Crazing of acrylic sheeting

We too had problems with crazing plexi which was traced to a bad mix
in the adhesive used (although the problem was not found by the
original supplier but rather one of their competitors).

We do, however, have a different problem with UV plexi used in
picture frames.  After about six months of either storage or
exhibition, a greasy, clear film appears on the surface which is
exposed to the air.

The film is evenly distributed and very hard to clean off (it is
soluble in detergent).  Two different suppliers have no idea what it
is. Likewise, the University's industrial hygienist is at a loss.

It does not appear on all plexi items, just a few. Does anyone else
have *this* problem?

Don Sucha
Technical co-ordinator,
The Nickle Arts Museum

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                  Conservation DistList Instance 10:57
                 Distributed: Friday, December 13, 1996
                       Message Id: cdl-10-57-011
                                  ***