Foam rubber

In a very recent Cons DistList there was a discussion about the
ethics of removing degrading foam rubber from  piece of electronic
equipment. At the Canadian Conservation Institute we have found that
it is relatively easy to consolidate degrading foam using the
parylene process. The degree of consolidation is excellent, the
colour change negligible, but any residual flexibility is
irretrievably lost and the deposition is irreversible.

We have used this procedure a number of times for disintegrating
foam rubber in a World War II radio; for polyurethane foam puppets.
The irreversibility has to be considered in light of the fact that
the parylene coating is minimal--much less material is added
compared to other consolidation processes--and that without this the
foam will be irretrievably destroyed.  In addition, for such fragile
material, any consolidation method is, in practice, irreversible. If
readers are interested, I would be happy to provide information about
parylene and where the process can be conducted.

David Grattan

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                  Conservation DistList Instance 10:73
                Distributed: Tuesday, February 18, 1997
                       Message Id: cdl-10-73-001
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