Film-Tech Forum ARCHIVE: cleaning old 35mm print

This is topic cleaning old 35mm print in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Christopher Woollard (Member # 2455) on 11-10-2019, 02:39 AM:

We have an old 35mm (1970's) print in generally good condition except it is marked with what appear to be remnants of a film cleaner/preserver throughout, possibly a very old application of filmguard. Very obvious when screening. We have the kelmar machine and wonder what would be the best impregnation to use. Possibly saturate the tapes with filmguard the day before cleaning and run through a couple of times? Use isopropanol instead? How about both of these approaches.
Any experience of remedying this most welcome. We do not have access to a lipsner smith film cleaning machine which would be my first choice. We are London based.

Posted by Sascha F. Roll (Member # 9043) on 11-10-2019, 02:53 AM:

I doubt that these are leftovers of Filmguard - so far I have never encounteres any negative after effects of FG, even years after application. It just seems to evaporate.

Posted by Christopher Woollard (Member # 2455) on 11-11-2019, 03:50 AM:

I do not know how or with what this print was treated, obviously done on a platter as the intermediate leaders are not affected. I thought possibly filmguard because of its smell.

Posted by Leo Enticknap (Member # 534) on 11-11-2019, 07:29 AM:

Without a more detailed description and/or a photo of the visible artifacts, it is difficult to speculate what they could be, but I will do so anyways, and opine that the contaminant is more likely to be projector oil than a cleaning product. The only cleaning or preservative process I am aware of that is known to cause visible defects over time is Scotchgard/Photogard, and this will also cause deformation (curling and/or cupping) of the film base.

If it is projector oil, the only treatment that stands a good chance of getting most of it off without causing any damage to the emulsion is ultrasonic cleaning, rewashing, and (if the film base is acetate or nitrate; not polyester) polishing. You indicate that this isn't an option in your case. Unless the deposits are flaking off, PTRs are unlikely to help.

A pass through media pads impregnated with Filmguard certainly can't hurt. Depending on the type of release print stock involved (and especially if it's b/w), IPA (by which I mean isopropyl alcohol, not India pale ale!) could, especially if it's denatured rather than pure. In some jurisdictions, alcohol not intended for drinking has to have stuff added to it that makes it undrinkable (i.e. it provokes a gag reflex if you try to drink it) in order to be exempt from booze duty. In California at any rate, IPA that has been so treated is labeled "denatured." These additives can leave deposits on anything you try to clean with the stuff: it often won't evaporate without leaving a trace.

Posted by Christopher Woollard (Member # 2455) on 11-11-2019, 09:58 AM:

Thank you Leo,
Perhaps the following:
Multiple passes (perhaps as many as ten) through the kelmar using filmguard impregnated tapes. Then several passes using virgin tapes impregnated with isopropyl alcohol, we have this very high purity. This is an almost zero cost route for us. If the above does not resolve matters the print will have to be ultrasonically cleaned when the budget can be found.

Posted by Leo Enticknap (Member # 534) on 11-11-2019, 12:53 PM:

I can't think of any way this could make the print worse, unless the unknown contaminant has affected the emulsion such that the IPA removes the emulsion along with the contaminant. Once you get to the IPA passes, if it were me, I'd stop after, say, the first 50 feet of the first reel, and look at it carefully for any sign of any ill effects.

Posted by Christopher Woollard (Member # 2455) on 11-11-2019, 01:15 PM:

Well, I can always try simple virgin kelmar tape without the IPA
I thought of IPA because Kodak mention it as a somewhat effective film cleaner being an alternative to compounds now banned which were superior.

Posted by Buck Wilson (Member # 5885) on 11-14-2019, 10:16 PM:

I like the ideas posted above. I'm no expert but purely from a soil cleaning point of view, I would personally run in the following order

1- dry media run to absorb the excess oil/mystery cleaner
2- IPA to actually clean the oil off and leave a clean slate
3- Filmguard to condition/protect/perfect

Posted by Steve Guttag (Member # 268) on 11-15-2019, 06:56 AM:

quote: Leo Enticknap
IPA (by which I mean isopropyl alcohol, not India pale ale!) could, especially if it's denatured rather than pure.

Isopropyl Alcohol does not need to be "Denatured." It isn't drinkable in natural form (and you should seek it in as pure as possible, not in the rubbing varieties which just add water to the mix). Most "Pure" anhydrous IPA are 99%.

What Leo is thinking of is Ethanol (Ethyl Alcohol), which IS drinkable and needs to be denatured if to be sold as a chemical and not subject to the various liquor laws.

Posted by Mark Gulbrandsen (Member # 72) on 11-15-2019, 08:35 AM:

It's most likely residue fomr oil that got on the print. Its easily possible with certain projectors. Perc will clean it off easily and Perc is the common ingredient of brake cleaner. However, only use it outside!!

https://www.chemicalsafetyfacts.org/perchloroethylene/

Mark

Posted by Christopher Woollard (Member # 2455) on 11-16-2019, 12:15 AM:

How do you use Perc?
Neat or dilute with water. Soak pads and pull through? Given its very nasty nature and our terrible weather, it will have to wait until spring.

Posted by Randy Stankey (Member # 64) on 11-16-2019, 03:04 AM:

Perc isn't THAT nasty.

It's NFPA "Fire Diamond" is 2-0-0

"Health" = 2 - Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury (e.g. diethyl ether, ammonium phosphate, iodine)

"Fire" = 0 - Will not burn under normal conditions.

"Reactivity" = 0 - Will not react unpredictably under normal conditions.

Although it can make you sick it won't cause lasting injury unless you get a lot of it in your system.

It's main method of action on humans is through inhalation of vapors or absorption through skin.

Use it outdoors or in a place where there is excellent ventilation.

Wear Nitrile gloves and an apron while using it.

Be careful not to spill more than a nominal amount. Small spills will evaporate on their own in a few minutes. For large spills, treat it as you would paint thinner or similar things. Wipe and absorb spills, place in a safe container and dispose of responsibly. Most or all of it will evaporate.

One of its main uses in business and industry is as a dry cleaning solvent for clothes. When you take your clothes to the dry cleaner, that's what they use.

It's not "Methyl-Ethyl-Bad-Shit" but, as long as you respect it for the industrial solvent that it is you should have no problems.

Posted by Leo Enticknap (Member # 534) on 11-16-2019, 08:04 PM:

These chemicals went out of use for film cleaning not so much because of their immediate danger to human health, but because of their environmental nastiness. Until the mid-1990s, 1,1,1-Trichloroethane was the methyl-ethyl-bad-shit of choice for ultrasonic film cleaners (when they were first invented in the early '70s, they used carbon tetrachloride, but by the mid-1980s, most were using 1,1,1 because it was less of a direct poison risk to the operator). Then for some environmental reason (could be because it attacked the ozone layer, I can't remember), it was banned for all except a tiny number of uses, at which point ultrasonic film cleaning started to use perc. I gather that there are now environmental objections to perc, too.

Posted by Randy Stankey (Member # 64) on 11-16-2019, 08:48 PM:

I don't think the problem with Perc is ozone depletion. As I remember, it is something like 200 times LESS potent than Freon.

I think that one of its main problems in the environment is bioaccumulation...its half-life is something like 6 months and one of its decomposition byproducts is Phosgene.

The other thing that I remember is that there have been some studies that suggest that percloroethylene can cause cancer but it's one of those things that hasn't been definitively confirmed. I think it's one of those "some studies show that Substance-X causes cancer in laboratory rats" things.

I would say that the main risk, there, is from occupational or industrial exposure. People who work in factories where they are frequently exposed will probably be at risk while the average person who is exposed infrequently will have no risk if they use it properly.

I don't have a problem with "chemicals," per se, as long as one respects them.

If I handed you a loaded pistol, you might pick it up and say, "Nice gun. Is it loaded?" But, if I handed you a sealed jar full of sodium cyanide, most people would probably freak out.

As long as they are each handled with due diligence and respect there shouldn't be any difference between the two. Right?

Same thing with perchloroethylene. Learn the facts. Use due caution. No problem.

Posted by Simon Wyss (Member # 6218) on 11-18-2019, 02:11 AM:

I should give it two passes. The first is to degrease, so a cleaning machine run. Second should be a water wash-drying cycle on a film processor. Labs do that, surely not all. Make sure drying temperature is not too high.

Posted by Leo Enticknap (Member # 534) on 11-18-2019, 07:15 AM:

Christopher reports that he doesn't have access to a film processor, or any other lab or archival equipment or services: just a media pad cleaner of the sort that were used in release print distribution exchange depots and some better-equipped projection booths.

Posted by Christopher Woollard (Member # 2455) on 11-18-2019, 12:33 PM:

The lab route is just too expensive.
Has anyone actually successfully cleaned an entire film (not just a few feet) with Perc or any other solvent? If so, how. I fear applying chemical with saturated Kelmar tapes would leave the print wet with a possibly nasty chemical, I have never tried to do this in the past myself. We have no print drying cabinets

Posted by Jesse Crooks (Member # 9389) on 11-19-2019, 01:13 PM:

For anything besides Film Guard, you should make sure the cleaning fluid evaporates from the surface before the film is spooled onto the reel. It should evaporate quickly enough that you can wind it at a reasonable pace while cleaning it.