- Background: Research and case studies have shown that large quantities of water damaged library and archival materials can be stabilized and salvaged when frozen and stored at low temperatures (ideally -20 F). Freezing allows the institution time to plan, organize, control and coordinate their disaster recovery and drying plans. Freezing is not a drying method and will not kill mold spores. It does give the library time to plan and organize, and minimizes the damage to the materials.
- Definition: Freezing uses a self-defrosting fast freezer that has the capacity to freeze items very quickly, at temperatures below -10 F. This method is suitable for non-coated stock and smaller quantities. Items must be left in the freezer from several weeks to several months. As staff time and space permit, items can be taken out of the freezer and air dried before they are returned to their regular shelves.
II. DRYING METHODS:
A. Air Drying:
This is a very labor intensive task that requires a large work space and can only normally be used with small quantities of materials. Books with clay-coated paper (usually very slick paper typically used for books with photographs) are much trickier to air-dry and respond better to vacuum freeze drying (see below). Always consult a conservator before attempting to handle any rare or valuable materials.
B. Vacuum drying and vacuum freeze drying are both alternatives for freezing and drying large quantities of damaged materials.
Tables, Fans, Paper towels and/or Unprinted newsprint, Blotter paper, Wax paper, Nylon line, Extension cords, Trays, Water bottle, Polyester sheets, Press board, Cardboard, Weights, Plastic clothes pins.
- Recovery Operations:
- Make sure that all staff and volunteers are adequately trained and supervised for all air drying tasks. Because of the nature of the materials, it is also a good idea that this recovery station be in a quiet work area away from the stress of other recovery operations.
- Make sure that the work area is clean and dry with the temperature and relative humidity as low as possible with good air circulation. Moving air accelerates the drying process and helps to prevent or slow down the development of mold and mildew. If working outside remember that prolonged exposure to sunlight is detrimental to all materials.
- Bound Volumes: If books are dripping wet, handle as little as possible. Place them on top of absorbent paper (paper towels, blotting paper, etc.) and change the paper as it becomes soaked. When water is no longer dripping, stand the item up and proceed as described below.
- Bound Volumes: if not too wet, can be placed open on tables to dry. The best procedure is to hold the book by the spine, turn it upside down so that the top or head of the book is on the table. Then gently open the book so that the volume is in a wide "V" for support and ease in drying. If necessary, support it with plastic bookends or other non-rusting supports.
- Soft cover volumes can be supported with cardboard spacers so that they will stay upright.
- Once the pages can be easily separated, drying can be speeded up by interleaving the textblock ;with absorbent paper (paper towels or blank newsprint). Place a sheet of absorbent paper (one larger than the size of the book page) every 50 or so pages. Be prepared to change this paper quite often, putting the paper towels between different 50-page sections each time. Do not overstuff the volume with absorbent paper or it will distort the text and ruin the binding.
- Final Stage - When absorbent paper no longer clings to the book's pages but rather falls out when the book is placed upright on the table, discontinue interleaving. Instead, fan the book open as much as possible to let the circulating air get to it. Remember the spine and covers dry last as they usually absorb the most water.
- When books feel dry but are slightly cool to the touch, they should be closed, laid flat, gently formed into their normal shape and held in place with a light weight. THEY SHOULD NOT BE STACKED ON EACH OTHER. They should be completely dry before they are returned to the permanent shelves, otherwise mold will develop inside of the volume.
- Single Sheets: Stacks of wet single sheets should be interleaved with clean, dry sheets. They should be checked at least every four hours. Once the items are dry they can be sent to sorting for input into new file folders and boxes. If time and space permit, try the procedure described below.
Test if sheets can be removed gently one at a time and placed between blotters or unprinted newsprint. If necessary use a press board and weight to hold the stack in place.
- Dampen a sheet of polyester film (3-5 mil thickness) and lay it on top of a wet pile of single sheets. Press down lightly on the film. Gently lift one corner of the film, and use a bone folder or spatula to help ease away a sheet or sheets from the pile onto the film. Slowly roll the film away from the pile lifting up the wet sheet(s).
- If you pick up more than one, lay it polyester side down on a clean flat surface. Using a second piece of film, repeat the rolling motion to remove the top item from the pile. You will find that by careful, gentle manipulation you can roll the film back from the pile with a single wet sheet attached to it. Place the wet item between clean dry blotters.
- If space, time and supplies allow, individual sheets can be hung up on lines with plastic clothes pins and allowed to dry. Extremely wet papers are too fragile to be dried in this manner. Really wet items need to be dried between blotting papers and or newsprint.
- Vacuum drying: this method uses a vacuum thermal-drying chamber. Wet or frozen items are placed in the chamber, a vacuum is drawn, heat is introduced, and the materials are dried. The temperature stays above 32 F. This method is good for large numbers of materials, is easier and more cost effective than air drying, and is good for extensively water damaged items. Unfortunately this method often produces extreme distortion of books requiring them to be rebound. This process tends to also cause coated papers to stick together.
- Vacuum freeze drying: in this method frozen books and records are placed in a vacuum chamber. A vacuum is drawn and carefully controlled heat is applied. The temperature is kept below 32 F. This combination causes the frozen water to go directly from that state to the gaseous state. This process of sublimation eliminates further damage to the materials through distortion, bleeding and sticking together. It is an effective way to handle and dry large quantities of materials. The main drawback is the cost.
D. Select Bibliography:
- Definition - to remove the moisture from the air, the collection, and the building using large commercial dehumidifiers.
- Benefits and Disadvantages - This method is fairly new in the library and archival field, though it has been used extensively in office buildings. A major benefit is that staff does not need to remove and box any items, all of the work is done in-house. If it is not done within 24 hours though, mold & mildew can set in, and swelling and adhesion has started. Also additional testing and reports on this method still need to be conducted and checked into before an institution decides on this option.
Buchanan, Sally A. Resource materials for disaster planning in New York institutions, New York: New York State Library Disaster Planning Project, 1988, pg. 20.
Toronto Area Archivists Group Education Foundation. An ounce of prevention, Toronto: Authors, 1986, pgs. 67-68.
Waters, Peter. Procedures for salvage of water-damaged library materials, Washington DC: Library of Congress, 1975, pgs. 16-21.
III. SMOKE, SOOT, and CHAR DAMAGE:
[To print a handout for dealing with smoke, soot, and char damage, click here.
To print a handout on soot from Heritage Preservation, click here.]
Fire damage is usually irreversible, but it is possible to remove some of the surface soot and char by using some of the following methods. The paper should be completely dry and in good condition. Consult a conservator for rare and valuable items.
Start by finding a clean space to work in. Thoroughly vacuum the area with a machine that has a HEPA filter.
- Removing Soot
Don't use a dust cloth! Vacuum (on low speed if you can) the items carefully to remove dust and ash. Put cheese cloth or panty hose over the end of the hose and secure with rubber band to prevent sucking up pieces you might like to keep. Next remove soot from paper by use of chemical sponges, erasers, or a dry cleaner such as Groomstik or Absorene Paper & Book Cleaner which is available from archival supply companies such as Light Impressions, Archival Quality Materials, or Demco.
Use chemical sponges in a gentle, dabbing motion. Do not scrub since this will damage the paper. Try a test page before doing a whole book. It has been reported that chemical sponges are good for a quick cleanup, but that they leave a residue film and smell which impedes other types of cleaning.
Erasers or a dry cleaner also need to be used with a gentle brushing motion. Use an artist brush to remove the rubbings. One source reported that pink pearl erasers worked best.
Photographs and paper should be placed on clean white paper or a blotter. Brush them gently starting in the center and brush out.
- Dealing with Char damage
Vacuum as much loose material up as possible (again being careful not to suck up book parts that are important to keep). Then trim charred edges by using paper shears, razor blades, or scissors - keep the vacuum cleaner running nearby as you work. Consider the aesthetics of a damaged item prior to returning it to the shelf. Some suggestions for improving appearances are: rebinding, phase boxes, file folders, or adding a cover or jacket.
- Reducing Odors:
There a several things to try that help lessen strong odors in books and papers. Fresh air, and lots of it, is the first thing to try:
- Set up as many fans as possible, turn up the ventilation system. Open doors and windows (if the area is secure) and let it blow for as long as possible.
- To speed it up, set large flat pans of activated charcoal and/or baking soda around the room. Replace baking soda/charcoal every 8-12 hours. Your nose will know when to stop - then do it for another 24-48 hours anyway.
If the above fails and the affected items are few:
- Stand the books up and fan them open inside a box with a lid. Carefully place baking soda or charcoal or a strong smelling deodorant in the box with the books. Soak a sponge in the deodorant and set it a dish. Check it every 48 hours to replace deodorizer and make sure the books haven't fallen onto it.
If The Smell Is From Mold:
** The moldy "smell" is not the problem it is the indicator that there is/was a problem.
Getting rid of the smell does not get rid of the problem. You need to find out if you have an active mold infestation (gushy, slimy stuff) or dried (inactive, powdery) mold sitting around on books waiting for enough moisture to be able to bloom.
Inspect the collections thoroughly. If, after careful inspection you can't find any moldy books, suspect carpet, drapes, vents - inspect it all carefully.
Pull any books that show evidence of mold (inactive or alive) but separate the 'live' ones onto a different book truck. Remove all suspects from the room to the outside (don't put them in direct sunlight yet).
Follow instructions for "removing odors from books" above.
Accept that there may always be a faint odor to the item.
It is inadvisable to use an "ozone generator" around paper.
IV. BROKEN BOOKS:
Decide if the book is worth repairing. Is it vital to the collection? Can it be replaced? Is it rare or valuable, and should it be kept?
- If the answer is yes, the book is to be kept, consider mending, rebinding, or use of a phase box. Consult a conservator in the case of rare items.
- If the answer is no, the book will not be kept, discard the book following the institution's deaccessioning procedures.
A. Mold and Mildew:
Mold and mildew are fungi that form under certain conditions. If untreated they can severely damage library material. Conditions are particularly favorable when the disaster involves water, but they can form at any time.
B. Insects and rodents:
- Factors favorable for the development of mold and mildew.
- Temperature (+75 F).
- Moisture (+60% humidity).
- Little air circulation.
- Steps to take:
- Transfer all infested material to an isolation room.
- If number is large, prepare for freezing.
- Thoroughly clean and sterilize infected area.
- Mass methods (DO NOT ATTEMPT WITHOUT EXPERT ADVICE. MAY BE HAZARDOUS TO BOOKS AND HEALTH OF WORKERS):
- Fungicidal fogging with Thymol
- Fumigation with Ethylene Oxide
- Treatment of individual items infested with mold and mildew:
- Treatment of books:
- Supplies: Blotters, Cheesecloth, Lysol spray, Q-tips, Gloves (optional), Mask (optional), Wax paper (optional)
- Lay the item on a clean white blotter. Wet the Q-tip with the Lysol and test ink to see if it is damaged by Lysol. If it is, stop!
- Lightly spray item with Lysol. Use wax paper to cover uninfected areas.
- Use cheesecloth to carefully wipe or blot the infected area. Repeat if necessary. DO NOT SCRUB!
- Let item dry while working on the next one.
- Surface cleaning for flat papers or books.
- Supplies: Dry cleaning pads or powder, Weight(s), Soft, wide brush, Scrap paper, Waste basket, Air bulb (optional), Mask (optional) Gloves (optional)
- Examine item to see if it is completely dry. Do not proceed if paper is not in good condition, or is flaking, so that the item will not be scratched or damaged. If in doubt get expert advice.
- Lay item on clean working surface. Use gloves or make certain hands are clean.
- Lay item down and use weight to hold it in place. Use air bulb to blow away large pieces.
- Pretest on a small area before continuing.
- Sprinkle dry cleaning powder on item to be cleaned. Gently roll powder with your fingertip over stained areas. Powder picks up surface dirt and turns black or gray.
- Brush away powder from the center out to the edges. Do not leave any powder residue on item.
- Identify pest.
- Consult with a professional. Remember that anything used to exterminate should be considered hazardous. Don't proceed unless you have thoroughly discussed the situation with several professionals, including safety experts.
- Try to locate the way pests entered and carefully block their entrance way.
- Before cleaning a book or paper, make sure that it is completely dry and is not fragile or brittle. Surface dirt can be removed by gently brushing away with a soft artist brush, by use of a special eraser, or by use of a dry cleaner such as Groomstick or Absorene Paper & Book Cleaner.
- Mud on books can be washed off if the books are already thoroughly wet and won't be damaged further by contact with water. Otherwise, mud on fairly dry books can be dried and then cleaned off.
- For thoroughly wet books, use a tank with clear, running water.
- Immerse the book in the water.
- Keep the book closed and clean with a gentle, dabbing motion of a soft sponge. Avoid brushing and rubbing.
- Hard to remove stains can be dealt with by a professional conservator after the book dries.