Film-Tech Forum ARCHIVE: RUST in booths=Bad things

This is topic RUST in booths=Bad things in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Alan Brandt (Member # 426) on 04-11-2000, 01:37 AM:

As I was responding to Dustins inquiry regarding the use of dry-erase cleaner on rollers and such, I thought of an interesting topic...Rust. Here's one for the table: Has anyone ever encountered rust forming on so-called "stainless steel" parts. Once here at Sony, I found rust beginning to form on things like gates, sprockets, and --

believe it or not

-- the worst of all was on a sound drum in the sound head. Perplexed by this phenomena, our supervisors called a meeting (they call it a meeting, I call it a pizza party) to figure out what to do about it.

Posted by Ken Layton (Member # 133) on 04-11-2000, 08:04 AM:

I usually keep a can of chrome polish around the booth to use when I spot some rust developing. The chrome polish helps--even on stainless steel.

Posted by John Walsh (Member # 168) on 04-11-2000, 08:29 AM:

We had the same problem with out Simplexes. Got so bad, the manufacturer sent someone out to replace them only a few months after being installed.

Of course, it's the air conditioning and cheap stainless steel.

What make of projector do you have?

Posted by John Pytlak (Member # 331) on 04-11-2000, 09:49 AM:

High humidity (above 65%) is not good for metal (rust and corrosion), electronics (e.g., xenon ignitors), or film (causes "negative curl", and soft/sticky gelatin emulsion). Use air conditioning or dehumidifiers to remove moisture, and ideally maintain a 50-60 percent relative humidity. Use an accurate digital humidity gauge (e.g., Radio Shack or Edmund Scientific) to keep track of humidity levels in the projection room.

------------------
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 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Alan Brandt (Member # 426) on 04-11-2000, 03:11 PM:

We have simplexes...with the rusted sound drum. The problem my team encountered was that #1)

Static- we were too busy trying to keep the humidity above 20% and with 2 humidifiers in our 4 screen cinema, should've been plenty. It wasn't.

#2) An ex-bozo-co-worker decided to use 80 grit sandpaper to clean the rust off the projector heads...yeah, real fun that was!

As I mentioned above, he dont work in a booth no more!

Posted by Aaron Sisemore (Member # 145) on 04-11-2000, 10:12 PM:

Alan said:
"Static- we were too busy trying to keep the humidity above 20% and with 2 humidifiers in our 4 screen cinema, should've been plenty. It wasn't."

Humidifiers, or 'mist vaporizers' (the kind that deliver a visible mist into the air as opposed to evaporating the water into the air as a real humidifier does)?

If the answer is Mist Vaporizers' you have found your rust problem. These things are a definite no-no in the presence of electronics and ferrous metals. You got static problems? Get Film-Guard. No more static. Or at least get a 'swamp cooler' or evaporative humidifier that will not emit a visible (read WET and potentially destructive) mist into the air. Turn off the A/C (or heat in winter) to the booth as these can cause static nightmares due to super low humidity.

Good Luck

Aaron

Posted by Alan Brandt (Member # 426) on 04-11-2000, 10:36 PM:

We were using those conveyor-like

humidifiers with the sponge doo-hicky inside. Once we were able to get the dead mice out of it, it still wouldn't work very well, because it was hard wired into the A/C system, so it would go on only when the A/C or heat was on.

Posted by John Pytlak (Member # 331) on 04-12-2000, 12:24 PM:

Aaron is correct --- do NOT use humidifiers or vaporizers that SPRAY or MIST the water directly into the air.

These include ultrasonic and "cold mist" units. If the mist contacts anything before it evaporates, it actually WETS the surface. And any minerals in the water are put into the air, and will settly out as a white salty deposit.

Humidifiers that EVAPORATE the water by blowing air through a damp paper or foam media are more effective, and don't put water or minerals into the air. Humidifiers that actually boil the water (hot mist) are okay, but quite expensive to run.

Don't forget to keep the humidifier clean, and use the chemical additives that retard mold and bacteria growth.

Posted by Mark Gulbrandsen (Member # 72) on 04-13-2000, 08:13 AM:

There were a few theaters in Chicago running Century SA's that had such bad condensation problems that the shafts would actually rust where they passed through the bearings. And these even ate up the LaVezzi stainless steel verticle shafts too! This would happen to the verticle shaft, shutter and main drive shafts after about 6 months This necessitated sawing the shafts apart to be able to get the bearing blocks off and rebuild the particuluar machine. I also experienced this at one theater in Wisconsin, but not on as regular a basis. We even tried more regular maintainance like tearing the machines down, cleaning up, etc.
Anyone else ever see anything like this? We finally installed XL's in one location and they have had no problems with them doing this.
Mark