Parker Dinkins wrote:I think contact with a smoother surface might cause this, and not necessarily because it's another record-layer. I've seen the record-layer binder come completely off on the smooth hub of the reel, and especially on early 3M plastic leader tape, which is relatively shiny and smooth. Then when the wrap is against the back-coat, everything stays in place.
I have had this problem as well, only once with the hub, but more often with the 3M plastic leader. I asked about how to deal with it during the "Ask the Technical Comittee" session at the last ARSC conference, and the only answer I got was to "unwind the tape very carefully". In my experience, the leader tape problem seems to occur with 3M plastic leader used between late 1977 and early 1978, and seems to be confined to Ampex 406-407 and 456-457. In the current project I am working on I see it on virtually every one of the tapes from that period from those tape stocks. Tapes from early 1976 and late 1978 are not affected, and in the few cases where yellow leader is used on 1977 tapes, the problem does not occur. There are a few reels of Maxell tape from the same time period that don't have the same problem (and don't require baking either).
The layers nearer to the outside would unwind fine, but the closer to the hub, the worse it got (tension-related?).
The problem seems to be exacerbated by baking.