[Nhcoll-l] Opening specimen jars with jammed ground glass stoppers?

[Fabian Francesco Neisskenwirth genannt Schroeder]

Dear Truth,

I had the same issues last year in Bern. I made a paper on the  
subject, to be released in 1 month in "Der Präparator", but its in  
german. I dealth with over 1000 jars that were about 100-70 years old..

So my quik advice:

If its possible try to afford the "Universal Jar Opener" from Alcomon.  
Its realy very usefull and helped me a lot opening jars with ground  
stoppers. Link: http://alcomon.com/about/

Before you do anything, document every jar to be opened (take  
pictures) and before using anything that could damage the outside  
labels (as Drik pointed out), try to take them off the jar with lots  
of care. Warm water compresses help (specialy on old gummed labels).  
You can try other solvents like ethanol or acetone (with care) if it  
doesnt work with water.

Cracked jars are useless, so here you can try to take of the top with  
a bit more of strengt... (take care of little glass splinters,  
specially on the specimens and your hands)

Wax can be solved very well with heat, use a hairdrier. If the heat  
becomes a problem, use orange terpene (Histol).

Congealated fluids between stopper and jar seemen to be all kind of  
residues, specialy lipids from the specimens.. Try some of the  
mentioned solvents on the jar openings. Little trokes on the jar help  
the solvents to spread between the opening and stoper. Do this gently...

And be carefull with the hot water method, because old jars crack  
pretty fast with temperature changes. Use this method just in case no  
solvent helps.. The less stress for the jar, the more likely it with  
still be usefull.

Finally, change all the screwtops from the TwistOff Jars. They are  
easy to open, but have a lifespan of no more than a few years...

For more detailed information, please write back.



Hope this helps you a little bit.




Zitat von Truth Muller <tmuller21 at coa.edu>:

> Hello,
>
> I am currently one of a small team of students from College of the Atlantic
> doing extensive restoration work on the George B. Dorr Natural History
> Museum collections. We are preparing the entirety of the Museum's
> collections to be moved to a new, modern storage facility which is still
> under construction.
>
> I am responsible for the Ichthyological and Marine Invertebrates wet
> collections, which have unfortunately suffered from neglect over the past
> 10-15 years. Only about 60-70% of the Ichthyological collection specimens
> are in modern jars with screw-top lids, and the rest are in e in much older
> jars with ground glass stoppers. Some of them are sealed with silicone, a
> few with an unidentified wax, and others have simply self-sealed with their
> own fluids congealing between the jar and the stopper. Many of these jars
> need to be topped off, and a few are cracked and urgently need to be
> replaced, but almost every single stopper is stuck fast as though
> super-glued. We have not yet found a way to open them without putting the
> specimens inside in harm's way.
>
> What is the best method that we can use to open these jammed jars,
> preserving the specimen, and, ideally, the jars as well? Any help or advice
> would be greatly appreciated!
>
> ~Truth Muller
> George B. Dorr Museum of Natural History
> College of the Atlantic '21




--
Fabian Neisskenwirth

Naturwissenschaftlicher Präparator
MA Stundent Restaurierung & Konservierung von Kulturgut

CICS-TH Köln