Ethafoam

Kasey Brewer <kbrewer [at] royalbcmuseum__bc__ca> writes

>We seem to have a large quantity of Ethafoam in artifact storage
>areas that is deteriorating.  It still appears sound, but if one
>presses a finger into it, the product compacts and crushes, leaving
>a hole where the finger was inserted.  It also leaves a white powder
>on the finger and surrounding areas.  I believe, but am not 100%
>sure, that this Ethafoam was purchased about 15 years ago when there
>was a large storage project underway that included making custom
>Ethafoam inserts for a huge number of drawers and shelving units.
>
>I contacted Dow Canada to enquire about the problem and was told
>that this was the first they have heard of it.  I asked if the
>problem could be associated with a change in blowing agent,
>instigated by the move away from CFC's around that time.  The
>representative emphatically stated that the blowing agents, several
>of which have been used over the years, are all inert and should not
>cause any breakdown of the polyethylene.  I asked if they had
>subcontracted out the manufacture of Ethafoam at some point, and
>perhaps lost some control over the production methods and was told
>that manufacture of Ethafoam has never been farmed out.  All they
>could suggest is that we had purchased something marketed as
>Ethafoam, but which was, in fact, another product. ...

I am heartened to hear that we were not the only ones who have had
this "fake Ethafoam" problem.  It's too bad you're not able to find
records of 15 years ago to identify the supplier and manufacturer of
your "Ethafoam". I'd be surprised if the manufacturer was Dow. We
had a similar experience when I used to work at another museum.
Within a few years of installation, the "Ethafoam" lining the
shelves was disintegrating much in the same manner.  As it turns out
another department had ordered the foam (without checking with the
conservators for testing) and it came from a different manufacturer
as a "knock-off" product.  It probably was less expensive than the
real Ethafoam, though not in the long run as we had to replace all
of it.  I'm going on memory as this was also about 15 or 20 years
ago and unfortunately I don't have access to the purchase order now,
but I do recall it wasn't the DOW manufactured material.

Maybe someone else has had this experience and still has the
original purchase documents.  I'll be curious to hear other
responses.  Our experiences are good reminders of why we continually
test materials before using them for collections storage, packing or
display. Testing your old foam along with some 15-year-old and new
Dow Ethafoam would might reveal variations in composition other than
the main polyethylene component.

As you suggested, there could be a relation between the "fake foam"
and the rust on your metal objects. I've seen the "real Ethafoam"
hold up longer than yours has and I haven't seen it rust any metal
objects.  Coincidentally, I recently wrote an article coming out
soon in "Collections" on conservation management that uses this
"fake Ethafoam" experience as part of a case study.  Here's hoping
you're able to solve the mystery.

Katharine Untch
Conservator
Architectural Resources Group
Pier 9 The Embarcadero
San Francisco CA 94111
415-421-1680 ext 247
Fax: 415-421-0127


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                  Conservation DistList Instance 19:13
                 Distributed: Friday, September 2, 2005
                       Message Id: cdl-19-13-009
                                  ***