I stole that line from Eddie Ciletti www.tangible-technology.com, who first turned me on to the wonders of the Snackmaster Pro food dehydrator. You may have heard people talk about "baking" old tapes. That sounds scarier than it is.
It seems that around the late 70s, the tape companies (Ampex, Scotch, and AGFA) tweaked their tape formulations, making some changes to the "binder" which is the glue that holds the brown magnetic stuff onto the plastic tape backing. What didn't become clear for some years was that this new formulation did not age well... the "binder" slowly absorbed moisture from the air, and over the course of years, it would soften and get sticky. Old tapes started to "shed", which means when you play them, brown stuff comes off and sticks to the heads. Some of this is normal and always happens with tapes... many of you have used a Q-tip with alcohol to clean your cassette deck heads. We do the same thing to clean the heads of 24-track machines. But with this new problem, you'd take a tape out of storage 10 years later, play it, you'd be 2 minutes into the reel and suddenly all the high end would disappear. You'd stop and look, and the heads would be COVERED with solid brown gunk. Clean the heads, play it again... and the same thing would happen. In other words, old tapes were unplayable! Sometimes, the tape would just stop, as it became glued to the heads! I even heard of capstan motors burning out when the tape got stuck like that.
This even happened with some cassettes. I remember the black "chrome" tapes in the clear cassette shells that all the tape duplicators were using in the early 80s. Many of those tapes did the same thing after a few years, except they deposited white gunk on the tape heads.
Someone discovered that you could solve this problem, at least temporarily, by bathing the tape in warm, dry air for some hours, driving the moisture out of the tape and re-hardening the binder. Then the tape could be played, transferred to digital, whatever you needed to do. In a few weeks or months the tape would revert back to "shedding" again, so you had to deal with it promptly, though you could actually dry the tape out again without harming it, if you were careful. The danger was, if you used too high a temperature, after a few hours the recording would start to lose some of its high frequencies. So the procedure evolved: "warm" air, for several hours, never too hot to touch.
They used to use something called a "convection oven" with a temperature control... hence, "baking the tape" entered the lexicon.
A few years back Eddie turned me on to the Snackmaster Pro Dehydrator. It's a big round thing with a fan and heating element on the bottom, and a temperature dial on the side. It has removable circular trays which stack on top of each other... and a reel of tape fits exactly in a tray! I sent away for it for 80 bucks or something, and have since baked probably hundreds of tapes. Anything from 1978 to 1994 almost always seems to need it, at least here in the humid northwest US. I've had to bake 2-inch, one-inch, half-inch, quarter-inch, and cassettes. I've never had to touch an ADAT tape or any decent consumer-grade cassettes like Maxell and TDK. Oddly enough, I have some old reels of Maxell quarter-inch that I used to use with my quarter-inch four-track, and they are all fine 20 years later... but a reel of TDK tape I bought in 1983 was shedding a year later. My friend Scott Crane gave me some tapes of his dad's old radio show from the early 60's (the Bob Crane show) and they needed some baking, but the shedding was relatively minor; biggest problem was, the splices had deteriorated and come apart. I have some Scotch tapes from the 50s which are fine.
Amazingly, after you "bake" it, a tape will play all the way through, end to end, and you'll look afterwards and the tape heads will be absolutely spotless... no shedding at all. Very satisfying. The sound will be perfect, as long as you don't use too hot a setting for too long. I rarely go over 125 degrees F, which is like a very lukewarm hairdryer. It takes six to eight hours to bake a 2-inch tape, and you have to turn it over halfway through the process. One-inch tape takes 5 or 6 hours; half-inch and quarter-inch, 4 or 5 hours. Cassettes, 2 or 3 hours. You play the tape a couple minutes in, and look for stuff on the heads. If you still see any gunk, bake it another two hours and try again.
Some of the Nirvana reels had to be baked like this.
I recently had one truly disturbing experience. My friend Al Ensign brought me the spliced, edited album master tape of an indy record he had done in the 1980s, "Come To Amerika" by his old band Child Support. We put the reel on, and it was shedding a bit, so I said, whoa, I better bake it. There was something disturbing about it... one particular song in the middle of the reel seemed to be shedding way too much. Actual slivers of brown stuff were all over the place. So I baked it, spooled it up and got ready to transfer it. Tape played fine, perfectly, for the first few songs. When it got to that one song in the middle, I freaked out. Huge strips of brown oxide just peeled off the tape in front of my eyes and fell on the floor, leaving bare black plastic backing tape! There went the song... there was no binder left whatsoever!
All the rest of the songs played 100% perfectly... so we had to get that one song from an unplayed vinyl copy. With some careful mastering and manual click removal, you can't tell the difference, but what a near-disaster. I'd heard about "defective batches of tape" but never saw anything like this before. Talking to Al about it, I learned the songs had all been mixed at different times, onto different batches of tape... and that ONE song, apparently, was the unlucky one. I hope I never see such a thing again.
Best for this purpose is the Model FD-50, American Harvest Snackmaster Pro. Someday, I might even try making apple chips with it.