I have LTO tapes that I want to have stored outside of sight in a friend’s house in his attic (his wife doesn’t approve of having random tapes on top of a wardrobe) as a secondary cold storage location, but I’m concerned about the temps and humidity.
I put a temp probe into the attic and during autumn the temps swing between 11c to 20c on a sunny day, which is within archival temperature range, but the humidity is too high due to living in Ireland.
Is there anything that I could do to make storing the tapes safer and more resilient to the high humidity?
My current idea is to grab a plastic storage box with a locking lid, create a rubberized seal with E6000 and store the tapes inside with silica gel satchels
Silica gel is not a long-term solution, as it will eventually adsorb as much water as it can (this will not be a very long time (a few months at best for even a few kg of silica), I live in similar ambient humidity and have experienced this firsthand), and become ineffective, requiring baking/drying/etc itself before it can be useful once more (and hence you end up with this big annoying maintenance cycle).
If you can get some form of power up there, Rosahl do these solid-state dehumidification membrane things that sip just a few watts and keep humidity low without needing servicing. You need to email them to buy them, but they’re not unreasonably priced, and they’re more than welcoming to average consumers (i.e. they’re not exclusively B2B). There’s a couple limitations on material and sealant compatibility (something something volatiles interfering with operation of the membrane), so be thorough in your checking. Their documentation is good, though.
Looks like you can buy some of the smaller kits directly from an online store. Unfortunately there’s no power up there so the solid state dehumidifiers won’t work in this situation.
The box I’m thinking of is 5L one. How often would I have to replace the silica gel? If it would be an once a month maintenance cycle in the sealed box I’d be fine with doing that as I check the tapes every quarter already.
5L is nice and small, if you have a decent quantity of gel (few hundred g, thereabouts) and a well-sealed container you will probably be fine lining it up with the quarterly check.
I advise to pre-bake/dry/etc the gel as soon as you get it, to be sure it’s going to do anything, it can turn up in really any state of humidity.
Ziplock bags… include desiccant in the bags if you want.
Putt everything in a container along with some thermal mass to help even out temperature fluctuations. Concrete and containers full of water work well.
That might be something like 50um LDPE which water vapour does travel through. What I’m not clear about is on what time scale does this start to matter.
If you’re thinking long long term, get one of those vacuum sealers that are usually used for food. Put your tape and a small bag of silica gel inside. You could even use anti-static bags, though I’m not sure if they work with food-grade sealers, just make sure to label them from the outside.
I think it’s kind of cool to „deseal“ a backup with the hiss coming from the bag
Tape is fragile. Have you considered M-Disk for your important data? I believe 100Gb on the BRay disk. One can compress data quite a bit. You can even mount the Blue Ray disk as a Luks encyrpted partition and save your compressed data on it.
In addition to this, use the mylar bags, they should hold up better to moisture ingress than the cheap transparent plastic ones. I know that DigiKey sends ICs in sealed mylar pouches, and they also work well for keeping flour and sugar dry.
I’d go bankrupt if I tried to backup to M-Disc as I’m storing over 1tb per tape (lto5)
Anyway I tried an experiment with a reusable ziplock bags with a wireless temperature probe and the seal failed within a week, so the food sealing method might be a good shot
I wouldn’t try to improvise a seal on a cheap case, I’d get one that’s rated to be waterproof and heavy duty:
If you’re really determined to go guerrilla with your important data storage… Try sugar storage containers which seal tight, and don’t skimp on the silica:
