This article is a compilation of posts from the FCLS List Server.
From Martin Hart:
The breakdown of triacetate film base,
causing the release of acetic acid vapours, can be controlled somewhat. First of
all, as has been mentioned, film should not be stored in air tight containers.
The process will be accelerated if this is the case.
Secondly, there is a material that
will slow the process once it starts. It's a desiccant called Molecular Sieve.
It chemically aDsorbs the acetic acid so that it won't continue to eat away at
the film. I spent 30 years working in the refrigeration industry and molecular
sieve is commonly used in filter driers for moisture and acid cleanup. Where
you obtain it for the purpose of film protection I can't say offhand, but if
you look in the Yellow Pages under scientific products, beakers, etc., those
people can probably fix you up. It shouldn't be very expensive. Vinegar
syndrome cannot be reversed but it can be brought to nearly a halt.
From Jay Pregent:
Molecular Sieves are available from
FPC. They have many items that would be of interest to us film collectors. I
have dealt with the company several times and have always had a good experience.
I don't have their number with me but
I have a link to them on my web page:
www.capital.net/com/jaytp
(ed: unfortunately the link to FPC is
dead... but visit jay's page..it's great) Using them causes you to do one thing
that is the opposite of the normal recommendations. You seal the film in low
density polyethylene bags. The sieves will absorb moisture and if exposed to
the humidity in the room for too long they will be worn out. Under proper
storage they can last up to 5 years on a print that is showing little or no sines
of the VS.
Use them before you have the VS to
help prevent it before it starts.
They absorb any acetic acid that is
present since the VS feeds off of itself. This slows the process down hopefully
to a crawl. They also absorb moisture. Water molecules are needed for the acid
to bond to in the reaction. so the less moisture, the less likely the VS will
start or it will slow it down.
The down side is that such a dry film
can become brittle. I have never had a film crack because of this and get
around the problem by simply removing the film from the storage bags a few days
before I show them to let them acclimatize.
From Martin Cope:
Big Reel had a reprint about the
Vinegar Syndrome that covered the topic of the Molecular Sieve. What I
remembered most about the article was that the Molecular Sieve was for film
archivists (OK, we're all film archivists in a way), and the Molecular Sieve
really dried the film out. It spoke about allowing a week to put moisture back
into your film before showing it. What I was concerned about, can you be
assured about getting the moisture back in when you need it?
From Frank Angel:
Any chemists out there know of an
non-toxic gas that has an alkalin pH that could be released in the area around
film or maybe even enclosed in a plastic bag with a reel of film that has begun
to exhibit acidosis? Seems to me if you could "wash" the area where
the film is stored with an alkalin gas (or is it a base that is needed -- I
wish I hadn't goof around during those chemistry classes), that would be even
better than the molecular sieve. And the sieves are not all that inexpensive,
if you are talking about large amounts of film. I am experimenting with this
substance that is sold via mail-order -- it looks like small white pebbles an
it is in a mesh bag. Supposedly it absorbs moisture and odors (so presumably
it will absorb the acetic acid gas) from basements. I have a box that smells
like vinegar and I am going to put on of these absorbo-bags as they are called
inside the box to see if it eliminates the vinegar smell. I think it is safe to
assume that if the vinegar smell is gone, the acidic gas is gone and thus the
catalytic reaction that the gas causes. The other scenario is that the film is
still deforming away but the smell is gone. I am hoping for the former to be
the case. And what about the guy who put a lay of baking soda in the bottom of
his film boxes with eggshell cardboard to raise the film above it. He claimed
that the baking soda not only absorbed the vinegar smell but it has a alkaline,
antacid pH which naturally counteracts the acid of the print.
Keeping triacetate film in tight cans
is bad enough, but worst case scenario is a coating on the film that traps in
any acid gaseous by products trying to escape. I hear from other collectors that
coated prints that have typically been "rejuvinated" by a number of
lab processes to get extra life out of them, turn vinegar and progress very
fast. No amount of "airing out," or neutralizing with washes of base
or alkali baths, seem to stop the process. So much chemical deterioration takes
place that the film will not run through the projector. The reason given for
this happening so swiftly and so irreversibly on the rejuvenated prints is that
the coating that has been applied entraps the acid byproducts of the chemical
reaction, causing it to cascade within the film base itself rather than gas-out
into the environment (unlike untreated film where the gases can escape to the
air). <BR.
I am not a chemist and I don't pretend
to understand the chemical reaction fully, other than I know what the results
are; I know how to sniff out a print in which the reaction has begun (the smell
of vinegar is not difficult to detect). So, what I want to know as a collector
is, if Photguarding my collection will be doing more harm than good. Is the
coating of such a nature that chemically it "breaths" or is it more
like a plastic bag wrapped around the filmstrip, encasing it in its own
self-destructive chemical reaction? I won't treat any of my collection with Photoguard
until 3M answers these questions in depth and to my satisfaction. I would
suggest all serious collectors do the same. Especially, don't get taken in my
those ads some application labs pass around with clips of Photoguard treated
film, because it DOES look and feel great. Question is, what will it look like
10 years from now. Will it go through my projector?
From David Koeggel:
NB: Please use caution if following this article and be
sure to read the posts following it.
Frank: Actually, there is something
that should be even more effective than baking soda (chemical name: sodium
bicarbonate) or molecule sieves for absorbing moisture and vinegar. That would
be sodium hydroxide, commonly known as lye. It's the principle ingredient in
Drano (along with aluminum flakes and other stuff). You almost have to go to
some small non-chain grocery store to buy it, like the kinds that attract many
foreigners. It's next to Drano if at all. I used to buy it as a kid for my home
chemistry lab. I believe the brand name was "Red Devil" or something
like it. Commercially pure sodium hydroxide looks like flat, white flakes about
the same size as dry parsley, but thinner than half the thickness of a dime.
You would want this purer stuff. If you can only find potassium hydroxide,
that's fine as well.
When lye is left out in the open, it
absorbs moisture from the air and appears to melt, when in reality it is just
absorbing so much moisture that it is forming a solution. Sodium (and
potassium) hydroxide is an extremely powerful base, meaning it's the opposite
of acid. It will readily react with acetic acid ("vinegar") to form
sodium acetate (or potassium acetate), thereby neutralizing it. It is also VERY
CAUSTIC. But I'd see no reason that you couldn't place a pound of it in say the
bottom of a 5 gallon PLASTIC paint bucket, place some PVC pipe pieces over it,
lay another smaller paint bucket lid (like from a 2 gallon one) over that --
after drilling some holes all throughout it -- and laying your reels of film on
that. Plastic reels would almost be certainly required here, as the minor
"fumes" would rust metal. I'd probably go with some sort of plastic
mesh over that lid as well. But if you then sealed the bucket, trust me that
all the moisture would be sucked dry from the film as well as would any free
acetic acid (vinegar) , with that lye eventually liquifying.
I wouldn't try this with any valued
prints first, though, until you feel comfortable with the process. If nothing
else, it would form a very dry environment; with no water, there'd be no more
catalytic breakdown of the triacetate. But it would be a very cheap "poor
man's" molecular sieve, and the stuff can be dumped down the drain with
plenty of water.
A couple of CAUTIONS:
1. Wear heavy rubber gloves.
2. After carefully pouring the
granulated lye in the bucket, let any dust settle and wipe the upper insides of
the bucket with a slightly damp cloth to collect any lye dust that might have
settled there.
3. Remember that lye will burn your
skin. The best test for me to see if I've got lye on my hands is to wet my hands
and see if they feel slippery. If so, it's just the lye dissolving a layer of
skin off. BUT plenty of water is all that's needed to clean up.
4. The lye in the bucket will
eventually liquify, so make sure that the bucket will not tip over or get kicked.
5. If you don't seal the bucket well,
you'll just be absorbing moisture from the air.
6. Adding water to the lye when
disposing of it will generate a lot of heat, giving you a hot lye solution.
7. Plastic goggles would be highly
recommended while dealing with lye.
However, lye is very cheap, and if you
aren't a painter or a drywaller (spacking comes in these same buckets), the
buckets can be bought with gasketed lids at the large paint stores or found
free at any construction site.
Of course, the downside is that the
large reels won't fit, and that you might have a floor full of buckets after a
while!
And, once the reels are taken out of
this environment and exposed to humidity (which will be needed to run the now
dried-out film), you've started the clock again with respect to the vinegar
syndrome. However, you could take these films out of these chambers and them
place them in film cans and seal them with heavy tape.
Or, for those with the space, seal
them in plastic and refrigerate them, as I've done with VS IBTech 35mm reels.
You can't reverse VS, only stop it.
Have I done this? No, not yet, as I
haven't owned any VS prints for very long and feel I've got a little more time
yet. Will I? Yes, but first with junk VS prints. The biggest hazard is if any
lye "dusk" settles on the film or reels, as that dust will then
absorb moisture and not only get "wet" but will then be corrosive.
How'd I get so smart about this? Chemistry
major in a chemical engineering degree, as well as a boyhood love for chemistry.
I've got other ideas but they deal with less common chemicals and would want to
experiment first. --
From Martin Hart:
I want to express my gravest concern
over any scheme that uses caustic materials to try to solve the vinegar
problem. This is not something that should be done without extreme caution. The
use of commercial desiccants is perfectly safe and is the only method endorsed
so far by film libraries that have millions of dollars worth of film to be
worried about.
From JLCAMPANA:
Just one word of caution, when you
deal with lye (sodium hydroxide) , never let it get into your eyes because if
it does, there is no way of washing it out because it will bind to your tissue
and keep destroying it no matter how much water you use to wash it out. It will
not only destroy the cornea (the clear central part of the eye), but it will
also destroy the conjunctiva (the clear tissue covering the white part of the
eye) and its glands which are necessary to maintain the health of the eye. The
destruction is so great that even a corneal transplant would not be effective
in restoring sight. So, BE CAREFUL!
