Re: [ARSCLIST] Ampex 456

[Robert Hodge <rjhodge@xxxxxxx>]

Hi,

I suspect that due to the increased surface area of your tape, you
would have to increase the baking time normally used for 1/4 inch tape.

Library Of Congress recommends 8 hours at 130 degrees for pre 1975 and
5 hours at 130 degrees for post 1975 and later for 1/4 inch tape.
I've never baked 2 inch , but this is the path I'd follow unless
someone has done it differently with success.
64 hours at 130 pre 1975 and 40 hours 130 for 1975 and later.
 ( Seems like a lot. ) But the math indicates it so. And the same
amount of time for cooldown which is equally important.. 

Best of luck  !

Bob Hodge

Robert Hodge,
Senior Engineer
Belfer Audio Archive
Syracuse University
222 Waverly Ave .
Syracuse N.Y. 13244-2010

315-443- 7971
FAX-315-443-4866

>>> arclists@xxxxxxxxxxxxxxx 6/16/2006 8:42 AM >>>
At 06:51 AM 6/16/2006, Lars Gaustad wrote:
>Hi,
>I have got a 2" Apmex 456 that is really sticky.
>I has been stored at 8 C 35% RH for 8 years,
>which makes me believe that the stickyness is not related to
hydrolysis
>(SS),
>as such storage should rejuvenate the tape just as well as baking
will.
>
>Any suggestions?

Baking should still rejuvenate it if past history is any guide. I'm 
looking for a good explanation of precisely why baking works, but 
I've been told by people who understand these things that the 
generally accepted explanation is not the whole story.

There does appear to be mounting evidence that there is interaction 
between the back coat and the oxide binder system. Again, no answers 
at this time.

I'm not being mysterious, I'm slowly studying this.

Thanks for a really useful data point.

Many of the people working on this are not on this list and I'm 
taking the liberty of passing on your observations to them.

Cheers,

Richard


>lars gaustad
>preservation adviser
>national library of norway
>www.nb.no 

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 
Quality tape transfers -- even from hard-to-play tapes.