Styrene-butadiene rubber

A colleague and I are currently in the process of finding a suitable
conservation method for a painted sculpture by Serge Lemoyne.  The
sculpture includes "bundles" made of polystyrene foam blocks wrapped
in pieces of industrial carpet.  The verso of the carpet (a glued
underlay that is a thick layer of black rubber foam) is the visible
part and is painted with acrylic paint.

We had a sample of the black rubber foam analyzed: it is made of
styrene-butadiene rubber with calcium carbonate and carbon fillers.

The main problem is that the rubber foam is now fairly brittle and
oxidized. Small pieces of it fall every-time we manipulate the
sculpture. Yet we don't have a good access to the foam for treatment
(like brushing a consolidant) because it is almost completely
covered with acrylic paint.  Despite our warnings on its fragility,
it will be put on permanent exhibit next year.

We would like to find a treatment to stabilize and consolidate the
rubber foam, but little information is available on the subject,
therefore if anyone has successfully treated similar objects we'd be
happy to hear about their findings.  One of the avenue we are
considering at the moment is the application of an antioxidant such
as Irganox, followed by a consolidant impregnation, if we can find a
suitable application method.

Photos available on request.

Myriam Lavoie, Sculpture conservator
Centre de Conservation du Quebec


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                  Conservation DistList Instance 26:33
                 Distributed: Sunday, January 13, 2013
                       Message Id: cdl-26-33-020
                                  ***