Casting

Margaret Contompasis <mcontomp [at] indiana__edu> writes

>The Indiana University Art museum needs to explore options for
>making a replica of a 15th century bronze sculpture of Parvati in
>good condition. ...

It is now possible to produce very accurate high quality replica
sculpture in almost any material using 3D laser scanning, rapid
manufacturing techniques and skilled hand-finishing/patination.
Laser scanning produces a 3D digital model of the sculpture, which
is then used to produce the replica directly or a master pattern
from which a mould can be taken and the replica(s) cast.  By going
down this route, there is no contact with the original sculpture and
no risk of damage, staining etc.  There is also the added benefit of
having a 3D digital archive of the sculpture, which could be used
for condition monitoring, research, digital reconstructions of
colour, damaged or missing parts, interactive 3D animations for the
gallery/website and many other applications.

To produce a bronze replica of the sculpture of Parvati would
involve the following steps: laser scan the original sculpture;
process the data to produce the 3D digital model; print the master
pattern from the data using a technique such as stereolithography or
selective laser sintering (these techniques build the model out of
resin or powder in very thin layers); produce a mould from the
master pattern and cast the replica in bronze; hand-finish the
bronze (mainly patination).  It is also possible to scale up the
digital model (and hence master pattern) by a few% to allow for
shrinkage of the bronze as it cools so that the replica is the same
size as the original.  Alternatively, it would be possible to use
the master pattern as the replica and patinate the surface to look
like bronze.

At National Museums Liverpool, we have been investigating the
potential of these techniques for high quality replication of
artefacts for many years and now use them regularly to produce
replicas for museums and other bodies within the heritage field.

Martin Cooper
Conservation Technologies
National Conservation Centre
National Museums Liverpool
Whitechapel
Liverpool L1 6HZ
+44 151 478 4904
Fax:  +44 151 478 4810


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                  Conservation DistList Instance 20:24
                 Distributed: Friday, November 3, 2006
                       Message Id: cdl-20-24-001
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