Books + Papers
Books, paper-based artwork, and paper records can sometimes be salvaged after being exposed to water, smoke and other extreme conditions during an emergency. Use these tips to evaluate what damaged items can be salvaged, and then to salvage what you can.
How to Safely Dry Wet Documents and Art
As you begin salvaging your artwork and records, you will need to decide how to dry out the damaged items. There are four basic ways to do this. The first step, and most important to remember, is that freezing will buy you time and stabilize your collections.
Again, this all depends on your time, resources and the scope of the emergency. If you have hundreds of things that are damaged and wet, then freeze them and figure out salvage methods later. If you have 50 wet items, then air-dry them or send some things out to be frozen. This is more an art than a science.
Step 1: Freezing
Wrap objects in paper, wax paper, parchment paper in bundles, in zip-lock bags with paper toweling, or interleave if time permits; then place in freezer. Then proceed to one of the next three steps.
Step 2: Air Drying
This is the most obvious and immediate way to dry almost any paper item. It’s suitable for drying relatively small numbers of damp or slightly wet materials.
Use fans in your workspace — but only to circulate the air. Don’t have them blowing directly on the drying objects.
Have tables or flat space prepared with absorbent materials.
Blot wet objects to remove as much moisture as possible.
Single leaves can be laid out on tables, floors and other flat surfaces.
A clothesline can be strung and durable papers, prints and photos can be hung up by the corner, using plastic clothespins.
Interleave damp to slightly wet books every 10 to 20 pages with paper toweling, and change it often..
Flip books from end to end — and continue to fan out pages as you replace interleaving.
Air-drying requires no special equipment.
It’s extremely labor-intensive, and can require a great deal of space. That’s why it is suitable only for relatively small numbers of materials.
Books will be at least 20 percent bigger when dry, and will require more shelf space. Bindings may need to be replaced.
Step 3: Vacuum Freeze-Drying
Salvage vendors will have access to vacuum freeze-drying facilities. This process is especially suitable for large numbers of wet books and records. It is a good way to deal with the problems that can’t be successfully air- or freeze-dried (water-soluble inks, watercolors, coated paper).
Objects/artworks must first be frozen, then placed in a vacuum chamber. Air is drawn out of the chamber, and a source of heat is introduced. The chamber is usually -20° F, and the introduced heat brings the temperature up a bit — but still well below 32°, so the artifacts remain frozen throughout the process.
The physical process known as sublimation takes place, in which ice crystals vaporize without melting. This means there is no additional wetting, swelling, stress or distortion beyond what happened before the materials were frozen.
Step 4: Vacuum Thermal-Drying
Books and records that are slightly to extensively wet can be dried in a vacuum thermal-drying chamber. The vacuum is drawn, heat is introduced, and the materials are dried, theoretically at just above 32°. (This means the materials stay wet while they dry. This method does not sublimate ice into gas, as does vacuum freeze-drying).
This method is quick and relatively inexpensive. For large numbers of books or documents, vacuum thermal-drying is easier than air-drying.
Vacuum thermal-drying can cause enormous distortion in books. Expect them to need extensive rebinding, along with expanded shelf space. To lessen these impacts, some companies restrain books with metal plates during the drying process, and this can be quite effective. But regardless, coated papers will stick together. Water-soluble paints, inks and dyes may bleed. And heat accelerates the aging process.
As a result, this is an acceptable method of drying only for wet records that have no long-term value.
- RAP, the Regional Alliance for Preservation, has several members throughout the United States who have field service programs that provide phone assistance in an emergency.
- The Northeast Document Conservation Center, a RAP member, has a number of technical leaflets on preparedness and salvage posted at its site, and runs a 24/7 hotline at 978-470-1010.
- Munters and Belfor-US are two of the large salvage vendors in the United States. with resources in every part of the country. They have freezer and freeze-drying facilities.
- The Minnesota Historical Society has a fabulous salvage website and provides good technical leaflets as well as up-to-date links to other web resources.
- The National Park Service offers technical “Conserv O Gram” leaflets on the care of collections and what to do with damaged artifacts.
- The American Institute for Conservation is a membership organization for the art conservators in the United States and abroad. If you need to locate a conservator near you, use their find-a-conservator service.
- The Library of Congress: Emergency Drying Procedures for Water Damaged Collections