[Nhcoll-l] PTFE tape on jars

[Simon Moore]

Dear All involved,

I have tried PTFE tape also and find, as John suggests, that it works well on jars with lids that are getting past-their-best and would normally need replacing.  However it does string together and fall apart when the jar is opened again and the time saved in having to replace it each time might well justify purchasing new jars anyway. 
However, I recall the Mmes Steigerwald and Laframboise tested some tape by 3M back in the 1990s that went around the outside edge of the jar seal and was effective.  I know that this has since been superseded by something else...?

With all good wishes, Simon. 

Simon Moore MIScT, RSci, FLS, ACR
Conservator of Natural Sciences and Cutlery Historian,
www.natural-history-conservation.com 

  ----- Original Message ----- 
  From: John E Simmons 
  To: Callomon,Paul 
  Cc: NH-COLL listserv (nhcoll-l at mailman.yale.edu) 
  Sent: Saturday, January 11, 2014 2:34 AM
  Subject: Re: [Nhcoll-l] PTFE tape on jars


  Paul,

  Whether or not the Teflon (PTFE) plumber's tape helps will depend on quality of the closures on the jars. If the closures are made of good plastic (such as flexible polypropylene) or metal that is not oxidized, and have a good liner (e.g., a Teflon liner or in the case of metal lids, a compressible gasket around the inner edge) but the threads of the jar a a bit deep or the lid fits a bit loose, the tape can help by closing the gap between the jar and the lid. If you have a good quality lid that fits tightly on the jar, then its probably not worthwhile to use the tape. If you have lids that have tiny perforations (e.g., metal lids with micro-oxidation points) or plastic that is very thin or has microscopic cracks, then the tape probably won't help.

  There is an easy way to test whether or not the tape application improves your jar/lid combination. Fill a number of jars with storage strength preservative fluid (no specimens!) and close some with the Teflon tape and some without. Either mark the fluid levels on the outside of the jar with a grease pencil, or better yet, weigh each jar. Put the jars in a water bath and heat it to around 40-50C for a couple of weeks, then check the amount of remaining fluid in the jars and compare.


  --John




  John E. Simmons
  Museologica
  128 E. Burnside Street
  Bellefonte, Pennsylvania 16823-2010
  simmons.johne at gmail.com
  303-681-5708
  www.museologica.com
  and
  Adjunct Curator of Collections
  Earth and Mineral Science Museum & Art Gallery
  Penn State University
  University Park, Pennsylvania
  and
  Lecturer in Art
  Juniata College
  Huntingdon, Pennsylvania




  On Fri, Jan 10, 2014 at 4:48 PM, Callomon,Paul <prc44 at drexel.edu> wrote:

    Folks,



    At least 20 years ago (before my time here), white plumbers’ tape was wrapped around the edge of the lids and onto the sides of all the bottle and jars in a certain section of our alcohol collections. This is the PTFE tape that plumbers use to seal threads; it is thin, soft and non-adhesive. Presumably the idea was to provide a secondary vapor barrier in addition to the jar lid seal. 

    We are now doing long-overdue major maintenance on this collection, and are trying to assess the efficacy of this tape. I’d be very interested to hear from anyone who (a) has used it and can show it works (b) has used it and can show it doesn’t work, or (c) who considered using it but decided not to, and why.





    Paul Callomon
    Collection Manager, Malacology, Invertebrate Paleontology and General Invertebrates


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