ClockworkHome at aol.com wrote: > Some of the films were on nitrate film stock rather than acetate > safety film. Any old film that has a smell of vinegar usually means > that it is nitrate and becoming unstable.
This isn't quite right; it's *acetate* film that smells of vinegar. Three bases have been used for film, in historical order: Cellulose Nitrate: Highly flammable. On decomposition it produces nitric oxide, nitrogen dioxide, and other gases, which may be irritating to the eyes, nose, and throat. Does *not* smell of vinegar. Cellulose Acetate: Not particularly flammable, produces acetic acid as it decomposes (hence the vinegar smell); the film base also shrinks and wrinkles. Polyester: The modern base, strong and stable. This Wikpedia article gives much more detail: http://en.wikipedia.org/wiki/Film_base -- Bill Burns Long Island NY USA http://ftldesign.com
