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Peter:
 
It was clear from your posting, that good airflow in a container will help to slow down the rate of acetic acid build-up, thus helping to slow down the rate of deterioration. My concern with your posting, is when you mentioned that "cardboard boxes would work well". It needs to be added that the "old" cardboard boxes are usually not inert to begin with, and have a very high Ph, they will decompose over time and eventually give off acid on their own. Certainely, we have all seen old acetate tapes that have turned brown, sometimes even leaving an imprint of the plastic reel. Since this is true, then the acid that is emitted from the breakdown of the cardboard boxes will actually help to speed up the deterioration, unless new inert boxes are utilized.
 
Thanks,
Lance Watsky
Preservation & Media Specialist
The Georgia Archives
5800 Jonesboro Road
Morrow, GA 30260
678-364-3764 (phone)
678-364-3860 (fax)
[log in to unmask]
www.GeorgiaArchives.org

-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]]On Behalf Of [log in to unmask]
Sent: Tuesday, August 10, 2004 6:25 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] audio reel archival containers

From the testing I've reviewed, it's pretty clear that acetic acid will catalyze the breakdown of acetate.  As such, any method (that does not otherwise damage the acetate) of removing traces of the acid from  proximity to the tape should help slow down the reaction.   Testing has shown that acetate tapes will decay slower if they are exposed to an air-flow that removes the residual acid than will tapes that are in sealed containers that trap the acid inside.  Cardboard boxes would work well for the simple reason that they are not air-tight and allow the acid to escape.
 
It's also important to have a positive air pressure and air flow in the storage area so that the acid is removed from the area.  Removing the acid from the proximity of one tape and then trapping it in a room can catalyze breakdown in other tapes stored in the same space.
 
The Tuscan cans should work ok as long as there is enough air movement in the room to allow some air to circulate through the air vents and channels in the cases.
 
Peter Brothers 
-----Original Message-----
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]]On Behalf Of [log in to unmask]
Sent: Tuesday, August 10, 2004 9:02 AM
To: [log in to unmask]
Subject: Re: [ARSCLIST] audio reel archival containers

In a message dated 8/9/2004 5:11:12 PM Eastern Standard Time, [log in to unmask] writes:
I'm suspicious
that the traditional cardboard box is functioning something like a
molecular sieve and absorbing some of the acetic acid outgassing/effluent
from the tapes and retarding any vinegar syndrome.
***************
 
Keeping tape in unsealed cardboard boxes does seem to help preserve it.
 
"ProVent Audio's vented design allows active airflow through the container to prolong the life of audio tape or 8mm film."
 
Everything I've seen indicates that you want to get the acetic acid out of the room completely, not trap it near the acetate.  Controlling the room's humidity should prevent excessive drying.
 
The thickness of film base may be a factor in preventing the acetic acid from leaving the material, explaining the faster deterioration, however the compulsion to seal film in metal cans in sealed vaults certainly has a greater effect. I've yet to see vinegar syndrome in any of my 40+ year old tape or film, however the material I just received from a friend who was meticulous about "protecting" his material definitely does show the effect (now stored in a separate room for airing).
 
Mike Csontos