[Nhcoll-l] Bakelite

[Callomon,Paul]

Following Dirk's comments on Bakelite: a distinction should be drawn between Bakelite and phenolic resin. The former uses wood dust as a filler, and is not stable under mechanical stress (such as in a screw top) for long periods. Phenolic, however, seems (from our sampling of 50-year-old-plus bottles) to be very stable, showing no micro-cracking or other stress symptoms. However, as Dirk points out, neither material should be exposed to Formalin vapor or submerged in preservative. If (as was previously done in our collection) submerged internal vials are capped with phenolic lids, the latter will stain the alcohol even if Formalin was never present.

Paul Callomon
Collection Manager, Malacology, Invertebrate Paleontology and General Invertebrates
________________________________
Academy of Natural Sciences of Drexel University, Philadelphia
callomon at ansp.org Tel 215-405-5096 - Fax 215-299-1170

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20151101/2904ac89/attachment.html