Replicating bronze sculpture

Helen Privett <hprivett [at] museum__vic__gov__au> writes

>We have had a request for a replica to be made of a bronze sculpture
>in our collection.  I would appreciate any advice regarding the best
>moulding process to use.  I'd also appreciate any advice from
>Australians regarding access to and experiences with non contact
>replication methods (ie. laser scanning).

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 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
+44 151 478 4810


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                  Conservation DistList Instance 20:45
                  Distributed: Friday, March 16, 2007
                       Message Id: cdl-20-45-005
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