I apologize for not responding sooner to your question.
Magentophonband Typ C was produced up until 1944 when the factory burned
in an industrial accident. From then until the end of the war (and
beyond) Typ L was the only tape manufactured in Germany (as far as I
know). Typ L is Luvitherm (PVC) and is one of the few homogeneous tapes
ever manufactured. Typ C is a much more conventional coated acetate tape.
When I transferred several dozen reels of Typ C (a total of 51 mostly
Typ C and Typ L from the Mullin-Palmer collection and a few dozen more
from the Eve Mullin Collier collection) all of the Typ C tapes played
well, even though they were somewhat stiff. I can imagine that they have
become even stiffer in the intervening years.
I transferred a half dozen Tonschreiber B reels (also Typ C, if I recall
correctly) a few years later for Stanford (these were part of the Ampex
Museum Collection which is now housed at Stanford). These had been
stored in metal cans as opposed to the cardboard boxes of the other
collections (I also did a few reels of mostly Typ L for the Pavek
Museum). These reels stored in metal cans were suffering from vinegar
The first caveat I have is that these tapes are 6.5 mm wide as opposed
to 6.35 mm wide and if you are having difficulties playing them or they
are bouncing around part of the issue may be binding in the guides. I
ended up taking a file to the worn side of a set of fast guides in one
of my Sony APR-5000 head assemblies in order to widen the guides to more
easily accommodate the tape (I can loosen the guide and turn it back to
a never-worn side for 6.35 mm wide tape).
The one tape that I had from the Eve Mullin Collier collection that was
very stiff (much like a carpenter's tape measure with the cupping in it)
was of concern. This was the early (circa 1935) tape and was only made
for about two years if I recall correctly). I called Friedrich Engel in
Germany and we talked about it a bit. He suggested a process of
hydration. I placed the tape above some water in a closed plastic
storage bin for about 24 hours.
When I removed the tape, it was like a silk ribbon--very pliable. The
tape played fine (unfortunately, Mullin had used it as an experimental
tape and there were only series of test tones on it. I ended up not
digitizing it at all. Too bad, after all that work, but it proved the
I tried rehydration once more with an acetate tape that had fallen
behind a wood stove in Vermont and stayed there several winters. It was
of no use because the edges of the tape were actually fused together in
spots, so nothing would help. It appeared that the rehydration process
weakened the tape, but the wood-stove treatment didn't do it any good
If you are looking for more information about acetate film, the Image
Preservation Institute (IPI) at Rochester Institute of Technology has
some information on their website.
Some of their papers are cited in my paper on tape degradation that was
originally presented at the Audio Engineering Society's 121st convention
in October 2006 in San Francisco was published in the ARSC Journal in
the Fall of 2008. It is available here:
IPI is also a source of information on vinegar syndrome. As Tom
mentioned, Kodak tape is quite susceptible.
Here are a few links related to Vinegar Syndrome from my site, including
the old German tapes in cans.
Here is a list of many degrading tapes and the current thoughts of what
to do with them.
I see while I was typing this Don Tait mentioned rehydration.
On 2011-12-08 6:48 PM, Simon Kunz wrote:
> Dear all,
> I would like to use camphor on a brittle acetate tape to smoothen it and make it playable. I have recently read of this procedure for film and I wondered if it would work in magnetic tapes as well.
> Does anyone have some experiences with this kind of treatment? Are there any published articles concerning this topic? (whether applied to film as to magnetic tape)
> The tape I would like to treat is a Magnethophon Typ C from 1943.
> Every hint is appreciated! If you prefer you may contact me off-list.
> Simon Kunz
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Quality tape transfers -- even from hard-to-play tapes.