Film-Tech Forum ARCHIVE: Sticky sound drums.

This is topic Sticky sound drums. in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Keith Peticolas (Member # 971) on 09-25-2005, 09:34 PM:

Howdy Lords of Film, I have a Century sound drum that on occasion will develope a gummy sticky coating of ...? GM thinks it may be film-guard. Possible that we use too much and are gumming up the works? (I say no.) Projector is a Century sa. Gunk comes off with elbow grease and alcohol. Any clues as to what may be happening would be greatly aprreciated.

Posted by Frank Dubrois (Member # 3042) on 09-25-2005, 09:57 PM:

I'd have to guess its nothing more than crap thats being picked up, transferred to the film, then transferred to the drum. What is the consistancy of the gunk? oily? solid? what does it smell like? gummy and sticky cover a lot of substances.

Posted by Dan Lyons (Member # 1454) on 09-25-2005, 10:18 PM:

Sounds like masking tape goo. Sometimes there is sticky gunk from tape left on the heads and tails that will transfer onto your sound drum and then all over the print. Cheap tape on the heads and tails so you can read the title can also ooze gunk from the edges.

Posted by Keith Peticolas (Member # 971) on 09-25-2005, 11:08 PM:

Thanks guys, let's see... it is actually kind of dry and tacky, and rubs off as a dark green gunk. We are 99.9% first run and I don't use masking tape during build up at all. Any old tape is removed and all prints are Film-Guarded as per Brad's instructions. We clean the projectors daily and run a nice and tidy booth. This stuffs shows up very rarely and doesn't coat the entire drum, just blotches of it around it. But when it does show up the prints sticks to drum as if glued. Nothing else in the proj. seems to have this stuff on it. Strange. The house it affects is one of our smaller rooms and usually the print comes from the bigger room after a couple of weeks. Checked the first run proj. and no gunk there.

Posted by Randy Stankey (Member # 64) on 09-25-2005, 11:35 PM:

It MIGHT be FilmGuard but, if it's sticky, I have serious doubts that it really is.

Sometimes, if you use too much FG there will be some residue left on the drum but:

A) It's not sticky.
b) I wipes off easily with a rag and your favorite projector cleaning substance.

If you're wiping projectors down in between every show I can't imagine how it would be FG. Any residue that did build up would be removed immediately upon cleaning. It would never have a chance to build up.

Does anybody use any liquid cleaners to clean projectors, platters or rollers? Could somebody be using, for instance, "Formula 409" to clean platters but not wiping them perfectly dry before allowing film to go back on them? "409" and other water/glycol based cleaners WILL turn film into a sticky mess if it gets on them! It is an OK cleaner to use PROVIDED the surface is completely dry first.

Another thing I would suggest is to see if you can correlate the problem with a specific brand of film stock. Does it happen only with Fuji? (Does Agfa even make movie film anymore?)

I have tried all kinds of tourture test with lots of different substances on movie film. (Old trailers.)
I have never been able to MAKE FilmGuard hurt film. Even under the most extreme conditions.

Posted by Monte L Fullmer (Member # 2797) on 09-26-2005, 12:53 AM:

..got an intermittent assembly that is leaking a bit, which could be throwing oil on the print and collecting on the drum? Or, got a platter assembly that could be tracing oil on the film as well?

SA's being a greased gear machine instead of an oil bath or belt driven and wonder if any overgreasing is being involved..

-Monte

Posted by Keith Peticolas (Member # 971) on 09-26-2005, 01:08 AM:

Thank you gents. No... this stuff does not come off very easily. We clean with iso and clean white rag. We do use 409 on platters, but wipe it dry. Will pass the grease and oil thoughts along to tech and check those myself on Mon. Have serious doubts about FG causing this too. Will check film stocks.

Posted by Brad Miller (Member # 2) on 09-26-2005, 02:13 AM:

You might want to try ceasing using the iso in your cleaning. Just use a dry shop towel and a dry toothbrush. If you have some crud that doesn't want to come off, take a lintless paper towel, fold it up a couple of times and put a small bit of FilmGuard on it.

I say this because whenever this sort of problem arises, it is usually some solution that is being used. When all liquids are removed from the booth for cleaning, the problem generally just goes away. If you are FilmGuarding your prints, they shouldn't be shedding but a very little amount, if at all.

Posted by Keith Peticolas (Member # 971) on 09-26-2005, 11:32 AM:

Thanks, will do so.