobo Ware was my 1991 solo show to celebrate the move of Master
Works to new premises in Parnell. The pieces used a single white glaze for the
first time with a variety of textured surface treatments. Lighting designer Tim
Dowson provided a changing lightscape which sequenced over ten minutes,
effectively changing the colour of a piece in many ways.
I
decided to identify this series by the descriptive label ‘White Ware’ as a
reaction against pretentious ceramics with names like ‘Impressions of
Nature—Part II’. The generic title came from playing on the collective term
for refrigerators, dishwashers and washing machines, and followed on from Vortex
Ware in that it is produced by a loosely defined owner-operated factory from
‘within the Pottery Manufacturing Industry’.
RIDGES,
ZIGZAGS AND GROOVES
I
have always responded to lathe turning after making a plumb bob in fifth form
metalwork. An early edition of Glenn Nelson’s Ceramics
showed a guy turning a huge electrical insulator, and another guy throwing a
piece upside down using gravity positively. They were my heroes. I responded to
the idea of equipment specially made for a specific use. At the Royal College of
Art we went on a ‘School Trip’ to the Dickensian world of Stoke-on-Trent.
Armitage-Shanks made urinals, but they also made one metre cubed acid vats 50mm
thick that were raw glazed and once-fired after drying for a year. T.G. Green
made the blue and white striped kitchenware by coating the white clay body in a
blue slip, and then lathe turning the blue away to make the stripes. Industry
took on a whole new meaning.
The
‘Hand Potted’ labelled Crown Lynn and the Wedgwood pieces, designed by New
Zealander Keith Murray, I had collected fascinated me because of their ‘studio
potterness’ made from within industrial factories. The pieces were made as
blanks and then, when leather–hard, tapped onto a horizontal chuck and
lather-turned with chisels much like a metal or wood turner.
The
first ridges came out of teaching—I asked a student if the slight bumps on the
sides of a piece were meant to be there and if so to make them more pronounced.
My first Ridges were swoops and grew out of finger groove throwing marks left on
a quickly thrown piece. They were turned to accentuate the bad throwing, thus
recording the process—the underlying architectural structure perhaps. Bowls
had the knob that often forms in the centre turned into a sharp point feature,
like the concentric ripples in a high-speed photograph of a water droplet.
Finger
ridges also became sharpened into concentric, pointed, triangular ridges. These
were later expanded in scale into the Zigzag pieces, which owed much to the
Brancusi ‘endless column’ idea.
I
have always been a better turner and finisher than a thrower. Lucie Rie and Hans
Coper introduced me to the idea of constructing a piece from smaller parts you
could throw well. The necks were thrown as a number of diabolo forms, turned and
then joined into a stack, when leather-hard. The join is always easier at the
widest point. I use water, not slip on the leather-hard pieces—water
evaporates, but slip shrinks. It is a Lucie thing.
The
Grooves evolved through overlapping Venetian blind-type ridges through to making
deep, regular furrows. The graded positioning of grooves are intended to give a
false perspective, like the tapering of classical Greek columns.
1966
Freehand Sgraffito
‘JP’ appears as a continuous stroke with a cross bar on the ‘J’. It is scratched directly into the underneath clay surface. Sizes vary but the mark usually takes up the whole base.
Mid-1966―1977
Plaster Seals
The cross bar on the ‘J’ was dropped in favour of making the ‘JP’ into a symbol (approximately 15mm square) like a branding iron. Placement is usually vertically as near the base as possible, or in the centre of the footring with unglazed pieces such as agate. Use of this type of mark began when I increased the turning of footrings.
1977
onwards Metal Type
Three
versions of metal printer’s type are used randomly according to the amount of
visible bare clay. There are two font styles of ‘JP’ (approximately 10mm
square) and one of ‘JOHN PARKER’ (4 x 30mm). From 2002, pieces are dated
using a from of roman numerals: a square to represent 'I' and a triangle to
represent 'V'.
I
use all the regular pottery tools, but I end up modifying most of them. It is
basically just problem solving. If you can’t do something you create a new
tool that will do the job, such as the tool I created to make the Vortex
‘coils’. Many solutions are the same as for working in wood or metal.
Metal
kidneys, for example, come in fixed generic shapes and are often unsuitable for
a specific application. I always buy the largest ones and cut them with kitchen
snips into the curves I want. The early ones were thicker and made of flexible
spring steel that rusted, but they were the best. I still covet a few and use
them sparingly. I have never been able to find the raw material at a supplier to
make my own. The newer ones are of stainless steel. They are thinner and don’t
rust, but sharpen themselves into dangerous razor sharp edges so I trim them
back continually. The straight edges also curve through wear and require
realignment. I also use various sizes of stainless steel rulers as long thin
metal ‘kidneys’.
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I
use angled metal tools for turning, continually sharpening them. However, I
mainly use metal strap loop trimming tools for turning. (The round wire
sculpting loop tools are useless for my applications because they do not have a
cutting edge.) I attach some of the metal strap loop tools to longer handles,
for getting to the bottom of cylinders for example. The hardest trim to make is
at right angles, such as reaching down from the top of a cylinder to trim the
inside vertical sides.
I
use ‘U’ shaped golf umbrella spines as an extra long thin finger for closing
in throwing of the narrow necks on bottles. The ‘U’ shape lends strength,
but it also provides a cutting edge for turning when leather-hard.
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