Leap -- Creating the mold and cast for the lifesize piece April 2008
The process of creating
a cast sculpture is
complex and I thought
viewers might enjoy
seeing some of the
stages. On the right is
the piece in the final days
prior to casting as it
stands on all its
armatures. (A flexible
wire armature is inside
the clay at this stage
providing grip for the
clay.). On the left, my
son has cleaned up the
piece in Photoshop to
remove the pipes for a
publicity shot.
a cast sculpture is
complex and I thought
viewers might enjoy
seeing some of the
stages. On the right is
the piece in the final days
prior to casting as it
stands on all its
armatures. (A flexible
wire armature is inside
the clay at this stage
providing grip for the
clay.). On the left, my
son has cleaned up the
piece in Photoshop to
remove the pipes for a
publicity shot.
April 7 The mold making
process begins: I am the
assistant now to my mold
maker, Fiona, for the next
three days. On the left,
Fiona has placed shims
which will mark the eventual
outlines of each of the
pieces of the mold. We
have taken off the hands
for later casting in a more
flexible (and costly) rubber
mold.
The current mold here is
called a 'plaster waste mold'
as it will be used for only a
single cast of the piece.
On the right, Fiona begins
applying the initial coat of
plaster, stained pink,
splashed on to pick up
every detail of the clay.
process begins: I am the
assistant now to my mold
maker, Fiona, for the next
three days. On the left,
Fiona has placed shims
which will mark the eventual
outlines of each of the
pieces of the mold. We
have taken off the hands
for later casting in a more
flexible (and costly) rubber
mold.
The current mold here is
called a 'plaster waste mold'
as it will be used for only a
single cast of the piece.
On the right, Fiona begins
applying the initial coat of
plaster, stained pink,
splashed on to pick up
every detail of the clay.
While I mix plaster, clean
buckets and generally scurry
around a lot, we start filling in
the piece with a thicker layer of
plaster providing the body of the
mold shell, all the while being
careful to keep our shim lines
from being covered. On the
right, we have finally got the
piece fully encased. Next step is
to brace all the pieces with a lot
of steel conduit bars. I spend a
lot of this day cutting and
bending steel to the exact sizes
and proportions.
buckets and generally scurry
around a lot, we start filling in
the piece with a thicker layer of
plaster providing the body of the
mold shell, all the while being
careful to keep our shim lines
from being covered. On the
right, we have finally got the
piece fully encased. Next step is
to brace all the pieces with a lot
of steel conduit bars. I spend a
lot of this day cutting and
bending steel to the exact sizes
and proportions.
Here is the piece, fully
piped. Note that each
piece of pipe must start and
stop within the confines of
the piece of mold it is
attached to, and preferably
going right to the corners.
The conduit is attached with
plaster-soaked strips of
burlap. The conduit gives
strength to the final mold
pieces.
With much scraping and
pouring and squirting of hot
water into the cracks at the
shims, we get our first piece
of the mold freed (right)
piped. Note that each
piece of pipe must start and
stop within the confines of
the piece of mold it is
attached to, and preferably
going right to the corners.
The conduit is attached with
plaster-soaked strips of
burlap. The conduit gives
strength to the final mold
pieces.
With much scraping and
pouring and squirting of hot
water into the cracks at the
shims, we get our first piece
of the mold freed (right)
One by one, we squirt water and tug and dig and jolly
these pieces along, freeing them along their shim lines and
arranging them for scrubbing. (Plaster will not stick to
shims, tiny strips of aluminum, so they provide a clean line
break at the edges of each piece of the mold)
these pieces along, freeing them along their shim lines and
arranging them for scrubbing. (Plaster will not stick to
shims, tiny strips of aluminum, so they provide a clean line
break at the edges of each piece of the mold)
The final mold piece, the entire front of
the sculpture, is the last to go. You can
see the original internal armature now
with most of the clay pulled off and the
mold piece slowly emerging from the
remains of the sculpture. All the clay
gets recycled into my next large piece.
the sculpture, is the last to go. You can
see the original internal armature now
with most of the clay pulled off and the
mold piece slowly emerging from the
remains of the sculpture. All the clay
gets recycled into my next large piece.
Casting: In these shots, the mold
has been used to create a polyester
resin cast of the piece, and the mold
was destroyed ('wasted') in the
process of freeing the piece from the
mold. This resin piece, a faithful
reproduction of the original clay, is
shown here midway through its
construction. Steel reinforcing rods
have been placed into the piece to
support its weight, and the various
sections are being created and
assembled together into the whole.
The finished piece will be exhibited
and when a purchaser is found, will
be used as the basis for creating a
second multi-use mold for all
additional castings. This more
expensive mold will be a rubber mold
and unlike this plaster mold here will
be suitable for casting multiple casts
of resin, plaster or wax for bronze.
has been used to create a polyester
resin cast of the piece, and the mold
was destroyed ('wasted') in the
process of freeing the piece from the
mold. This resin piece, a faithful
reproduction of the original clay, is
shown here midway through its
construction. Steel reinforcing rods
have been placed into the piece to
support its weight, and the various
sections are being created and
assembled together into the whole.
The finished piece will be exhibited
and when a purchaser is found, will
be used as the basis for creating a
second multi-use mold for all
additional castings. This more
expensive mold will be a rubber mold
and unlike this plaster mold here will
be suitable for casting multiple casts
of resin, plaster or wax for bronze.
All images copyrighted Bob Clyatt Sculpture 2005-2008
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