Part of my development of the new bronze casting is to find a suitable inner former to support the woven wax during its casting, so the inner core has to be able to withstand the heat of molten bronze.
Looking back into my research into ancient Greek casting techniques shows that by the late Archaic period (ca. 500–480 B.C.), Sphyrelaton went out of use as a primary method when lost-wax casting became the major technique for producing bronze statuary. This was replaced with solid lost-wax casting using a solid core or clay.
I want to use this method but replace it with a material that doesn’t shrink quite as much as clay, and use casting powder to make a solid block which I can carve into to create my desired shape. This block of plaster will then support the woven wax.
After discussing this with other artists and the foundry one of my biggest obstacles could be air bubbles. When mixing plaster and water you unavoidably get air bubbles in the mix, this is fine for usual plaster uses, but not if the plaster is going to be kiln heated to 800°c. As you know when air is heated it expands, and if it is trapped in a hard substance it will try and find a way out, this could cause an explosion in the plaster.
Many artists and specialists suggested a vacuum chamber or an oscillating plate to either suck out the bubbles whilst the plaster is wet or to shake the bubbles out by vibration. Both these pieces of kit are a bit on the expensive side, so it was back to the drawing board.
I was thinking about this problem and how to overcome it, so to help I typed in ‘Vibrating’ into a search engine. Along side the many items that vibrate for 'other’ reasons, was an exercise machine. You set the vibrating plate to your chosen level and stand on it. Apparently the vibrations help to get rid of fat deposits in the body, and I thought “If this machine can vibrate the weight of a person, it should have no problem vibrating a large bowl of wet plaster”. After some more researching I found a second hand exercise machine only 20 minutes drive from my home listed for only £30, a few emails later I was on my way to collect it.
So can my bubble problem be solved with a fat busting machine or will it just vibrate the plaster out of my mixing bowl and all over the floor? I’m not sure, but the machine is now safely in my little van awaiting the first day back in the studio after the Christmas break to give it a try. I can’t wait.