Faraday Cage/ EMP Proof Box





In the event of a nuclear strike an EMP or Electromagnetic pulse is released frying all circuits near the area.  This inscrutable will teach you how to build a  Faraday cage. A  Faraday cage is a box that protects all electrical items placed in the box. I'm sure there are better ways to build a Faraday cage but this is a cheap version.

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Step 1: What You Need

- A metal box
-Duck tape
-Something that you want protected

Step 2: "Building the Box"

1st you need to line the inside of the box with newspaper, use lots of it. 2nd wrap the objects in newspaper and place them in the box. 3rd if there is extra space put more newspaper on top of your items, that have been wrapped already, place in the box  .4th Close the lid and tape it shut.

Step 3: How It Works

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31 Discussions

It is just something to read. I mean for entertainment value. It could get really boring in a post-apocalypic world where all electronics have been destroyed. Probably a good idea to throw in a paperback novel too, since it probably won't take long to completely read the newspaper.



Question 1 year ago on Step 3

Hi. How can you check that it is working? I mean not only by f.e. making a call to the phone hidden inside, but with a special measurement equipment. Do you know which could be use for that?

1 answer
Jack A LopezAnetaM7

Answer 1 year ago

As a koan, to help your thinking about this problem, I ask you to consider the case of Troy Hurtubise, a Canadian inventor who wanted to build a suit of armor to protect the wearer from an attacking grizzly bear.


Obviously the best, most complete, way to fully test this armor, would be to simply put it on, and then go pick a fight with a grizzly bear.

Is there an analogy here, with the EMP-proof box?

Does the best, most complete, way to test the EMP-proof box, require that you have a source of EMP, and some small (small enough to fit in the box) electronic devices, capable of being damaged by EMP?

I do not want to spoil the surprise for you, but I am going to give you one more hint.

I claim the problem, of building an EMP-proof box, is essentially the opposite of the problem of building an antenna,


and if you can get your head around antenna design, I think you will also understand EMP-proof box design.


4 years ago

a microwave is also a good solution. just don't start it with your cellphone in or it's gonna be fireworxx lol

1 reply

Reply 3 years ago

This isn't true for all nukers. I've placed phones in to test, and they've never lost signal. The mesh prevents microwaves from escaping, sure, but it does not appear to prevent 500-900mhz ranges.


3 years ago

The blast can contain x ray and gamma. Mesh doesn't work with these high frequencies. Use thick, solid sheeting. The denser the metal the better, generally. Using a mHz band radio to test with will give you false hopes. Try something with a much higher frequency such as a 5 or 10gHz walkie talkie. This will be much closer to reality, but still, this research has all been done before. So it is probably best to just look it up. Also, according to the Naval EW guide, the best way to combat EMP is to use grounding to the Earth. Any metal object that isn't grounded at the time of the blast will become a high voltage capacitor creating a huge electrical potential with the Earth. The eddy currents that course though the metal box can resonate, given the proper frequency, and act as a repeater, ON THE INSIDE. (In an EMP scenario there is a broad spectrum of RF and likely a resonance will be found.) The design in this instructable is good for keeping static away from your bullets. NOT EMP.

Here is a better method, line a fireproof same with a conductor (aluminum foil) and mesh to keep it from tearing, use conductive tape at any seems. Line with rubber or wood to insulate and place stuff like HAM Radios, usb drives, and car computer components inside. Anything else that you want to protect can go in too. Remember to ground properly. To check proper sealing, place radio inside and if when closed inside you loose reception you have yourself a fireproof/emp proof safe with electronics that could save you and your family.


4 years ago

idd, put your devices inside rubber boots and put em in the box.
The thicker the walls of the box, the better shielded it will be.
your car will most likely be okay. It will shut off while running so could be a bit dangerous but you'll probably be able to just restart it after the emp.
They did studies on those things. http://jalopnik.com/5937778/how-to-prepare-your-car-to-handle-an-emp-and-why-you-shouldnt-bother

So this might be a dumb question, but could you use something like "Flex Seal" to line the inside of the can? Since it creates a rubber seal, wouldn't it be an insulator? And if so, how thick would the coating have to be?


6 years ago on Introduction

First let me say that __I could be Wrong. the way i remember it,is that govenrnents are spending a lot of money on research to build a EMP proof "box"....."".In the event of a nuclear strike an EMP or Electromagnetic pulse is released frying all circuits "".........and they have NOT yet come up with something that WILLwork.. maybe since(in the meantime) they have. if not,EMP type weopon might send us back to"DARK ages".

2 replies

Reply 4 years ago on Introduction

I worked on one of the projects in the 80s, and yes they do work.

The how to may still be classified so don't ask, I won't tell you how.

But for the Ammo can I would use aluminum tape to seal, not duct tape.

Actually, a Faraday cage is quite simple to make. It must simply be an interwoven cage of copper and steel, or perhaps brass. Mythbusters built one that was quite effective, blocking radios, cell phone signal, etc, out of a simple box of brass mesh. The only requirements are that the material be conductive, and that any holes be smaller than the wavelength of the desired radiation. It is also advisable that the cage be grounded and very thick, if full blockage of radiation is desired.

The idea of the newspaper is to keep your device from touching the steel. I wouldn't use paper though rubber definitely would work better, if you can't find that get something else nonconductive plastic sheeting, foam, etc

gstephens1The Greene

Reply 7 years ago on Introduction

They do, but this is certainly a lower cost option, especially if you have an old ammo can available.