Fireproof safes

Sherry Byrne <sbyr [at] midway__uchicago__edu> writes

>Does anyone have any experience with the use of fireproof safes for
>the storage of books?  We are working with a collector who keeps
>most of the valuable items from his 18th century book collection in
>fireproof safes in his home.  The size is about 3 1/2 feet.  The
>concern is about the relative humidity in the safes.  Instructions
>explain that there is water in the walls as part of the fire
>prevention design.  This also causes vaporization.  The manufacturer
>sends desiccant tablets that need to be regularly replaced and
>advises that books and other valuables be kept in Ziploc bags.  We
>always advise that people not keep books in baggies because of the
>moisture.   Does anyone have information, insights or references
>that might help us with this question?

I have a few comments that might be of use: The late nineteenth
century safes we have in our building were filled with great amounts
of plaster between steel inner and outer shells. I was told it was
the moisture in the plaster that made the safes fireproof. I gather
some things haven't changed since 1890.

Zip Loc and other grocery-store purchased bags are made of
polyethylene, which is not an effective barrier film. Plastic does
not create moisture or promote condensation, although in some
circumstances condensation may be localized in plastic bags. Much
depends on the storage conditions, and in a sealed insulated safe
kept at close to room temperature, containing a book that has does
not contain an unusually large amount of water, I think the risks
are far outweighed by the advantages of plastic bagging.

The use of properly sealed barrier film bags with silica gel (and
possibly an oxygen absorber) might be a simple and direct solution.
Information on such bags is on our web site.

Jerry Shiner
Keepsafe Systems
Supplies and Solutions for Microclimate and Oxygen-free storage
800-683-4696
416-703-4696
Fax: 416-703-5991


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                  Conservation DistList Instance 15:59
               Distributed: Wednesday, February 27, 2002
                       Message Id: cdl-15-59-008
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