DEAR JOHN, The first thing I would do is separate the Kodachrome from the B&W. Then see which one (if not both) is (are) emitting the acidic smell. There is the possibility that, if the films had unstable acetate bases they would, in the presence of moisture and warmth, deteriorate into acetic acid and other goodies. I am also worried that what you might be smelling is nitric acid from nitrate film. If this is the case you have a very serious fire hazard on your hands. To test for this, take a small snip of the b&w film FAR AWAY from the reels in a fire safe place like over the kitchen sink. Hold it with tweezers and light it with a match. If it burns like a very fast fuse (Pssst!) then you have nitrate and a significant storage challenge at hand. If it is acetate it will melt and blacken slowly but not burn fast. You will still have a problem if the acetate base is deteriorating into acetic acid but not a fire hazard. I am sure that many who reply will insist that nitrate films went out in the 30s or, at the latest, 40s but you might be surprised. I discovered some nitrate film in some local collections of negatives. Beyond the fire concerns nitrate film must be segregated from other film or the nitric acid will cause image deterioration of the other films. In any case it is time to find one of those 16mm scanning services that will convert your films into DVDs. CHEERS! BOB -----Original Message----- From: pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of john stockdale Sent: Wednesday, March 26, 2008 12:20 AM To: pure-silver@xxxxxxxxxxxxx Subject: [pure-silver] Deteriorating movie film I have just retrieved from storage a large box of 16mm movie film from the 1950s. Some is Kodachrome taken by my father, and some are black and white commercial copies from the US of various types of entertainment, such as cartoons, Charlie Chaplin, travelogues etc. The box smells strongly of acetic acid, which I understand is the result of some breakdown of the films. Can anyone tell me if the two types of film are equally likely to deteriorate, or would there be a difference between the Kodachrome and the black and white commercial films? The colour of the Kodachrome looks very good. John Stockdale ============================================================================ ================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there. __________ NOD32 2972 (20080325) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com ============================================================================================================= To unsubscribe from this list, go to www.freelists.org and logon to your account (the same e-mail address and password you set-up when you subscribed,) and unsubscribe from there.