Film-Tech Forum ARCHIVE: Looking for DTAC soundtrack of THE GREATEST PLACES

This is topic Looking for DTAC soundtrack of THE GREATEST PLACES in forum Large Format Forum at Film-Tech Forum ARCHIVE.

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Posted by Jeffry L. Johnson (Member # 453) on 08-13-2015, 12:52 PM:

My 35mm mag fullcoat (Kodak FPC thin stock) soundtrack for THE GREATEST PLACES (IMAX feature produced by Science Museum of Minnesota) has started shedding and clogging the "dubber" head. The residue left on the Teccon head is sticky and hard to remove.

Does anyone have a DTAC version of the soundtrack? I would like to borrow it and load it into my AE-1 for future playback.

Posted by Bill Brandenstein (Member # 7758) on 08-13-2015, 08:55 PM:

That would be the way to go, but it sounds like you have sticky shed syndrome (is the stock 25+ years old?). You could make it playable again for a few months by baking it CAREFULLY in a convection oven at 135 degrees for 8 hours and letting it cool as slowly as possible. Google "sticky shed syndrome" etc and you'll find some expert advice on how to do this without destroying anything.

Posted by Jeffry L. Johnson (Member # 453) on 08-14-2015, 08:54 AM:

The Greatest Places was a 1998 release. I started playing this print in 2001. So the soundtrack is at least 14 years old, Kodak FPC thin base.

Thanks, I was also suspecting sticky shed syndrome. I have 14 additional "dubber" feature soundtracks. This is the first and, I hope, the only one with this problem.

Posted by Jeff Kane (Member # 6372) on 08-18-2015, 12:12 AM:

Don't bet on it. If the same binder was used in making the other fullcoat, it'll exhibit hydrolysis/sticky-shed as well. Carefully examine the other soundtracks, and if they're exhibiting shed, DO NOT PLAY THEM! As mentioned, baking can restore the tapes for a few weeks or months. That said, it requires a convection as opposed to conventional oven, and must be performed at a far lower temperature (~140 degrees) and higher accuracy than generally achievable by consumer-available ovens. Food dehydrators seem to work well but that's for a reel of 1/4" tape, not a 35mm reel of fullcoat!!

There's an article I can't find about baking tapes that described the process in full.

Richard Hess is one of the main authorities on just about anything that can go wrong with magnetic tape (and to some extent, mag on film). If you're so inclined, the linked article will provide quite a bit of background and info.

http://www.richardhess.com/tape/history/HESS_Tape_Degradation_ARSC_Journal_39-2.pdf

Posted by Bill Brandenstein (Member # 7758) on 08-18-2015, 10:40 AM:

15 years is the youngest "oxide" I've heard of with sticky shed, but fullcoat at 18ips is a lot less forgiving than many open reel tapes (much less surface area per second), so we shouldn't be surprised.

Nice link for Richard Hess!