[NHCOLL-L:629] Re: Long term effect of compactus storage onwe t specimens

[Panza, Robin]

We have compactors for our dry collections, and they are manual for the
reasons John gives.  It didn't occur to me that people talking about the
smoothness of operation were referring to manual systems.  I find it hard to
believe there aren't regular sloshings with the manual ones.  I just know
how often people lose their grip on the crank, causing a sudden deceleration
of the mechanism.  

In addition, the units are moved much more frequently than any particular
jar in our pickle collection, so I would expect a lot more frequent contact
between liquid ethanol and gaskets if the pickle collection was moved to
compactors.  As for replacing all the jars (glass-topped with bails), not
bloody likely in my lifetime!

Robin

Robin K Panza                         panzar at carnegiemuseums.org
Collection Manager, Section of Birds          ph:  412-622-3255
Carnegie Museum of Natural History       fax: 412-622-8837
4400 Forbes Ave.
Pittsburgh  PA  15213-4008  USA
_____________________________________

We opted not to use the electric system for several reasons.  Electrical
systems have more moving parts to break, they are more difficult to open
when the system is down (and our institution is famous for saving money by
not having maintenance contracts), we can control the smoothness of stops
and starts better by training people to use the manual system, and
electrical systems have the potential to produce sparks.  As ethanol fumes
accumulate at floor level, using a mechanical system is a bit safer.

As for the issue of the fluid on the gaskets, this was considered.  When we
had the collection sitting on stationary shelving, we had gasket problems.
Every time a jar is moved, the gaskets get wet, not to mention, while they
sit on the shelf, there is an alcohol atmosphere above the fluid that
affects the gasket (we know this from evaporation studies).  So whatever
movement you get from the compactors probably is not a signficant increase
for gasket problems.

At any rate, the solution to this problem is to use screw-top jars without
rubber or synthetic rubber gaskets, a solution we hope to implement here in
a
few years (once we find the funds to replace 25,000+ glass top jars!).

--John