For those who were interested in oak and teak I came up with the following
information. The information was supplemented by collection managers and
conservators at several museums.
Paul Callomon, collection manager at the Academy of Natural Sciences in
Philadelphia wrote to me that "From my carpentry days I remember that teak
is very oily, which is why it cannot usually be varnished. This makes it
suitable for ships' decks, garden furniture and other applications where
water resistance is important. I imagine that it must be fairly acidic, as
at least part of the oil will be volatile. I would expect it to be as
unsuitable for storing specimens as any other hardwood."
Pam Hatchfield in her very good article "Wood and Wood Products" in Rose,
C. L., C. A. Hawks and H. H. Genoway, editors. 1995. Storage of Natural
History Collections: Volume I. A Prevention Conservation Approach. Society
for the Preservation of Natural History Collections, Iowa City, Iowa. 448
pp., lists the pH value of teak as 4.5 (the pH of oak ranges from 3.3 to
4.7 depending on the species). In addition to its acidic pH, teak is one
of the hardwoods that tends to off-gas more organic acids.
Another source is Jean Tetreault. Coatings for Display and Storage in
Museums, Technical Bulletin No. 21, published by Canadian
Conservation Institute (CCI) in Ottawa, Ontario, Canada. Also, Guidlines
for Selecting
Materials for Exhibit, Storage and Transportation by Tetreault and
available from CCI. Their website: www.pch.gc.ca/cci-icc.
The pH range of:
teak is 4.5 - 5.5.
cork oak pH 4.6
sessile oak pH 3.9
black oak pH 3.9
American red oak pH 3.8 -4.2
American white oak pH 3.8 - 4.1
European oak pH 3.3 - 3.9
While teak is generally not as acidic as oak, it is still somewhat acidic.
Carol Brynjolfson, Canada; Rachael Perkins Arenstein, USA; and Lisa
Bengston, Canada provided some of the above information and references.
Bases upon these data, I would not recommend teak for cabinets that would
be used for storing natural history artifacts. It is uncertain how long
these woods (teak and oak) can continue to off-gas volatile organic
compounds so it would be risky to even use old cabinets for storage.
Hope this helps some of you.
Regards,
Charlie
******************************************************************************
Charlie Sturm, Jr
Research Associate - Section of Mollusks
Carnegie Museum of Natural History
Pittsburgh, PA, USA
Assistant Professor - Family Medicine
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