Faraday Cage

Faraday Cage

As Preppers we like to think that we are pretty well prepared for most eventualities. One event that can seem daunting to prepare for is an Electro-Magnetic Pulse (EMP) event. If this type of event occurs, the vast majority of your electronic devices would be wiped out. Communication, research, record keeping etc would be made a lot more challenging. One way we can TRY and protect them from an EMP is by building a Faraday Cage.

What is an EMP?

In simple terms, an EMP occurs in either of two ways: (1) when a nuclear event causes Gamma Rays to be released above the atmosphere, or (2) from a natural, Coronal Mass Ejections – solar flares from the sun (as happened across the US in 1859 – melting telegraph wires, and in 1989 in which many orbiting satellites lost control and the power grid of Quebec was brought down for 9 hours).

Gamma Rays are protons with extremely high energy and these protons collide with atoms in the atmosphere. This causes high levels of electrons to become free from the atoms, generating an EMP. An EMP will overload the circuits in any unprotected electronic device rendering it completely useless.

What is a Faraday cage and how might it protect your electronic devices?

A Faraday Cage is a structure that is made of a conductive material that allows an EMP to flow around the cage as opposed to through it. By doing this, the pulse does not go through your devices that are stored in the cage, the pulse goes around it. These cages can be extraordinarily complicated or very simple depending on the amount of time, money and resources you have at your disposal.

Almost anything could potentially be turned into a Faraday Cage providing they meet the following criteria:

It must be made of a conductive material
It must be properly grounded (also known as Earthed. Basically meaning attached to a source that can absorb an unlimited amount of current without changing its level of charge. An example of this is the Earth, or the ground, hence the name!)
It must adequately surround anything that is going to be protected inside
Anything placed inside the cage must be insulated from the cage itself.

Build your own Faraday Cage

A simple way of making your own Faraday Cage is by using a metal rubbish bin. With a few simple adjustments, the bin could act as a perfect shield for all your electronic devices should an EMP occur.

Faraday Cage
A metal rubbish bin can be used to build your own Faraday Cage
Step 1

Insulate the inside of the bin to prevent your electronics from touching the metal. This can be done by lining the inside edges with cardboard. An additional layer of foam can be added if you want to add some extra insulation.

Step 2

Prepare your electronics for placement inside the bin. Another layer of protection can be added by wrapping all devices first in heavy wrapping paper, then in aluminium foil. By doing this you now have four levels of protection between each device and the sides of the cage.

Step 3

Pack all of your devices into the cage making sure that none of them are touching any metal.

Step 4

Place another layer of cardboard and/or foam on top of all your packed electronics. (This will stop them touching the metal on the inside of the lid)

Step 5

Place the lid on the bin. You will need to seal the edges of the lid down with a metal foil tape to ensure it is completely sealed.

Step 6

Attach a ground wire to the outside of the cage, and the other end to either a heavy metal object (a pipe, for instance) or to a spike which is driven into the ground. If at all practical, place the cage in the lowest, most protected part of your home for extra protection.

This is your completed Faraday Cage.


Something to remember

The full ability of this DIY Faraday Cage can not be fully tested in a real life situation unless a real EMP occurs. There is no guarantee that this or any other EMP protection method will work as well as expected as there is just no way of knowing how strong an EMP might be. Some people suggest placing a mobile phone in the cage and call it. If it doesn’t ring you have sufficient protection. Others say do the same with a portable radio and once it cuts out due to receiving no signal, then again protection is sufficient. However, these are not fool proof tests.

If you are preparing for world changing events then you may want to build your own Faraday cage in the hope that it might just save your electronics. Doing something is better than doing nothing! If you do decide to use this method, remember to put some means of powering your devices inside the Faraday Cage too so you can get your electronics working with no power. Batteries, small solar panels etc could be considered.

1 thought on “Faraday Cage”

  1. You don’t need to ground a Faraday cage as the radiated wave travels around the surface of the conductive medium and will just pass it by.

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