Audiotape Baking..

Lorraine Algera (
Wed, 01 Oct 1997 13:26:25 -0700

Hi all, I gave a copy of the discussion on audiotape recovery to our audio
specialist and he gave me this info.



To build a simple tape-baking oven, acquire the following materials:
1 cardboard box, of about 2 feet x 1 foot x 1 foot
1 cardboard box, of about 5 inches x 5 inches x 2 inches
1 cardboard box, of about 16 inches x 7 inches x 7 inches
1 lamp socket (about $1.00)
1 used thermostat (about $2.00 at a flea market)
1 thermometer
1 60 watt light bulb
1 power cord with plug
The attached diagram illustrates how I set up the system. (Since we are
unable to email this diagram it can be faxed by request.)

1. Mount the lamp socket on the bottom of the smallest box, with lamp cord
going through and out at the side or top.

2. Connect power cord to the input side of the thermostat, and lamp socket
to the output side. A mercury thermostat will work, but it must be placed
as on a wall (for your furnace) and is motion sensitive. A bellows type
will work in any position and is not motion sensitive.

3. Stand the large box on end. Place the small box with lamp on one side.
Place the medium box on end beside it. Tapes to be baked will lie on top
of this. Place the thermostat at the bottom inside it so that it is
shielded from the lamp.

4. Place the thermometer at the top, near where tape will be placed for
baking. A household thermometer will do, but you have to open the box to
read it. A photographer's dial thermometer with a long stem can be
inserted through the side of the box for easier reading.

5. Since the temperature at the top of the box will be higher than at the
bottom, placing the thermostat at the bottom will allow the baking
temperature to be set at, say, 100 degrees Fahrenheit, while the thermostat
is within its limits at about 80 degrees Fahrenheit.

6. I find that baking from 3 days to a week is sometimes necessary, and
some tapes just stay sticky anyway.
Since audio tapes from the late 50's are on acetate base, baking may make
them extra brittle. Handle with extreme caution!
Personally, I've never had this problem with older tapes. The sticky ones
were mostly made from about 1970 to 1985, and are on polyester base.

Lorraine Algera, Media Consultant
Instructional Media Centre -- Simon Fraser University
ph: 604-291-4300 fax: 604-291-4900 e-mail: