How to Build a Simple Faraday Cage for EMP Survival

SurvivalWoman SurvivalWoman  |  Updated: December 16, 2020
How to Build a Simple Faraday Cage for EMP Survival

Of all of the reasons to prepare, one that we all need to take seriously is the possibility of a catastrophic EMP, or electromagnetic pulse. This is a frequent topic in many post-apocalyptic novels and something that most of us are aware of, even if we do not completely understand the science.

How to Build a Simple Faraday Cage for EMP Survival - Backdoor Survival

As I wrote way back when in the article Prepping for an EMP and Solar Flares:

To be blunt about it, an EMP, if large enough, would affect the entire planet. In an instant, civilization as we know it would change as we get swept backward in time by a century or two.

Understanding the risks of an EMP goes hand in hand with threats of a cyber-attack since there is a cause and effect relationship between the two. In this article I want to accomplish a few things:

Explain EMPs and the risks in simple, easy-to-understand language
Give you instructions to build a simple Faraday cage to protect your electronic equipment.
Provide a list of items to put inside your Faraday cage

What is an EMP?

An electromagnetic pulse or EMP, is an abrupt burst of electromagnetic radiation. EMP energy can be very powerful. Let’s explain that a little better.

To start with, an EMP is caused by certain types of high energy explosions. An explosion from nuclear weapons, for example, will surely cause an EMP. Likewise, an EMP can be the result of a suddenly fluctuating magnetic field. Or, as I have mentioned before, it can be the result of Coronal Mass Ejection (CME) from solar activity. But perhaps most sobering of all, is the possibility of a man-made EMP weapon that is purposely deployed in order to wreak devastation on our planet. Scary stuff.

Regardless of the trigger, an EMP can be devastating to the power grid, resulting in rapidly changing electrical fields that will create fluctuating electrical currents and wild voltage surges. Bottom line? The electronic gizmos we have come to rely on would be toast. The microchips would be fried or so severely damaged that they would become useless.

So what would life be like following a massive EMP event or episode? There would be no power, no transportation systems, no communication systems, no banking, no internet, and, no surprise, no food and no water delivery systems. This would truly be an End of The World As We Know it situation.

Ask yourself these questions:

What if the power went out and never came back on? Could you fend for yourself?

Could you keep yourself warm in the winter and cool in the summer?

Where would you find food?

What would you use for money if credit cards and ATM’s no longer worked?

How would you get from one place to another without transportation?

How would you wash your clothes?

How would you keep yourself healthy if sanitation systems were no longer functional and medicine could no longer be manufactured.

And the biggest question of all, how would you communicate with the rest of the world?

An electromagnetic pulse could potentially fry the vast majority of all the microchips in the United States. In an instant, nearly all of our electronic devices would be rendered useless.

Back in 2004 the Wall Street Journal wrote:

No American would necessarily die in the initial attack, but what comes next is potentially catastrophic. The pulse would wipe out most electronics and telecommunications, including the power grid. Millions could die for want of modern medical care or even of starvation since farmers wouldn’t be able to harvest crops and distributors wouldn’t be able to get food to supermarkets. Commissioner Lowell Wood calls EMP attack a “giant continental time machine” that would move us back more than a century in technology to the late 1800s.”

With that introduction, today I would like to introduce you to the Faraday cage, and further, how to build a simple Faraday cage.

The Faraday Cage

In the simplest of terms, a Faraday cage is any shielded enclosure that surrounds your electronic devices and protects them from an EMP blast.

You may have heard Faraday cages referred to as an EMP box or EMP proof box.

Commonly used enclosures include galvanized metal garbage cans, popcorn tins, and even tightly sealed metal filing cabinets. In all cases, the metal container is lined with insulating material to prevent the contents from having contact with the metal. Examples of insulating material are cardboard, Styrofoam, and even carpet scraps.

More elaborate structures can be custom built from sheet metal but for the home user, why bother? As a matter of fact, I suspect that wrapping your devices in plain, ordinary, aluminum foil will work as well.

Factoid: Faraday cages are named after English scientist Michael Faraday, who invented them in 1836.

How Do They Work?

Effective Faraday cages protect what is inside of them from static electric fields. This could be an electron or proton as it is a force field surrounding a charged particle. As your probably already know, electromagnetic radiation is all around us, but it is also what Faraday cages are trying to keep out. Electromagnetic radiation is in microwaves, radio waves, ultraviolet light, and visible light, but when it is in these forms it is not harmful. However, when it is stronger, it can be disruptive and harmful to many electronics, and this is when we need Faraday cages.

When an outside object with an electrical charge gets near the outside of the cage (the conductor, ex: aluminum mesh), the positive and negative particles separate. The electrons that have the opposite charge of the approaching object are drawn to it, and at the same time, the electrons with the same charge are repelled and move away from the external object. This process is called electrostatic induction.

Virtually any type of metal will work as a conductor to build your Faraday cage with. It is usually alright if the cage has small holes in it, as long as they are not too large in comparison to the wavelength of the incoming electromagnetic wave. You can also use an existing metal box to serve as your Faraday cage as long as there aren’t too many large gaps that would allow leakage, so creating a Faraday cage could cost you no money and minimal effort!

What About Using a Microwave Oven?

In my research, I read that a microwave oven, new or used, can be used as an effective Faraday cage. On the surface, that seems logical since, by design, a microwave oven keeps the energy it creates confined to the interior which likewise, should prevent strong electrical pulses from getting back inside.

This was easy enough to test. I put a cell phone inside my microwave oven and tried calling it. It rang. Oops. On the other hand, I wrapped my cell phone in aluminum foil and called it. Nothing. Nada. No Michael Buble ringtone; the call went straight to voicemail.

Protecting Small Electronics from an EMP - Backdoor Survival

A foil-wrapped cell phone blocked the cell signal

Granted, cell phones operate at various radio frequencies so while one cell phone may not work, another one will. Still, with this being so easy to test, why chance it?

Testing the Faraday Cage

Aside from calling a cell phone, you can test your homemade Faraday cage by putting a portable radio inside the shield after tuning it to a strong FM station. If you can hear the FM station while the radio is inside your Faraday cage, then you need to go back to square one to ensure your shield is properly sealed.

Sealing your garbage can with duct tape will help tremendously.

A Second (Expert) Opinion

I asked my friend George Ure to comment and to offer his perspective on Faraday cages since EMP preparedness is something he covered in-depth on his subscriber site, Peoplenomics ($40 a year but worth it for the technical information on the many topics he covers.).

He was quick to point out several things about EMPs. The definitive public information is contained In the 2004 Congressional Research Service (CRS) issued a report “High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments”. The following diagram shows how an EMP causes the complex systems we rely on to provide everyday essentials for living, to fail in a cascading manner.

EMP Cascade Effect

So, a quick inspection of the EMP failure modes, George offers, is one way to build a list of items to put in your Faraday cage.

He also told me some personal research he’s done that seems to indicate that about 90% of cars will continue to operate after an EMP event of moderate size. The problem, he points out, is that with an EMP, the grid is likely to fail, and with that, power transformers will likely fail, along with the supervisory control and data acquisition systems (SCADA) control systems for railroads, power, water, and other utility distribution.

George’s personal Faraday cage is a 33 gallon garbage can. He considers his metal garbage effective by itself because the metal lid overlaps the can itself by an inch and radio waves don’t like to go around corners, too well. Still, the ultimate prepping device would be a metal garbage can which has the top cover sealed to the bottom of the can with aluminized duct tape such as the type found at Lowes, Home Depot and other hardware stores.

What to Put in the Faraday Cage

The equipment you store in a Faraday cage should encompass those devices that will help you communicate with the world following a devastating loss of the grid. Short-range communications will be critical after an EMP event. A good starting list would include:

Multiple GMRS radios and chargers along with cables to plug in for solar charging.

Multiple 2 meter and 440 MHz ham radios (such as the portable Baofengs), again with charging cables and solar power adapters.

A laptop computer with a fresh battery, a charger, solar adapter, and all the key software on CD so if you need to bring up a fresh copy of the operating system, you’ll have the product key and then any prepping articles or references you might need.

An AM/FM/Shortwave/NOAA Weather radio that includes a solar panel charging mechanism.

High-capacity USB thumb drive holding pertinent financial information including past year tax records, scanned copies of birth certificates, passports, marriage licenses, deeds, vehicle registrations and medical records.

A flashlight or illumination devices to help you see in the dark if the power goes out. Having all of the supplies you will potentially need will make everything much more convenient for you in the event of an EMP attack.

Walkie talkies may also be useful for short distance communications, especially with famuly members. Remember that your cell phone is not something you can rely on during and after an EMP event.

George also recommends simple insulation for your electronics, so that units do not touch each other, He uses low tech insulation: a combination of cardboard and bubble-wrap works well.

Protecting Small Electronics Day to Day

This article would not be complete if I did not mention the availability of small, shielded metalized bags that can be used to provide EMP protection on a daily basis. I am currently testing this type of bag from Mobilsec and am quite impressed. While my phone is in the bag, it reads “no service”.

If a cell signal cannot be detected, I can only assume that an EMP would also not touch it. Good to know and certainly an option, especially for a laptop that could be placed inside a properly sized bag when not being used. Couple the Faraday bag with a solar charging system and if there was an EMP, you would still have a working computer.

One other thing. You may find sources online that say that when a device is turned off, it will not need EMP protection. I reached out to Joel Ho, the developer of the Mobilesec Bagsand asked him about that. Here is what he said:

I’m assuming you are referring to the part about devices being off not needing protection – it’s simplified a bit – essentially, devices that are off are extremely difficult to damage because there’s no existing current to piggyback on.

Imagine that an EMP is a tidal wave. If it approaches a full reservoir (electricity and current) it can keep going. If the reservoir is empty (no juice), the tidal wave loses energy navigating the reservoir.

There are hints of this in the article Electromagnetic Pulse Protection by Jerry Emanuelson.

The major reason [most sources] don’t say “your devices are safe if off” is because most devices are usually still connected to power lines and thus susceptible – but if devices are in EMP bags (which by definition are almost always disconnected as the filters are expensive), AND the devices are off, it is unlikely, given the relatively high FCC shielding regulations to prevent excess energy from bleeding OUT into the environment, that enough can get IN to damage those electronics.

This is NOT true for every device – more like a guideline than a hard 100% rule. Different devices have different levels of built-in shielding – a computer has much more than a $10 Radio Shack timer, for example.

Protecting your credit cards is also something that you can easily take precautions with. There are wallets that are made with RFID-shielding technology (like these). This may seem like something small, but having one less item to worry about in the case of an EMP attack, can save you a ton of stress.

Vehicle Faraday Cage

Keeping a Faraday Cage in your vehicle with you at all times is a necessity because if your vehicle gets disabled by a massive EMP or solar flare, you’ll want to be able to communicate with others in the event that you get stranded.

All you will need in your vehicle Faraday Cage is a spare radio and a spare cell-phone. Having multiple communication devices is a good idea in case one of them has been disabled by the EMP. This can be kept in your glove box or under your seat.

Faraday Cage Myths

  1. Chicken Wire Works Well – Chicken wire provides very little protection from EMP in comparison to foil and metal boxes.
  2. Faraday Cages Must Be Grounded
  3. All Electrical Devices Will be Taken Out by an EMP Blast – Different nuclear/solar EMp blasts have different frequencies so they won’t all affect the same devices or be able to affect some devices.
  4. All Modern Vehicles Will Not Work After an Attack

The Final Word

Should a massive EMP occur, stores won’t be open, credit cards won’t work, and the gas you have in your car may be all the gas you’ll ever have for months, or even possibly years. When you think about it, an EMP will become the “Ebola virus of electronics”.

That said, you know that I am not a doom and gloomer. Quite the contrary. I am an optimist to the nth degree. Yet even the optimist is sobered at the ramifications of an EMP and especially at the prospect of a weapon-based EMP. If nothing else, I would like to have a mode of communication following a massive EMP.

Will the DIY Faraday cage work? It is speculation to say for sure. My own research plus my limited understanding of electronics tells me it will, but this premise will remain unproven until an actual EMP event occurs.

The bottom line is that I hope a catastrophic EMP never happens. But if it does, I want to be ready to fend for myself without electronics. Sure, having communication gear and other electronic gizmos in a working Faraday cage will be a wonderful thing. But even if it doesn’t work, the goal of preparedness is to prevail, even if that means living in an off-grid society for weeks, months, or even years.

I would like to acknowledge my pal George Ure for his assistance with this article. His research and first hand experience with Faraday cages, along with his perspective, is appreciated.

Update: Clearly, there are many unanswered questions and that is to be expected. Rather than answer them individually, I will compile the questions and seek answers from individuals whose technical experience and background far exceeds mine. Please leave your questions in the comments area below.

Enjoy your next adventure through common sense and thoughtful preparation!

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Bargain Bin: Below you will find links to the items related to today’s article.

Behrens 10-Gallon Locking Lid Can: This 10 gallon can would make a perfect Faraday cage from small electronics. The locking lid is a bonus although I would still seal the edges with 2” duct tape. This price, by the way, is less than my local Ace Hardware store. Also available in this larger size 20 Gallon size.

3M Duct Tape: A good quality duct tape is an absolute necessity when sealing your DIY Faraday cage. For slightly less, you can purchase 3M Utility Grade Duct Tape

Midland 36-Mile 50-Channel FRS/GMRS Two-Way Radios: These are the handheld radios that I own. There are lots of good uses for the these radios. Handy while hiking, traveling, or simply keeping in touch with your partner while out shopping. Just be aware that getting a 36 mile range out of any handheld FRS radio is a myth.

Pofung/Baofeng UV-5R Ham Two Way Radio: Redundancy is the name of the game. I also have two of these inexpensive HAM radios. Keep in mind that if you are just planning to listen, you do not need a license (I am still working on mine). The price is right. Also consider the NAGOYA Antenna for BAOFENG UV-5R and the USB Programming Cable for Baofeng UV-5R UV-3R+. Note: the Pofung was formerly known as the Baofeng UV-5R).

SunJack Portable Solar Charger: SunJack® helps mobile users stay charged on the go anywhere the sun shines. The SunJack® is able to fully charge its internal battery pack in about 5 hours of direct sunlight, or directly power any USB device. When the sun isn’t shining, users can still energize their devices from the powerful SunJack® battery, which holds enough charge to power up to 4 iPhones.

Kaito Voyager Trek Solar/Crank AM/FM/SW NOAA Weather Radio with 5-LED Flashlight: This simple to operate radio can be powered by three AAA batteries or the built-in rechargeable Ni-MH battery which in turn can be charged by hand cranking, by solar panel or even by a PC. . The 7-weather channels are pre-programmed and numbered from 1-7, you can easily and conveniently tune into the stations by adjusting the switch. Note that not all emergency radios include the NOAA weather band so this is an important feature.

Cell Phone Faraday Cage Bag: This is the bag I have been testing. It is also stops hacking and the tracking of your phone. Mobilsec also has a laptop sized Faraday Cage EMP Shield

Help support Backdoor Survival. Purchases earn a small commission and for that I thank you!


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109 Responses to “How to Build a Simple Faraday Cage for EMP Survival”

  1. I am just learning about EMP and I have one question. We have a large gun safe with an electronic lock. Does anyone know of a way to protect that so that we could open our safe?? Or would it be prudent to get a safe with a manual lock?

    • Thanks. I did check on our safe. There is no manual override with a key. I called Liberty and after taking the serial number, I found out that the lock on our safe is military tested and considered EMP proof. The customer service person was very good and told me that while it is tested, there is no absolute proof that it would not fail in a true EMP scenario. She suggested that if we have any doubt at all and are concerned about EMP that we should order manual locks and have a locksmith install them. Lesson learned here for me to ask more questions when we buy something like this.

    • It also depends on the type of electronic lock, some Will Not work even with key, ALL my gun safes have a manual old school dial. Better safe than sorry! Oh and you can replace your electronic lock with a manual, there is a good You Tube Video showing how.

  2. How about the washing machine and dryer as faraday cages? Metal with large
    openings, easy to access and just about everybody has one.
    The oven also may work or the dishwasher. Any thoughts on these suggestions?

    • You were scammed in this entire write-up. Mains Alternating Current you nor me can control, and that’s dependent on the the type of wave radiant based on Galactic or Geodesic Coordinates, and the write never explains the differences in EMP’s or explains that even using his parameters; w/o a mode of self-generation and diode or invert rectifier bridges or Wheatstone combinations: no receptacle will have any flow of electrons, Terra has EMP’s every day with upper lightning auroras. Don’t listen to magazine writers. Resource and Reference books learn the decimal system and then worry about a cage.

  3. I don’t know what type of dishwasher you may have but I tested mine, a built in. Didn’t work, I put my and Dahubs phones in it shut the door and called each phone. Both rang when dialed. I believe it may be that the built ins don’t have as much exterior metal around the insulation when its in the cabinet area. I think it’s to cut down on the weight and space the machine takes up when it’s built into the cabinetry. Now a portable dishwasher(if they still make them ;)) may work differently as it’s encased in a metal “box” with a lot of sound deadening insulation around the interior.

    • Interesting point which makes me wonder if a portable microwave oven would work. When I have time, I will run to the thrift store and see if they have one I can test. (My microwave oven is built in.)

    • A micro wave has a perforated grid that in conjunction with the glass in the door, let’s you see inside. That perforation is designed to stop microwaves only, not other wavelengths. And in normal operation, is grounded. Without a functional ground, any “barrier”, becomes energized itself.

      A simple grounded screen will stop some wave lengths, but apparently not an EMP. Used to know of a dude who carried a copper wire cage to the top of mountains, squated in it, and rode out electrical storms. I think that he drove a ground rod and connected the cage to ground of course.

  4. I am new to all of the Emp information….if we have an emp will we have time to get our electronics into the faraday cage in time…since most of our electronics always being in use….and if we do have an emp..won’t all things go down (such as towers and stations) will we have any use for our phones and radios and such….

    • Therein lies the dilemma. Once the EMP occurs, the gizmos become toast; there is no time to protect them after the fact. Many of us put spare (and even outdated) electronics in our Faraday cages. An old laptop would be a good example. As it happens, I just pulled an old laptop (Windows XP era) and have been updating it with all of my eBooks and documents before putting it back in the Faraday cage. I try to do this every six months or so.

      You are correct about cell phones and radios not working initially but current guesses (and they are just that) speculate that the military and government will work on restoring service as quickly as they can. No guarantees but it seem probable.

      Our laptops, eBook readers/Kindles should be okay though. They will become our reference library.

    • Thank you…so if I would put some old cell phones…and some electronics not really being used right now into a cage they would be ok… hubby has all kinds of ham radios and equipment…what to do with all of these very expensive equipment since they are used often…

    • Don’t forget about flashlights, especially LED lights. And it helps to have solar chargers or small solar panels protected too.

      I have a Kindle, a bunch of radios (with wind-up and battery options), a SunJack 20W panel, a few C. Crane solar battery chargers, a few FRS walkie talkies, and more flashlights than in most convenience stores. I also have a few cheap solar calculators and two basic multimeters just in case. I went the galvanized trash can route and after viewing a YouTube video recently bought some of that aluminized duct tape you mentioned here. Two of my cans are sealed that way, and the third has the things with rechargeable batteries since I recharge them every few months.

      One thing I haven’t seen mentioned here is the likelihood of an EMP event not being a one-time deal. If someone is truly trying to destroy America’s technology, then they will most likely use a second device a few hours or days after the first event, thus frying anything taken out of the faraday cages. It’s why I have lots of flashlights and radios, so I can take out one of each after the first event and wait as long as I can before I grab anything else in case of further attacks…

  5. Gaye – love the simplicity of the article, but have some questions.
    I’m all for protecting my electronics, cell phone, etc. I get the use of ham radios for communication, but why am I protecting the cell phones if the network will most likely be down? There won’t be any signal or any way to reach anyone I know (because likely all their phones will be toasted). Text uses a different carrier signal, but again, its doubtful there will be an active network or phones to receive them. Same for pcs – there likely won’t be an internet to communicate through.
    OR – did I miss something in all the expert talks that says those types of things are protected at their root source – ie: Verizon has taken precautions against an EMP wave.
    If the world in general (or even just America) is set back two hundred years, what’s the point of keeping my cell phone active?

    • @Jennifer – while it’s true the cell network will most likely be down, a modern smart phone is really a pocket computer that makes phone calls. In mine, I have a 128GB SD card that has over 1500 ebooks (many on how to do things in a ‘shtf event’), numerous other data that I want to keep. I have it in my phone I use every day and a backup one I keep in a protected cage. Even if I can’t make phone calls, I’d still be able to get at the data. Also, WiFi would still work so I would imagine we could setup small clusters of WiFi “mesh” networks. So keep that in mind. Get a second phone (and if your phone does not allow SD cards then I’d get one that does) and make sure you sync the data periodically. I personally don’t think such a device will be used but there’s no sense in not preparing in case it ever is.

    • A nuclear EMP will most likely fry any electronics not protected by a faraday cage, but there are plenty of events that can take down the electrical grid while leaving electronic gear intact – solar CME, coordinated terrorist attacks, hackers, etc.
      That said, I prepare my 64GB iPhone by loading apps and data that will be useful without networks. I have a map program that can work with just GPS access, so in a grid down situation, as long as I can keep my phone powered I have detailed maps and my location available. I also have a few hundred Kindle books loaded and can read them on the phone (I have about two thousand books on my Kindle that is stored in a faraday cage every night, and anytime I’m not charging it or loading new books.)
      And while I’m not preparing to setup a mesh network, if you want one that’s great. Just remember to have some sort of server to push data to the clients and test it in the field before an event so you can make sure nothing needs to be redone, since after an event it will be hard getting replacement gear or updated software….

    • Right, for the most part, my preparations while I’m taking into consideration an EMP ‘event’, are mostly for stuff like major disaster or other things that take the power grid out along with Internet access. That’s why I have “backup” devices in a hardened EMP safe and even inside the safe the devices are inside (supposedly) EMP bags. Every few days I take the cards out and sync them. I have a project I’m working called “going offline” where I’m replicating things like Wikipedia (I was surprised that you can download the entire Wikipedia database and it’s only ~100Gb or so) and numerous other web sites. I have a number of solar charging stuff I’m testing, both the kind that charges an internal battery along with a 15Wat one that charges a phone in a few hours. I just hope I never have to activate the “offline” protocol.

    • deandownsouth, Please describe how you download the entire content of Wikipedia, and what other useful (or not) sites where you can do this.

    • I’ll go back over my notes and maybe come up with some step by step of what works for me as there’s several options, A full download with pictures will be several 10s of GB but there are text only versions that come in under 1GB of disk space. If you want multi media content, it will be much larger and probably wouldn’t fit on most phones which is a reason to use a laptop in addition to a tablet/phone, that way you have either a subset on the tablet/phone and the full content on the laptop. It all depends on what you want. So, by I’ll start by giving you some links to read up on. Start here: //

      For mobile devices, the best app I found is Kiwix. Kiwix’s site has downloads of several Wikis and for Wikipedia and you can choose under topics like medical or no pictures and so on depending on how much space you have on your device, browse here: //

      I mostly use Wikipedia offline on my laptops since that’s where all my stuff is.

      BzReader seems to be the best but is a Windows app, however, runs just fine under Wine so OSX and Linux users can run it and it runs just fine. There’s several Java versions but I stay away from Java for the most part.


  6. Another item I would add to the list (which you also mentioned in a reply) is a tablet. Whether an iProduct or Android, with the micro-SD card, it’s an electronic library. Much easier to transport after “the event” than a shelf of books. There are also several solar chargers on the market (which would also need to be in the cage) that can support tablets and cell phones.
    Cell phones may not be useful as phones, but they have cameras. With enough storage capacity, they can be useful to record a variety of events. What did the world look like before the event, and how did it change. Pictures are also a good way to reference locations and potential stashes. Stock up on a few extra cards and the volume of pictures can be massive.
    Less expensive than a solar setup for the laptop might be a simple inverter designed for use in a car or camper. The laptop won’t like the output of the inverter much but will probably still charge.

    • Is an iPhone 6 capable of somehow using micro-SD cards? If so, how does that work?
      I have also always wondered how you go about keeping an older iPhone “active” for offline use.

    • iOS devices don’t have SD cards (and several Android devices like Google’s Nexus don’t have one either) so unless you have a larger model, 64gb or 128gb, it will be a challenge to store a lot of stuff. The other question will have to be answered by someone more familiar with iPhones. My advice would be to get a small inexpensive Android tablet that can handle a 128G SD card and make that your content device. Wikipedia offline is between 15 and 60GB depending on what you download, so it will take a huge chunk of space.

    • My el cheapo Kindle Fire has a slot for a micro-SD card. The device (purchased 3 or 4 months ago), was about $80 plus the SD card. It is slow but storing my eBook library was a cinch. The is the one I purchased: Link.

    • Sorry to be tedious, but I’m techno-challenged. Can you fill as many SD cards as you want with the Kindle Fire, and just remove and insert the ones you need as you need them later? Or does one card need to stay in place at all times?

    • If all you have on the SD card is content like books or videos, then yes, you can unmount the card and insert another one. You can even pre-load them from your computer via and adapter.

    • Dean, do other file types than the books & video, not work with the SD cards for a KindleFire

  7. I have been waiting for this article, I have been so confused in the past about conflicting points of view about what will or wont be affected and what will or wont work for shielding. If seen the 90/10 statistic about vehicles affected from both sides of the argument. Some say 90% will fail, others say 90% will be fine. Thanks for weighing in on this Gaye. I know you put a lot of research into your articles and I know your maternal feelings for us readers means you wont steer us wrong. I have some things in a faraday cage already but there are some things that I just cant determine if need protection. Things that I deem more valuable than electronics. Will my tiller start after an emp? how bout the chainsaw? I know they are not connected to the grid but I don’t know if there is any sort of electrical component to their starting or running, and I don’t know how to find out.

  8. I’m more concerned about two way radios, small tv with omni directional antenna
    Old lap top with research material and clock radios

  9. We have a stand-by generator that automatically goes on if there is a power outage. It also starts weekly for testing. Is there a way to protect that? While we are not survivalists, we like to be prepared.

  10. To everyone who has commented and asked questions: Clearly, there are many unanswered questions and that is to be expected. Rather than answer them individually, I will compile the questions and seek answers from individuals whose technical experience and background far exceeds mine. Please leave your questions in the comments area below.

    Please continue to ask away!

    • Im doing a science experiment and am wondering if // this would work. im pretty sure it would but would like some answers.

    • It’s indeed a galvanized trash can, so as long as it isn’t dented too much in transit it should be fine. I like to buy mine locally so I can check the can is free of dents and more importantly that the lid is tight fitting with no gaps. Even then it’s probably a good idea to get some of the aluminum tape mentioned here and seal the lid to the can, just in case….

      I have mine stored in the basement on some of that soft flooring mat system to make sure the can doesn’t start rusting which may impact its ability to ward off EMP.

  11. I am a retired contractor and use an old “gang box”. Fully enclosed in heavy steel with no openings. You can find old ones at flea markets or on the internet or local papers. It holds all of my extra FRS/GMRS, 2 meter, 440 meter, 70 cm baofungs, my HF rigs and linear amps along with windup radios, chargers for the solar array. Keep in mind that some radios like the HF have internal batteries. You might want to keep an extra set in the box. I also put in a couple of cases of MRE’s, don’t know how hungry I’ll be if I ever need to use the box.

  12. Many preppers may already have a faraday bag! Have you tried sealing your cell phone in an aluminized mylar bag? I have a one board FM transmitter that I found was radiating spurious signals and interferring with other radios. Since I was using it to listen to an audiobook I just laid a mylar bag over the transmitter (the antenna wire still outside) and it cut all the extra signals.

  13. Another good source for a faraday bag for your electronics is “Tech Protect”.
    Not certain whether or not weblinks are allowed here… but for the benefit of readers, I will try posting the weblinks for their faraday products: or

    I’ve purchased various sizes of their bags and they are high quality and do the job.

    By the way…
    much thanks to Gaye and Shelly for the great service you are providing!

  14. Not much talk about nuclear plants and meltdowns. Imagine parts of there systems would get fried. Generators would only last a few days. Gov. trucks if rolling
    might bring in some fuel. Won’t take long to leak into water table, and massive amounts of radiation. How to bug out into area away from plants when vehicles
    won’t run? 61 plants with 99 reactors in US.

  15. Some more thoughts on Faraday cages.

    You can also create a cage of any size and shape from wire mesh netting, so long as it completely surrounds the space to be protected and is fully sealed (connected along all edges with conducting materials. The wire mesh can have openings as large as an inch but not much more. Any door or hatch must electrically seal along all edges when closed.

    Increasing protection by connecting the Faraday cage to a grounded conducting post with a very thick/braided cable to drain off the received energy from the pulse. Give it a path to ground similar to lightning rod systems. The grounded post should be at least 4′ to 6′ into the earth (Not encased in concrete).

    • If the EMP protective wire mesh is effective with up to as large as an inch, why would a galvanized trash can have to have the lid sealed with aluminum tape since the overlapping space between the can and the lid considerably less than an inch and has intimate contact all around?

    • Dr Bradley has a great video on YouTube that explains this in detail:


      His testing shows that while a trash can does reduce the amount of energy penetrating the can, the aluminum tape makes it even more effective. And since we can’t know how energetic an EMP will be until AFTER the event, it makes sense to take extra precautions just in case.

  16. Ok, I may NOT be an expert but let me inform ya’all of a few things. EMP ElectroMotivePulse come in 3 fun varitions. E1(quick and will damage electronics-even non-conected ones) E2 (slower, like lightning-yes lightning speed is “slow”) E3 (Real slow real long -as pulses go- easiest to stop but this is the one most likely to take down the grid or any other long transmition lines- think 40′ of line connected to solar or generators) Also, NOT ALL FARADY CAGES ARE EQUAL. You need to reaserch the db reuction of a given cage. Yes Aluminum foil works at ~96db, but some mylar bag are about 40-45db. At the typical nuclear bomb -closeish range- output of 50,000v/m2 you need 74ish db. And to answer the grounding question- grounding is not nessasary for smaller cages! larger one hold a charge though-think static shock but bigger and don’t HAVE to be grounded but can discharge on touch-which COULD be like touching an electric fence-OUCH- until is it alowed to disapate. All spelling error were cause i don’t have f7 and do your own reaserch -don’t assume I know what I’m talking about.

  17. Great article with lots of useful/helpful info…and great feedback from commenters.

    MUST correct one misconception, however…your lead paragraph is misleading:

    As I wrote way back when in the article Prepping for an EMP and Solar Flares:

    To be blunt about it, an EMP, if large enough, would affect the entire planet. In an instant, civilization as we know it would change as we get swept backward in time by a century or two.

    FYI: EMP is a line-of-sight thing…if you are located on the opposite side of the planet, you need NOT fear a directed EMP attack.

    For a GREAT book about EMPs, read A Nation Forsaken. It covers many details including how high an EMP burst must be to affect a given area (typically 200 miles above the CENTER of the USA to affect most of the nation).

    • I think it depends on the can. If it’s conductive metal then probably. I keep my USB flash drives in an Altoids tin overnight then take it with me to work, but when I get home at night I put the drive back in the tin. Might not save it from a strong EMP, but it takes almost no effort and I’m just not willing to open my real faraday cages in the basement twice a day for something I don’t really need in a disaster.

    • I’m new at this, but I wanted to thank you for the simple suggestion here of the Altoids tin. I immediately went and found a Whitman’s chocolate tin (you know — from the Christmas 4-piece chocolates) that I had some coins in and transferred my USB flash drives into the tin instead. Small, but a start. Every little bit helps, and I am learning SO MUCH from this site. Thanks for taking the time to share.

  18. I do a lot of reading about a possible EMP event and “moving us back to the 1800s”.
    I don’t think that is an accurate statement.

    In the 1800s people lived and survived because, for most people, the resources they needed to survive existed in everyday life. Then, they had horses and plows and wagons, candles and lamps, axes and saws, wood stoves, guns, and skills that hardly exist today. They were hardy, resourceful people and could take care of themselves with those tools. A large percentage of the population lived on small farms in the 1800s. The pioneers going west had the basic resources and skills for taking care of themselves for an extended period. More importantly, in the 1800s, the population didn’t have to defend themselves and their possessions against marauding bands of looters as would be the scenario in the aftermath of a modern day EMP event.

    The basic tools of the 1800s are only held by some preppers today. Many people think the Amish would fare best in such a scenario. I believe they would, but only if they were willing to fight to keep what they have.

    No, most people would be set a lot further back than the 1800s. The tools and skills of that era hardly exist today.

  19. Thank you to ‘someguy on April 9, 2015’ for pointing out the various EMP types. It is SO RARE to see this talked about. Not all EMP’s are equal. While many worry about the EMP generated from man, I’m personally worried about the EMP generated from a Solar CME (Coronal Mass Ejection). With the span of time that these events can span, coupled with the fact that it affects an entire side of the planet, and the fact the planet rotates… it is likely possible for an event to affect more than half the Earth.

    I’d love any information regarding how to build a lightweight faraday cage to protect an e-reader (Nook Simple Touch eInk, w/ microSD slot) that will be stored in a get home bag. It *must* be lightweight and still provide access to the device to be able to update the electronic library of books from time to time. A trashcan or even a shoebox is simple too big to stuff into a backpack.

    I’d also like to see more information regarding the decible levels of protection from various materials (like foil vs mylar vs EMP bag vs standard electrostatic bag) and how it affects its ability to protect the device inside it. It wasn’t clear to me based on ‘someguy’s post whether if -74db is the goal whether I should be looking at using the foil at -96db or the mylar bag at -45db. As I understand decible readings in sound, the smaller the number the closer to 0 and the louder the noise is. Its unclear to me how that relates to protection from electrical signals as a rating on the EMP bags. Another way to ask it is the foil or the mylar better to use? 🙂

    • A solar CME based event won’t be like a nuclear EMP. As long as you unplug all your devices and disconnect any antennas they shouldn’t be fried. But if you want to be sure, placing the items inside a decent faraday cage won’t hurt. Plus if there is a nuclear EMP you’ll need that kind of protection.
      But now a digression on dB measurements – dB measurements can be for any of a number of things. In most cases people are talking about dB of sound, but in the electromagnetic spectrum, dB of reduction is the standard way of measuring shielding. And fiber optic installations that use long haul lasers sometimes need pads (think sunglasses) that reduce the amount of light at the receiving end and those pads are also measured in dB.
      Ok, now that we’ve gotten the professorial mode out of the way, the 74dB for a faraday cage is a kind of minimum if you’re within the footprint of a nuclear EMP event. If you’re at the very edges of the footprint, then your gear may survive with less shielding. But the more shielding the better in most cases since if say Russia or China were trying to fry the USA electronics they may be using an enhanced EMP device in order to fry protected military gear.
      Layering faraday cages will increase the protection, but you can get silly about it. The key to layering is having an insulator between the layers – something like cardboard will work fine. For my peace of mind, I wrap my boxed electronics in aluminum foil, then place them in a galvanized steel trash can that is lined with cardboard. I then sealed two of my three cages with the aluminum tape to get maximum protection. The third cage has items that I need to charge periodically, mainly lithium battery packs that my solar panels (also in cages) will recharge after an event – so I felt that peeling off the tape each time I do a recharge cycle was a bit excessive. If international tensions ramp up, then I’ll probably tape up the third cage just in case since the aluminum tape isn’t all that expensive.
      In your example, I’d probably look at mylar anti-static bags as a solution. Put the Nook in a paper bag, put that in your smallest mylar bag, tape it shut with aluminum tape, wrap that in another paper bag and put it in a second mylar bag that is taped shut with aluminum tape. You could continue the layering, but obviously each layer adds bulk and weight. But I wouldn’t do less than two layers since mylar bags aren’t as thick as the metal on a trash can and undoing the tape each time you need to recharge the Nook will be a pain in the neck. Actually if you scrounge around, you may be able to find a metal DVD case like the ones used in some special edition DVD editions. Since the nook is small enough to fit in a normal size DVD case that might be a better bet since the metal case will be thicker than the mylar bags. Just make sure you use something like parchment or butchers paper to wrap the Nook before stuffing it inside the case.

  20. After reading all this, I’m definitely going to get 3 or 4 of those Christmas popcorn cans and
    some aluminum tape. I’ll seal my solar charger, Baofeng radios, a tablet with important personal information and pictures on board, and a couple of old cell phones, and a few 64 gb thumb drives with loads of important info and pictures, along with a laptop I just retired. A few of the other items mentioned would also come in handy. Thanks for all the great info!!
    In my humble opinion, an EmP attack would be the easiest way for a foreign enemy to “hurt” us here in the U.S.A. Even a relatively small intentional attack perpetrated from the air could affect millions of people. Gotta go get started…

  21. I didn’t see any answers to the questions about using dishwashers, refrigerators, ovens, etc, as faraday cages. Generally speaking, your faraday enclosure should have good electrical continuity throughout. The rubber seals used on appliance doors to contain water and air are electrical insulators – so the continuity is lost. This is sometimes an issue even with ammo cans which have a rubber seal to protect against moisture. The paint on some of the appliance may also significantly impact the continuity of the electricity, even if tape is applied around the opening. Best to assume a really easy to use solution will not be a strong solution if a high power EMP hits.

  22. Can someone help me here? I am confused about what good an “old cell phone” would be after an EMP, given that you wouldn’t have an account open for an old phone—and even if you did…what functionality would it have if all systems are wiped out?

    • And along the same lines, if the grid is down, then would a laptop have much value? Anything that you’ve stored in the “Cloud” would be inaccessible, wouldn’t it? And with having to now have paid-subscriptions for Word, Excel, etc–I’ve just read that you would only be able to read your saved documents, but not be able to edit or create new ones. One other question: While in LTS in the Faraday Cage, do you need to recharge the computer & tablet (and all other) batteries on a regular basis in order to keep them from dying? (Sorry I am so technology-stupid!).

    • Peggy — Once the grid is down, most cell towers only have a day or two worth of backup power before they also would go down. Once those few remaining cellular towers go down, there would be no making phone calls from a cellphone. However, it might be nice to keep a device (old cell phone) with some digital pictures on it. In the case of a nuclear EMP, the cellphone would need stored in a faraday cage to protect its electronics. In the case of a solar CME, only devices plugged into the grid would be damaged. So an old cellphone in a drawer, would still power up if you could find power to charge it.

      As far as a laptop or other personal computing device.. I think post-grid-down, their primary utility would be as a library. Provided, that you took the time to download a library into it. You are correct that the Internet and the cloud would be inaccessible. However, anything stored locally would still be usable. If your intention is to store a device like this with a library on it, it is important that you have the correct software on it that is NOT dependent on the Internet or any sort of online service. You may consider looking into OpenOffice or LibreOffice as free Microsoft Office alternatives.

      All rechargeable batteries should be stored with a charge on them and should not be allowed to completely drain while in long-term storage. Otherwise, if you let the battery completely drain while in storage, you would find that the battery would not hold a charge very well when you get around to using it. So this would mean any battery you store in a faraday cage should be pulled out every so often to charge back up to a full charge.

      I hope this answers your questions!

    • Just to add a few things. I keep a lot of info stored on my smartphone that wouldn’t be lost in a CME event, only an EMP event. Since I’ve loaded it in preparation for loss of network, it will still be useful as a mini-library (the Kindle app), and I have maps of most of my part of the country on it stored in an offline map program ( Initially I got the Kindle app to read the books that the wife and I have been reading on our Kindles, but then I decided to load up a bunch of reference books with info. And the mapping program has been very handy when I drive into Canada where I don’t have a cellular data plan, but as long as the GPS satellites keep working and I can charge my smartphone, I have detailed GPS maps available to me. 🙂
      As to batteries, only Lithium type batteries (Lithium ion, Lithium polymer, etc.) that have computer chips need to be stored in a faraday cage. NiMH and NiCd are dumb batteries and will be unaffected by an EMP. So most laptop batteries or battery packs fall into the need to be protected category, but AA and AAA rechargeable batteries are mostly safe. If you have room in your faraday cage, great, but if space is tight, the Enerloop batteries can be stored on a shelf and left out of the cage. Battery chargers, especially solar panel chargers however are sensitive to EMP and definitely need to be protected.

    • Thanks so very much for your detailed response, Shouden!! I truly appreciate it. Just didn’t see it till now, unfortunately.

  23. You can turn your entire house into a Faraday cage. Cover your interior walss ceilings and floors with metal window screening (Do the underside of the floors in your basement or crawl space). Plaster over all the window screening then paint it a color you like . Applying the screening to windows and then covering with gel coat. Do not forget your doors.

  24. EMP Survival: 10 Amazing Survival Tips to Protect Yourself and Your Family in Case of Electromagnetic Pulse (electromagnetic pulse, emp survival, Emergency Essentials)
    Kindle Edition
    Sold by Amazon Digital Services LLC

  25. I scanned the above comments,,, and noticed comments about the 1800’s,,, and solar corona events… but no mention of what happened roughly in the 1850’s. PBS had a good show a few months back,,, that described the effects of EMP and solar events… and how it would shut down the power grid.

    They also mentioned a solar even happened back in the 1850’s,,, but nobody knew it… because electricity wasn’t used for power until 30 years later,,, so life went on as usual. The solar even covered most of the northern hemisphere,,, alsmost to the equator… and if I remember correctly,,, it lasted for almost 6 months.

    My point is… how would any of us know when a solar event would shut us down… AND how would we know when it was again safe to pull our electronics out from our faraday cages? If we pulled them too soon,,, they would get fried anyway. Either way… there would be no heat, gasoline, electricity,,, or other things we take for granted… and it could be a VERY long time until things were restored,,, if EVER.

    The best plan is to store up food and ways of growing your own food,,, and have alternative sources for heat and water. If you use a well for water… there are hand pumps that mount on top of the well casing that will pump up to 100 feet or so.

    The best plan is to be able to shelter in place,,, and make it through 6 months of diaster… even for the extra necessities needed in nothern climate where winter can be a bear.

    Can you put a wood burner in your basement,,, and safely vent it through a window without burning your house down??? Can you section off a portion of your house,,, and shut the water off to unused portions of the house to the pipes dont freeze and burst??? Can you even get water???

    To me… the electronics are inconsequential,,, unless things get so bad that you have to bug out. Then all you will need is a running vehicle and a supply of gasoline,,, along with wahtever you can fit in your vehicle. Those should be some of the same things that were used to shelter in place.

    Just food for thought……….

    • While the effects on our lives would be the same between an EMP (from nuclear blasts) and a geomagnetic storm (from CMEs/solar flares), the effects on our electronics is quite different.
      EMP is a short pulse of extreme intensity that burns out any unshielded electronics. If you’re at the edge of a pulse then some electronics may survive, but the more wires in them (or antennas) the less chance of the device surviving.
      Geomagnetic storms will cause induced currents (large currents in the case of a Carrington style event) which can fry anything with a long antenna, or electronics plugged into the electrical grid (the grid acts like a giant antenna in geomagnetic storms.)
      So chances are your car and cellphone will be completely fried by an EMP, but with a geomagnetic storm both will be fine. Of course the grid will probably fry and even if your gear is safe in a cage you better have solar panels and batteries stored in the cages you won’t be able to power those devices for long.
      Also, with geomagnetic storms we get at least a few hours of warning, maybe as much as 48 hours prior to an event because there are satellites watching the sun for coronal mass ejections (CMEs) and it takes time for the CME to arrive and start a geomagnetic storm. With enough warning the electrical grid operators may be able to reduce the damage to the grid, so recovery time might be weeks to months rather than years to decades.
      EMP events are most likely going to be a complete surprise unless we’re in a shooting war with a nuclear power and then we’d have 15-30 minutes warning, assuming the public gets warned at the same time as the military. But a rogue state with a nuclear satellite could hit us with EMP with no warning. That’s why when Iran put up a satellite I bought a faraday cage, and when NK put up a satellite I bought two more, and taped up two cages after sorting through items that needed periodic charging (which are stored in the third cage.)
      I have non-electronic backups for almost everything: lights, cooking, heat, washing, etc. But I store electronics in faraday cages because they can make life so much easier in some cases. (e.g. I’ll run out of lamp oil and candles well before my rechargeable batteries wear out and my solar panels can’t charge them anymore.) I also store LOTS of duplicates in the cages, because if we’re attacked by an EMP, I suspect it won’t be a one time event. So I will take out one radio, one flashlight, one radiation meter and two dosimeters (for when the nuclear plants starting having issues…) and wait for a few weeks before taking anything else out of the cages. Having a galvanized trash can with a tight fitting lid that you seal with aluminum tape is cheap insurance for LED flashlights, radios and small solar battery chargers.

  26. I experienced the blizzard of 1978 as a kid. No electricity,,, which meant no heat or running water. Dad shut the water off to the house,,, and drained the water lines. Fortunately,,, we had a gas stove… so blankets were hung on the archway going to the bedrooms and bathrooms to close off half of the house. We lived in the living room, dining room, and kitchen… and slept in the living room. We bused everything up in the fridge and freezer first,,, that couldn’t be put outside in the snow. Then we got into the canned goods,,, and mom started Making and baking bread. We melted snow for water for cooking,,, and flushing the toilet. We lasted decently… until power was restored in about a week and a half.

    Since then… I usually keep about 3-6 months of canned and dried goods on hand,,, and rotate the stock.

  27. I forgot to add… that where I live now,,, there are no natural gas or water lines. I use propane for heat,,, and have enough of a supply to last a year for cooking, water heating, and heat. I also have a propane powered generator… but if a solar event or EMP wiped it out,,, I could still find a way to heat a portion of the house. Would I miss electricity??? Of course!!! But it is a luxury,,, not a necessity.

  28. I own a kindle, I have several books there that are needed for after an EMP event. My question is (that I have NOT see answered yet)……

    When the system fails, and I want to pull that kindle out and use it, will I still be able to get the books if they are “downloaded” to the device? Is the download like it is on a computer where I can access it if the equipment is protected? Or will that information all be lost in a “cloud” somewhere? I am not sure how the kindle works with everything being clouded these days. The lady that I spoke to when I called customer service for the kindle either thought I was nuts as hell, or didn’t understand English.

    My mother is wanting to purchase a kindle and have her books put on it to save having to tote them around, but I cannot answer the questions she has and we are both getting frustrated. Thanks for any answers.

    • Slightly longer answer:

      The Kindle keeps copies of anything you have downloaded until you delete them (just like your computer.) However we’re depending on 1) the device survives whatever event this is, and 2) that Amazon didn’t hide any requirements for periodic check-ins.
      I suspect Amazon didn’t do #2 to the software because they have been great about communicating (via email) when a required software update is coming and when things will break if you don’t update. And by break, I mean you can’t download fresh books from their cloud, not that it breaks access to downloaded content.
      I have a Kindle Touch that I have loaded around 2000 books onto as my prepping library, and while I have some physical books as backup for critical info, I’m really hoping my Kindle works for years to come.

    • I’ll just add that I’ve learned not to trust that things I can’t control won’t change without notice so my advice is to not rely on Amazon or any other ebook provider to not one day in the future put such a check in there or in some other way get in the way of opening content and make sure that you have another way to get at them. Again, open protocols and standards are the only way to go in the scenario where we may be without Internet or apps. That’s why, IMO, it is better to use a more generic device like a general purpose tablet that isn’t tied so much to the Internet and stuff an SD card with all your content. The advantage there is if the tablet breaks, the content can be opened on anything else that can handle standard pdf or epub (or even text files) formatted books like a laptop or phone or another tablet, etc. So to me, relying on a content provider’s app-even if the content is downloaded, be it Kindle, BN Reader, Google Play Books, iTunes etc. as the path to getting to my books isn’t something I want to take a chance on.

    • In general, once I went nearly all electronic for my books and information, I made it a rule to not rely on the cloud for ANY content that I have. This goes beyond EMP events (and of course assumes the devices were protected in such an event(s)). For that, I now have two (supposedly) EMP proof boxes with the idea that only one is opened at a time. I cycle through them syncing data and making sure they can still hold a charge etc every couple of months (no, it doesn’t take long, just made it part of my house maintenance tasks). In any case, you should develop an “offline” mode–i.e. what would you do if for any reason other than brief outages you couldn’t get to the network. Turn off your wifi at home and see how much stuff you can get to. Same for your phone-put it in “airplane” mode or just turn off the data connection. If there’s books you want/need that all of a sudden you can’t get to, that’s a good indicator of what you need to change. There are many scenarios which don’t involve some sort of conspiracy or apocalyptic event that could take out your Internet connectivity. I also don’t rely on cloud apps like Kindle or BN or Google Play Books (I don’t have any iOS devices so iCloud/iTunes is not an issue) so I make sure I can open content such as ebooks or videos etc. in standard apps like FBReader (epub/pdf) and VLC (audio/videos). You may have to find a way to export them and remove restrictions of find versions that do not have them. You should always stick to open formats. Another thing, if you have an Android device, take the time to export your apps so you don’t have to rely on the cloud based Google Play store. There’s several that allow you to save the .apk file. And the list grows from there. Also, make sure your backups of your devices are stored locally in addition to the cloud. Just to be clear, I’m not so much anti-cloud but I just want to get to my stuff whether the cloud is there or not. And for the stuff that is really important, should there be some sort of regional or otherwise event, you should have a physical copy. I’m taking about things like medical and other “survival” type information that would come in handy should a real shtf event happen. This is what I do anyways, so if you find it useful, have at it.

  29. Just dawned on me that maybe my propane Big Buddy space heated needs to reside inside a cage. It’s pretty large, so can anyone confirm that I need to do this?

    • The only thing on your space heater that would be affected… is if it had electronic ignition. As long as you have a Zippo lighter or basic Big disposable,,, you should be ok. Long term souce of propane would be my concern at that point. Especially if you live in a colder climate.

    • I’d be concerned about the thermocouple safety system that shuts the heater off in low oxygen environments. If that gets damaged (not sure how sensitive that is to EMP) who knows what condition the heater will be left in if the thermocouple is fried. There is also a fan, but that’s not important to the heater function so if it fries, not a big deal.

    • Thanks for your thoughts, dmwalsh. Would that be a dangerous situation? I had intended to use the heater only with a window cracked open.

    • Depends on how the heater responds to a fried thermocouple. Most likely possibilities are: it won’t turn on at all, or it will turn on, but won’t stop working until O2 levels are low enough to not support combustion anymore. Possibility 2 is the most dangerous since if there isn’t enough airflow to replenish O2 levels you can easily suffocate before the flames are snuffed out. Although a complete lack of heat in frigid temps has its own risks…
      Opening a window a crack for air might be enough, but I’m not an engineer so I couldn’t tell you what airflow rates would be necessary to be safe. I have a Big Buddy myself, but haven’t put it in a trash can due to its size, just wrapped the box in heavy duty aluminum foil. But I have plenty of candles and other plans in case the Big Buddy fails. Layers upon layers…can get excessive, but I like to have at least 3 ways of doing any given task just in case. Obsessive? My wife thinks so, but at least she humors me. 🙂

    • Thanks again so much for your thoughts, dmwalsh. I think I will put my heater in a trash can since I am still unsure if it would be put completely out of commission with an EMP. I think multiple layers are a great plan, whether others consider that obsessive or not. I don’t live in a frigid winter environment (NC), but I sure want to be prepared for the cold. Any idea about whether a Weber propane grill will be disabled by an EMP?

    • I suspect not. Most propane grills just use a piezoelectric igniter which wouldn’t be affected by an EMP. It’s just a crystal that makes a small spark when it’s hit. Unless you have a grill that has fancy electronics or a rotisserie then there’s nothing that could be damaged by an EMP.

    • Oddly enough, there’s no reply button under your last response to my question about the grill. So thank you again, dmwalsh! Hope you find this.

    • Thank you, Mike. How will I know whether the space heater has an electronic ignition? Do they operate the same as a gas grill? I really am counting on my gas grill as well, and I don’t think I can fit that in a trash can, haha!

  30. with all the nuke testing done since the 40s why hasn’t this problem come up decades ago. think of all the countries that set off nukes. hi in the air all the way to underground and no phd said stop your going to hurt tv? I SMELL PEOPLE MAKING MONEY ON SCARE. 44jon

    • There have only been a limited number of nuclear bombs exploded above the earth’s atmosphere. The most well known is known as Starfish Prime and wikipedia has a nice article on it at: //
      Basically, not only did the test prove that EMP effects are real, but it damaged electrical equipment about 900 miles away in Hawaii, and this is 50s and early 60s electrical equipment, not the more sensitive integrated circuits we use today. Inferring from the Starfish Prime results, unless serious steps are taken to protect the electrical grid and critical infrastructure we’ll be in a world of hurt after a well placed nuke, say above Kansas.
      As for folks making money scaring people…that always happens, but is it money making selling plywood and generators to folks in the path of a hurricane? Or selling out of shovels and ice melt for people in the path of a blizzard? But I have to wonder how well (or if) you read the article….galvanized trash cans and aluminum foil aren’t exactly high priced items, yet they are highly effective as “simple faraday cages.” So to protect a few useful items from an EMP, wrap the box in aluminum foil and if you really want to be safe, put that foil wrapped box inside a galvanized trash can that has cardboard lining and a tight fitting lid. I have 4 of those cans setup myself. So for under $120 I have protection for MUCH more value of prepping electronics – flashlights, lanterns, small solar chargers, LED light bulbs, multimeters, radios, civil defense radiation meters, dosimeters, etc. Basically, I consider the foil and trash cans as cheap non-expiring insurance.

  31. I find it amazing that some people are more worried about if they will be able to download e-books from the cloud,,, rather than being concerned about their own survival. Maybe some people don’t get it… but if a solar corona event,,, or multiple nuclear EMP’s fry the power grid… we will be shoved back into an 1800’s lifestyle or further back.

    Any kind of SCE or EMP will fry the power generators at ANY electrical producing power station. When that happens,,, the gasoline/diesel/propane producing refineries will explode… because those chemical processes don’t stop on a dime with the closing of one valve. Natural gas pumping stations will shut down also.

    With no fuel souce we will have no power for the construction equipment needed to rebuild the power plants and refineries. Once gasoline runs out… we will have no transportation,,, no jobs… and no money. We will go back to a barter and trade sytem and food and heat will be the main sources of trade, (currency), just to survive. Most water won’t be safe to drink without distillation or boiling. I really don’t think most people on this site realize how bad it will get.

    Where do I get my knowledge from??? As a construction worker that has spent most of his career working in refineries and power generation plants. Trust me!!! A SCE or multiple EMP’s will do more damage to soceity than most people realize!!!

    A SCE or multiple EMP’s would take YEARS to recover from,,, and most likely half of the population in advanced societies would end up dying or killing each other off. Third world countries will fair much better because they are still living an “old fashioned” lifestyle… without what we have become dependent upon.

    WAKE UP!!!

    • I agree. but even if using a metal trash can and lid, how effective can using aluminized duct tape be when only the exterior surface is metal – the inside is just glue? There would be no conductivity. What can be done to protect the computers on a vehicle? Cover them with tin foil and use a chain bolted to the frame to drag on the ground. Maybe attach a wire from the frame to a ground rod in the driveway, using a wire disconnect that would pull apart automatically if you forgot to disconnect it? I even disconnect my ham radio antenna at the radio just in case.

    • I thought the same think initially about the aluminized tape, but Dr Bradley has some good youtube videos about some testing he did. The old link I posted above seems to have gone away, but I found it again at:


  32. Anyone can build a Faraday cage, of any size with simple household materials. Start with a wood frame, depending on the size, you can create it from a 1″ x 1″ or from 2″ x 4″ lumber or larger; to the cubical frame, staple copper window screening, but make sure the copper screen section are in contact with one another. Some soldering could be easily involved. Just make sure that there is an opening for you to access the inside to place and remove you items. Other screen material can be used, like aluminum but not a nylon or other synthetic materials. Copper is by far the best all around and is easiest to solder to maintain electrical continuity of the “circuit”.

    • Hello. I’m kinda techno-challenged, but with regard to using a galvanized trash can to shield electronics from EMPs, could you remove the handle, using the up-side- down lid as a base to stack your items such as your solar generator, laptops, ipads, etc., and use the can as the cover?
      Access might be easier, but would there be a danger of bouncing EMP?

    • As long as you aren’t creating any holes in the outside of the can or lid, and you remember to keep an insulating layer on the inside between the can and your gear, then the orientation of the can shouldn’t matter. However, depending on how strong the lid is, you may have trouble with it buckling under load. The barrel of the can is designed to take the weight, not sure if that was ever considered for the lid.

  33. Will a metal trash can with a cardboard liner truly work as an absolutely effective Faraday cage? Has this been scientifically tested? I’m starting to think it might be too simplistic. Does the tape need to achieve a completely air-tight seal around the cover of the can? The bottom of the cans are certainly not air-tight seals in their construction….Just asking.

    • Yes, check out //

      He tests with a meter with just the can and a taped can to show the difference.

    • Thanks very much for the link, dmwalsh568! I’ve just watched several of the videos by the same guy, and find them very reassuring. Getting to work on putting mine together this afternoon. Things seem at a near-boiling point on this planet, and there are a couple of insane people leading countries with nuke buttons….

  34. Yet another question—If anyone has had their stuff in a tape-sealed trashcan cage for an extended period of time (like a year or two), I really would like to know whether there have been any problems with moisture & mildew collecting inside. I read somewhere that it would take a very large amount of desiccant to be effective for such a large space. I am putting a wealth of electronics in there, and don’t want them all destroyed by such a pathetic cause, after all that!

  35. Unfortunately, most of the information on your website regarding authentic EMP pulse weapon yeild is naive. A nuclear EMP **WILL** burnout almost any metal structures comprised of circular shaped metals. Objects such as chain-link fences will burn, automobile wheel-rims,gold-stripe around porcelain dishes on your shelves, bracelets, aluminum window-frames, etc. Of course the closer one is to the epicenter of the device, the more severe the metal damage.

    I am not guessing at this and the information was not acquired through other folks studies; the limited information I am allowed to share here was learned as result of my having instrumented (1988) the effects of an EMP pulse weapon system used to irradiate commonly available items found the public sector as well as household items, such as FM radios, TV sets, automobiles, toaster ovens, hair-blowers, electric pencile sharpners, and yes, microwave ovens too. The purpose of the tests were to determine device survivability. From that research data that I generated under DARPA contract, military vehicles, communication systems and other things were developed to remain functional following nuclear weapons detonations.

    Also the notion that simply placing an electronic device inside a microwave oven, by doing so will protect it from being damaged by an EMP pulse is uninformed, although its a cool idea, and if far enough away from zero?…its sketchy. On the other hand, a survivable Faraday cage would need be quite robust, but can be home fabricated. Make it large so that you can get inside of it along with your gadgets, solar-panels, for post detonation power, and of course a few pumps, for water, and gasolene, etc.

    The reason a microwave oven blocks cellphone RF signals is that the construction of the microwave oven enclosure (metal box) and the see-through pin-hole metal-mask ‘glass’ door of microwave ovens, operate on similar wavelengths and are designed to ‘stop-band’ those frequencies. Phrasing it another way, the RF energy of a microwave oven and a cell-phone are very nearly the same frequencies and the oven door is specifically designed to prevent that energy band from leaking out, or in your scenario, from leaking in. Blocking just one narrow band of frequencies, while an EMP pulse weapon generates a huge multi-spectral (lo-bands, mid-bands, hi-bands, ultra-hi-bands…millions of bands) EMF field that moves in and out. And it critically rings over hundreds of miles. While it is true that the microwave oven could block the band of frequencies it is designed block, it will not block any of the OTHER millions of bands emitted by the EMP pulse weapon. So everything inside the microwave oven as well as the microwave oven ‘itself’ would be burned out, including your dishwasher, your garbage disposal, your ceiling fans, your digital clock, your chain-link fence around (catch fire and melt) the yard, the rings on your fingers or nose, etc.

    EMP pulse weapons are very nasty.

    DC electricity is generated by moving a magnet back and forth through a length of wire, which has been coiled. A small light-bulb may be lit by putting it on the wire ends. Remove the bulb and twist the wires together creates a ‘short’, while moving the magnet back and forth causes the wire to heat-up, and if the magnet is strong enough, the wire will melt.

    A ring on one’s finger is a 1-turn shorted ‘coil’ when exposed to the moving ‘magnetic’ field of a nuclear EMP pulse.

    Best defense, no nukes.

  36. A lot of great info on EMP and survival .Footnote when i was 4 yrs old 1948, we lived in a log home my father built in western Virginia after he returned from WW2 . It had no heat except a wood burning cook stove No electricity No running water(it came by bucket from a spring )we had a out house for a toilet and a Sears catalog for toilet paper,or frig was a ice box with blocks of ice to hold Butter and other small perishables. We had a huge garden and my Mother canned about 90% of our crop.
    Lets move up 73 yrs. Suverability is something that you could achieve with a small amount of planning
    I have at my home in Fl. a solar still easy to build out of plywood and a piece of glass,I have a 6000 watt off grid Inverter charger, powered by 12 agm 105 amp hr 12 volt wired for 24 volt batteries. To charge them I have One 6000 watt gen and a small 2000 watt for my camper.The inv. is wired to a sub panel to feed my main. It allows me to run the frig and freezer and Irrigation well pump for a water source.Since in a Majuro event Fuel will be non existent in short order,I have 4 220 watt solar panels mounted on a cart to position for max sun gain.
    Lets return EMP prep inthe event of an attack from a foreign power, Hopefully NORAD would be able to give us about 15 min Waring of incoming < the weather channel could give us days of impending Solar flares or the Ham URALL keps track of this also. So a lot of time to move sensitive equip into Protective cages. That only leave saboteurs against our grid , which could also interrupt water supply as well as communication. I think this is the greater threat after social discord.Plan for the worst hope for the best .( buy C rats )
    As a bragging foot note I lived in Homestead Fl.The house I had built there survived Hurricane Andrew with only wet carpets, My Family of 6 lived on gen Power for 31 days. We were one of the first to have power restored some went 4 or more months, as you know parts of Porto Rico are still without power 8 months after a simple Hurricane.

  37. having trained in electronics in the Navy I begin building my faraday cage from electronic theory. first is that the EMT which is a form of electricity will follow the rules determined by years of research. the electron like the photon tends to follow a straight line when in the free air only air molecules providing the path. second power will follow the path of least resistance. if given a path it will follow it to ground. the faraday cage is nothing more than providing this path. the ideal condition provides the lesser resistance thus providing protection. copper and aluminum providing the best. a gap or opening will let in a signal. using the first rule we see that it will be reflected and with the amount of power in the EMT a reflected signal is as bad as a direct. The goal is to attenuate and weaken the signal. this is where I have an idea that may provide the attenuation and redirection of the EMP. I have tried using some iron powder. the powder I had was quite consistent and did work with the limited power signal I had. my abilities to test are limited so I put this idea out so others with better labs can try it. I also think that using particles of a multitude of sizes would provide more protection. I would embed these particles in a carbon paste that wires are embedded to provide the final path to ground. the design of the container is designed with a cover that requires a signal to reflect twice. the areas providing the reflection surface would also provide the most absorption and path to ground. this providing the best attenuation of signals. the boxes I have built with my poor skills seem to work well enough. what I would like is someone with equipment that is sensitive. to provide testing to prove it works. the idea is to provide a media like a moldable composite of carbon and iron particles. these form the main storage box. the cover providing the blocking path that attenuates all signals. because I am old and time left is short I want to pass on my ideas for others to prove in hops I will have provided answers and protection that is affordable and will work. if it doesn’t? well, I tried. all I want is to provide a safer world for my grandkids.

  38. Gaye, You are doing a great job.

    I am a little sceptical regarding some of the solutions proffered; one specific issue is the use of silver foil.

    Whilst silver foil has the ability to protect against an E (electric field) it will not necessary protect against an M (magnetic field). For every E field there is an associated orthogonal M field. One needs to consider the thickness of the protecting material to mitigate M field damage.


  39. Never has your column generated as much interest as this one. I find most of the concerns about saving electronic devices a little humorous, since I didn’t have a television, microwave, computer, or cell phone until well into my 30s or 40s. I well remember living without any electronics, and don’t think I would miss them all that much. Water, food, heat, cooking fuel, and light sources, concern me far more than whether I can access my Kindle ebooks and cell phone. Don’t get me wrong, I DO have a faraday cage that holds several electronic devices that might be nice to have in a long term emergency or crisis, but not really counting on them surviving and EMP or CMP.

    • With a small solar charger, some rechargeable batteries and an electric lantern or flashlight, I can have light for years post event in a small bag. To have a year’s worth of candles or lamp oil would take much more room and weight – important if I have to bug out. Same thing with books. Any critical books I have in printed versions, but I have a Kindle with over 2000 books on it that is lighter than one hardcover book…with the same solar charger I can keep it running for a few years post event at least, maybe longer.
      One item that I’m not sure has been mentioned is radiation measuring gear (geiger counters and dosimeters.) I have a bunch of them stored in two faraday cages since an EMP event would likely cause problems for any nuclear power plants even if it wasn’t the opening salvo of a nuclear strike on US soil. It’s pretty hard to know if you’re being exposed to radiation without electronic detection gear, at least until it’s much too late to do anything about it….
      So, sure the electric light and Kindle are luxury items and not strictly necessary, but I consider a geiger counter and dosimeter (or three) a very important prep.

  40. Thank you for this well written and informative information. I have been wanting to build a faraday cage for a long this is a big help. I am also building a solar back up using this design has anyone ever tried this design?

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