My theory is there is more degradation product which needs to be
"evaporated" out or otherwise processed. I don't think anyone has
definitively described the process to a good deal of satisfaction. Ric
Bradshaw made it plain to me that he doesn't buy the reversible nature
of the hydrolysis reaction as described by Bertram and Cuddihy. He
indicated that it just doesn't happen that way in a filled matrix--the
chain ends can't find their way back through the other material and join
up. But we know baking works.
20 °C and 33 % won't fully stop degradation. I do not know what the LoC
vaults for tape are kept at, but 20 °C is not that cold. 33 % is pretty
dry. But your tapes are better off than most.
I don't do enough rebakes to know. I have followed Tom's advice for a
long time. Get a good transfer and be done with it. Ric Bradshaw was
unequivocal about this as well.
The best reason to keep the original tapes is that we have not recovered
what Jamie Howarth calls "Mechanical Metadata" from them yet. He's made
strides towards recovering the mechanical metadata even without
processing it. There are certainly materials that are worthy of this
approach. I don't know if there is a business case for this for me or
other independent restorers.
On 2013-04-01 5:00 PM, Peoples, Curtis wrote:
> We have stored our tapes for ten years in an environment averaging 68 degrees F and a RH of about 33%. It used to take 4-6 hours to bake a tape. We are now at 8 hours. I am interested to know why these tapes are now taking longer.
> -----Original Message-----
> From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Tom Fine
> Sent: Monday, April 01, 2013 3:42 PM
> To: [log in to unmask]
> Subject: Re: [ARSCLIST] Sticky SHRED
> Any theories as to why baking times are increasing?
> Also, are you finding you need the longer baking times for re-bakes as well as first-time bakes?
> -- Tom Fine
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada 647 479 2800
Quality tape transfers -- even from hard-to-play tapes.