Film-Tech Forum ARCHIVE: Covering films overnight?

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Posted by Jesse Skeen (Member # 586) on 05-21-2001, 08:13 AM:

What do the rest of you think about those cloth platter covers? Should they ALWAYS be put on the films before closing, or are they just a waste of time? I'm not going to post my opinion since I don't want to influence anyone else's.

Posted by Randy Stankey (Member # 64) on 05-21-2001, 08:44 AM:

In my home theatre the air conditioning ducts would occasionally belch dust bunnies and other random filth when they fired up in the morning after being off all night. The diffusers were mounted directly above the projectors. (A real genius idea if I do say so myself!)

If the prints weren't covered at night they they would be filthy the next day when you came in.

So how much time does it take to cover the print and uncover it in the morning? Maybe a minute total? Is a minute's time THAT valuable to you that you can't cover the prints at night?

I say do it. Better safe than sorry.

Posted by Ian Price (Member # 14) on 05-21-2001, 08:53 AM:

I covered my prints at the Esquire
I covered my prints at the Mayan
I covered my prints at Thornton
I covered my prints at the Greenwood

And I sure as hell cover my prints at the Rialto!

Posted by Adam Martin (Member # 641) on 05-21-2001, 09:13 AM:

I have always covered prints or put 'em in the cabinets. Everyone knows that the roof only leaks above something important.

Also have the habit of not leaving prints on the top platter overnight unless absolutely necessary.

Posted by Gordon McLeod (Member # 33) on 05-21-2001, 09:58 AM:

The best covers I ran across were made of the same vynl material as covers for outdoor barbaques. They were treated with a staticside. The company also had a bag to fit over reels left on the upper reel arm.
I think cinex in canada still sells them.

Posted by John Pytlak (Member # 331) on 05-21-2001, 10:43 AM:

I agree. Covering prints between shows is a good idea. Certainly cover them if there are activities (e.g., masonry demolition, construction, drywall work, painting) that could put dust into the air. Certainly cover them if the air conditioning system is so dirty that it spews out a flurry of dust when the fan turns on. Certainly cover them if there is any possibility of water dripping on the film.

But, keep the covers clean! Too often, the covers are thrown on the dirty floor, or never cleaned. It does more harm than good to put a cover full of dust and debris onto the print.

In addition to print covers, consider other things that will keep the projection room dust-free. Use HEPA filters (the pleated paper kind) over the heating/air conditioning ducts to trap any dirt that may be airborne. Use a central vacuum system or damp mopping to keep floors and work surfaces clean. (A normal vacuum cleaner or shop vac often doesn't filter out the fine dust particles, and spews them back into the air). Limit traffic through the projection room, and change from dirty outerwear (e.g, muddy boots, raingear) BEFORE entering the projection room.

Here's a quick test of cleanliness: clean a dark smooth surface by wiping it clean with a damp cloth. If enough dust settles and accumulates in a week to clearly write your name in the dust, you need to take measures to reduce the ambient level of dirt. Or do the "white glove" test of wiping your finger on surfaces of the platter and rewind bench to see if there is any dust that the film may contact.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Brad Miller (Member # 2) on 05-21-2001, 03:35 PM:

This is something humorous to me. Let's say a given print runs 5 shows a day and the operators only use the top 2 platters (come on guys, admit it). The film on it's first day starts on the top platter, so that at the end of the day it ends up on the middle deck. The print is covered and the breakers are turned off as the projectionist goes home. The next morning, the projectionist powers up, removes the cover and runs the day's shows. What's wrong with this picture? The top platter, which is the one that will catch the most airborne dust overnight was not cleaned, so that print that was covered all night long is now being ran onto a dusty deck. (How many will fess up to this one?) Also, what was done with the platter cover? Most booths I see either wad it up and toss it on the floor (dirty), toss it on top of the lamphouse (dirty and can cover up important ventilation) or hang it on a hook on the wall. The best of these 3 senarios is to use the hook, but if the bottom side is not kept against the wall, it will just get dirty throughout the day. While I am speaking of this, how many people actually pay attention to the top vs. the bottom of the cover? On some nights is the top (aka: dirty) side of the cover being placed against the film? I see this all the time.

Ideally, the film cover should be neatly folded (bottom side folded inward) and placed in a dust free environment (like a drawer) for daily storage. Even just placing the folded cover on the bottom platter deck is better than setting it on a shelf or the electrical wireway, for at least there is some amount of protection from dust via the middle platter.

The other senario is on the next day when the film ends up on the top platter at the end of the day. Does the roof leak? Cloth platter covers can virtually glue themselves to a print if water gets on them! I much prefer a plastic cover. Even a plain thick drop cloth cut into a square makes for a better platter cover than the cloth ones if you have a roof leak (and it's a lot easier to fold as well! )

Hmmmm, where's my buddy Steve to speak of how he covers his prints?

Posted by Paul Konen (Member # 41) on 05-21-2001, 04:30 PM:

I cover my prints because, like I, they like to stay warm and cozy while they are sleeping.

Posted by Gordon McLeod (Member # 33) on 05-21-2001, 04:42 PM:

"Hmmmm, where's my buddy Steve to speak of how he covers his prints?

"
Like all good projectionists I am sure he puts the reels in the neumade storage cabenet

I have found that drop sheets and garbage bags add to the static on the print

Posted by Jerry Chase (Member # 660) on 05-21-2001, 06:06 PM:

Bravo for pointing out the fallacies, Brad.

Unless a booth is under construction or otherwise unusually dusty, covering the print is something that can cause more problems than it is worth. Even in a worst case scenario, a film can always be wiped off with a lightly dampened rag.

Some circuits have a policy of leaving projectors threaded for at least some of the features, usually to cut "prep" time, but also in case of the not so rare circumstances at the beginning of the day (technicolor <cough> ) that require attention to other matters. (I'll leave that for others to debate, I've seen good points for both points of view on pre-threading in an imperfect world.)

The real question is "Is the booth dusty and dirty enough to require covers?" If it is, it needs new AC filters, better seals, and perhaps a good vacuuming and mopping, along with a thorough cleaning of dusty surfaces. The booth will never be a cleanroom environment, but one smoking projectionist can deposit more crud on a print than leaving it uncovered for days.

Flame away.

Posted by Brad Miller (Member # 2) on 05-21-2001, 06:09 PM:

No flame here. I know several booths that do not cover their prints in any fashion and have the best presentations in town. I agree it really is a situation of if your booth requires the use of a cover, you've got bigger problems. That being said, I am still for covering prints *if* done properly like I detailed above.

In regards to movies being threaded overnight, I could rant for about 10 pages about what bad practice that is. I will spare everyone by just saying do not do that.

Posted by Gordon McLeod (Member # 33) on 05-21-2001, 07:38 PM:

Over the years I have been noted for turning around and leaving on a service call if I come in and find a machine to be serviced left threaded overnight. It is a bad practice (imperfect world or not)
One does not get into their car and turn on the engine and gun it out the driveway imediately they let it warm up first.
Any mechanical device requires that. Oil filled machines to circulate lubricant and on belts to remove the set. Most cases of a stripped gear or snapped belt have occured on the startup of the first show in a theatre that leaves everything threaded. Frankly I don't have time to waste serviceing that form of damage when we are busy enough doing work assureing quality presentations at locations where that is the primary importance.

Posted by John Pytlak (Member # 331) on 05-21-2001, 07:51 PM:

Jerry said: "Even in a worst case scenario, a film can always be wiped off with a lightly dampened rag."

Please, NO!!!

Even a slight amount of water can soften the gelatin of the film emulsion, causing it to either stick in the gate, or stick the layers of the film together causing severe "cling". Better to use a vacuum with a soft brush to pick up the dust. Then, use a clean, lint-free cloth very slightly dampened with FilmGuard or a solvent-based film cleaner.

I do agree with NOT threading/lacing up the night before. As Gordon said, the unthreaded/unlaced projectors should be allowed to run a few minutes to "loosen up". And all that exposed thread-up leader will pick up dirt sitting there overnight.

Posted by Scott Norwood (Member # 30) on 05-21-2001, 08:54 PM:

I know about not leaving film threaded overnight in platter booths. This just makes intuitive sense as being a Bad Thing (tm) for getting the film dirty.

What's the feeling about doing this in reel-to-reel booths, though? The ones where I've worked have had a custom of leaving the first reel (usually trailers) to be shown threaded up the night before. Is this really such a bad thing? It seems like it would not be a major problem, especially with enclosed reel magazines (so that the entire film path is enclosed and thus protected from dust). Thoughts?

Also, what about using compressed air (either from a can or from an air compressor) to clean the film path? I've heard differing opinions on the wisdom of this: one says that it's quick and easy and the other says that it does nothing more than get dust in the air and onto the film.

Posted by Gordon McLeod (Member # 33) on 05-21-2001, 09:00 PM:

Even leaving reel to reel booths threaded still does not allow the machine to be warmed up a few minuets before being put to work allowing belt set and lubrication.
Also if it is a simplex the odds are that the sound pinch roller will be left closed and develop a flat spot.

Posted by John Pytlak (Member # 331) on 05-21-2001, 09:04 PM:

Again, it's always a good idea to let the projectors run a few minutes without film (without load) to "loosen up" and get the oil flowing and overnight kinks out of any belts. I was taught this was especially important in a drive-in, where the booth could get quite cold during the non-summer nights.

IMHO, compressed air should NOT be used. Indeed, you are just stirring up the dirt. High pressure air jets can be especially bad around lenses, where dirt, moisture and oil can be forced into the optics. Use a vacuum and brush to pick up any loose debris inside the mechanism (make a fitting so you can have a tiny vacuum hose for tight spots). Wipe up any oil with an absorbent cloth.

Posted by Jerry Chase (Member # 660) on 05-21-2001, 09:15 PM:

John, I wondered if you would react in horror.

I have to say that I came into the industry from a different part of film, specifically photography for television. I had ample opportunity to watch film dry, and learn the characteristics of wet, dry, and damp emulsion, even watching wet 16mm get slapped on a film chain. Wet film is a bitch, no two ways around it. From personal experience, I still have nightmares of a brain wrap I once had around the drive shaft of an Eprad platter, caused by a drip through a vent onto a film on the top platter. There is no way to recover gracefully from one of those.

Damp film is funky, sticky, and requires a lot of TLC to baby until it is dry. By a damp rag, I mean a lint-free rag spritzed once with a spray bottle of (ditilled) water and massaged, just to give the rag some "tack." This will not wet or even dampen the edge of the film as you brush up the dust. It also will not redistribute or remove the edge wax, which could happen when using some solvents. Using Film-guard could be an option, though. I leave that one to Brad's expertise.

I suppose one could vacuum a film on a platter, though I've never seen it done as far as I can recall. Could that cause static problems? Air moving at velocity can be a way of moving electical charges.

I'd be curious to learn the results of tests of the various methods. I suspect the _lightly_ dampened rag might win out in removing dust.

Re: starting cars and gunning them. I can think of many many shade tree mechanics that do this. When I lived in apartments, I used to take perverse delight in walking up to these fellows intent on tuning engines and waking me up at 9AM on Sunday morning after I'd just arrived home from the midnight shows, and casually saying "Ya know... you could throw a rod doing that." It usually wasn't appreciated, but it was fun anyway.

One area where the wet film and pre-threading could have a serious effect is if a damp film were to stick in the gate from being left overnight. In a contest between stuck polyester and an older fiber gear, my money would be on the polyester being stronger.

Posted by Randy Stankey (Member # 64) on 05-21-2001, 11:02 PM:

If using a compressor to clean a projector was used as an adjunct to cleaning with a cloth & brush I would have no problem with it. Problem is that people seem to think that a compressor actually cleans a projector.

1) Any dust in the projector is instantly accelerated to the speed of sound. No matter how inoccuous dust may seem when it's standing still, it would be like a sandblaster when it's moving at that speed. Continued use of a comressor without removing the bulk of the dust, IMHO is just asking for trouble.

2) I have seen projectors that have been cleaned exclusively with compressors. The visible areas like the trap look squeaky clean. But when you remove the trap you'll find all kinds of dust bunnies caked around the inner workings. Same goes for the sprocket bearings. I have taken sprockets off and found a ring of icky-goo caked around the shaft. This is rarely the case with projectors that are cleaned exclusively by hand.

3) When you compress air you are also compressing the water vapor in the air. Take the nozzle and put it up against a smooth surface or a piece of glass or something. You'll see little droplets of water forming as it is blown out at high speed. You might as well clean the projector with a garden hose!

4) If you use a compressor that has oil in it and don't use a oil/vapor trap you'll get water vapor AND oil vapor. That's even worse.

5) How many people do you think would really be careful and not knock the nozzle around inside the projector?

6) Why the heck do you want to lug the compressor around with you? You can do a good job of cleaning the thing with a shop rag AND it'll take you a fraction of the time.

As an occasional thing (as part of your take-apart cleaning, for instance) the compressor is OK if you use it carefully.

Posted by Bill Enos (Member # 440) on 05-21-2001, 11:35 PM:

On Warm up and lubrication. Whether it's a start up for a "warm up" or starting the feature ,gears are just as likely to strip on the initial surge and lubrication starts immediately assuming oil level is proper and the booth temp. isn't too low, so what's the difference other than the unnecessary hours of operation accumulating for so called warm up. I put a tachometer on the motor several years ago just to see if there was any difference with and without film--there was none. This is with a reel to reel system so there is the load of pulling the supply reel and take up, the drag is minimal.

Posted by John Pytlak (Member # 331) on 05-22-2001, 08:46 AM:

Bill:

I agree that film puts a negligible load on the projector drive train (you measured no acceleration difference with your tachometer), but the load on the intermittent components is significantly higher with film in the gate. The gate often provides quite a bit of back-tension on the pulldown sprocket, especially when the film has been sitting in the gate overnight (core-set and "stiction" of the emulsion). Even a few ounces of film tension puts quite a strain on that relatively tiny starwheel slot and cam pin at the high accelerations required. Running the projector a few minutes without film to "warm it up" and distribute the oil is good practice.

Posted by Steve Anderson (Member # 364) on 05-23-2001, 01:01 PM:

Unfortunately when I worked for Regal 27 they would schedule you in at 11am with a 11:30 start for some of the features. Also when you are by yourself with 27 projectors to thread it got pretty active those first 25 minutes....but I loved it!

Posted by John Pytlak (Member # 331) on 05-23-2001, 01:09 PM:

With 27 projectors, a little extra time to let each of them "loosen up" before the show would probably pay dividends in reduced repair costs. The temptation in this kind of situation is to thread up the night before as each final show drops, to save time in the morning. For the reasons cited in this thread, avoid the temptation.

Posted by Tom Evans (Member # 857) on 05-23-2001, 08:36 PM:

A few ideas:-

You know how powerful the air compressor can be, well imagine if the air compressor sucked air into the nozzle instead of out. Imagine all the loose film debris and gunk you could clear up - but be careful you don't suck the oil straight out of the machine

Has anyone thought about a platter cover that can cover the film when it is playing?

Also, I was trying to explain to a fellow workmate that running PTR rollers on the first show of a brand new print was pointless as this must compress the dirt and particles collected from the adverts and trailers into the virginal film emulsion, is this true?

Posted by Jeffry L. Johnson (Member # 453) on 05-29-2001, 10:07 AM:

If you use PTR's on a new print you'll be amazed at all the orange paint flecks and fibers from the shipping can liner that will be removed from the print.

Posted by Scott Norwood (Member # 30) on 05-29-2001, 11:12 AM:

I don't see the problem with PTR rollers being used with new prints.

Personally, I don't think that PTR rollers are as useless are others have said. They seem to be effective _if_ the print is new or in mint condition from day 1 and _if_ the PTR rollers are used for _every_ show. Under these conditions, the rollers are only picking up small amounts of dirt and don't get overloaded to the point where they simply move dirt around. In this situation, they do seem to help keep prints looking good for longer periods than they otherwise would (without any film cleaning device in use).

Having said this, I do think that Filmguard is more effective (when used with a media cleaner) and is extremely useful for older prints, where PTR rollers tend to be rather useless.

If you have only PTR rollers and no media cleaners, they are certainly better than nothing, but I'd take FG and the Kelmar/Christie cleaner over PTR rollers if the option existed.

Posted by John Pytlak (Member # 331) on 05-30-2001, 02:02 PM:

Jeffry L. Johnson said:

"If you use PTR's on a new print you'll be amazed at all the orange paint flecks and fibers from the shipping can liner that will be removed from the print."

One of the things about PTR film cleaning is that it is very easy to analyze the dirt that is being removed from the film.

Under a microscope, it is easy to tell whether the debris is film-related like base or emulsion, or from other sources like construction debris, bearing wear, packing materials, carpeting, linty clothing, or even dandruff. The most "unusual" debris captured on a PTR that Kodak analyzed was identified as "hemp". Wonder where THAT came from???

Posted by Will Kutler (Member # 770) on 06-25-2001, 04:56 PM:

I agree with covering prints-especially if you do not have a good booth air filtration system! Also make sure platter decks are clean! Keep covers clean, folded and off the floor. Another thing to consider; remove pay-out head(brain) from deck and place it aside or over the cover. Our area service tech told us of one case where the prints were covered, but platter was not turned off over-night. Cover had cought in the pay-out head, and the platter tried to rotate but could not. Result: fried platter motors and wiring.

Posted by Steven Privett (Member # 718) on 06-06-2003, 02:56 AM:

[ 10-03-2003, 03:16 PM: Message edited by: Steven Privett ]

Posted by Carl Martin (Member # 1146) on 06-06-2003, 04:00 AM:

i've been mulling over throwing them in the laundry. the one thing that worried me was whether the elastic band around the edge would hold up or deteriorate. admittedly this isn't that big an issue for us as only one of our covers has working elastic.

when removing the covers, we grab the center and lift up, collapsing them umbrella-style, then fold them in half. this nicely isolates the 2 sides. unfortunately it tends to end up on a floor-like surface in one booth. and our floors are not clean. i like the idea of a drawer, but i fear that if it's not visible it won't get used. for the time being there are too many dust hazards in our booths not to use them.

some interesting points in this thread. we never thread the night before, but i always saw it as merely a dirt issue. the motor does get run every morning as part of routine cleaning, just for a few seconds though.

carl

Posted by Michael Rourke (Member # 1142) on 06-06-2003, 04:44 AM:

Just get one of those single drawer plastic containers they sell at K-Mart or Wal-Mart and put it in between the legs of your platter and keep the covers in there.

Posted by Stephen Furley (Member # 1277) on 06-06-2003, 06:40 AM:

Kinoton re-invents the spool box

http://www.kinoton.com/spulenkasten.htm

I haven't seen these in use anywhere.

Posted by Steve Guttag (Member # 268) on 06-07-2003, 09:50 AM:

I'm actually a STRONG advocate of the pre-show warm of of the projector...especially the mechanical ones.

One of the biggest load points of the projector itself is the intermittent...turn the machine by hand with and without film in the gate...you don't need a tension guage to feel the difference.

In the case of Bill's theatre, he has Simplexes....the intermittent has only a oil film left from the previous night to start up on...then the pump needs to start drawing and sputtering...finially it makes it out the discharge tube and heads to the govenor weights...to be slung to the intermittent funnel...then it must slowly wick down the funnel to the drop tube to land on the intermittent flywheel gears to finally be drawn into the intermittent cam and star. This isn't an instant process and in fact takes several seconds. Furthermore, this gives the oil a time to heat up and thin down a bit.

After several minutes of operation, recheck the oil and verify a nice smooth stream of oil is still flowing out of the intermittent funnel tube and you know the oil level is not only good but the oil system is functioning properly, before the show starts!

This procedure will also help the operator discover little surprises that the previous operator may have left...I'm sure I'm not the only one to come into a stripped feed sprocket gear. The previous operator always pleads ignorance but the dented tooth brush always gives them away. Again, better to find out before the show than during.

Steve

Posted by Daryl C. W. O'Shea (Member # 1303) on 06-07-2003, 03:51 PM:

I'm with Steve on a pre-show warm up of the projector. In the winter I'll even manually turn some projectors (especially Brenkerts) for quite some time before I'll start the motor.

This practice has also saved me from starting late (albeit only a minute or two, but still late) due to belts breaking on startup (Cinemeccanicas). Out of all the belts breaking on startup I've only once had one that waited until I actually started the show, the rest have been when I first turn the machine on when I walk in the door.

Lots of people think I'm wasting time running the machines before I thread them, but it really doesn't take any extra time, especially in a multiplex. In a plex, I walk around turning on house lights (and sound racks if they are off for the night) and removing platter covers, while also starting the projectors. By the time I get all of the equipment turned on and the machines started, I start back at the beginning and thread each one. Since it takes a minute to thread each platter and projector (darn non-op side platter) each machine will have been running (usually) long enough to exhibit any problems they may have.

In change-over situations, with only one or two, or three screens, I'll go booth to booth turning everything on, starting the projectors and placing the supply reel on the supply arm shafts. Once again, by the time I get back to the beginning the machines have had time to warm up.

quote:
I'm sure I'm not the only one to come into a stripped feed sprocket gear. The previous operator always pleads ignorance but the dented tooth brush always gives them away.

You sure aren't. Unfortunately it doesn't stop at feed sprockets.

Posted by Frank Angel (Member # 248) on 06-07-2003, 04:01 PM:

Without my knowledge, one day some construction guys came into the booth to install some required fire alarm indicators. They drilled through the foot thick cement booth roof. Did they bother to cover any equipment? Not a chance. I discovered a coating of plaster/cement dust covering everything the next time I went up to the booth. It took a week to clean the projectors and get that highly abrasive dust cleaned up. I had to uses a wetvac that sprays a liquid cleaner in front of the suction squeegy as it sucks the dirty water back up. And that was just the floor. You have no idea how difficult it is to get that scouring dust off surfaces -- you literally have to create a negative pressure in the room while you are cleaning otherwise the stuff just moves from one place to another. It's a disaster.

From that point on, I cover all the projectors. Luckily the booth has fireproof film cabinates from the days of old -- 16 bins in all for the longest double features -- so that is not an issue as reels sit in the bins overnight, but covering the projectors is now routine. Also, our operation is such that weeks can go buy without running a film, so it's not like the machines get a cleaning every day. Covering up the equipment for the specialty booths that don't run every day is also a good idea.

Frank

PS -- I also changed the locks. Now the college morons have to call me before they can have at my booth.