Out of curiosity has anyone tried running tapes at different temperatures, for instance in a relative cold or hot environment? Either on a simple winder or even a recovery drive.
On Tue, Apr 28, 2020 at 11:47 AM Chuck Guzis via cctalk < cctalk@classiccmp.org> wrote: > I'm a bit surprised that this is even a "thing" in the audio business. > Restorers have been baking audio tapes for a long time. > > One thing not discussed (maybe it doesn't occur in audio) is that there > can be issues in binder formulation, at least in digital tapes. In > particular, 3M tapes, most notably Scotch 701 and 777 formulations, have > an issue where the binder "liquefies" under motion and solidifies when > tape motion slows or ceases. So, you may be running a tape through a > drive just fine and then suddenly, everything freezes up as the tape > becomes firmly "glued" to the heads or other objects in the tape path, > usually with a loud squeal. > > In the current batch of 60 tapes from the late 60s-mid 70s, every single > 3M tape exhibited this behavior. It didn't matter if they'd been baked > or not. There was a note of this on Ed Thelen's site where someone had > encountered this and given up. > > Isopropanol does not clean the sticky deposits from equipment--you must > use a stronger solvent. Acetone, Perc or MEK generally does the trick. > > Rather than try to clean the gunk off the tape, which is probably a > fool's errand, I coat the tape with cyclomethicone, using a felt > applicator in my cleaning machine--it doesn't take much to create a > slippery film on the tape surface, perhaps 10 ml will do a 2400' tape. > Cylcomethicone is non-toxic and relatively inert--and is somewhat > volatile, so that it evaporates in a couple of hours, leaving the tape > as it was. Very slippery stuff, so don't spill it on the floor! It > does not appear to have a solvent effect on the binder, as nearly as I > can tell. It also doesn't appear to bother the equipment either. > > I've achieved 100% success using this method. > > I think it's interesting that tape quality tends to better the older the > tape. Audio Devices, Ampex and IBM Series 500 tapes tend to survive the > best. Memorex seems to get worse, the younger it is. (e.g. MRX III > tends to behave better than MRX V). > > For whatever it's worth, > Chuck >
