Hi;
[In response to the comment on varnish steel food cans,] I have some experience with long term storage and especially underground storage. Since there aren’t any books that I could ever find on this subject, trial and error is how you learn (or maybe you get lucky and the subject is covered on SurvivalBlog!).
Metal cans eventually will rust and especially if in an underground shelter or root cellar. Moisture is always in the air, no matter how well your structure is built. This may not be true if you have the means to have something professionally designed and built, for for everyone else, expect some moisture. Sometimes cans will have a tiny dent in them and the edges of that dent will be weak and rust through right there. So glean out any dented cans, and check them periodically, just because they weren’t dented when you bought them does not mean they aren’t dented now. If one can rusts through the liquids inside will leak out onto other cans and provide sticky moisture that will rust those next.
The best way we found to store cans is inside food grade buckets or barrels. As long as there is no moisture in that bigger container, you will be safe. But, if you put in a dented can and it springs a leak, then all that moisture will be trapped in your bucket and every can in there is doomed if not found fast. Watch those dents. Buckets are also nice because you can grab the handles and move a bunch of cans fast. If you need to, they can be buried and hidden. If buried the metal handles will rust/rot and be ruined, so after digging them up moving them will then be harder.
Plastic totes are worthless. They are too thin and do not have a waterproof seal. When stacked with anything heavy the ones on the bottom will collapse. We stored toilet paper in these and plastic trash cans and ended up with a lot of soggy and worthless toilet paper. No, duct taping the lids on won’t avoid this. Don’t use totes for anything.
Army surplus medical chests are a gem if you can find them. They split into two [clamshell] sections and will hold a lot of cans (or weapons, gear, etc). They have a big rubber seal to keep them air and water tight. These are great for #10 cans. They are made out of aluminum so they won’t rust, but the 4 handles are steel and will rust. If you tar those handles these can be buried for a nice cache. Or you can stack these in a shelter to protect your food or anything. Need to bug out fast? Moving these will be heavy if loaded with food, although not bad for gear, blankets, etc.. These can be moved and dumped into a forest fast. They are OD green so they blend in. There is a scenario in “Patriots” where this would be an obvious advantage. (I don’t want to post “spoilers” that would ruin the book for anyone that has not read it yet.)
You can sometimes find large plastic [or fiberglass] crates that are military surplus. These are also [usually] water and air tight, but harder to find. They can be found up to 4’x4’x4′ and come in all sizes and shapes. Check these for cracks and splits. Make sure that their rubber gaskets are not torn.
I’ve had people tell me that they store food in ammo cans. Ammo cans are great for some items, but I would avoid them for food. Some cans have a residue of gun powder [or other chemicals] inside them, and they may have been used by the military to store something else after the ammo was emptied out. A chemical in a can that touches your food or food container and ends up in you could make you sick or worse.
Metal 55 gallon barrels work well, too. Just make sure what used to be in them won’t poison you and have them completely cleaned. You want ones with removable lids. They are steel so they may rust after a long time.
Watch for mice and rats, they will wiggle into any shelter you can build. They will chew up all kinds of supplies and may chew through plastic containers. I’ve never had them chew through buckets or barrels, but they have chewed through plastic totes. Metal medical chests will stop them.
We had metal cans of lantern fuel stored and after about 10 years every can developed a tiny pin hole somewhere. The result was once that pin hole developed, the fuel evaporated out. So while the cans looked fine, some were 1/2 full. No odors from the fuel to warn us.
Batteries should never be left installed in the item you need them for. If they get too old they will leak acid and can destroy a critically needed item. I would store batteries in a way so that if one leaks it won’t contaminate all the others. You can try zip lock bags to separate a dozen or so.
If you are considering storing fuel to cook or for heat, consider coal. All oil-based fuels will eventually go bad. Wood rots after awhile (I’m talking long term here), so you can’t cut a 10 year supply and have it last. Chainsaws make noise that may attract people and require gas and oil. A chainsaw cut to can be deadly or at a minimum it will take some medical care. But coal is basically a rock. It doesn’t go bad, evaporate or require a noisy dangerous saw to produce it. [JWR Adds: But coal should be stored out of the rain to prevent deterioration.] You can buy wood/coal cook stoves and heat stoves from Lehman’s in Kidron, Ohio. (They also stock spare parts and know about what they sell so they can answer questions) You can buy as much coal as you can afford and stockpile it. If you want to hide it you could dig a trench, fill it in with coal and bury it. If it’s fine sized you might want to line that trench, but if the pieces are big you might not need to. Or you can fill big culvert pipes. Use your imagination.
If you are burying containers you will want to defeat metal detectors. It isn’t practical to dig to China with a backhoe to go real deep, someday you want to dig that back up, and then you might only have a rock to scrape the dirt. So your cache may be found unless you can fool the detector. Consider burying your cache in a junk area full of scrap metal. A few junk cars with old pipes, barrels, anything strewn about will help. Bury some metal around as well. Nothing obvious, just a few pieces of junk to discourage people from looking any deeper. Stacks of old pallets, lumber, all kinds of junk can make a good junk pile as a distraction. You could even stash some old tools [hidden above ground or buried just below the surface] to help dig up your cache!
Hopefully this will help someone and save them spoiled supplies. – Don in Ohio