THE CRAFT OF FIRE

(I have notes for the 2nd time we cast pewter but haven't posted them.) This time what we wanted to do is to burn out the wax and melt the pewter at the same time, with everything all together in the kiln. Like that, the molds would be clean and at more or less the same temperature as the molten metal. It might result in a better casting, and would be more efficient energy- and time-wise, too. But of course it wasn't. First, we loaded up the kiln with our molds and the pewter in a crucible as well. But we needed something to catch the wax from the molds. So we used this aluminum food tray, figuring that since the temperature would be very low, it would be all right. It wasn't. Hole in tray My dad joined us that day so we put him to work fashioning a new tray out of sheet metal. That worked. With our pieces on little stilts, the wax dripped out fine, as you can see. But somehow the pewter in the crucible didn't melt. There it is below the tray...

Things fall apart!  The door of the oven is the place where repairs are needed most often, since it can get banged every time something goes in or out. After a long winter and rainy spring, it was time. Whole pieces of it had come off, and some of the quick repairs I had done in the fall hadn't held. So I mixed up some more mud and sand and grass and made sure that both surfaces were wet enough so that, with enough pressure applied, the new mix would gel with the old. Et voilà. As you can see I wasn't going for a seamless look. Maybe some day I'll apply a full, smooth finish over the whole thing... After a day or so drying on its own under the tarp, I decided to dry it further by firing it up. And as the temperature got hotter, suddenly, they appeared. Thousands of them. (Not the best macro video, no. I leave that to the pros .) Ants came bursting out of cracks in the oven from all over. And they were evacuating their young!...

In a recent pewter casting session, I cast a yoni-lingam (and two Venuses). It came out pretty well, but what was of special interest was the tiny crystal formations on the yoni-lingam, where the lingam meets the yoni. (No crystals on the Venuses.) Alex said that the crystals might depend on different rates of cooling of the object in the mould. So maybe that part cooled more slowly and it allowed these little crystals to form. Cool! Cool enough to inspire a little study of crystals: what they are and how they form. And then -imagine!- how fortuituous that a few weeks later my daughter and I should discover this crystal-making kit on the sidewalk outside a neighbour's house, sitting there for the taking. So we mixed up a solution on the stove called "Red Ruby Geode" (aluminum potassium sulphate). We poured in the crystals and then stirred to dissolve it in the heated water. Because warm water increases the material's solubility, the solution gets s...

Who knew that our own young city of Toronto played a part in the ancient technique of lost-wax casting? As I was researching the history of this technique, I discovered this : "It  was in 1934 that a Danish engineer, Thoger Gronborg Jungersen, working with a firm of manufacturing jewellers in Toronto, devised the flexible rubber mould from which any required number of identical wax patterns can be obtained. This made  it  possible to produce substantial quantities  of  small castings possessing all the fine detail of the original master pattern." Who was this T.G. Jungersen, and did he really invent the idea of using a rubber mould to produce multiple wax copies - a process we all follow today? In 1938, he received a patent for the following invention: "A method of casting articles of jewelry of intricate design consisting in first producing a model of the article to be cast, then forming about said model a primary mould of a plastic material which wi...

We've entered the Age of Metals! Back in September, we did our first backyard pewter casting, using the lost-wax process with plaster molds. It took us while to source the metal ingredients to mix up the pewter ourselves, but finally we found them and then followed this recipe, by weight: 70% tin    (melting point 232° C) 20% zinc  (melting point 420° C) 10% lead  (melting point 328° C) Jorge and I mixed up the metals in a big pot. You first melt the one with the highest melting point, and then the others in descending order. 1 lb of zinc 1/2 pound of lead shot after adding the tin and mixing, the oxidation produced these amazing colours We also heated up our plaster molds to about 235° C, in the kitchen oven, so the metal would flow better and to reduce any possible thermal shock. And then we poured:  Next, after a number of hours of cool-down, comes that truly magical moment of breaking the mould and ...