Re: [AV Media Matters] Newbie to list question - tape baking, is it

[smolians@erols.com]

I can only second this basic information.

I use an environmental chamber which gives a greater degree of control.
Having done hundreds of these in all configurations (I had to bake some
non-US cassettes recently.  I wonder what they were slit down from...).

I've found that wider tape requires more bake time.

Too high a temperature causes print-through.   I bake a bit more slowly at a
lower temperature, both for myself and other local studios, and have never
haad a failure- so far.

Steve Smolian

-----Original Message-----
From: Graeme Jaye <gjaye@retemail.es>
To: AV-Media-Matters@topica.com <AV-Media-Matters@topica.com>
Date: Monday, December 20, 1999 5:39 PM
Subject: Re: [AV Media Matters] Newbie to list question - tape baking, is it
wrong?

>Hi WIll
>
>At 06:02 18/12/99 -0800, you wrote:
>
>>I've got a circa 1982 Ampex 2" 16-track tape that I want to transfer to
>>ProTools. It has been stored in various conditions and levels of
>>humidity since that time, but has not been played since then. I've been
>>told that I'll need to "bake" the tape to keep the acetate from coming off
>>on the heads. Is this normal (and is it the only way to do it right?)
>
>This is a well-known problem which affects tape (not only Ampex) of this
>vintage.  It is to do with the binder chemistry being changed around that
>time for something which (over a period of time) becomes 'sticky'.  It's
>commonly known as 'sticky shed syndrome' and it's not the acetate which
>comes off, but the iron oxide!!  If I recall, Graham Newton has some
>information on his website about this subject
>(http://www.audiorestoration.com) which you might like to have a look at.
>
>Baking the tape is the accepted solution for the problem, although it does
>*not* effect a permanent cure.  Something like 6-8 hours at 130-140
>Farenheit is the usual sort of figure recommended.  I have baked many tapes
>(must be well in excess of 100 by now) and have not had a failure so far.
>All my tapes have been 1/4" masters, but I don't see that a 2" would be any
>different.  It does no harm to leave the tape for longer, but I would be
>very wary of going over-temperature.
>
>You can be fancy about it and use a temperature controlled, electric oven
>(not a gas one).  Personally, I do mine in a cardboard box, about  2 ft
>cube, with the tapes supported on a wooden dish rack, two electric light
>bulbs, a dimmer unit and a photographic thermometer :-)
>
>After baking, spool the tape a couple of times before playing.
>
>>This person said that after baking, the tape would only be good for about
>>2 to 4 plays, so I want to make sure.
>
>I don't think it is a case of the number of plays, so much as the time it
>will take for the binder to re-absorb moisture from the atmosphere (which
>is what causes the problem in the first place).  After baking, I place the
>reels inside a sealed polythene bag (assuming I am not going to use them
>immediately).  They have certainly been playable after a month when treated
>this way.
>
>>Aside from the difficulty in finding
>>an old 2" machine with a 16-track head (I know you can play them on a
>>24-track machine with some level of reliability) - I'm cautious about
>>going forward. I'm located in Austin, TX.
>
>I would have thought that many studios still running that type of machine
>would have a 16 track headblock as well as a 24 track one - but I'm open to
>correction on this point.  You can certainly *play* a 16 track tape using a
>24 track block, but some of the tracks are not covered properly and the
>head is also partly reading the guard band, which will lower the
>signl/noise ratio of course.  I used to know which tracks were which and
>the amont of level correction required, but I'm afraid it's a long time
>since I last did this and my memory fails me now.
>
>The one thing you should *not* do is to try playing the tape before baking
>- apart from the fact of losing a lot of information off the tape, it will
>make one heck of a mess of the headblock and guides!!  Otherwise, I would
>say this is a reliable method of recovering these tapes.
>
>
>Graeme Jaye
>gjaye@retemail.es
>
>Audio CD stuttering?
>DVD dodgy?
>CDROM not reading?
>PlayStation stationary?
>Saturn not flying?
>
>No Problem - Check this out!!!
>http://www.personal-cd.com
>
>
>
>