JOHN WHEELDON.

‘A LIFE IN CERAMICS’

September 3rd Seminar, 2005

at Aberystwyth Arts Centre

JOHN WHEELDON showed examples of his work from his earliest days until now, generously offering technical advice , recipes and anecdotes.

 He has used matt white glaze with Tenmoku or orange glaze stains (like David Leach used), sponged on, and 50% Nepheline Syonite with 50% Calcide Holmide (High Iron Ball clay.

He uses “T material” with a mix of oxides kneaded into it- copper, iron, manganese and cobalt.

Terra Sigilata Recipe:

“To make Terra sigilata you need about 2kg of clay and deflocculant in a dustbin of water to break the clay up, as you need to get water into all the particles. After leaving the clay for a week, you mix it with an electric mixer.  (Hand mixing isn’t as good- without a mixer you need to soak, stir, soak, stir.)

Terra sigilata literally means ‘Earth seal’. Brownium motion keeps the clay in suspension. After one week the water is drained off. The more water is drained off, the less shine in the resulting Terra sigilata.” John remarked “The Romans used it. Well dressing clay works well. That clay comes from a mine off Brassington Moor.”

Copper glaze recipe

John’s copper glaze recipe is: Copper 90%, Frit 10% (Alkaline, with a little bit of bentonite, about 3%), and about 1% Polycell wall paper paste to keep it suspended in the bucket.

John always waxes pots to resist glaze. He uses warmed candle wax mixed with white spirit, as wax emulsion leaves a scum at these temperatures.

“For graphic quality, to draw with, I always use Copydex too, which pulls two areas together. I use a recycled slip trailer (a hair dye bottle). Copydex is thicker than wax and works just as well, but doesn’t run like latex. Copydex also works as a resist.”

Raku Firing: The Kiln

John explained that he had made his kiln, and that kits are available to buy. His is of a square/cuboid construction, made from six pieces of mesh. John used a layer of body friendly fibre sewn with element wire onto ‘weld mesh’ e.g. British Steel, with fibre on the bottom. He also used “Turkey foil” (large/catering tin foil) externally, between the fibre and the mesh, to protect the fibre. The mesh was clamped together in the corners with metal clamps, to hold the structure in shape.

Sodium silicate and water can be sprayed onto the inside to harden the surface and ridgidise it. Sodium silicate impregnated fibre is available from Capital Refracteries in Clowne near Derbyshire.

The Firing

During these discussions John was preparing his area for raku-ing, using a recycled Frankfurter tin out of a skip from Austria, and Pine sawdust/Builder’s sawdust. He advised that if the sawdust is damp to use a little white spirit- “but never use when burning- Health & safety!!” John put the sawdust on a kiln shelf, ready to put the hot pots on top.

 “The kiln fires to about 1030c and the lid has to stay over until its cool- about ¾ of an hour.”

After cooling them, John removed the lid off the fired Raku pots. He brought some of the pots inside and blow torched them to complete the colour and surface texture.

At all times John was careful to wear suitable protective clothing (some of which he had made himself) and to stress the importance of care for oneself and others while firing his kiln.