We developed a procedure at our lab that usually works (about 80% of the time) with tapes suffering from binder-base adhesion failure.  We call the procedure "cold desiccation" and it takes about 60 to 90 days.  The two keys are to greatly reduce the RH in a chamber to force cross linking while simultaneously reducing the temperature to loosen the pack.
Of course if the oxide has already come off, it doesn't work very well - don't know of anyone who can retrieve a signal off "clear base" but it would be a neat trick (sorry, poor attempt at humor this last part).

Peter Brothers
(201) 440-6589

Celebrating 20 Years of Restoration and Disaster Recovery Service

-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]]On Behalf Of [log in to unmask]
Sent: Wednesday, February 04, 2004 12:58 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Oxide flaking off tape from the 1950's

In a message dated 2/2/2004 1:04:07 AM Eastern Standard Time, [log in to unmask] writes:
I think there are many people on the list who can gently play tapes. I can
on Studer (A810 or A807) or Sony (APR-5003V) equipment. I've played tapes
dating back to a 1935 Carbonyl Iron tape, but while I've had to sweep up
after them, I've not encountered an early tape with oxide totally flaking
off. This is very interesting.
I have found reels of the cheap green boxed "Shamrock" brown oxide mylar tape that shed oxide in sheets leaving clear base.  That is probably why it ended up in those boxes.
The oxide sheets just fell off as the tape was unwound; no bond to the base at all.  It would be very hard to salvage.
Mike Csontos