Ive been doing a couple of sculptures lately a small piece of a woman with a towel and a larger more complicated owl in flight. The owl will be challenging to make a mould from due to the wings and claws. I think I will need about 5 separate molds for the two wings, two claws and the body. The woman I am almost ready to cast as it was a simple two piece mould and only about 18cm high with base built in (no stone work required). This means I can make them relatively cheaply with less labour so hopefully they will sell. As usual I have shown the process in pics and hopefully it may help some of you considering lost wax and ceramic shell.
The owl still in pieces. I will photo the process of casting the owl when I get around to it. Still not quite happy with it at the moment
Towel girl. I cheated a bit with the towel instead of sculpting it as it was so small I dipped kitchen paper in liquid wax and folded to shape. There were things that weren't quite right and some modifications were made before mould making (hair, ears)
Base not quite finished, replicating a tiled floor.
A simple two piece silicone mould with two piece plaster mother mould
Clay walls in place for front side. The vertical wall is not critical but is just to give a neat edge to the rubber
Silicon rubber poured
Vertical section of wall removed and the scraggy bits being trimmed with a blade
Front part of plaster mother mould applied and in process of shaping while still damp (easier to cut)
Turned over ready to start on the back. You can see some extra blobs of clay pressed around the legs to give extra support for the clay forming the wall
The bulk of the wall removed. Some sticks to the sculpture.
The remaining clay (water based) is easily washed of in a bowl of water with the aid of a soft brush. The oil based clay of the sculpture is uneffected. If the sculpture was water based clay I would use a release agent and be more tidy with the back of the wall so it would be easier to remove. The outer part of the plaster which overlapped the edge of the clay wall is shaved down to the level of the silicone
A vertical wall is built again just to give the silicone rubber a neat edge. The wall is thick and has to be pressed down hard so that it sticks to the wet plaster.
Silicone applied to form the back part of the mould
Wall removed and scraggy bits of rubber trimmed off
Second half of plaster mother mould applied and shaped. The mould hasnt been separated yet and the original sculpture is still inside.
Some wax patterns quickly cast. Im testing a few waxes with this one kindly supplied by FL
Decided to do some experimentation with the sprueing and pouring. For the first one I am doing two together and having the metal enter from the top. The link between the two heads is just for support for more than anything else.
Ceramic shell nearly finished. Will have the following layers. Slurry with sprinkling of molocite flour (200), then slurry between each of the folowing, 2 x medium grain molocite (30 - 80) then 2 x course grain molochite (16-30). Finish with slurry to stabilise loose grains
pics of the casting to follow