Alan Watt

THE COMMONWEALTH OF AUSTRALIA

  [ 上一页 ] [ 主页 ] [ 上一层 ] [ 下一页 ]

   For most of my recent work I have used a reductive Process of engraving from the block of clay rather than the conventional approach of building up the form through a wheel throwing or handbuilding process.
    The simple reason for this approach is the fact that the form and surface desired can not be achieved in any other way despite the difficulty. This method presents in having to hollow out the form for eventual firing.
    The general approach I take is to create a range of components from which I can make a selection to produce single of multiple forms. While I can envisage and aim at producing general forms at the beginning of the process. the eventual form is arrived at by responding to particular circumstances and effects as the making proceeds.
     I am conscious of the sculptural dynamics as the work emerges making adjustments to the form for heightened impact.
     The usual beginning is to cut into the block with knife, cutting wire or textured tool such as a saw blade or rough cut timber, to create a formal and often pristine slice though the clay. The clay is then forced apart creating a contrasting torn and textured surface from the natural breaking of the clay. If the clay is firmer or allowed to dry for some time the break will be quite different, offering a sharper fractured surface.
     Gradually a range of components is built up from which a selection is made to begin a construction often incorporating the joining of numerous parts to create the whole form.
     As there is a difficulty in hollowing out complex and tall structures often sections are temporarily joined together to be hollowed out separately and then rejoined prior to firing or after firing.
     Often at this stage further refinements and adjustments may be made to the form in the way of additional slabs, textures and knife cuts binging a sculptural integrity to the whole piece.
     The final stage, after the form has firmed to a point where the surfaces will not be marked, is to hollow out the centre so that firing can be successfully achieved. This is a tedious and time-consuming process.
     The clay used is a fine white earthenware to which is added about 20% of 100 mesh calcined alumina. This retains a refined surface but reduces the risk of warpage and cracking.
     As the clay becomes leather hard it is sprayed with a thin coat of terracotta which, during the final firing, aids the response of colour during the fuming process.
     When dry, the works are fired to 1050℃ in a conventional electric kiln.
     The final firing is in a simple outdoor cross-draught brick kiln which is largely open at floor level to allow the gases to pass readily through the kiln .The works are placed above the floor level with enough space for the free flow of gases. A gas burner is directed beneath the floor towards the back wall of the kiln.
     The firing schedule is to gradually heat the kiln to 700℃ at which point a mixture of copper carbonate, borax and sodium bicarbonate, in equal parts, is introduced into the kiln next to the burner on a V-fold piece of cardboard.
     This process of introducing approx. 50 grams of the powdered mixture to the kiln is continued every 50 degrees until the kiln reaches 1000 degrees at floor level. The gas is then switched off. A few more loads of copper/soda mix is introduced into the kiln as it cools and at 700 degrees an L shape metal pipe is inserted into the burner hole and everything is sealed with a slurry of clay/sand mix
     Once every opening is sealed waste motor oil is trickled from a tank into the kiln interior creating dense smoke and hence a severe reduction atmosphere. Should there be a small gap in the brickwork a fine plume of smoke will appear which should be immediately sealed with the clay/sand slurry.
     The fine dribble of oil should continue to trickle into the kiln through the metal pipe until the kiln has dropped in temperature to about 300 degrees. Be aware that the floor of the kiln can remain hot and there is a risk of the kiln re-oxidizing if the oil is turned off too early.
     Once cool the kiln can be opened.
     It seems that here is always some variation in results although the procedure in firing may seem identical. Despite many years of firing by this process I am not entirely sure why such variations occur. At least one can be certain of either exhilaration or deflation when opening the kiln. If disappointed in the results there is always the possibility in a second firing.