[NHCOLL-L:2431] Re: Evaporation, taping of jars

[Paul Callomon]

Hi Dustin,

My predecessor as collections manager spent months wrapping plumbers' tape (Teflon tape) round each of about 25,000 jars in our alcohol collection. Unfortunately, she did not check the condition of the lids first, and I have found dozens of old metal lids happily rusting away under their bright new tape covering. 
As far as I can tell, taping up jars in this way does not help much. If vapor has made it past the initial seal, then tape may or may not trap it The principle is that the tape provides a secondary barrier to vapor escape, but this assumes a very clean, tight seal against both the jar (which must thus be free of molding marks) and the lid (which should thus not be knurled). In practice, most collections contain a combination of lid and jar types. For us, any reduction in vapor release that taping might have achieved has not justified the considerable time taken to apply the tape and the difficulty I now have in visually assessing the condition of older metal caps. Instead, I have bought a big box of new lids in each of the sizes we use, and apply these to older jars every time I find one that is leaking. 
I guess if you used a tape whose adhesive had good bridging qualities, such as medical adhesive bandage (which we use for jar labels, with great success), then taping up lids would work better.

Regards,

PC. 

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
Secretary, American Malacological Society
On the web at http://erato.acnatsci.org/ams/


>>> "Dustin Wood" <dwood at sdnhm.org> 09/21/04 05:37PM >>>
Dear Paul Callomon,
I got your email off the nhcoll-list serve from a discussion on taping the
outside of fluid-filled jars to take an extra step in preventing
evaporation.  I'm interested in the product you use for sealing the outside
of the jars?  I've noticed some evaporation on some of our new jars/lids
(even with foam-backed Teflon liners) and would like to take the extra
precaution.  Thanks in advance for your help.

Dustin


Dustin Wood
Collections Manager
Department of Herpetology
San Diego Natural History Museum

1788 El Prado
San Diego, CA 92101

Phone: 619.255.0305
FAX: 619.232.0248
Email: dwood at sdnhm.org