Hi, I'm Taylor Hales.
I'm here in studio B at Electrical Audio, and today I'm gonna talk about tape degradation
and how to bake and transfer your analog audio tapes.
[clunk, clunk.]
Baking and Transferring Tape, Part 1:
Testing for Sticky-Shed and Baking Tapes
So, analog audio tape has two or three main layers.
There's the base film, which, since the 1970's, has been polyester or PET.
Onto that base film, there's at least a magnetic coating on the inside of your tape.
The mag coating is slightly brownish in color and a little bit shiny.
The mag coating is where the analog of your audio is actually written.
On the backside of your tape is your back coating (if your tape is back-coated).
Your back coating will be a little bit darker and more matte in color.
The back coating has a few different functions. It serves to prevent the buildup of static
and prevents print-through.
And it also adds some strength to your tape.
The problem is that the PET base will absorb water through the humidity of its storage
environment, and the two coatings are susceptible to degradation through exposure to water.
The result of this process of hydrolysis is the tape goes from a strong and resilient
form to a rubbery, sticky one.
If you play back a tape that's been degraded in this way, you risk damage to
the tape, itself, and to your machine.
The remedy for this is that you bake a tape at a low temperature for a long period of time.
Before you put your tapes in the oven, it's
good to establish whether they NEED to be baked.
First and foremost, check the composition of your tape.
If it's a cellulose acetate base film, it does NOT need to be baked, and actually it's
flammable, so don't bake those tapes.
If your tape is a polyester PET base film tape, you can do a series of playback and
wind tests to determine whether it needs to be baked.
So go ahead and mount up that tape.
So first, any time you mount up a tape, you always wanna clean your machine and wipe down
your heads with alcohol.
You can also clean off the lifters and any other pieces in the tape path that are non-rubber.
Your first test will be a simple wind test. So go ahead and spool up your tape,
and do the slowest-speed library wind you can for a short section of the tape -
maybe 50 to 100 feet.
If you hear the tape shearing apart from itself, if you hear a very loud scraping sound, or
even this little squealing sound that you can hear... you probably want to bake your
tape.
Otherwise, go into edit mode or de-tension your tape otherwise, and then check the lifters
to see if there's buildup on the lifters themselves.
You wanna check your lifters to see if there's any tape bits that have shed off, or kinda
sticky residue that's formed on the lifters themselves.
You wanna do this before you do any playback just so that you don't even risk putting tape
over the heads that's sticky.
If your lifters and the rest of your tape path are clean, you can go ahead and re-establish
tension on your tape.
And then play back a short section, maybe 50 to 100 feet.
And then wipe your heads with alcohol.
And check for any residue or tape pieces that have shed off on your Q-tip.
If they have, it's time to bake the tape. If not, you're good to move on.
You can go ahead and re-tension your tape.
And then you're going to wind back a little bit further, and play just a slightly longer
section of the tape. You always wanna library wind, too. Do the gentlest wind you possibly
can on your machine.
So for this run-through, play maybe a few hundred feet of tape.
And then again, you're going to wanna de-tension your tape and clean your heads.
And if you see stickiness or residue, time to bake that tape.
If they're clean, you can move on.
OK, now that we've arrived at the very inside of the reel, we're going to play a short section.
And then again, clean down the heads with isopropyl alcohol, and just look out for sticky
tape particles that have come off on the heads.
...and if you see any, it's time to bake.
So, after you've played back a section of the inside of your tape, you can go ahead
and wipe down your heads one last time with alcohol.
And you're following the same pattern that you've established here, you're just wiping
the heads, and then looking at your Q-tip, and then trying to see if you see any discoloration
or tape fragments that have flaked off onto the Q-tip.
If you see anything on the Q-tip, it's time to bake the tape.
But if at this point, the Q-tip is clean, you can go ahead and transfer the tape.
Once you've determined that your tape needs baking, you have to find an oven that's suitable
for baking tape specifically. DO NOT use a conventional oven.
At Electrical Audio, we use this food dehydrator, which is suitable for tape for a couple of
good reasons.
First, it can do a low temperature, way lower than a conventional oven.
And also, it keeps the air inside the oven circulating to maintain a consistent temperature
throughout the volume of the oven.
At Electrical, our first bake is always for 24 hours at a temperature of 130 degrees,
so go ahead and load your tape up.
And set the temperature, and the time.
And after this 24 hours of baking, you wanna let your tape rest for another full 24 hours
before putting it up on a machine for a transfer.
Once your first bake is done, go ahead and grab your tape out of the oven.
And be sure to also grab any boxes or documentation that accompanied the reel when you took it in.
The first thing that you're gonna do is re-do the full kinda series of tests that we did
for stickiness and tape shed.
So, put your tape back on the machine and just re-do all of those tests,
and
at any point, if you notice any stickiness or sheddy-ness anywhere in the tape path,
re-do your bake, but do it for 48 hours, so double the amount of time that you did your
initial bake for.
And then, again, let it rest for 24 hours before attempting your transfer.
If you do the suite of tests and there's no stickiness anywhere in the tape path, you're
good to go ahead and start your transfer.
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