Deteriorating Foam

I'd like to provide a quick update and thank you to all of those
people who responded to my posting about deteriorating foam.  This
is what I have learned.

DOW Canada states that they have never subcontracted out the
production of Ethafoam and have never lost control over established
manufacturing standards, methods or materials.  They have changed
blowing agents, but do not believe that the changes have resulted in
the production of an inferior foam.

A few weeks ago I was fortunate to find the uncut, labelled edge of
a piece of deteriorating foam.  Mystery solved!  The foam is
actually PolyPlank, a non cross linked polyethylene foam that looks
virtually identical to Ethafoam.  I suspect that this foam was
purchased with the belief (either implied or inferred) that it was
Ethafoam.  I believe the PolyPlank is the problem throughout our
storage areas and will have to be replaced.

One further note: I tested the pH of the deteriorated foam and it
was neutral.  I don't believe it to be the source of our corroded
metal. Rather, the corrosion seems to be more localized around the
cloth tape wrappings that cover the handles of several of the tools.

Kasey Brewer
Head of Conservation
Royal British Columbia Museum
675 Belleville Street
Victoria BC V8W 9W2
Canada
250-387-5518
Fax: 250-356-8197


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                  Conservation DistList Instance 19:20
                 Distributed: Tuesday, October 18, 2005
                       Message Id: cdl-19-20-002
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