Being a nomad, I have several "homes". In each, we leave some stuff. One place has temps that exceed 120F, another -40F. Another has very hot and humid weather for 6 months of the year.

In each, I use new 30 (?) gallon metal trash cans. I use aluminum tape to cover anything that looks like a hole. Put the stuff in and add a wrap of good quality duct tape around the seam between the lid and the container.

Been doing this for over 18 years now, mostly with the same containers. Last one I bought (about 2 years ago) was $18 at a rather overpriced very rural hardware store.

Nothing, not even ants have breached the containers. No rust, no water, nothing has entered.

Because it is a "metal to metal" seal, it would probably function well as a Faraday shield.

The handles are strong and I have loaded one so that two people were needed to move it. No problem.

There are a variety of sizes and shapes to choose from.

Works for me....

Nomad.