So the local hardware store around me had a sale on new and used ammo cans. I've always been a fan of them for storing things. They're durable, waterproof(ish) and ever so stylish.
I've tried an experiment with one of the larger ones. I'm using it to store more mission critical electronics. Collect up some of the oh shit gear and store in a safe place. Crank radio with Weather band, capacitor shake flash light, that sort of thing. But then I started to think about solar flares and other such grief. Possibly due to the cache article the other day. So I figured I should probably turn the thing into a faraday cage. Which really isn't hard, since, you know it's a steel box.
Huzzah! Project done!
But being the paranoid kind of guy I am, I wanted to go a little further. If there was damage to the pain or a strong enough discharge, anything metal touching would likely be affected. I decided to add an insulation layer. I formed an inner cardboard box, about 1/8th inch or so thick to slide inside of the ammo can, with a lid. I also coated the outside of the cardboard with electrical tape for extra protection.
The box still seals tight as a drum. I did a few signal reception tests with radios, cell phones etc, and it definitely prevents any signal in or out. For more protecition items in the box are going to be stored in mylar bags, some silica and 02 packs as well. For full protection I would likely seal all edges with aluminum tape to ensure there's a conductive seal all around the container.
The upside is also, when I really don't want the office to call, I can drop my phone in there. It's a win win all around.
Not a bad use of old cardboard, and a few dollars with of duct tape and electrical tape.