Firings took around twelve hours and the quality of the clay and glaze was as you would expect from a reduction fuel kiln. I first used Neil Grant's burners, but settled in the end for Teddy Twiss' masterpieces. Inevitably came the trusty Tellus vacuum cleaner motors as blowers, and a much cleaner firing method. In a residential area, that didn't last for long. The aim was to fire natural-draught, dribbling diesel down the front surface of a brick in the fire box, with all the resulting smoke, smut and pollution. The kiln was designed after I stayed with Barry Brickell, and it followed a sort of Roy Cowan plan. I built, with Grant Hudson, my first two-chamber down-draught kiln, in my parents' backyard. Back then one had raku parties and drank tea out of hot recently fired cups, raw lead and all.īernard Leach Grape Purple ( A Potter's Book, p.154) This produced the very new, reduced copper, metallic luster effect, which was to haunt raku until Rick Rudd in the mid-seventies did something about taking it seriously as a medium. The glazes I used were straight out of Bernard Leach's A Potter's Book.īernard Leach Clear Raku ( A Potter's Book, p.150īernard Leach Kenzan Bright Apple Green ( A Potter's Book, p.150) This was augmented with the ubiquitous vacuum cleaner blower to actually achieve some sort of melting temperature of 700-800☌. My first kiln was an up-draught wood-fired raku affair. It had a galvanized tin, soldered drip tray. My wheel was a home-made version of the Pantheon of Wheels-The Leach Kick. My father drove petrol tankers for Mobil and my mother made electric fence shock units. My parents were ex-farming working class. I currently fire in two Elecfurn kilns: a 5.1 cubic foot top loader and a 15 cubic foot side door.
After 1977 I have used a couple of Talisman electric wheels. Then I complete the firing at the usual 150☌ per hour up to the final temperature.Īll pre-London work was thrown on a home-made Leach kick wheel. However, if desperate, I can fire just turned leather-hard wet pieces by a slow climb of 15☌ per hour to 95☌, followed by a five-hour soak with all the spy holes open. The variations from the same bucket were astronomic until we standardised the rate and soak time.īisque firings-especially of my later, much thicker, grooved work-need to be of absolutely bone-dry pieces to fire at 150☌ per hour to 1000☌. This standardised rate originated from a Middle Fire Glaze course I taught at the Auckland Studio Potters Centre, where we all tested the same glazes in our individual kilns. (Cones measure heat work rather than specific temperature, so the rate is crucial.) I never soak at top temperature except with crystal glazes where soaking, while cooling down, at around 1000☌ for a number of hours can aid large crystal growth. With the exception of bisque or specialist firings, all my firings are standardised at the climb rate of 150☌ per hour because this is the rate at which the large pyrometric cones are calibrated. What worked for me, worked for me at the time I did it.Īll glazes are sieved through 100 mesh sieves and are mostly sprayed on. Each variable produces its own flow-on effect. Glaze materials, clays, water source, application techniques and firing methods vary from location to location and person to person. Gerstley borate for example is no longer available, neither are white nor red lead.Īs with using all published formulas, it is imperative that you test the recipe first. Materials may also have changed since the recipes were formulated with changes to supplier or mining source. Because of ongoing modification, the quantities of materials are often no longer percentages (that is, formulas may not add up to 100). The glaze formulas are replicated here exactly as they were recorded in my notes. Facts are from the various notebooks I have kept over the years and also from memory, which is dangerous, but as honestly accurate as I can make it. This Notebook is intended to explain the context for my conceptual ideas, influences, sources and processes and provide technical information about my making and glazing techniques. PITTED/VOLCANIC/LAVA WARE 1971― and 2015+ John Parker Ceramic Artist and Designer - Auckland New Zealand My Technical Notebook expanded from the pages in John Parker CERAMICS Contents
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