Film-Tech Forum ARCHIVE: Sandpaper/Steelwool attachment

This is topic Sandpaper/Steelwool attachment in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Bill Enos (Member # 440) on 01-30-2003, 12:09 AM:

In inspecting prints received lately it has become quite apparent that some theatres have installed a device to hold steelwool or sandpaper against the film. I have checked equipment manufacturer and dealer web sites and can't locate one.I feel like I'm not doing my part. Does anybody know where I can buy one of these devices and where in the film path of my reel to reel operation would it be installed? Many thanks in advance.

Posted by Paul G. Thompson (Member # 655) on 01-30-2003, 12:33 AM:

What????????? Surely, you must be joking.....

Posted by David Favel (Member # 1125) on 01-30-2003, 01:44 AM:

Yes, I suspect he may be joking, but don't call him Shirley.

This post is sponsored by the recent region 4 release of "Flying High"

Posted by Paul G. Thompson (Member # 655) on 01-30-2003, 02:27 AM:

Surely and Shirley are two different critters... [Big Grin]

Posted by Philippe Laude (Member # 79) on 01-30-2003, 07:36 AM:

Bill, you don't need to buy that device. You can get the same result, for less money just by pouring a hanfull of wet sand in each film can and then shake it for one minute. You'll see, it makes wonders! Even Filmguard can't cure it!

Philippe

Posted by John Pytlak (Member # 331) on 01-30-2003, 07:56 AM:

When Kodak was developing Particle Transfer Roller (PTR) film cleaning technology, we sprinkled sandpaper grit on the PTR surface, and then cleaned rolls of negative film with the dirt-laden PTR. Because of the soft polyurethane surface and the "rolling" contact with the film, the grit did NOT scratch or damage the film, even after several passes. [Cool]

PTR film cleaners have proven to be such low risk for damaging film that they are widely used by labs, archives, and telecine transfer facilities to clean valuable original negatives:

http://www.fpcfilm.com/supplies-particle-transfer-rollers.html

http://www.rtico.com/bhp/6131e.pdf

http://www.sanlabsystems.com/rollers.html

http://www.vision4tv.de/abtast-e/liste/reinig/ptr.htm

http://www.filmlab.co.nz/

http://www.jcon.demon.co.uk/magna.htm

Generally a buildup of dirt on the PTRs as they clean film will reduce the cleaning effectiveness, but unlike a DRY media web cleaner, PTRs have very low risk of damaging the film.

Posted by Bill Enos (Member # 440) on 01-30-2003, 08:38 AM:

I thought I had seen every kind of scratch possible until a couple or three weeks ago when a print came in with very fine scratches on the base side, as though done with 0000 steel wool. They were in a circular pattern about a half inch wide down the center of the film, there must be something specially designed to do this. I'm completely baffled on this one.

Posted by Don E. Nelson (Member # 1049) on 01-30-2003, 02:44 PM:

Hi Bill,
I saw a unit like you described on E-Bay last year. The guy wanted a lot of money for it, the reserve was I think 15 bucks. The photo's showed where you load the sand into the hopper, and how to re-load the roll of double stick tape onto the roller assy. There was even a friction tension adj. knob for controlling the amount of pressure applied to the moving film. His unit only worked on 35mm projectors, and at the time I was looking for one for my 16mm film rental business.
I think your mistaken about the steel wool, there was no provision for anything like that. He even included a copy of the instruction manual, it was 87 pages long and listed almost every projector on the market and where the unit was installed on each one. The name of the unit was quite clever, Sand FX Generator, Model 12.
I wish I had bid on it now.

Posted by David Favel (Member # 1125) on 01-30-2003, 03:55 PM:

I had ET delivered to me with almost the exact problem. Luckily the film is set mostly in dark places so till I got another print it was only just bearable. I contacted the cinema that caused the damage but they could not find how it was done. I no longer accept films from these guys as Et was the second movie that arrived with these strange scratches.

Posted by John Pytlak (Member # 331) on 01-30-2003, 04:01 PM:

Can you post a photo of the circular scratches? Do they repeat on a frame-by-frame basis? Or are they random? Were all reels affected?

Posted by Bill Enos (Member # 440) on 01-31-2003, 08:59 AM:

The circular scratches were actually more an elongated oval about an inch long and half inch wide.

Don, the Sand FX could really be improved if the machine is an oil bath type by drilling a hole in the back of the housing to allow a fine oil spray to mix with the sand resulting in much better adhesion. Also the pile of sand accumulating on the floor would be more campact and would be easier to return to the hopper.

Posted by John Pytlak (Member # 331) on 01-31-2003, 09:22 AM:

quote:
The circular scratches were actually more an elongated oval about an inch long and half inch wide.

Ahhh --- "scope" scratches. [Big Grin]

Posted by Darryl Spicer (Member # 711) on 01-31-2003, 09:28 AM:

Sounds like a loop was too big but it would have to be a loop made going in the direction of the screen.

Posted by John Pytlak (Member # 331) on 01-31-2003, 10:37 AM:

I doubt a simple "loop scratch" would have such a large oval shape. [Confused]