Mold on plaster

I am working on cleaning a life sized, white plaster sculpture by
George Segal that has mold growth in several areas.  There was a
flood in the storage area where this sculpture was stored and
shortly after the clean-up of the facility was completed, numerous
small dark patches were discovered on the surface.

The sculpture has been isolated from the rest of the collections and
was loosely wrapped in paper to prevent mold spores from easily
spreading.  The plaster surface is unpainted, unfinished and very
absorbent.  A HEPA vacuum has been used to vacuum the entire
surface, but the entire surface is soiled from years of being on
display, and vacuuming does not reduce the staining.

Tests with ethanol by itself and a mixture of O-Phenylphenol and
ethanol (Lysol disinfectant spray), to try to deal with the mold,
were successful in reducing the appearance of the dark spots, but
they posed other problems.  Gently rolled application of the solvent
using cotton swabs tended to lift not only the darkened areas, but
also general surface soiling and plaster residue as well.

Are there any suggestions on other methods that can be used to treat
the mold and clean the surface of the plaster sculpture without over
cleaning?

Teresa Moreno
Assistant Conservator
Preservation Division
Arizona State Museum
University of Arizona
PO Box 210026
Tucson, AZ 85721
520-621-6314
Fax: 520-621-2976


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                  Conservation DistList Instance 20:43
                  Distributed: Tuesday, March 6, 2007
                       Message Id: cdl-20-43-022
                                  ***