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Re: [ARSCLIST] Delaminating tape article
Somewhere in my computer, I have pictures of 2", 1", 3/4" and 1/2" video
with this problem. We have seen it on audio tape but it is much more
prevalent on a number of video formats.
A couple of years ago in Scandinavia, we did a project with between 5,000
and 6,000 standard audio cassettes stored in a variety of the worst possible
conditions imaginable. We encountered less than 1/2 a dozen that had
serious binder-base adhesion failure. In contrast, collections with large
amounts of 3/4" video that have been poorly stored, are now starting to see
this problem quite frequently.
The audio field should be happy that this in more a problem in video
restoration than audio. Advanced cases of binder-base adhesion failure are
near impossible to fix and can usually be considered "end-of-life" for a
tape. Many of the collections with large amounts of 3/4" video will soon
need to come to grips with the fact that a significant number of their
not-yet-remastered recordings are becoming un-recoverable.
The procedure we developed for dealing with cases that are not too far
advanced is called "Cold Desiccation". As stated earlier, it takes a few
months and is only effective about 60% of the time. As to Richard's
question about risk, we have tested the procedure on hundreds of tapes and,
while it isn't 100% successful in getting all tapes to a fully playable
condition, testing has never shown the procedure to make a tape worse- with
one exception. If a tape is so badly hydrolyzed that the oligomer residue
has migrated to the surface in sufficient quantities to form visible
"puddles", Cold Desiccation should not be used! Cold desiccation can harden
these "puddles" into nodules that cannot be removed from the tape surface
without damaging the tape.
Peter Brothers
President
SPECS BROS., LLC
(973)777-5055
www.specsbros.com
Restoration and Disaster Recovery Service Since 1983
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx]On Behalf Of Richard L. Hess
> Sent: Monday, April 03, 2006 6:00 PM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] Delaminating tape article
>
>
> At 01:02 PM 4/3/2006, Peter@xxxxxxxxxxxxx wrote:
> >Richard:
> >
> >This is an increasingly common problem with a number of video
> tapes as well.
> >If, in past postings, you have seen me mention "binder-base adhesion
> >failure"- this is what we have been calling the phenomena for
> the last few
> >decades.
> >...
> >Final comment- we developed a procedure to deal with binder-base adhesion
> >failure about 10 or 15 years ago. Unfortunately, the procedure
> takes a few
> >months and is only successful about 60% of the time.
> >
> >With the work in tape restoration and recovery we have done over
> the last 23
> >years, we consider binder-base adhesion failure to be a much
> more serious,
> >though less frequent, decay problem than binder hydrolysis.
>
> Well, this is the first major instance of BBAF that I have seen, but
> the Cal State Fullerton tapes were showing an incipient version of
> that and we did trace that to a nightly economizer cycle in the HVAC
> system. We also found this to be a self-healing situation as I've
> previously discussed. The conditions were precisely as you describe
> with daily variations in relative humidity ranging up to 75%
> overnight on some days.
>
> In your treatment of BBAF is there any risk that the currently stable
> portion of a tape showing partial BBAF might have the now-stable
> portion made worse during the treatment? That was a discussion we had
> and we opted to look for the stable sections as the opening was
> stable and we felt there was a chance that it was stable farther on.
> We got 10 of approximately 13-15 minutes of total family voices
> recording on the tape. The clients were pleased.
>
> When we unspooled the BBAF sections, many of the portions came off
> like a badly started roll of toilet paper with two separate layers
> coming right off the spool.
>
> Thanks,
>
> Richard
>
> Tape Restoration Seminar: MAY 9-12, 2006; details at Web site.
> Richard L. Hess email: richard@xxxxxxxxxxxxxxx
> Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
> Detailed contact information:
http://www.richardhess.com/tape/contact.htm