Geoff Crispin |
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Historical1987-2007
From 1986 onwards the pottery production changed over slowly to wood fired porcelain. By 1990 most stoneware was stopped and porcelain became the major production ware. The porcelain was initially local raw materials but now (2007)is a mixture of local materials and commercial supplies. This mixture of materials means that the impurities contained in the local raw materials have a different response to the comercially homogenised product. The original kiln two chambered wood fired bourrie fire box kiln lasted until 2002. When I returned from PNG I pulled down the kiln and built a new one. When I retuned to Whiteman Creek from Jamaica in 1987 I changed production methods from all thrown work adding slip casting and slab building. The slip casting enabled complex shapes to be made that could not be thrown. Eventually these three methods have been combined in making some pieces.
One of the first porcelain pieces produced. Thrown then cut. ash glaze.
The first porcelain piece fired unglazed producing the characteristic flashing of the wood firing.
The first slip cast covered box produced in 1988 Slip cast form produced as a blank then carved, unglazed outside surface
Slip cast piece, fluted, with ash glaze
Slab built pot, ash glaze
Thrown platter cut, ash glaze dia 56cm
The new kiln was of simiar design but modified to take account of new work being produced and to take advantage of over 29 years of firing. It took 6 months to build in 2003. It has only had 6 firings. Both chambers are fired to cone 13, 1320-1330oC Time at the fireface is about 18-20 hours. The kiln uses about 1 tonne of split wood. larger pieces in the firebox for chamber 1 and much smaller pieces to side stoke chamber 2. The kiln is preheated overnight with a LP gas burner so that the next morning early (5-6am) it is at about 300oC when the wood is started on the floor of the firebox. The fire is moved to the hobbs when the ash pit is full of burning ember and wood approx 600 oC The first chamber reaches cone 13 top and middle of the setting in about 16-18 hours from early morning. The second chamber is at about 1100-1150oC. The first firing only took 45 mins to reach cone 13. very scarey. Since then it has settled down to about one and half to two hours which is somewhat less scary. The quality of the insulation bricks linning the inside of the kiln contribute to this very quick firing as well as the preheated air inlets into the throat of the second chamber. Also after some 30 plus years of firing this type of kiln the firing routine to get temperature is well established. The essential flashing effects are as always more elusive. Pieces produced in the new kiln since 2003.
Slip cast piece, carved, ash glaze
Jug thrown celadon glaze
Thrown pot, Copper red glaze
. Thrown pot, carved, celadon glaze Ht 58cm
The new kiln built in 2003 before being fired. | ||
The new kiln is some 25% larger with approximmately 120 cubic feet of setting space in the two chambers. The kiln incorporated better quality bricks and some design modifications although the kiln was essentially the same as the original two chambered design. The design and building of the kiln has been written about in some detail in "Ceramics Technical" magazine. "Building the Whiteman Creek Kiln", pp 104-109 Vol 18 2004. "Firing the Whiteman Creek Kiln", pp48-54 Vol 20 2005. |
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