Film-Tech Forum ARCHIVE: Projector's cleaning method for archive

This is topic Projector's cleaning method for archive in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Anhtu Vu (Member # 7689) on 05-17-2016, 08:12 AM:

We are looking for the best cleaning method for our 35 / 16 mm. This is for an archive environment. These machines are being used to project very rare copies.

I usually recommend my tech to simply use a brush and special cloth but they prefer the air gun, of course this method is much quicker but i found it dissipates way to much dust in the air.

What's your take on this subject and any suggestions ?

Posted by Gordon McLeod (Member # 33) on 05-17-2016, 08:45 AM:

depends on what is the type of dirt
Air is fast and easy a brush works well but some debris that is left behind usually requires a solvent to remove

Posted by Leo Enticknap (Member # 534) on 05-17-2016, 10:51 AM:

You need to be careful with brushes and plastic rollers, because you don't want to abrade the smooth surfaces (especially given that they make physical contact with the SR-D and SDDS tracks).

For our Norelcos, I do a start-of-shift deep clean consisting of the following routine:

Remove all pad rollers from their shafts and clean them by holding them in a car waxing non-abrasive cloth and rubbing. If that doesn't get all the dirt off, then use another cloth, slightly moistened. Last resort for baked-on crud is to use a tiny amount of rubbing alcohol. Replace rollers on shafts (relubing spindles if necessary), checking and double checking that they rotate freely, and that none are sticking or binding.

Remove gate assembly, backplate and shutter housing cover, and clean both the same way, but using a small paintbrush to get into smaller holes in the gate assembly, and/or an air spray if absolutely necessary.

Remove pad roller assemblies and do the same thing.

With all removable components out of the film path, clean the interior surfaces of the chassis with a barely moistened (with disilled water) non-abrasive cloth.

Sprocket teeth - with a soft, dry toothbrush (softest grade the store will sell), then spray the area with compressed air and remove the dislodged crud from nearby surfaces with a cloth. Soft metal and easily damaged - be careful.

Audio scanning drum(s) - pay close attention, as this is the only surface that actually touches the picture area of the film. Take a lens cleaning cloth moistened in rubbing alcohol and rub while rotating, being very careful not to touch the photocell.

Reassemble all components.

In between reels, clean gate components with a dry cloth, remove aperture plate, clean, clean behind it, then reinstall.

I would consider this a necessary cleaning routine if you're showing rare or irreplaceable prints.

Posted by Steve Kraus (Member # 476) on 05-17-2016, 12:58 PM:

And then run a reel of something on each machine. Hopefully something clean that won't dirty back up what you just cleaned. Sometimes it seems that no matter how careful you are to clean everything thoroughly there's going to be something, some bit of dirt left behind that will make itself known during the subsequent screening so going directly from the cleaning to the important screening isn't always the best idea. Run a reel and then re-clean the gate and trap as needed.

Posted by Leo Enticknap (Member # 534) on 05-17-2016, 01:58 PM:

For me that would be a relatively fresh RP-40 loop to line up the focus and framing before the audience walks in, and, yes, observing if a stray piece of dislodged crud is causing any scratching. Agreed completely: just after a deep clean is, paradoxically, a high risk time for scratching, because particles will have become dislodged from the film path and could still be floating around.

Posted by Anhtu Vu (Member # 7689) on 05-17-2016, 02:14 PM:

Leo...what would you recommend for in between project and end of day cleaning ?

What you describe is fine for a major job where we have time but i'm more interested to find out about routine everyday cleaning.

thx

Posted by Leo Enticknap (Member # 534) on 05-17-2016, 02:29 PM:

The procedure described above takes around 25-30 minutes. So, for a dual projector installation, that's an hour at the start of each shift in which film is to be run. It doesn't even have to be at the start of the shift: for example, if I have a DCP feature playing the night before an archival print, I'll do the projector cleaning while that DCP is playing. To protect a rare or irreplaceable print, I don't think that an hour of projector preparation time is too much to ask.

In between each reel (i.e. after the changeover but before rethreading), I will clean all the gate components with a non-abrasive cloth, remove and clean the aperture plate, clean behind the aperture plate and then replace it, briefly check the other components that contact the film surface (especially audio scanning drum(s)) for visible dirt and clean if necessary, and then give the entire gate area a brief squirt with compressed air, to reduce the risk of hairs sticking to the aperture edges from dislodged dirt.

Posted by Simon Wyss (Member # 6218) on 05-18-2016, 01:52 AM:

Not much to add to what’s been said, only that a professional projectionist keeps the equipment clean rather than cleaning this and that from time to time. Advantage pair of projectors with hands on

Posted by Brad Miller (Member # 2) on 05-18-2016, 11:08 AM:

While this is more critical with some projectors vs. others, let's not forget something very important and that's the pad roller clearance. It's pretty trivial to grab a few short strips of film and check the clearances during a full cleaning. I've seen lots of film damage because nobody ever paid attention to them.

Posted by Monte L Fullmer (Member # 2797) on 05-18-2016, 06:35 PM:

Film-Guard on the location works wonders also.
I've dampened down brushes with FG for wiping on gates, sprockets and rollers.
I've used FG on 8mm and 16mm prints.

Others may have other techniques.

-Monte

Posted by Justin Hamaker (Member # 2165) on 05-18-2016, 09:12 PM:

Out of curiosity, when dealing with rare or archive prints, are you still able to use Film-Guard?

Posted by Leo Enticknap (Member # 534) on 05-18-2016, 09:55 PM:

FIAF's technical commission recommends against the use of proprietary compounds (chemical mixtures for which the precise "recipe" of ingredients is considered commercially confidential and not published) in treating film elements, in line with their philosophy that the custodian of an archival film should do nothing that is or even possibly could be irreversible to it. The last time I looked at their technical documentation, the only film cleaning method they approved was ultrasonic, using 1,1,1 or perc.

Most FIAF member archives, therefore, will make it a condition of loaning prints to theaters that they must not do any sort of chemical cleaning to it whatsoever. In reality there is usually no need, because a print from a FIAF archive will almost always be a new or very lightly used print that the archive itself will have cleaned recently, anyways.

FIAF's policy is definitely debatable, especially where release prints are concerned. If a print is designated as viewing status (i.e. it is not being kept for preservation as a reference source for future work on the movie), then it exists to enable the movie to be seen, and IMHO the projectionist showing it should be entrusted to do what is necessary to make it look and sound as good as possible to the audience here and now, even if that does incur the slight risk that a treatment used may, say, slightly increase the risk of dye fading in 20 years' time (for example). But "no chemicals" is FIAF's rule, and it is one that their member archives expect theaters borrowing their prints to obey.

The commercial archives (e.g. the studios) are as a general rule less strict. Furthermore, many of their prints are former general use release prints that have been used heavily, and show it, before being pulled from circulation at the end of the main release and designated one of, say, two or three keeper prints for use by the small number of arthouses and revival houses that might want to play the title again. Most of these archives probably wouldn't even notice if I FG-ed one of their prints, and in many cases doing so would absolutely enhance what the audience sees.

Posted by Bill Brandenstein (Member # 7758) on 05-18-2016, 10:04 PM:

Leo, what chemicals would have a reputation of accelerating color fade? Anything in common use?

Posted by Leo Enticknap (Member # 534) on 05-18-2016, 10:06 PM:

Scotchgard/Photogard did, but I was just using that as a "for example."

Posted by Bill Brandenstein (Member # 7758) on 05-19-2016, 08:07 PM:

But not any of the many petroleum-based solvents, then. Makes sense with Scotchgard and other sealants because of the radical alteration of the film surface/breathing. Thanks, Leo.

Posted by Scott Norwood (Member # 30) on 05-19-2016, 08:52 PM:

Film Guard doesn't really apply to most repertory screenings, anyway, since they are usually one-offs. The real benefit to it is for long-term engagements, not single screenings.

Posted by Kenneth Wuepper (Member # 1174) on 05-19-2016, 09:00 PM:

The old remedy for "green prints" was to have a little block of canning wax available to apply to the film edges outside the sprocket holes. This paraffin stopped the gate chatter and was acceptable to the exchange.

Posted by Mark Gulbrandsen (Member # 72) on 05-21-2016, 09:56 AM:

Ken,

I don't think they have made canning wax since 1892.

Mark

Posted by Martin McCaffery (Member # 37) on 05-21-2016, 11:02 AM:

Au Contraire, Mark
Gulf Wax

Posted by Gordon McLeod (Member # 33) on 05-22-2016, 09:38 AM:

camphor was was very popular for years
https://en.wikipedia.org/wiki/Camphor

Posted by Leo Enticknap (Member # 534) on 05-22-2016, 09:48 AM:

Edge waxing acetate (and maybe nitrate when it was in use - don't know) prints was very common. It was done by at least one major archive, too - British Film Institute archive prints in the 1980s and '90s would often arrived with large red WAXED stickers on the cans. The smell of a waxed reel was distinctive when you opened the can, and in retrospect I wonder if those vapors weren't helping when it came to acetate decomposition.

I've never (that I can remember) come across a waxed polyester print, though. I'm guessing that the thinner stock means that the friction issue that can be addressed by edge waxing acetate doesn't exist, and therefore that waxing a polyester print wouldn't achieve anything.

Posted by Gordon McLeod (Member # 33) on 05-22-2016, 12:24 PM:

deluxe canada edge waxed all prints until they closed the facility

Posted by Kenneth Wuepper (Member # 1174) on 05-22-2016, 01:10 PM:

Thanks Gordon,

I knew that the practice was still being done.
KEN

Posted by Leo Enticknap (Member # 534) on 05-22-2016, 03:02 PM:

Maybe not, because Deluxe Canada has now closed.

None of the prints I've seen coming out of FotoKem recently have been edge waxed.

Posted by Manny Knowles (Member # 1171) on 05-25-2016, 06:05 PM:

Scott, take a look at Steve Guttag's bench setup for Film-Guard. Photos are part-way down the page.

There have been a few occasions where I got permission to clean up a filthy repertory (or "sub-run") print*, and Steve's method is, in my opinion, the best way to do it, because it affords the ability to do multiple passes in less-than-real-time. Perfect for a "one off" screening.

*I do make a distinction between "repertory" and "archival" prints.

Posted by Monte L Fullmer (Member # 2797) on 05-25-2016, 06:32 PM:

Some Kelmar tables did have the threaded hole made to attach these Kelmar brackets as with what Steve had set up for bench cleaning.

I'd did the same with 16mm films on a Kelmar table since the rollers on the bracket had the inner grooving set for the 16mm width.