 |
 |
Stored in direct sunlight for many years - I mean? On 11/09/2018, CJB <[log in to unmask]> wrote: > Stored in direct sunlight for many ears? > > On 11/09/2018, Tim Gillett <[log in to unmask]> wrote: >> Hi Peter, >> >> Is it possible the tape had been reshelled at some point, or some >> combination of parts assembled together? >> >> Tim Gillett, >> Perth, >> Western Australia >> >> >> ----- Original Message ----- >> From: "lists" <[log in to unmask]> >> To: <[log in to unmask]> >> Sent: Tuesday, September 11, 2018 6:14 AM >> Subject: [ARSCLIST] very strange/unique decay found on u-matic >> >> >> Today I received a พ" u-matic tape with the strangest damage I have ever >> seen and was wondering if anyone else had seen something similar or had >> an >> idea what might have caused it. >> >> We have processed nearly 500, 000 tapes and we do quite a lot of disaster >> recovery. I have seen tapes that have been exposed to virtually every >> negative influence imaginable (and some not so imaginable) so I was quite >> surprised to see something totally new. >> >> The tape: >> >> The tape is a 3M UCA-60 from 1984. The cassette and hubs are white(ish) >> plastic and the interior posts/guides and the door lock mechanism are >> made >> out of black plastic. The access door is anodized black metal. >> >> The damage: >> >> The tape is entirely discolored where exposed. The discoloration is only >> near the edges a few wraps into the tape. I have not spooled the entire >> tape yet to determine how far the discoloration continues. The metal >> cassette access door shows many small spots of corrosion on the inside of >> door where it would be closest to the tape. There is no corrosion on the >> outside or the edges of the door. The tops of the metal screws on the >> back >> of the cassette are badly corroded. The entirety of the black plastic >> tape >> guides and black plastic door lock mechanism are very brittle/damaged, to >> the point where they are falling apart and partially missing/destroyed. >> There is no other indication of damage. The white plastic shell and tape >> hubs are intact and clean and the plastic slip pads inside the cassette >> are >> undamaged. There is no staining, no warping, no breakage and no >> brittleness >> anywhere else. Whatever happened, only the exposed tape and the black >> plastic tape guides, the black plastic door lock, the inside of the metal >> access door and the metal screws were affected. Everything else looks >> fine. >> >> The damage to the tape "could" be consistent with either exposure to >> liquid >> or heat, but- there is no staining anywhere or damage to the paper >> label >> to indicate liquid contamination and there is no brittleness or >> deformation/melting anywhere else to indicate exposure to high heat. The >> overall damage is not really consistent with either liquid or high heat >> damage. I even considered the unlikely possibility that the tape was >> contaminated with some corrosive element during playback/rewind and the >> posts were damaged as the tape was wound into the cassette. This could >> explain why plastic guides are nearly destroyed and the metal access door >> was only corroded inside, near the tape, and nowhere else. This, >> unfortunately, doesn't explain the corrosion on the screws and heavy >> damage >> to the plastic door lock mechanism, however, since neither of these parts >> ever touch the tape. The plastic hub flange and slip pads inside the >> cassette, which do contact the tape, are also undamaged. >> >> Ok, how about some highly corrosive gas that reacts very aggressively >> with >> one specific type of plastic (the guides and door lock mechanism) and >> uncoated metal (the screws) but doesn't react at all with any of the >> other >> plastics in the shell/ hubs/slip pads and/or with anodized metal and >> reacts >> differently with the plastics in the tape (or maybe the metal in the >> tape?) >> in such a way as to produce a byproduct that corrodes nearby anodized >> metal >> (the inside of the cassette door) but dissipates quickly (so the rest of >> the >> anodized cassette door is unaffected). Sound crazy? Yes it does. The >> damage is so very specific and selective that I can't figure out what >> could >> have happened. >> >> Any ideas? Magic? Space aliens? >> >> A very perplexed >> >> >> Peter Brothers >> SPECS BROS., LLC >> 973-777-5055 >> [log in to unmask] >> Audio and video restoration and re-mastering since 1983 >> >> >> >> >> --- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus >> >