Some of the items contained in our "flooded" collection were compact audio cassettes and VHS tapes. We separated the items in these groups according to the three "flood" conditions (lake water, oily water, and clean water) to see if the different types of water affected the media differently.
Most of the audio cassettes were inside their original plastic cases. The VHS tapes were in a variety of cases, including a plastic "clamshell" case and cardboard cases. For a description of how well these cases survived, see our separate post on the subject.
When we pulled the items out of the water, we observed that the plastic cases all performed fairly well in keeping moisture away from the cassettes. The cardboard cases, however, did not because they are open on one end and readily absorbed water.
Because the plastic cases blocked water from the cassettes, the tapes themselves were not overly wet. However, we did notice small droplets of water were visible on the inside of the clear windows of the cassettes.
Clean water itself is not damaging to the tapes. However, any particulates in flood water will damage the tapes, especially during playback when the tapes are wound back and forth at high speeds across a tape machine head. Even particulates as small as those left by a fingerprint (see image below) are larger than the distance between the tape and the playback head. Playback can drag those particulates across the surface of the tape, damaging the tape binder and possibly even the tape substrate.
Additionally, the presence of moisture could eventually activate mold existing on the tape or in the enclosure. If this were to happen, the tape would need to be cleaned and rehoused in another cartridge.
We tried several methods to extract the water from the inside of the cartridges. One group of cassettes were placed standing on the cartridge edge that opens up during playback. The goal of this was to let gravity pull the water down and out of the cassette housing, similar to the way a dish drying rack works.
Some tapes were propped up to "air-dry," without concern for which side of the enclosure was up or down.
We submerged the second group of cassettes inside a pile of rice. We hoped that the rice would dry the tapes by absorbing the moisture. This is similar to the method we used to dry out a pair of phone chargers.
We checked the tapes after a week to see if either the gravity or the rice approach worked. The inside of the tape housings that we stood on edge were visibly drier than when we pulled them out of the water. The tapes that we submerged in the rice did not show any noticeable difference. We then tried the gravity approach with these tapes and a week later they were dry as well.
We are not sure why the rice method did not work. Rice is recommended to dry electronic devices that have been submerged in water, suggesting that rice can absorb water from fairly sealed enclosures. It is possible that we did not allow the rice enough time to extract the water from the cartridges. However, the longer the water is allowed to sit, the more chance there is of mold growing in the enclosure. For our experiment, we found that air drying, with the help of gravity, pulled water out of the tape enclosures the fastest.
Even after water is extracted from tapes, be sure to clean them before playback. Unless you know the water that touched the tapes is clean and distilled, there is a chance that particulates are still on the surface of the tape. They will need to be removed to avoid damaging the tape, and machinery, during playback.
Most of the audio cassettes were inside their original plastic cases. The VHS tapes were in a variety of cases, including a plastic "clamshell" case and cardboard cases. For a description of how well these cases survived, see our separate post on the subject.
When we pulled the items out of the water, we observed that the plastic cases all performed fairly well in keeping moisture away from the cassettes. The cardboard cases, however, did not because they are open on one end and readily absorbed water.
Because the plastic cases blocked water from the cassettes, the tapes themselves were not overly wet. However, we did notice small droplets of water were visible on the inside of the clear windows of the cassettes.
Clean water itself is not damaging to the tapes. However, any particulates in flood water will damage the tapes, especially during playback when the tapes are wound back and forth at high speeds across a tape machine head. Even particulates as small as those left by a fingerprint (see image below) are larger than the distance between the tape and the playback head. Playback can drag those particulates across the surface of the tape, damaging the tape binder and possibly even the tape substrate.
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| Image taken from: Van Bogart, J. “Magnetic Tape Storage and Handling: A Guide for Libraries and Archives.” National Media Laboratory and Council on Library and Information Resources, 1995. http://www.clir.org/PUBS/reports/pub54/index.html. |
Additionally, the presence of moisture could eventually activate mold existing on the tape or in the enclosure. If this were to happen, the tape would need to be cleaned and rehoused in another cartridge.
We tried several methods to extract the water from the inside of the cartridges. One group of cassettes were placed standing on the cartridge edge that opens up during playback. The goal of this was to let gravity pull the water down and out of the cassette housing, similar to the way a dish drying rack works.
Some tapes were propped up to "air-dry," without concern for which side of the enclosure was up or down.
We submerged the second group of cassettes inside a pile of rice. We hoped that the rice would dry the tapes by absorbing the moisture. This is similar to the method we used to dry out a pair of phone chargers.
We checked the tapes after a week to see if either the gravity or the rice approach worked. The inside of the tape housings that we stood on edge were visibly drier than when we pulled them out of the water. The tapes that we submerged in the rice did not show any noticeable difference. We then tried the gravity approach with these tapes and a week later they were dry as well.
We are not sure why the rice method did not work. Rice is recommended to dry electronic devices that have been submerged in water, suggesting that rice can absorb water from fairly sealed enclosures. It is possible that we did not allow the rice enough time to extract the water from the cartridges. However, the longer the water is allowed to sit, the more chance there is of mold growing in the enclosure. For our experiment, we found that air drying, with the help of gravity, pulled water out of the tape enclosures the fastest.
Even after water is extracted from tapes, be sure to clean them before playback. Unless you know the water that touched the tapes is clean and distilled, there is a chance that particulates are still on the surface of the tape. They will need to be removed to avoid damaging the tape, and machinery, during playback.
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