On a sunny day in August, Dave, Steve and I prepare for the final lava pour of this initial R and D project. I have copious amounts of flux, several different crucibles and 8 different mould prepared. Unlike my first moulds of spheres these sculptures are diverse. I wanted to try and cast a cut diamonds and small shelters within flat plateaued landscapes. Confident of a methodology, we setup two kilns and started the oil powered furnace. One kiln is a lined steel box which heats up quickly that we use to preheat the moulds. The other is a refractory concrete lined barrel that heats up slowly but can retain heat for a long time. We use this later kiln as an annealing kiln to try and make the sculptures stronger and provide a chance for crystals to grow within the structures. I decide the running order and over the course of the day we manage to pour 7 of the moulds.
The first mould of a 57 faceted cut diamond produced some interesting results. It was poured in a reasonably open ludo style mould and then placed in the propane fired kiln for around 8.5 hours for annealing. The kilns exhaust provided a peep hole so I was able to regularly monitor what was happening. After 4 hours, I noticed that the surface of the mould had dropped. Worried the kiln was too hot and was melting the refractory material and destroying the mould, I turned it off. This anxiety was justified, as in one of my early attempts we had completely melted a mould, producing an ugly looking mess which stuck to the inside of the furnace (see post “Live Lava” for a picture). Four hours later, I needed to place another sculpture in the kiln for annealing so tentatively turned the kiln back on to receive the next sculpture for a couple of hours. The outcome of these two sculptures won’t be known until they have cool very slowly and I can open them back at the studio at Spike Island.