What I say here are words of a layperson with respect to restoration, but I am somewhat familiar with organic polymerization being an contact lens practitioner.
Tom, do you know whether the two recordings were done on the same batch of tape? Because if they were different, they a) could have been polymerized differently, and/or b) could have been handled differently prior to Mercury receiving and using them to record on. In the short run that might not make a difference, but in the long run that could have a profound effect.
Rigid contact lenses are made from buttons that are cut from long rods of plastic. It is well known that the quality of the polymerization at one end of the rod can be different that at the other end and this can lead to differences in quality when the contact lens is finished.
Cellulose can consist of hundreds to thousands of D-glucose units, and so cellulose is not cellulose. It’s makeup can vary, the quality of the polymerization can vary, and it’s subsequent breakdown from heat and moisture can vary.
I’ve even seen things like this with spectacles, when a lens is cut very slightly off. It fits into the plastic frame well enough when new, but in 2+ years you can see the lens buckling inside the eyewire.
Again, I’m not an expert here, nor am I a chemical engineer. Just food for thought.
> On Mar 1, 2015, at 11:43 AM, Tom Fine <[log in to unmask]> wrote:
> Interesting case in point -- the 1956 1/4" master tapes for the mono Mercury "1812 Overture." Side 1, the overture and the spoken narration by Deems Taylor, the master tape is a mess. It's badly edge-warped and smells of vinegar. Side 2, the Capriccio Italien, the master tape is in perfect condition. Both Audiotape, both made at the same time. Both tapes have been treated and stored the same because they are of one single album. Why has one fallen apart and the other not? Very strange! Have you seen any such things with acetate media in the Hollywood vaults?
> -- Tom Fine