How to Make a Faraday Cage
A Faraday cage can be made out of any metal container such as tin canisters, filing cabinets, metal desks, garbage cans, or ammo cans. I use small file boxes as Faraday cages because I want something that’s portable in case I ever have to bug-out. If I ever have to get the hell out of Dodge in a hell of a hurry, I want to be able to heave it into the back of a truck or trailer without having to mess around with unpacking and re-packing something that’s too big and bulky to carry. I also like these metal file boxes because they’re cheap; I buy them at thrift stores and garage sales for a dollar or two.
Start with a metal container and something to insulate the items inside from coming into contact with the metal: newspaper, magazines, cardboard, or styrofoam, which is my preference.
Line the container with your insulating material. It's not rocket science.
Collect the electronics you wish to protect. I have a bunch of Faraday cages with a wide variety of items inside. This particular box holds various items such as solar lights, flashlights and batteries (I don't know if an EMP will effect them or not, but better safe than sorry); walkie-talkies, AM/FM radios, worldband receiver, and a car inverter that lets me plug any electrical appliance into a car battery.
Some people say that if you wrap an item in a plastic baggie as your insulating layer, then wrap the baggie in tinfoil, that's all you need to do. It's true that when you treat a radio or cell phone this way, the signal is lost, which indicates that electronic waves are not able to get through the barrier. I prefer a more substantial Faraday cage than a single layer of ungrounded tin foil, but I tend to be a *little bit* OCD about my preps, so I'm going to hedge my bets and use BOTH tinfoil AND a metal box, so I'll be doubly protected. Here I've wrapped the various items in 1. A baggie; 2. tin foil; 3. Another baggie, to protect the tinfoil.
Another reason for the extra layers of protection is that I'm going to be grounding this Faraday cage by attaching it to plumbing pipes. I live in earthquake land. Plumbing pipes tend to break during earthquakes. I don't want my EMP preps to get ruined by flooding, so the extra layers are worth the extra effort. Here I've made sure everything is thoroughly labeled so that if I'm frantically searching for my walkie-talkies, I don't have to rip open package after package in order to find them.
Everything goes into the metal box, packed nice and tight. I don't like packing empty space, so anything I pack is packed to the very brim.
Next I've sealed up all the cracks and crevices in the metal box using aluminum tape, which is on the same shelf as the duct tape at your local hardware store. Not only does this prevent stray ions from penetrating the box, but it also prevents water from burst pipes from getting into the box.
Here I've clearly labeled what's inside the sealed box, to make it easier to locate stuff on the day after Doomsday. Did I mention I tend to be *very* thorough? That's my cat Lily checking things out.
The finished Faraday cage, waiting to be boosted into its permanent home.
Faraday cages ought to be grounded. The easiest way to do that is to attach it to copper plumbing pipes, which go into the ground, thereby bleeding the electrical charges away from the box. Here I've attached the handle of the Faraday cage to the plumbing pipe using copper wire.
A closer view of the twisty wiring wrapping numerous times around the handle of the box and the copper pipes. I have several places in my home where the copper plumbing is accessible and I try to spread my various Faraday cages out so that if one gets crushed or drowned in a quake, I still have the others to fall back on. If you do not have copper pipes conveniently exposed, you can tie your wire to a stake driven into the ground or a metal fence post or some such. Even if you cannot ground your Faraday cage, it should still offer you more protection than no Faraday cage at all.
Here's another Faraday cage I made using a popcorn tin lined with newspaper.