How to work with moisture affected sound film

[Andrew Wise]

Hi all, as the title suggests, I’ve received some 16mm colour film with a magnetic sound stripe. it’s a tv reel, a field interview. 
 

it seems they kept the box in quite a wet area as there’s a lot of rust on the reels. 
 

The film is lightly stuck together, enough that it can be unwound without affecting the emulsion, but unfortunately if it’s unwound the magnetic sound strip will come off, sticking on the other side it was pressed against. 
I only unwound about 20cm before putting it back to find advice on how to proceed. 

thank you!

[Brian Drysdale]

I would get advice from a restoration specialist.

I've been involved in the digitalization of an old 16mm black and white drama that I made years ago. For copyright reasons, the music has to be replaced, fortunately, I had the sep mag tracks, which I hoped could just be used for the new soundtracks. Unfortunately, we discovered that they were suffering from vinegar syndrome, plus the coating from the spacer had come off in places and stuck to the magnetic film in places.

For budget reasons, we only put the dialogue tracks through the restoration process (3 out of the 9 tracks). The high frequencies were gone, but with EQ and denoising, quite good audio was transferred to WAV files. I also had a digibeta master, from which the other audio could found, but it will involve recreating new sections of the soundtrack for the new mix.

Check out if there are any restoration companies where you are. My audio work was done by Cinelab in London, they do archival work.

[Tyler Purcell]

We've had similar issues with magnetic soundtrack. 

Vitafilm is a great start. Buy a container. 

Stick the film in a can/bucket not much larger than the roll itself and fill it with vitafilm. 

Then just let it sit. 

It's a lubricant and it will slowly start to seep into the actual emulsion itself. This should help considerably, but I will warn you, I haven't tried it with magnetic film yet, just optical film. I would google search and research if it will damage soundtrack. It may not do anything to the soundtrack because it's not "emulsion" and it can't absorb it. 

But that's the substance everyone uses and it works to fix sticky film like this. 

Since it's actual image too, you can't just bake it, which is what you'd do with full coat. I'm pretty sure it will damage the picture elements when you do that. The other thing is, depending on how fragile the picture element is, the stiction of the magnetic track may not even allow the film to unwind. I've seen this as well, where the film is so brittle before Vitafilm, that it just tears where the soundtrack is. Quite common on poorly stored magnetic super 8 film. 

So yea, recap. Vitafilm for picture elements. Do some research. 

[Frank Wylie]

Go slow with Vitafilm and mag stripe! 

Try a short section that has a section that has lifted before you commit the entire roll. There were many ways mag stripe could be applied;  most often you have what came from Kodak/whomever manufactured the film, BUT there were post processing applicators that used solvents and even mag strip applied via an adhesive strip. 

Test to be sure.  Vitafilm is a good impulse, but test to be sure.

Iron oxide is the perfect catalyst for Vinegar Syndrome, unfortunately.

You may just have to live with interruptions in the track if the oxide starts falling off the film.

Not many real cures for this problem. 

Edited August 12, 2023 by Frank Wylie
added info

[Brian Drysdale]

Was this TV interview shot on commag film, as used by 16mm news cameras? That tends to be the usual way that mag strip gets used by TV stations.

Edited August 12, 2023 by Brian Drysdale

[Tyler Purcell]

59 minutes ago, Brian Drysdale said:

Was this TV interview shot on commag film, as used by 16mm news cameras? That tends to be the usual way that mag strip gets used by TV stations.

Usually this OR prints made very fast for broadcast. 

[Andrew Wise]

4 hours ago, Brian Drysdale said:

Was this TV interview shot on commag film, as used by 16mm news cameras? That tends to be the usual way that mag strip gets used by TV stations.

I think it was, local TV station story. It’s positive film

[Frank Wylie]

Last ditch suggestion:

Go down to the next "adhesion" on the roll and try gently inserting an Xacto or scalpel in between the winds to see if you can divide the stuck mag oxide without it popping-off.  Pull up slightly and with gentle wiggling, try to break the surface in the middle where the adhesion begins and sometimes it will allow you to separate stuck elements.

May or may not work, but I have done this lots of times with melted nitrate film and managed to save footage that seemed hopelessly stuck together...

Edited August 12, 2023 by Frank Wylie
typo

[Perry Paolantonio]

On 8/11/2023 at 6:27 PM, Tyler Purcell said:

Since it's actual image too, you can't just bake it, which is what you'd do with full coat.

Please don't bake your full coat mag stock. 

Most mag that would require a treatment for sticky shed syndrome has an acetate base. (Sticky shed is the problem that baking addresses with audio and video tape) . Baking acetate based stock will destroy it. Acetate shrinks with heat. Please don't bake mag. 

That said, baking might work for newer polyester based stock. ...maybe. But poly based mag was introduced much later and is usually in much better shape than acetate to begin with, so it's less likely to need much treatment at this point. There is some very old poly stock (i think it was introduced in the early 70's, but I'm not positive about that). We've worked on films from the mid-80s that still had acetate mag stock. And the widespread use of fullcoat tailed off not that long after, in the 90s, when digital audio became the new standard.