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Subject: Thymol


From: Paul Storch <paul.storch>
Date: Friday, November 15, 2002
Jenny Dickens <jenny.dickens [at] doi__vic__gov__au> writes

>We have some oak barrel components from a shipwreck which were
>treated by a non-conservator in 1984.  A mixture of PEG and Thymol
>was used.  ...
>The Thymol seems to have been used to prevent biological growth in
>the PEG treatment tank.  The items display surface cracks
>(insufficient PEG seems to have been used) and smell very strongly
>of Thymol.  We will be looking at re-treatment but in the meantime
>need safe storage. ...
>....  We cannot find air tight containers large enough and so
>are considering heat sealing the items into transparent barrier film
>packages eg Escal (they need to stay visible).  Our heat sealer
>produces a 5mm wide seal.  Our store is environmentally controlled.

Given the conditions, I think that is a good option.  In this
particular case, I would suggest using odor adsorbent and absorbent
materials such as zeolites and activated charcoal, respectively.
Hydrophobic zeolites would be best suited to adsorb thymol, since it
is mainly non-polar, and there would be less risk of pulling out
available water from the wood.  You could create one or two
resealable packages with smaller sections to serve as controls.
Weigh the zeolites before putting them into the package, then at
regular intervals to track any adsorbance that may occur.  There may
be more effective, but more complicated, ways to do this, but it is
certainly the most expedient, simple, and cost effective application
for an archaeological repository to use.

Paul S. Storch
Senior/Lead Objects Conservator
Daniels Objects Conservation Laboratory (DOCL)
B-109.1, Minnesota History Center
345 Kellogg Blvd. West
St. Paul, MN  55102-1906
Fax: 651-297-2967

                  Conservation DistList Instance 16:34
                 Distributed: Friday, November 22, 2002
                       Message Id: cdl-16-34-013
Received on Friday, 15 November, 2002

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