Just a hypothetical response: plastic is an insulator, which means that
it will not heat up as quickly as metal.  Therefore, where the tape is
contacting the flanges and hubs, it will not heat up as quickly.  The
result might be non-uniform heating of the tape pack where areas exposed
to air will heat more quickly (and be more baked) than those exposed to
the reel flange/hub.

Whether this non-uniform heating of the tape pack has any real impact
on the results of the baking is another question.  From David's
comment, any non-uniform heating has been a non-issue.

If you are baking for a long duration, obviously the plastic reel will
come up to temperature.  Assuming a good quality tape pack, the pack
should be able to resist any small dimensional distortions caused by
initial non-uniform heating.

FWIW, I use a scientific oven (Yamato DH-42) with a controlled
temperature ramp up and ramp down that minimizes any potential problems
with non-uniform heating.  I've profiled the oven, and it is accurate
to +/-1.0F throughout the oven space, so there are no localized hot

The scientific oven may or may not be overkill.  It's really a
question of how much latitude there is in the baking process
(duration and temperature).

Eric Jacobs
The Audio Archive

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]]On Behalf Of David Seubert
Sent: Monday, June 06, 2005 9:40 AM
To: [log in to unmask]
Subject: Re: [ARSCLIST] baking tapes

Why are metal reels necessary? Anything hot enough to melt plastic reels
would be damaging the tape too. We bake tapes on plastic reels and
U-Matic videos in the cassettes all the time with no problems.


Robert Hodge wrote:

>Baking your reel to reel tape requires the following:
>1- VERY  IMPORTANT !!- Put the tape on a metal reel.   When
>transferring the tape to the metal reel, don't allow it to rub against
>guides or heads in the tape machine as it will cause the sticky shead to
>build up in clumps randomly on the tape, and make it all but impossible
>to remove. Wind the tape loosely on the reel.   Reels should be evenly
>spaced with an empty reel between each full one.