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12. Cost of vacuum-drying and freeze-drying

There is DO universal method available for determining the cost of drying water-damaged archival and library materials in vacuum chambers. The estimates, generally based on the quantity of materials to be treated, may include a calculation of man-hours spent by technicians and operators of the chambers, amount of electricity used, supplies and materials, plus the profit factor. At the other end of the scale there are many cases of moderate to no costs, thanks to a desire, on the part of the owners of the chambers, to foster good will or to render a public service. And because the mission of most archives and libraries is of a nonprofit nature many organizations often are willing to charge only the costs involved.

In the cases that follow, some prices quoted are old. A calculation upward will have to be made for inflation. The prices do not include transportation and storage. Nevertheless, they will convey a general idea of what vacuum chamber drying can cost as shown in specifically cited cases.

The recovery operations incident to the Charles Klein Law Library fire, in June 1972, were handled by a salvage company, Recovery Services International, which is a subsidiary of the insurance carrier, Insurance Company of North America. Since the library's collection was insured, the carrier wanted to recover as much as possible in order to lower the amount of the claim. To this end, the salvage company selected a vacuum chamber operated by the General Electric Space Simulation organization, Valley Forge, Pennsylvania, for freeze-drying the water-damaged books awaiting in a commercial food freezer storage plant. It was estimated that on the basis of the large amount of volumes involved, the cost would be under $2.00 for each book (32). At the same time, insurance officials at Temple University, site of the library, had calculated the cost of restoration would be about $4.00 per volume as opposed to $25.00 per volume for cost of replacement. However, it was recognized that many of the salvaged volumes could not be replaced at any cost (57).

The Stanford University Meyer Library flood, November 1978, involved over 50,000 volumes. The University had no commercial insurance, but was self insured for a specific sum of money. The use of the Lockheed Missiles and Space Company vacuum chamber for freeze-drying was estimated to be 340,000. However, the company decided to absorb the cost as a contribution to the University. The Modern Ice and Cold Storage Company where the volumes were stored in their frozen state absorbed some $8,000 worth of freezer space and labor. The Eastman Kodak Company donated $2,000 worth of film restoration. Various other businessmen contributed expertise, food, labor, trucks and supplies (58), all of which helped reduce the final overall costs of the recovery operations.

In January 1979, a burst water main flooded the Taylor Institution Library at Oxford. Some 200 volumes were taken in a frozen state to the Atomic Energy Research Establishment at Harwell where they were vacuum-dried in a laboratory chamber. It is interesting to note that this vacuum drying operation was the first successful attempt of its kind in England (59). There were no costs involved for the work done.

In January 1981, the fire and subsequent water-damage to the records of the Regional Office of Income Security Services in Winnipeg involved some 150 file drawers which, when emptied, filled over four hundred plastic crates used to freeze the documents. The drying process took place in a high altitude chamber used by the Canadian Forces Base at Winnipeg. The recovery costs estimated by the Income Security Services authorities were not to exceed $12,000. However, the Armed Forces contributed their efforts in the recovery of the documents as a public service. Hence, the final costs for the entire operation were considerably less (37).

In August 1985, an informal query on rates was made of a small company in the USA that specializes in freeze-drying of water-damaged documents and books. The following information was obtained: The cost of drying 100 frozen books, about textbook size, in a vacuum chamber with a capacity of 12 cubic feet (.34 cubic meters) is about five to six dollars a book (transport costs not included) (53).

At first glance, freeze-drying in sophisticated chambers of large quantities of wetted materials may appear high. However, if you weigh the costs of air-drying, hiring of additional personnel, requirements for space, rental or purchase of apparatus for control of humidity, cost of materials, loss of time, the risk of mold infection, against the costs of freeze-drying, the price begins to look reasonable.

A clue to where the cutoff point ends and the positive cost factor begins was provided recently in conference held by the American Institute for Conservation. One of the participants in a seminar, who has had considerable experience on the subject, felt that the cost factor per item factor becomes reasonable only when freeze-drying more than 2,000 books, or 3,000 to 4,000 manuscripts unless small chambers are used. However, these are less effective because they have less sophisticated equipment. Consequently, it takes longer to pus the vacuum, maintain and dry the contents (60).


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