[NHCOLL-L:3511] Re: Neoprene rubber stoppers

[Steve Halford]

When using the vial-in-jar technique John describes, Bakelite has
another serious drawback.   When submerged in alcohol the Bakelite can
expand over time to the point where the closure no longer engages the
threads of the vial.  I've had lids fall off vials and specimens and
labels floating loose in the bottom of the jar.

Steve.


-- 
Steve Halford (halford at sfu.ca)
Museum Technician
Department of Biological Sciences
Simon Fraser University             New Phone#
Burnaby, B.C. Canada               August 2007
V5A 1S6                                  778-782-3461


On 7/26/07, Simmons, John E <jsimmons at ku.edu> wrote:
>
>
>
>
> There is a better alternative to using screw-caps or snap caps on small
> vials.  We use a shell vial (straight sided, no threads, no neck) filled
> with preservative, and plug the top with polyester fiber.  Polyester fiber
> (which you can buy in large bags at fabric stores as pillow stuffing) is
> used because it is inert and because unlike cotton, it has great regain
> (when compressed, it springs back). With polyester fiber, you can make a
> nice, tight plug that fits into the mouth of the vial. We then submerge the
> vials preservative in a screw-cap jar with a good closure (we use the
> flexible polypropylene lids that fit tightly to the jar and do not unscrew
> themselves with temperature changes).
>
>
>
> Several entomologists have told me that their concerns with this system are
> (1) the plugs coming out of the vials (I have never had this happen if the
> plug is done right) and (2) they want to easily find the vial they need
> without looking through a whole jar full of vials.  The latter concern is
> easily solved by using smaller jars (3 or 10 or 20 vials per jar, whatever)
> with a label indicating which vials are inside.  The payoffs in security to
> the specimens and time saved in replacing stoppers or retightening Bakelite
> lids when the temperature changes cause them to unscrew or they crack from
> aging is well worth it (it is worth noting that Bakelite is
> phenol-formaldehyde polymer that offgasses formaldehyde as it ages).
>
>
>
> You can read more about this system and see a drawing in Conserve O Gram
> 11/4, available for free download from
> http://www.nps.gov/history/museum/publications/conserveogram/cons_toc.html,
> or in "Herpetological Collecting and Collections Management" (SSAR, 2002).
>
>
>
> --John
>
>
>
>
> John E. Simmons
>
> Collections Manager, Natural History Museum & Biodiversity Research Center
>
> and
>
> Director, Museum Studies Program
>
> University of Kansas
>
> 1345 Jayhawk Boulevard
>
> Lawrence, Kansas 66045-7561
>
> Telephone 785-864-4508
>
> FAX 785-864-5335
>
> jsimmons at ku.edu
>
> www.nhm.ku.edu/herpetology
>
> www.ku.edu/~museumst
>