Video tape baking with food dehydrator?
 

Has anyone had any success with "baking" tapes in a food dehydrator?

I have some tapes that sound a lot like this:

The article then goes on to say this problem can be solved (temporarily) by baking the tapes in modified food dehydrator, which they sell for a large markup.

An earlier version of that page has step-by-step instructions for modifying a different model food dehydrator (Nesco FD-75PR, which I've found for $60), and the modifications look extremely simple. Has anyone tried doing this? How well did it work for you?

I had to bake a U-matic tape recently. It was my first attempt at baking. I've been doing VHS for years and have been fortunate to not encounter sticky shed with that format. With U-matic it seems to be more the rule than the exception. The magic temperature range of around 125 to 130 F seems to be the rule for most formats.

I bought a dehydrator from a US ebay dealer in September 2021 for about $80, but the unit was manufactured in China. Many dealers sell the same item, and they don't mention what the brand is in their listings. Once I got it I found the brand was Tooluck, and is the 600 Watt model. You'll recognize it more by how it looks. See attached images I pulled from the ebay listing. It has a timer dial (up to 12 hours) and an analog temperature dial, so you can make fine adjustments. I bought a small one, and even that one could handle quite a few tapes at once. The design of the model I got is very convenient for tape baking. No concerns with having to modify any plastic insides or if things are big enough to fit.

Just like with the unit you mention, the key is to get an accurate thermometer (possibly two) so you are highly confident what the actual temperature is. I ultimately found the unit I got was off by several degrees, but it held a very steady temperature (which is a must). I first tried an oven thermometer that went down to 100 F, so I could try to measure a temperature of 125 to 130 F. I ultimately discovered that thermometer was off by a few degrees once I tried more accurate mercury thermometers that went above 120. I went with mercury because I had access to some, and knew they would be accurate. I used a flashlight to check readings while keeping the door closed. I believe they make digital thermometers that are accurate to 1 or 2 degrees F. I did not try a digital thermometer, because I had access to the mercury ones. The unit is metal, and has some ventilation slits on the sides that might allow a narrow sensor to slip through. If you have the tools, you could probably cut a bigger opening in one of the slits and then cover it back up once the sensor is inside.

I had success with one tape keeping the temperature around 127/128 F for 4 hours. There's tons of advice out there for how long it needs to bake. I took the conservative approach of 4 hours, then let it cool to room temp and tried the next day. My approach was if it wasn't enough, then I'd try for a couple more hours, let it cool for a few hours, and repeat that until success. Some would say go for 8 hours. Some would say longer than that. I think it depends on how thick the tape reel is and how sticky/sheddy it is. I am new to it, so I took the conservative approach. I don't think you can tell in advance, without a lot of time and experience with lots of different tape stocks. I took the shell apart and just baked the reels and manually wound the tape so that each reel had similar amount of tape on them to increase effectiveness. Especially with U-matic, the shell might be a real blocker of even heat transfer to the tape. I suppose any cassette shell could have a similar effect. I was not successful with another U-matic tape after many more total hours using my iterative approach of 1-2 additional hours each try, and at the same temperature as the other tape. Ultimately, I abandoned that tape and luckily found it didn't contain anything I needed. It was a more notoriously sticky brand of U-matic tape. So, that sort of confirmed with me that it is somewhat tape dependent just how much baking you might need or maybe how high the temperature may need to go to have success.

At least with Umatic, it was obvious that the picture went snowy almost immediately, and I quickly stopped and cleaned the heads (which confirmed it was shedding) and baked. One thing that I'd highly recommend is to only do it when you are there to keep an eye on it. Just like with an oven, you don't want to leave it unattended. The tape should be fine at 125 to 130 F. It's just in case something goes wrong with the oven. Just like a small space heater, it should be treated like a fire hazard.

I haven't tested it myself, but the advice ranges from a couple weeks to a few weeks of opportunity to play back before the tape begins to revert to it's prior state. I don't have personal experience with re-baking months or years later to see how often one can bake a tape. That's probably an unknown for any given tape. There may be issues with other things having prolonged heat exposure, such as breakdown of the adhesive that connects the clear leader at the end of the reel with the magnetic tape. Although, those could always be spliced back together. I suppose I don't worry about that. I just make sure I've got everything transferred right the first time so I don't have to bake it again.

Best of luck to you!

Great post, great story, very helpful. :congrats:

Has anyone had any experience with baking with VHS tapes? Any VHS specific advice? Most of what I've read has focused on reel-to-reel audiotape and stuff like U-matic. VHS seems less studied, but I understand it can still help.

Also, I can't remember where I saw it, but I read somewhere that putting the tape in a foil bag with a desiccant pack can keep them playable for longer after baking.

Anyway, I'm going to give it a try (and if it doesn't work I guess I can always try to make some jerky).

I Just had to jump down the baking rabbit hole. My setup is still a work in progress. there is a paper put out by ampex tapes that explains the baking process. they shoot for 130 degrees no higher then 140 no lower then 120.under 120 nothing happens and over 140 you start to risk "print through". I am trying two setups one is a seed propagation heat mat, this will start to reach proper temps if you place a baking sheet over it to trap in the heat a wool blanket can be added to trap more heat if needed. i like this setup because i have not seen the mat go over 140. this setup is conducting heat through the mat so the bottom of the tape will typically be 131-137 and the top will read 126 flipping the tapes every 1.5 hours or so. setup has to be monitored and adjusted depending on room temperature you can take the blanket on and off and put pencils under the cookie sheet to make a small air gap. the second setup is using a 2500$ glass annealing kiln. this has a fuzzy logic control and keeps the temperatures accurate to under 1 degree over 24 hour periods. this setup is hotter at the walls then the center of kiln and has metal coils that can heat things up more or less depending on surface colors etc.
the kiln is set to 160 degrees to get the center in the 130 zone but the heat is variable depending on where you are in the kiln might vary a few degrees from one end of tape to another . i set the tape in a card board box to make it heat up from the air temp in the kiln rather then from the radiation of the coils. today i am going to add a small fan to the kiln setup which should make things more even and allow me to lower the temps i am setting it at. so far i have played one baked hi-8 tape. i will claim successes the tape had less noise and was able to go 20 mins between slight head cleanings compared to 5 mins and heavy cleaning needed. now i can get away with putting in a brand new tape and recording 30 seconds onto it every 20 mins on the baked tape. the nesco dehydrator has the air circulation and can be set to keep a pretty narrow range it seems like an ideal solution.. i have heard storys of bad tapes taking several days up to 7 in extreme cases to sort out. i think if the temperature is on 130 and stable there is no danger to the tapes. i am going with 24 hours on hi8 and 3 days on betasp tapes

My understanding is VHS is much less likely to have sticky shed syndrome than for example Umatic and Betacam tapes. Baking tapes which actually need it does work if carried out properly but is fairly brutal and shouldn't be used unless that is really the problem.