Film-Tech Forum ARCHIVE: Filmguard vs Vinegar

This is topic Filmguard vs Vinegar in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Martin McCaffery (Member # 37) on 05-20-2005, 09:04 AM:

I recently came into possession of a 35mm feature that has been sitting in cans in a hot office for about 34 years. The smell of vinegar is lovely, but as it is a B&W film, no color fading to worry about. The one reel I looked at is in very good shape, the print was not played much, so I expect the rest of the feature to be ok.

I'm airing it out now and want to run the whole thing through the film cleaner. Just wondering if Filmguard will have any negative or positive effects on the film, especially if it is going to spend another 30 years in storage.

Posted by Mitchell Dvoskin (Member # 751) on 05-20-2005, 09:16 AM:

If the print is slightly warped, coating it with Film-Guard and tightly winding it will relax the warp somewhat. I have never found any negative's from using Film-Guard on old prints. If the film is very warped or shrunken, nothing will help it.

Posted by Don Furr (Member # 1469) on 05-20-2005, 09:45 AM:

Hi Martin....
I've got no idea how much experience you've had with VS film but for what it's worth.....sometime you'll come across an old B&W print that has a strong musty smell, not exactly the same as VS but nevertheless a strong smell. Maybe that's what you are smelling and not vinegar!! [Razz]

Don

Posted by Martin McCaffery (Member # 37) on 05-20-2005, 05:08 PM:

Oh, this is classic vinegar. The people in the room with me when I opened the cans started coughing and wheezing and eyes started watering. They didn't believe me when I warned them to stand back [Wink]

Posted by Brad Miller (Member # 2) on 05-20-2005, 05:28 PM:

If it's that bad, NOTHING will save it. FilmGuard may make it pliable enough so that it can run acceptably, but your projection booth will probably reek for some time afterward.

Remember, despite what some people claim about various products (their own or others), NOTHING actually "cures" VS. Once it starts, all you can do is try to slow it down as much as possible. FilmGuard does work pretty good in that regard. I have some prints with a noticeable vinegar smell and here 10 years later after cleaning/lubricating them with FG they don't reek at all and project fine...but the VS is still there. It's just hiding. [Wink]

Store your prints in cardboard boxes or "open air". Never store in cans, as the films need to be able to breathe. Climate and humidity control is mandatory as well. Don't store them in your garage.

If the print is curled, reverse-wind it. For example, if the base side is protruding, wind it base side against the hub of the reel. Tight winding is good, but I have also found that very loose winding can also help flatten out curled prints. Other than lubricating the print, storing it reverse-wound seems to be the best thing for flattening it out.

If the print is warped, odds are it was stored emulsion in. I have yet to find a print that was stored emulsion out that suffered from warping.

Posted by Leo Enticknap (Member # 534) on 05-20-2005, 06:07 PM:

quote: Brad Miller
Store your prints in cardboard boxes or "open air". Never store in cans, as the films need to be able to breathe.

...unless you're going down the molecular sieve route. If you are storing both autocatalytic and pre-autocatalytic acetate elements in the same space, then sealed containers with sieves might be the way to go. The danger with storing them all in vented containers is that the offgases from the elements which have already gone seriously vinegary could accelerate the decomposition process in those which would otherwise decompose more slowly if they were atmospherically segregated. Acid detection studs which fit into the side of cans (for easy viewing when the cans are stacked on a vault shelf) are sold by Dancan. They're very useful for monitoring a collection of elements in various different states of decomposition where you haven't got lots of different segregated vault spaces to play with.

Posted by Henry Titchen (Member # 3141) on 05-20-2005, 06:57 PM:

The previous posts all sound like good advice.

From my limited knowledge cold storage/humidity control is the way to prolong the film life.

Posted by John Pytlak (Member # 331) on 05-23-2005, 03:01 PM:

Two options:

1. Cool, dry and vented (but buildup of acid vapors can affect other films in the same storage area).

2. Cool, dry, and sealed with Molecular Sieves (but Molecular Sieves need to be replaced when they become loaded with moisture or acid vapors -- i.e., a weight gain of about 20 percent over the "fresh" weight).

See SMPTE Recommended Practice RP 131-2002 "Storage of Motion Picture Films":

http://www.smpte.org/smpte_store/standards/

Posted by Leo Enticknap (Member # 534) on 05-24-2005, 01:59 AM:

And if cool, dry and vented, ideally in a vault with an air handling system that scrubs acidic vapours out of the air before it's recirculated (though installing and running such a system isn't cheap - around £12-13k a year in power and servicing alone for ours, which conditions three vault compartments with a total capacity of around 40,000 elements).

Posted by John Pytlak (Member # 331) on 05-24-2005, 05:40 AM:

In most cases, carbon adsorption (e.g., activated charcoal) filtration is used to "scrub" acid vapors from the circulating air.

Posted by Leo Enticknap (Member # 534) on 05-24-2005, 06:25 AM:

That's what our (Munters) AHUs use. The replacement charcoal cartridges cost about a grand each and need to be changed out annually.