TURNING

Readers of this blog will know that I have been thinking a lot about how I turn my pottery after throwing it on the wheel. Thrown pots often need the foot to be cleaned up and shaped afterwards, and the way potters do it is to let the pot harden off a bit (the jargon is, till leather-hard), turn it upside down on the revolving wheel and trim it with a sharp tool. Flat items – plates and bowls – must be finished like this. Taller objects – cups and jugs – don’t, but the effect of turning is more elegant than leaving the base as it comes off the wheel.

Most studio potters are ambivalent about turning. In the early days of studio pottery (the 1920s to the 1980s) there was a mystique about throwing, which was considered to impart “vitality” to the pot, and there were reservations about turning, whose effect was thought to be “mechanical”. Those ideas came in part from the reaction against industrial pottery, but they were also influenced by Bergson’s anti-rational, vitalist philosophy, which was was hugely popular in the second and third decades of the 20th century and which made “vital” the vogue word in art and art-criticism. Bergson is not mentioned in Emmanuel Cooper’s biography of Bernard Leach, but Leach’s colleague and mentor, Soetsu Yanagi, was certainly influenced by Bergson and it is clear from Leach’s writing that he was too.

The practice in Stoke of Trent from the late 18th century onward was to get the rough shape of the pot on the wheel, then to hand it over to the turner, who imparted the outside profile on a vertical lathe. This process was described well by George Myatt, an old thrower interviewed by Gordon Elliott, and it is illustrated in the 1935 film (top), which shows an amazingly proficient thrower forming a rough shape in under ten seconds, which is then put in a plaster mould and then turned on a lathe.

In the Stoke-on-Trent production process, the work of the turner was more important in making the final shape, and therefore contributing to its saleability, than that of the thrower, and I guess that he was more highly skilled therefore more highly paid.

My preference for throwing over turning, and that of most studio potters, comes partly from the fact that throwing is easier than turning. Good turning is immensely difficult. The skill of the craftsman in industry was, I believe, superior to those of the studio potter, and understandably so, because there was specialisation in the industry and everyone concentrated on his trade.

 

GIFFIN GRIP

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The picture shows a vase I’ve turned in my new Giffin Grip. What a great piece of kit! How did I manage without one for so long?

Other potters I consulted before buying one were divided between those who advocated traditional methods for holding the pot (three blobs of clay or a clay chuck) and those who said the Giffin Grip was useful. It’s an expensive bit of kit, but I don’t regret buying it and it will soon pay for itself.

The Giffin Grip is beautifully engineered and makes turning pots of differing sizes an easy task. The instructions are clear and operation is simple. Setting up took about an hour and getting ready for a turning session takes three minutes.

For turning the odd bowl, three blobs of clay will do, but for repetition work, where time is important, this device is a huge leap forward. It is quick and easy to place and remove the pot and, unlike wet clay, does not leave a mark on the outside. Placing pots over chucks can also leave marks inside, and in the past I have spent a long time forming the chuck and then drying it with a heat gun.

I have to confess I dislike turning but I have decided to turn foot rings on hollow ware (mugs and vases) for a more elegant finish. The Giffin Grip makes it a more agreeable job.

Such a beautifully designed tool is useful for both the amateur and professional potter. For the amateur it makes centering easier and for the professional it increases productivity. I suspect that some of the opposition to it comes from potters who think their craft should be difficult, but my motto is “Work smart, don’t work hard”.

ALCHEMY IN THE CERAMICS STUDIO

I’m testing new glazes. I make small samples, using just 30 gm of dry matter, to which I add about 5% of stains. In these quantities, the measurement of stains has to be accurate to a hundredth of a gram. I have these great little scales, the little oblong thing in the middle of the picture, probably more widely used for weighing heroin than glaze stain, but perfect for the job.

I put the glaze samples on t-shaped tiles, suitably labelled, like the one on the left of the picture. After the tiles come out of the kiln, the bases are snapped off and they’re mounted on an A4 board. The best of the tests is made into a large batch of glaze.

I’m looking for a good yellow glaze to go inside tableware. The outside will be a matt grey, which is being tested at the same time.

This is the scientific side of ceramics, which I enjoy as much as the artistic side – but not more so. A colleague makes pottery only so that he can write reports about his glaze experiments. For me the experiment is only a means to an end.

Some potters can’t be bothered with this approach. I talked to Gordon Baldwin about his student days under Dora Billington, who was good on ceramic chemistry and who developed a range of glazes for her class at the Central School of Arts and Crafts. Gordon admitted he wasn’t a good student. “I didn’t have the right personality for that diligent testing,” he told me. “My idea was more like that of an alchemist, stir it together see what you’ve got and put a pinch more in it.” That approach worked well for him. Different potters, different personalities, different approaches.

COLOUR PLANS

A bisque kiln is opened and several dozen pieces are lined up for glazing and decorating next week. They are for an order from Byard Art in Cambridge and will be painted with my “Wisteria” design in anticipation of the spring. Every potter prefers one part of the making to another, and I prefer glazing and decorating, so there will be an agreeable week in the studio, warmed by a new efficient heater.

But the spirit is restless and as I work with one design I am already thinking of the next. Here are tiles with stain tests, a supplier’s catalogue of stains and a good crib, Colour Harmony. Development time is quite long, and it will probably be a year before my new range is launched.

NOTHING IS GOING PEAR-SHAPED

A pear. Familiar image. Simple shape. Would make a nice design – slightly assymetrical, bit of texture, can do things with the stalk and leaf. Off we go!

I’ve spent a day making designs on my ceramics based on the pear. But can I make a pear shape? Just about not quite to drive me crazy.

What is it with the pear shape?

It has to be asymmetrical, but not wonky. The narrow part must be not too narrow, must have a blunt top, one side of the top is slightly higher than the other, must be in the right ratio to the wide part.  The bottom part, the wide part is not exactly round, it’s slightly flattened. The pear shape is very subtle, and if you fluctuate slightly it doesn’t look right at all, and may not look like a pear.

Am I being very literal and precise here? Not at all. I can make a literal drawing easily with a pencil, but my painting technique uses a flat wash of yellow and a quick brush outline in a darker colour, and it’s that fluent line, capturing the pearness of the pear that is so difficult to do. The great Chinese painter Qi Baishi said that his calligraphic style of drawing with a soft brush had to be like and unlike the thing he painted, had to capture its spirit without being literal. I notice that Chinese pears, as painted by Qi are round and not pear shaped.

TO ADD A FIXED PERCENTAGE BY DRY WEIGHT OF STAIN TO A GLAZE SLOP OF KNOWN RECIPE

PROBLEM
To determine the weight of dry matter in the glaze slop.

SOLUTION
By Brongniart’s formula W = G(L-1000)/(G-1) calculate weight of dry matter in the glaze slop.

Where:
W = the dry weight of matter in the slop
L = the weight in grams of a litre of the slop
G = density of the dry matter relative to water (its relative density)

W is to be determined
L may be determined by measurement
G is unknown

Therefore G must be determined.

To determine G:

G = (Wd/Vd)/1

Where:
Wd = weight of dry matter
Vd =volume of dry matter

Weight  Wd of dry matter may be determined by measurement.

But volume  Vd of a given weight of dry matter is not known.

Therefore Vd must be determined.

Determine by displacement: take 1 litre water; add a given weight of dry matter and stir; measure displacement  Vd in litres.

Calculate Wd/Vd.

Calculate G.

Calculate W.