Many years ago, when these reels were relatively new, a friend of mine had a 
similar experience with some tape stored on a 3M self-takeup reel. He 
complained to 3M, they confirmed that this was a problem with the adhesive used to 
catch the end of the tape at the hub, and sent him a replacement reel with the 
warning not to use it to store tape.

I don't think one should draw conclusions about vinegar syndrome from this 
experience.  There are other reels that have little or no side openings so one 
could look for problems with them.

Mike Csontos

In a message dated 9/14/2005 6:20:25 PM Eastern Standard Time, 
[log in to unmask] writes:
I just transferred a reel of acetate tape that had been stored on a 
Scotch/3M auto-threading reel. It has solid sides (no windows) and 
three springy clips in the walls near the hubs. From the outside, the 
clips are chrome-ish. From the inside they are green.

There was some starting of blocking (layer-to-layer adhesion) of the 
wraps of tape near the hub.

There was no significant vinegar smell.

The tape/reel had been stored at approx. 21C 43%RH with limited 
swings for the last year, prior to that I don't know, but I think it 
had been in climate controlled storage.

I suspect this odd reel is not allowing the centre of the tape back 
to breathe much and concentrating whatever outgassing of the tape 
pack. Also, another very loose tape pack on the outside (not in the centre).

I'm not sure what this means, but I would think this supports the 
need to at least examine the acetate tapes in your collection and 
also look especially if you have this reel.