[Nhcoll-l] glass jar with ground glass stopper

[John E Simmons]

Chances are that you do not need any grease at all on the seal. Before you
add anything, you should check to see if the seal is good. To do this,
first wash the jar and the lid with soap to remove any residue. Then fill
the jar with 70% (no specimens) and insert the lid. Either mark the fluid
level, weigh the jar + lid + contents, or both. After 24 hr (to give the
lid time to settle) put the jar into a tub or sink that you can fill with
water, starting at tap temperature, then gradually increasing until you
reach the average temperature of your collection storage area (do NOT use
very hot water, keep the temperature at what the jar will be subjected to
in storage). You should know within a few days if it leaks or not.

When I was at the California Academy of Sciences we had thousands of
similar jars in use. Most of the older ones had lids that were ground to
fit the opening of the jar, which mean that if you got the right jar and
lid combination, they did not leak, but if lids were switched around
between jars, they often did.

If the jar does leak, follow Simon's advice and use Alsirol.


To remove these sorts of lids when they are stuck, try rocking the lid back
and forth or tapping the handle part of the lid *gently* with a piece of
wood, or *gently* tapping around the mouth of the jar (use a piece of wood
and tap gently to avoid breaking the glass). If neither of those techniques
works, you can put the jar in a sink, add warm water, and gradually
increase the temperature until the internal jar pressure pushed the lid
open--the drawback to this is that you will heat up the alcohol inside the
jar which will speed up deterioration reactions in your specimens.

The other means to get the lids off is to purchase the Universal
Stopper/Opener sold by Alcomon. The device is expensive, but works well:
https://alcomon.com/about/

--John

John E. Simmons
Writer and Museum Consultant
Museologica
*and*
Investigador Asociado, Departamento de Ornitologia
Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima


On Fri, May 3, 2024 at 4:09 PM Kathy Omura <komura at nhm.org> wrote:

> I have not worked with these types of jars and was wondering what to
> use on the lids so they can be reopened. The jar will be holding a wet
> preserved (70% EtOH) specimen.
> I heard vaseline on the ground glass part of the lid and jar makes it
> easier to reopen.
> To make a tight seal, after the vaseline application, seal the lid with
> wax along the edge.
> What other options do I have? I appreciate any help you can provide.
> Kathy
> --
> Kathy Omura, Collection Manager
> Marine Biodiversity Center
> Natural History Museum of Los Angeles County
> (213) 763-3386
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