And now, an update on the Bronze Casting workshop I have been taking part in on Monday Mornings. The next stage of the process was crafting a ceramic ‘shell’ around the bird. This was done by layering ceramic binder and crushed ceramic beads over the wax sculpture; thick binder and fine crushed beads for two layers, and then four layers of thinner binder, and larger crushed beads. This created a dense shell that once fired in the furnace, would create a very sturdy, albeit brittle, shell that would act like a mould for the poured molten bronze. The strange shape of the object is because of the need for a base, and then two ventilation shafts for air to escape from the mould, removing any danger of the shell breaking.
Once this shell had been layered and eventually dried (the process took around 5 days, as each layer would require at least a day to make sure it had dried and set successfully), I had made the mistake of covering the bas as well, which would then need to be filed down until a ring of wax could be seen. This was to allow the melted wax to escape from the mould once fired, and therefore not cause any unnecessary damage to the mould, as well as the heated wax and air exploding.
The fired shells, shining a brilliant white
The furnace that would melt the bronze, as it was heated to around 2000°c
As the bronze melted, then came the moment of truth. Once we had put on the correct protective clobber, we began. There were three of us, one who held the one side of the superheated bronze’s pouring apparatus, another who turned it to pour (myself), and then another who would scrape the slag off of the top of the molten metal. The process was hard, heavy work, and I could feel the heat coming off of the metal even through my layers of protective clothing. The metal took around a day to cool, but you could feel the heat coming off of it even after the substance began to cool in the moulds. Each mould had been buried in a pit of about 5ft Sand, which helped hold the mould together and help draw out the heat and cool the bronze quicker.
The finished bronze sculpture, with it’s ‘tree’ and base, which will be sawn off and remelted for another moulding and casting process. The way it has come out, it is equal parts fascinating and frustrating in how it captures every detail of the object that has been cast, but this is also a curse, as you can see all the imperfections that are inherent in a sculpture you have made by hand. All in all though, I am very happy with how the piece has come out, and felt quite proud when I chipped off the ceramic shell to unleash this sculpture that I have spent so long making. Now all it needs is a small clean up, to saw off the tree, and to buff and polish the surface up in order to bring out the lustrous surface of the bronze, which can be seen on the ventilation shaft (see below).
The beautiful glow of the bronze is really something to behold