Monday 24 September 2007

Waxing Lyrical

After a day of rest I am back in the studio. I need to get a firing of my own work through this week before we stack and fire the new kiln. The week before the workshop was wet and stormy, but the last week has been perfect weather and the pots are bone dry and ready to wax and glaze.

I don't bisque fire for a number of reasons; firstly it saves the labour of stacking, firing and unstacking one kiln load of pots; secondly it saves the cost of one firing; thirdly it is better for the environment to fire once instead of twice, thus reducing exhaust gases and use of natural recources; fourthly if I bisque fired in my wood kiln I would have to wipe off all the ash deposits before I glazed, when ash is what I ultimately want on the pots anyway (It seems such a waste!); and finally because it is unnecessary for the style of work I do.

Of course this means raw waxing and raw glazing. I wait until the pots are bone dry and then apply the hot wax with a brush. The wax resists the glaze, acting as a mask so that the glaze only sticks to the bare clay.

I melt the wax in glass jars in a large pot of water over a charcoal brazier. The wax is a mixture of paraffin and kerosene, so ventilation is essential. I would prefer to use beeswax and eucalyptus oil, but the first is too expensive for me at the moment and the second is unnavailable in Japan.

I have three jars, two of them just wax and kerosene (one for use, one for back up) and the other has alumina mixed in with the wax.

The alumina wax is used for the feet of pots or the faces where lids and bodies meet. When the wax burns off in the firing the alumina remains as a thin layer on the surface and prevents sticking.

The non alumina wax is just a resist and vanishes completely. It enables me to glaze specific areas of the pots, like the centre of dinner plates, and leave other areas bare for the wood fired effects.

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