Film-Tech Forum ARCHIVE: Edge Sprocket Hole Damage

This is topic Edge Sprocket Hole Damage in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Ottilie Young (Member # 4195) on 03-08-2008, 04:12 PM:

Hi:

I train projectionists for a college film society and am now involved in designing workshops. I would like to hold one on inspecting prints and dealing with edge and sprocket hole damage. I've projected there for a while and have received conflicting advice on how to make repairs. For example, I've been told to put splicing tape on damage where the film is ripped from the edge through to the sprocket hole) but I've also been told not to tape, but rather to cut at an angle out from each side of the sprocket hole.

We project EVERYTHING--archival, vinegar prints from the 70s, recent releases, foreign prints, etc. They come in all kinds of condition. So, any discussion of how people handle, e.g. sprocket damage where the film is ripped through to the sprocket hole, or something I call "feather nicks" at each sprocket hole where it looks like maybe the sprocket teeth scratched the film. Or how to handle several damaged sprocket holes in a row, nicks in the film that do not cut all the way through to the sprocket hole, etc. Or how to handle scallop cuts in the edge of the film. Also, any discussion of differences between whether the damage is to the soundtrack side or not.

Thanks,

Ottilie

Posted by Scott Norwood (Member # 30) on 03-08-2008, 04:33 PM:

The right thing to do is to get a Perfix machine and use that to repair torn sprocket holes. Unfortunately, these are expensive.

"Notching" works, but will cause issues if and when the print is run on a platter system or any other film path that involves twists. Acetate prints can break at the "notch" point. I have yet to personally meet anyone who believes in notching, although it seems to be common in older prints, so someone must think that it's a good idea.

If there are just a few torn perfs, most people just put splicing tape over the perfs and punch the holes. Pre-perforated splicing tape and an Exacto knife provide a neater way of doing this.

Posted by Kenneth Wuepper (Member # 1174) on 03-08-2008, 08:26 PM:

The notching idea was popular in the acetate days before tape splices. It was just easier to make the notch than to remove the entire frame and add another splice to the print. These split out edges were usually the result of poor winding of the film before shipping where the edge got crunched against the reel flange causing a split.

The Perf-Fix machine is the best method for saving a section of 35mm with destroyed sprocket holes. We once had to do an entire reel #8 of "The Crimson Ghost", an old serial cliff hanger. When we finished repairing and ran it they were able to use that reel to make another print as the negatives were gone. They were so sure we couldn't fix it they sent us the #8 chapter in 16mm.

I have not experienced the tearing with the new Estar based film stocks. That stuff is pretty tough to tear and the edge damage is usually in the form of creasing or folding deformity.

KEN

Posted by Frank Angel (Member # 248) on 03-08-2008, 09:39 PM:

What they said. I would only add, Scott, that it wasn't so much as anyone ever really thought it was a good idea to notch, but the only other choice back then was, as Ken points out, to loose a frames, which at the very least was a venial sin but more than not, downright mortal.

I have found that prepunched mylar splicing tape, if carefully applied, can repair longish lengths of damaged sprocket holes in much the same way Perfix is used. You apply a length of it over the affected area, but then instead of covering the entire frame, you press a razor blade just at the edge of the image and by pulling the rest of the tape against the blade, you cut a clean line, covering the sprocket holes without the tape covering the picture. It is tedious to be sure, but it is an excellent re-enforcement for damaged sprocket hole areas. I prefer Prefix, but have used the prepunched tape with just about the same level of success, albeit at the expense of man-hours. If I had to do large lengths of film, Perfix and the machine are invaluable.

Like Ken, we once repaired miles of footage of a 4trk mag vault print of WOODSTOCK for Warners. It was an unplayable mess when when we got it but went back to them nearly as good as new. IBTec it was too.

But Ottilie, given that you play older titles and all manner and shape of prints. Given that you seem to have a very commendable attitude about print care and preservation, I would suggest that you really press the powers-that-be in your organization to invest in a Perfix machine and repair tape. It really should be in the arsenal of tools at a projectionist's disposal if he/she is working in a retrospective/art house.