Sunday, April 29, 2012

$15 Faraday Cage and Why You Need One

We have  put one of these together about two months ago.
 Really simple and cost effective! SRN

$15 Faraday Cage and Why You Need One

By , April 27, 2012, Salt N' Prepper

There are a handful of emergency preparedness items specific to the disaster in which you are preparing. A faraday cage is one of said items. So unless you are preparing for an EMP (or an engineer), you may not have heard of one before. My personal preps include the necessity of a faraday cage and I suggest yours do as well. A faraday cage is the only thing protecting you from being blasted back in time 200 years.

What Is A Faraday Cage?

I’m no engineer and so even if I tried to explain the research I discovered about electrons and canceled out particles I’m sure I would butcher it to the point of offense. I can however give you a short description:
Firstly, a faraday cage is called such because it was invented by Michael Faraday. The basic premise of a faraday cage is electronically continuous all the way around. Meaning you have some sort of electronic conducting material surrounding it – like metal. There can’t be any large spaces left exposed for electronic waves to penetrate.

Because you create this barrier, your electronics inside will be left unexposed to dangerous electronic wavelengths coming from outside the faraday cage.
Watch an MIT professor explain it in greater detail:
Watch a Faraday Cage In Action – Microwaving Peeps

Why Do I Need One?

I have heard people express concern over a solar flare that could cause a dangerous disturbance in our electronic field. This particular disaster I haven’t done too much research on and couldn’t tell you the legitimacy behind it. I however have done a significant amount of research to validate the possibility of an EMP terror attack.

Once again, I will save you the rambling and give you the Sparknotes – EMP stands for Electromagnetic Pulse. An EMP is a burst (or pulse) of electromagnetic radiation so strong that it will fry pretty much any kind of electronic device (It doesn’t matter if it’s on at the time or not – Tom Cruise was lying to you about that in War of the Worlds).

One way an EMP can occur is by detonating a nuclear bomb in the atmosphere. This is particularly terrifying because now it is understood that a nuclear bomb doesn’t need to reach the ground in order to do catastrophic damage. This means any terrorist organization no longer needs to concern themselves with smuggling in a bomb on the ground. It just needs to get airborne and you’ve got millions of people without power.

Now our military has all of their equipment safe from an attack like this but the average citizen does not. This means within an instant we’ll be blasted back into the 18th century. Yikes!
Enter the faraday cage

By building a faraday cage you can protect your electronics by storing them inside. You can buy faraday cages but I really would advise against it. It’s not necessary to spend the amount of money many of those places will ask for a simple metal cage with some insulation.
Here’s How to Build Your Own with About $15


This is probably my most simple DIY project to date. All you need is an aluminum garbage can with a nice and snug lid along with a cardboard box.

Step One: Cut the Cardboard

From the bottom flaps to about the middle of the box you’re going to want to cut some slots about 8 inches wide. This just makes it so that the cardboard can conform easier to the shape of your can.

Step Two: Insulate Can with Box

You’re going to make a tube with your cardboard and slide it into the can. Go ahead and press against the edges of the can to make sure it’s right up against it. That way you have more room inside.

Step Three: Make & Place the Base Insulation

By tracing the bottom of the can on some extra cardboard, you’re going to cut out a circle that will fit in the bottom of your insulation. Then just push it down inside your can. You want this to be a tight fit.

Step Four: Tape the Insulation 

Tape in the creases where the base meets the sides of the insulation. Also tape along the cuts you made in the cardboard. Whatever you put inside of this cannot be touching the metal can – only the cardboard insulation. Taping these weak spots just ensures nothing gets past the cardboard to touch the metal.

Step Five: Trim the Excess

Just go around the edge of your can with a box cutter to cut off the excess cardboard insulation sticking out of the top.

Step Six: Put On Your Lid

Once you’ve put in all of your radios and other gadgets, you’ll just fit on your lid nice and tight.

There are many, many different designs and concepts for homemade faraday cages. This is just one of them. If you happen to find a design that calls for the use of wire mesh instead of solid metal, be sure to get some with the smallest holes you can find. Remember, you want the openings smaller than the electronic waves that will damage your stuff.

Other than that you’re good to go. This really is one of the cheapest and simplest DIY projects you can do and it will be so worth having when everyone else’s electronics are trashed and you’re still up and running.


  1. Could electronics be safely stored in a metal filing cabinet with cardboard lining?

  2. On how to build a Faraday cage... add styrofoam, wrap valuables in mylar! Have a HAPPY day prepping.

  3. A microwave oven makes a fine Faraday cage. Buy them cheap at rummage sales and create a bank of them in the garage for all your devices.


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