The sculptures were modelled in clay on an iron
framework. Phillippa, Kaori, Marion and Robert posed at various
times. I worked directly from the model and from drawings and
photographs. Steven helped me mix up all the plaster which is done in
batches. They were cast in plaster using the waste mould process,
so called because the mould is broken and destroyed in order to reveal
Plaster is thrown onto the surface of the clay in layers up to
2cm thick. The mould is designed with the front in one piece and
the back in five sections. The front 'mother' mould' is supported with a
wooden framework. Once set, the back pieces are prized
off and the clay is dug out of the rest of the mould. The
mould is cleaned, sealed and waxed before being laid up with plaster and
jute scrim to create the final piece. The cast is hollow from the
knees up. Because the cast could not support itself on its plaster
ankles alone, strong iron bars are introduced into the cast from the
base and run up to the neck.
The whole mould is put together with a final squeeze of
setting plaster along the seam joints. Twenty minutes later the
joyous task of chipping out the cast can begin. Firstly removing
the wooden structure and then gradually attacking the mould with a
hammer and mallet. Because the mould was made in layers the
plaster flakes off like an onion, finally revealing the pristine
smoothness of the cast.
This is not quite the end because there is always some
touching up to do, such as trimming the seam lines and filling any
indentations made with a too hasty chisel.
What about the paper hat you might ask? This is made to a
traditional design out of brown paper and serves the useful task of
keeping the flying plaster out of your hair. This was worn by
Italian bronze founders and most notably by George Mancini who taught me
this process at Edinburgh College of Art.
Unpainted Pictures and Derek Batty