[NHCOLL-L:5292] Tape on bottles

[Paul Callomon]

Folks,
 
A digest of some off-list correspondence on this topic:
 
My predecessors had our entire Malacology wet collection (25,000 jars) wrapped in Teflon plumbers' tape. They stretched it tight, and did several turns around each jar. Comparing fail rates ten years later with the adjacent (and not tape-wrapped) General Invertebrates wet collection, there is no evidence that the tape helped in preventing seal failure or retained vapor once the seal had gone. 
However, totaling up the hours spent doing the wrapping and costing that out - as well as the opportunity cost - it would have been cheaper to re-lid the whole collection. Even volunteer labor has to be costed, as while they are wrapping tape those people are not doing other things.
In addition, the tape made it harder to spot the older steel and bakelite lids that we would target as priorities for replacement. Extra time (and thus labor cost) was necessary to lift and examine every jar, rather than just eyeballing them. I have found steel lids that are rusted almost through and bakelite ones with cracks clear across them. Both look spiffy in their clean white tape jackets, though. 
In all the cases I have seen buying and fitting new lids is the most cost-effective approach, and it ought to be possible to demonstrate that to your institution by presenting a proper costed labor estimate. 
What was unusual in our case was that we had the opportunity to bench-test taping against not taping in two large collections within the same room over a long period - a unique opportunity. Our 2005-6 survey showed that the taping had effectively done no good, and that the labor had thus not been put to optimal use. Of course, we learned that the hard way. 

We too use a wide range of jar sizes, but interestingly I could find new teflon-lined lids (at www.oberk.com) for almost all of them! Unless you're using commercial jam jars, you should be able to get great lids for whatever you have. 
Finally, there are small grants available for this kind of thing. The NSF's collection care and upgrade program might be a good place to start. 
 
 
Paul Callomon
Collections Manager
Malacology, Invertebrate Paleontology and General Invertebrates
Department of Malacology
Academy of Natural Sciences
1900 Parkway, Philadelphia PA 19103-1195, USA
Tel 215-405-5096
Fax 215-299-1170
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