Film-Tech Forum ARCHIVE: Sticky prints and near brain wraps

This is topic Sticky prints and near brain wraps in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=011038

Posted by Andy Frodsham (Member # 4061) on 09-21-2011, 05:58 AM:

We have just started running our prints using a single Westar projector and a Kinoton ST200E platter. When watching closely I've noticed that during the odd reel join (not necessarily the actual splice itself) the feed module will simultaneously pull-off two layers of film from the inside of the roll. The adhesion is rapidly broken however and the remaining loop is quickly dispensed with automatically following one or two rotations of the platter deck.

My questions are: How can I minimise or eliminate these events? I am already performing a thorough inspection of each reel join and removing any apparent adhesive residues.

Am I being over fussy and neurotic? Is what I am observing a normal part of platter behaviour or is it a more serious symptom of something approaching a brain wrap?

Should I get a life and stop watching the platter so closely?

We are using a Kelmar cleaner with Filmguard but since the prints we have screened to date have been one night shows only, there has been little opportunity to observe any potential benefits of this.

Please help. My nerves (and heart) can't take any more!!!

Posted by Leo Enticknap (Member # 534) on 09-21-2011, 06:17 AM:

Adhesive residue would certainly be my first thought, especially if you're using a CIR joiner. I never encountered a CIR that could make a clean cut along both edges of the film, and almost always had to trim them with scissors afterwards. On an untrimmed join that was messy at the edges, it could easily have an effect for 4-5 film layers past the splice.

That having been said, a little bit of a sticky separation at reel joins, so to speak, always struck me as normal platter behaviour and not much to worry about. The only serious problems I had were when a previous cinema had coated a layer of chinagraph on the edge of the film several milimetres thick in order to assist in locating the splice when packing off the print. And anyone who does this on the soundtrack side of the print really does deserve to be escorted to a cellar and introduced to The Gimp, because it can easily cause 30-60 seconds of Dolby Digital dropping in and out.

Posted by Andy Frodsham (Member # 4061) on 09-21-2011, 06:26 AM:

Thanks Leo.

We are using a Splycemar splicer and it's making pretty clean joins. The problematic adhesions generally seem to be located about two or three feet on either side of each splice!

My suspicions have been aroused by the patchy appearance of white edge marking material (presumably used by a previous venue to indicate a join)which can be found on adjacent layers.

These things didn't cause a problem when we were reel to reel!

Posted by Leo Enticknap (Member # 534) on 09-21-2011, 06:29 AM:

I suspect it's chinagraph. What some 'projectionists' do is to press a chinagraph pencil on the edge of the film surface as the platter (or plate holding the 2k reel while building on the bench) rotates in order ot make an identification mark for breaking down. However, chinagraph is sticky stuff.

It could be worse - they could have used Tippex (US = Whiteout).

Posted by Kenneth Wuepper (Member # 1174) on 09-21-2011, 06:53 AM:

I have found that some operators use masking tape, or that blue painters tape, to attach the heads and feet to the imaged portion of the reel. This adhesive migrates to adjacent film layers while on the shipping reel. Best method for removing it is to use a wrap of the same type of tape with the adhesive side out and dab it on the effected areas. The adhesive likes the bits better than the film so you can remove the bits without harming the film base or image. Anhydrous Isopropyl Alcohol is a stronger solvent for these adhesives but must be used with great care and without any rubbing as scratches can be created.

Posted by Brad Miller (Member # 2) on 09-21-2011, 12:05 PM:

You could be using poor quality splicing tape as well.

Posted by Frank Cox (Member # 6258) on 09-21-2011, 12:54 PM:

It could also be static electricity, or it could even be rough edges where your splicer cut the sprocket holes in the tape where a little piece of tape sticks out and gets stuck in the sprocket hole next to it.

For some reason I always found static cling to be worst at the splices.

Posted by Monte L Fullmer (Member # 2797) on 09-21-2011, 02:27 PM:

One could dab a squirt of FG on a cloth and wipe the splice after its been completed..

Posted by Bruce Hansen (Member # 281) on 09-21-2011, 04:44 PM:

Does the person making the splices like jelly donuts? (sorry, could not help it).

Posted by Andy Frodsham (Member # 4061) on 09-22-2011, 08:58 AM:

Thanks guys!

Answering the points raised:

We're using Jack Roe splicing tape.
Could indeed be a static problem?
Will try the FG splice wipe!
No, not into doughnuts (and certainly not in the projection booth)!!!

Additionally, I'm learning to be slightly less neurotic (less platter watching). What will I do when we go digital?

Many thanks, everyone.

Posted by Martin McCaffery (Member # 37) on 09-22-2011, 09:06 AM:

quote: Andy Frodsham
Additionally, I'm learning to be slightly less neurotic (less platter watching). What will I do when we go digital?

Collect unemployment [evil]

(sorry, couldn't pass it up)

Posted by Andy Frodsham (Member # 4061) on 09-22-2011, 09:12 AM:

or sit watching the hard disks spin (try and spot the head bounce)!!

I can do this as well as being unemployed!!

Posted by Monte L Fullmer (Member # 2797) on 09-22-2011, 01:19 PM:

Jack Roe's is good stuff - just do splicer cleaning maintenance on a standard basis (and FG cleans splicers very well..)

This would be the tip to being the learning of digital so one can be a tech in this field instead of waiting for the pink slip to be issued...

Posted by Walter Rabey (Member # 5968) on 09-24-2011, 12:23 PM:

If its static and the humidity is a tad low where you are, you could try setting up a humidifier in your booth to see if it helps. Some find them to be a life saver during the cold when the furnace dries up the air.

Posted by Jen Pelto (Member # 6447) on 09-24-2011, 03:12 PM:

It sounds like if it resolves itself before actually brainwrapping, it is static. I notice this happens a couple of feet before splices especially. Maybe the extra thickness of the splice puts some pressure on the surrounding film and they temporarily "stick" together? I'm not a scientist, but it sounds right. At any rate, it happens to us ALL the time.

I literally look over and notice it happening sometimes when I am upstairs, and it's like everything goes in slow motion. You think, "Dear lord, thank god I'm up here to fix a brain wrap happening before my eyes!!" But it corrects itself. That is what those guiding rollers are for on the brain.

I think you're just being neurotic [Wink]

We bought a few humidifiers but our booth is HUGE (I know, lucky us, I'll try to keep bragging to a minimum). It never really made a difference in the booth for us. Knock on wood, the static has never resulted in problems.

We did have an issue with a print a few weeks ago (The Tree of Life). Some dimwit left (put?) something extremely sticky on about 3 frames mid-reel. Almost like a clear tacky glue. It kept "sticking" to the next layer of film and going through the brain in a double layer and causing a brainwrap. I misdiagnosed the problem the first time (based on what the projectionist told me happened) but the second time it happened, well, shame on me. So in theory it "could" be something actually sticky on those frames. If you notice it happening at the same time on the same movie, I would definitely take a lens tissue or cloth between your fingers and try to "feel" if there is something ON the film.

Posted by Monte L Fullmer (Member # 2797) on 09-25-2011, 01:20 AM:

When "poly" film first came out, it was the worst compound to use for making prints since it would hold the positive charge to cause static electricity, to where it was a mandantory thing to run the print through a Kelmar using Film-Guard.

Others, purchased 'wrap detectors' to mount on the platters to sense film travel problems and shut down the projectors so brain wraps would be prevented.

But, as anything manufactured, the next versions bettered the original.. The compound to make the "poly" stock improved to where static electricity was drastically reduced to where static has become a rare thing.

The ideal booth humidity is close to the 50% range when running polyester film.

Posted by Frank Cox (Member # 6258) on 09-25-2011, 01:35 AM:

I had a Kelmar cutter gadget on my platter that watched the film tension and would cut the film with a little guillotine blade if the tension got too high. It worked like a kind of spring-loaded scissor.

That gadget saved my butt twice, neither one due to static. Someone dropped a wad of old splicing tape in the middle of a reel and I didn't notice when I was making up the movie and it jammed real good when it got to that point during the first show. And on another occasion some really sticky goo was on the film at one point, also causing a real good jam during the first show.

For static I used to keep a humidifier running full time in my projection room. But a few years ago I got a high-efficiency boiler to replace my old standard boiler and I no longer have dry air in the theatre, so no more static.

The high efficiency boiler doesn't deplete your building humidity because it has an independent ventilation system. It sucks air directly in from outside, and exhausts it back outside. A standard boiler (or furnace) gets its intake air from the indoor atmosphere and blows that up and out of the chimney. So that air has to be replaced somehow and it comes in from the outside in the form of a draft under the door or around the windows or whatever. And the replacement air is dry. The high efficiency units avoid this; you aren't blowing your indoor atmosphere (and humidity) out of the chimney.

In addition to cutting your heating cost, a high efficiency boiler also makes a much nicer atmosphere to be in because it's not dry and there are no drafts or "cold corners".

Posted by Andy Frodsham (Member # 4061) on 09-26-2011, 04:13 AM:

Thanks, once again, everyone!

Jen, I particularly appreciated your comments. You summed-up my fears and thoughts perfectly.

I should say that, despite a number of double-layer pull-offs,the Kinoton platter has always managed to sort-out any resulting loops without causing a brain-wrap!

I have given the splicer another thorough clean and replaced both the cutting blades.

Thanks for all your comments about humidity levels. I'm keeping a close eye on these!