Emergency salvage of Photographs
Because of the number of photographic processes and their wide variety, responsible advice for the emergency salvage of water damage to photographs is difficult to provide. Some processes can withstand immersion in water for a day or more, whereas others would be permanently disfigured or even destroyed by a couple of minutes exposure. In general wet photographs should be air dried or frozen as quickly as possible. Once stabilised by either of these methods, there is time to decide what future course of action to pursue.
Ideally salvage should occur under a restoration specialist’s supervision. A restorer can minimize damage to a collection if there is the opportunity to direct the salvage and treat the collection immediately after the damage has occurred. Time is of the essence. The longer the period of time between the emergency and salvage, the greater amount of permanent damage that will occur.
Minimize Immersion Time.
Photographs in water will quickly deteriorate: images can separate from mounts, emulsions can dissolve away or stick together, staining can occur. Mould is another problem. Mould begins to grow within 48 hours at 60% RH and 70°F. Mould often causes permanent staining and other damage to photographs. For these reasons photographs need to be dried as quickly as possible. If photographs cannot be dried they should be frozen.
Salvage Priorities for water damage to Photographs
- In general films (plastic base materials) appear to be more stable than prints; therefore, prints should be salvaged first. Important exceptions include deteriorated nitrate and safety films, which are extremely susceptible to water damage.
- Processes that should be salvaged first include: ambrotypes, tintypes, collodion wet plate negatives, gelatin dry plate negatives, lantern slides, deteriorated nitrate or safety film, autochromes, carbon prints, woodburytypes, deteriorated or unhardened gelatin prints, color materials. Many of these processes will not survive any immersion.
- Processes that are more stable in water include: daguerreotypes, salted paper prints, albumen prints, collodion prints, platinum prints, cyanotypes.
Air Drying Photographs
- If personnel, space and time are available photographs can be air dried.
- Separate photographs from their enclosures, frames, and from each other. If stuck together or adhered to glass, set them aside for freezing and consult a restoration specialist.
- Allow excess water to drain off the photographs.
- Spread the photographs out to dry, face up, laying flat on an absorbent material such as blotters, non printed newsprint, paper towels, or a clean cloth.
- Photographs may curl during drying. They can be flattened later.
Freezing Photographs
- If immediate air drying of photographs is not possible or if photographs are stuck together, freeze them.
- Place the photographs in small plastic bags before freezing, several to a bag.
- If possible, interleave photographs before freezing with a non-woven polyester material or wax paper. This will make them easier to separate when they are eventually treated.
Drying Frozen Photographs
- Frozen photographs are best dried by thawing, followed by air drying. As a group of photographs thaws, individual photographs can be carefully peeled from the group and placed face up on a clean, absorbent surface to air dry.
- Vacuum thermal drying, where the frozen material is thawed and dried in a vacuum, is not recommended for photographs. Gelatin photographs undergoing this procedure have a tendency to severely mottle and stick together.
- Photographs can be vacuum freeze dried; in this process no thawing occurs. Gelatin photographs may mottle during the procedure, but they won’t stick together.
- Wet collodion glass plates must never be freeze dried; they will not survive. This would be true for all similar collodion processes such as ambrotypes, collodion lantern slides, and tintypes.
Salvaging Slides
- Slides can be rinsed and dipped in “Photo-flo”, slide cleaner, or a similar commercial product and air dried, preferably hung on a line or propped on edge.
- Ideally, slides should be removed from their frames for drying and then remounted.
- Slides mounted between glass must be removed from the glass or they will not dry.
