Now, finally the time has come for the last part of the mini-series about how to duplicate small forms and figurines. My smallest soapstone dragon was a good prototype for trying out the process of making a full 3D mould, which took place in several steps.
The prototype was “halfend” by a wall of plasticine, following the contours of the half-way line as straight as possible. A wall of cardboard was then built as a pouring area and the prototype was brushed with Vaseline to let the Silicone part from it when added. Small holes were pressed into the Plasticine wall as clearly as possible, they helped to “lock” the two mould halves together.
The Silicone was prepared with an additive to give it a gelly consistence so it could be brushed onto the prototype thoroughly. When this was done, the Silicone needed to cure. On top of this, a plaster jacket was applied. Messy? Oh yes 😉
When this had set, all of the Plasticine was removed thoroughly.
The whole process was repeated for the second half of the form. After the second plaster jacket had set, the mould could be taken apart, the prototype was removed and the mould was ready for casting.
My casting test was a hollow cast done with resin. The liquid material was spread and brushed very carefully into the put-together mould, held by the plaster jackets.
For the “serious” cast, I added some green pigments to the polyurethane resin. Here is the outcome – a nice little green dragon, light as a feather.
pic by Th. Schramm
I found it very interesting how many different ways there are to mould and cast, and the astounding and often suprising effects one can apply to the casts using a variety of materials. The possibilities of deception seem endless 😉