teflon tape fills gaps very nicely, and molds itself into whatever  
space is available. The rear-view mirror on my '84 car was loose,  
rattling, and un-repairable, so I wrapped a bunch of teflon tape  
around the base where it connects to the car. It took quite a bit of  
tape, but it worked very well, no wobble.

Gail




On 12 /09/08    , at 02 /04/09,  11:44 AM, Britt Griswold wrote:

> The Smithsonian uses glass lids held in place with the traditional  
> fruit canning mechanism: a rubber gasket and a pressure seal  
> applied with the metal lever lock. Though the teflon covered  
> threads sounds promising...
>
> Britt
>
> Bruce Bartrug wrote:
>> Catherine Bursh wrote:
>> On the tape subject.... Anyone know the correct tape to use to  
>> seal the
>> lids of specimen jars with alcohol in them? I'm tempted to use black
>> electrical tape but not sure if the alcohol fumes will mess with the
>> glue on the tape.
>> The purpose of the tape is to slow the evaporation that takes  
>> place even
>> with a threaded top.
>> Catherine, I have two suggestions for you -- neither of which,  
>> however, I've actually tested for the purpose you indicated.
>> The first is teflon plumbers' tape.  Which is not really tape per  
>> se (it has no adhesive) but is simply a thin film of a very inert  
>> and useful material.  One wraps the tape on the threads to be  
>> sealed and tightens the lid.  Very good at sealing the slightest  
>> leaks, even in gas lines.  I used it many decades ago to seal  
>> brass joints in gas lines for chromatographs -- a instrument used  
>> to analyse chemical substances.  Try to find some wide enough to  
>> fit the threads in question.
>> The second is a type of seal used to seal lids of packaged  
>> chemicals.  It's a circular sleeve of shrink-wrap type material  
>> that one positions around a jar or bottle lid and then shrinks  
>> with a hair-dryer.
>> As I said, I've not tested these specifically for the application  
>> you've mentioned, but I strongly suspect using both would  
>> significantly reduce alcohol evaporation from a speciman  
>> container.  I'm suspecting you're already using glass jars and  
>> metal lids?
>> /Suerte/,
>> Bruce

Gail W. Guth
Guth Illustration & Design
139 Lathrop Avenue
Battle Creek, MI  49014-5076
269-963-1311
FAX: 269-969-0652
www.guthillustration.com