We all enjoy all the convenience and utility that electronics provide for us.
But, unfortunately, there is a constant threat that could take these devices away from us. It is an unseen enemy that will overload our power grid and fry electronic devices without warning.
I’m talking about an Electromagnetic Pulse (EMP) or a Coronal Mass Ejection (CME). While EMP’s are generally going to be the work of unfriendly governments, a CME comes from the Sun, and there is nothing that we can do to stop it.
What Are CMEs and EMPs?
Coronal Mass Ejections are eruptions of magnetized plasma from the Sun. While these events occur several times a day, they are rarely strong enough to affect our systems here on Earth.
However, occasionally, a CME can be launched directly at our planet and be strong enough to cause problems. When a CME reaches our atmosphere, a geomagnetic storm disrupts the magnetosphere, releasing a lot of energy towards the surface.
The scale of damage will likely only affect radio communications, satellites, and our power grid. Still, there is the possibility that complex electronics could be affected by a CME as well. So while the probability of a CME frying your radios and computers is very low, you should still consider placing some electronics that you would want to have after such an event in a Faraday cage for safekeeping.
Related: The First Steps You Should Take Immediately After a CME
An Electromagnetic Pulse is when charged particles undergo rapid acceleration, which results in a sudden burst of electromagnetic energy. There are many potential causes of an EMP, one such common cause is lightning strikes, but the primary source of concern for these events is high altitude nuclear detonations.
After the United States military discovered that high-altitude nuclear detonations could produce a highly destructive EMP, many tests were conducted to develop the EMP as an effective weapon against an enemy population. However, in the present time, multiple countries have weaponized EMP and can launch direct attacks on enemy countries.
In the unlikely event of an EMP attack, the effects would be similar to a CME, with the notable inclusion of destruction of electronic devices. An EMP destroys electronics because it induces a high voltage and current within them, overloading the circuits, causing failure.
Related: 7 Actions to Take Immediately Following an EMP Strike
What Is a Faraday Cage?
In its basic form, a Faraday cage is an enclosure coated in a conductive material. This material could be copper, aluminum, steel, etc. the only requirement is that it readily conduct electricity. In some cases, wire mesh is used as the conductor, explaining why we refer to these enclosures as cages.
As long as the devices we place inside the cage do not contact the conductor, and the cage’s exterior is sealed and electrically conductive, the items inside should be effectively shielded from EMP and CME.
Many of us have a Faraday cage in our pockets in the form of an RFID-blocking wallet. Another great example of the use of Faraday cages is in MRI rooms where the walls are lined with copper to shield the equipment from interference.
How Does a Faraday Cage Work?
When we use a Faraday cage during an EMP or CME event, the electromagnetic energy follows the conductor our cage is covered in, dissipating its effects. This dissipation of energy renders the devices within the enclosure immune to the impact of the electromagnetic energy.
The key point to note is that the body of the cage and the lid must be connected electrically so that the electromagnetic radiation has no gaps to slip through.
Related: 15 Things You Think You Know About Faraday Cages But You Don’t
What to Put in a Faraday Cage
Inside a Faraday cage, we will put any electronics that may be affected by an EMP or CME, and we would like to have them available for our use after such an event or attack.
A few examples are:
- Amateur radios
- Flashlights and headlamps
- Shortwave receivers
- Power banks
- Rechargeable Batteries and Chargers
Poor Man’s Faraday Cage
There are many ways to build a cheap but effective Faraday cage using materials easily obtained through online retailers or local home improvement stores.
There is, however, a simple but effective Faraday cage that you can build with materials that you undoubtedly have laying around your home right now.
- Shoebox or another cardboard box of an appropriate size
- Heavy aluminum foil (make sure that it is the heaviest duty foil that you can find)
- Metal tape
1. Open your cardboard box and confirm that the interior is of sufficient size.
2. Wrap the outside of the box in aluminum foil. Make sure that no aluminum foil is on the inside of the box.
A Faraday cage only works when the items inside the cage are insulated from the conductive exterior.
3. Tape all of the seams with metal tape to ensure that the exterior has no gaps in its conductivity.
4. Load your poor man’s Faraday cage with the electronics you want to protect.
5. Close the lid, and seal the box with metal tape. When you are done taping, there should be no gaps in the foil shield.
Testing the Poor Man’s Faraday Cage
To test the cage, place an AM radio tuned to a local station in the box along with a cell phone and a VHF handheld transceiver (if you have one).
Make sure the AM radio volume is set loud enough that you can hear it through the box and that the cell phone and VHF transceiver are on and ready to receive.
**Tune the VHF transceiver to a local repeater because this will mean that the radio waves will be coming to the radio through the repeater rather than the second handheld radio that is probably right next to the box.**
When you seal the Poor Man’s Faraday cage with metal tape, you should hear the AM radio lose the signal and going silent. Next, try to call the cellphone, and if it goes to voicemail, you know the cage is blocking the signal.
Lastly, send a transmission on the repeater that the VHF radio in the Faraday cage is tuned to and listen to see if you can hear it through the box. If these tests are successful, you have a functioning, poor man’s Faraday cage. If not, then you may need to add layers of foil to the outside of the box.
Experiencing a destructive EMP or CME is highly unlikely, but they are scenarios that we should all be prepared to face.
One of the essential EMP preps is to have and use several Faraday cages to house the electronics that would make a post SHTF life far more survivable.
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Emergency Bag to Keep in Your Car in Case of an EMP
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Making Butter at Home, Like Our Grandparents
Of all of the challenges and dangers that we must contend with
the EMP is by far the most serious.Loosing the power grid would truly be the end of the world as we know it.
The Chinese and Russians are very patient.They are willing to
to wait for the United States to collapse from within.A Stone Age country is of no use to them.
The Muslims on the other hand just want to kill all infidels as soon as possible.If Iran builds a nuclear bomb they will use it
on Israel and the United States. The don’t think or act in any
normal way.They just don’t care.
Making or buying a Faraday device is essential to survival.This
article is an excellent starting place. There are numerous DYI
Faraday projects on the internet and in print so don’t delay.
I keep all of our communications in Faraday bags inside of a
fire proof steel safe.I hope they will be protected but I’m not
The EMP Shield Company has developed devices to protect
circuitry for homes,vehicles,and generators.The equipment is not cheap but if it works it is invaluable.
EMP Shield Company is way cool! Thank you for posting. You did good!
I am installing a 24kw Generac whole house generator. What type of faraday box should I enclose the generator in I don’t see that discussed anywhere? Is it just a much example of a homemade box u discuss here or is there a better solution?
On Faraday cage or box: while there should be no impact, add the following:
1. Charge up the rechargeable batteries on the devices to be stored.
2. Remove the battery from the device(s) and seal in a cheap zip lock baggie.
3. For radios with removal antennas, recommend removing the antenna.
4. Tape an index card to the outside of the box with the list of contents and, in pencil, the last time the batteries were charged. Charge about once a month.
Ref someone else’s comments: when I buy better stuff, the old stuff, if usable is what I put in the cage. This way I have a capability for before and after the event. On H/Ts or handheld, remember it works better if you have someone to talk to. . Might want to put two or more in the cage. I have 4 older FRS/GMRS radios in one of my cages. One is for my neighbor who is not a prepper. Over a period of 15 years, I have accumulated a lot of radios, many are not used. If they work, and are worth something, I put them in the cages along with power. I have more than a few cages in different places away from the house.
Your old microwave oven makes a Jim Dandy Faraday Cage.
To the best of my knowledge, which might not be much, anything protected after an attack may not be of much use if everything else is down because it is not protected. It would be smart to not only think about what you are protecting, but what are the expectations afterwards. What would be viable? What would really be worth while?
the GOV has been actively prepping for a nuke event since post WW2 – emergency broadcasting radio & TV and now reverse 911 telephone and the internet was actually created for the DOD for secure communications >>> if you do nothing else for yourself have devices available for all forms of communication – the GOV will have it’s BSing on max but you’ll be able to pull some good intel …
You could download all kinds of instruction manuals and instructional videos, entertainment videos, general reading, maybe a selection of Joe Biden’s greatest speeches, stick ’em in the cage with some compatible phones and pads. Make the Faraday cage big enough for a portable solar generator and a couple 60W solar panels to keep things charged. Maybe some battery powered tools, a hair dryer?
If we ever get back to our off grid truck camping I’m going to trade my old deep cycle battery and solar charging equipment for a portable solar generator, much better technology for not a lot of money.
CC, my plan is to store information such as articles, instructions, recipes, etc. on CD’s, DVD’s, thumb drives, and also on an older laptop that was replaced for a newer model but will accept the CD’s DVD’s, thumb drives, and also an old cell phone that has a lot of contact information including addresses already stored, a couple small two-way radios, and a small dual powered hand crank and solar AM/FM radio with LED light, as well as some small solar chargers and rechargeable batteries, all in cheapo food tins with the inside walls insulated with cut-to-fit cardboard, and the lid sealed with real metallic duct tape (not the plastic kind) , and then the tins will be stored inside a safe on a piece of insulating cardboard. These tins stack very easily, but I think I would put a layer of cardboard between each tin as a precaution. Another precaution if you intend to use an old laptop to access your stored information is to make sure the operating systems will open and read your stored files. It does no good to have a lot of stored information and no way to access it.
Now before all the EMP “experts” start the bash fest and pissing contests about what I should or should not try to save in my simple and inexpensive homemade Faraday tins, and how I should instead spend my resources and “do it their way”, my primary goal is to save information in compact formats that can be used after a serious Grid collapse, for subjects like water collection, purification, and safe storage. how to produce, process, and safely store foods, everything medical I can find that is in plain language, including recipes and procedures for making medicines from plants both wild and grown yourself. Recipes and instructions for anything and everything such as how to properly sharpen a handsaw, how to tan leather, how to make snares, how to identify and harvest plants and wildlife, how to weave baskets, how to make cloth, how to repair things, how to substitute and improvise with available materials, how to make gunpowder (black powder), and so on.
dz: I downloaded everything from an older phone to a file in the computer. From there, a printout. Sound like you got it all together. niio
Why would CD’s be damaged with a EMP? The nice little tin foil kit is a nice idea but EMP isn’t exactly going to be as large of a issue as people think. you have to be directly close to the center of one for anything serious to happen. The largest issue you might see is the power lines would burn and start on fire. So the grid goes down and unlikely to get back up.
All my important survival information is written down on PAPER! Paper is immune to EMP, and doesn’t take up that much room!
That’s right. If the cellular network has been fried, then your working cell phone is useless.
Couldn’t you just wrap your cell phone in small bubble wrap. Then wrap heavy aluminum foil around that and carry it with you.
CC: If you have downloaded maps stored on your phone, they will still work because now they are stored on your phone and not in the cloud. Anything that is actually stored on your phone will still work if your phone is shielded. If it is stored on a SD card and you have a computer that was shielded, the info on your SD card will still work. Books stored on your computer or on your phone will still be available to read. For those who just can’t live without music in their lives, music stored on your phone or your music device or an SD card will still be available. Those are some of the things that will still be available if you have a method of charging them such as a solar charger. That said, most of the smaller solar chargers are slow to charge via solar, so you won’t be able to run your phone down and expect the solar charger to have your phone fully charged in an hour. It may take two days of sunny weather to charge your phone, especially this time of year.
Look carefully at the list of what to put in the box. Notice cell phone isn’t on the list but what is would allow you to communicate with other people who were prepared.
I don’t understand. You want me to put all that stuff in the box and seal it? So I guess I have to have duplicates to use until that day comes? Forgive me, I’m tech challenged.
Put an od cell phone and radio into the box. I have several old burner phones I keep just for things like this, and emergency crank radio/ flashlights are fairly cheap.
Why not just place your equipment in tight fitting plastic containers and put them in tight fitting galvanized trash cans? Bat-ta Bing bat-ta Bong! ALL DONE
metal containers like garbage cans usually need modifying – but – they can be prepped to be a continuous use Faraday cage that will be necessary for a “use & scoot” usage scenario ..
both EMP and CME won’t be once and done pulse emissions – there’ll be random bursts after the initials and could be even more intense >> you’ll need to listen to the “on the hour” news broadcasts – and then scoot your receiver back to safety >>> same same with your other broadcasting and computing devices …
It sounds good, except the plastic containers will still be able to allow the electrons to pass through and hurt the electronics. You have to insulate the things you want to save from the metal container itself.
RICK , you are spot on! the $25 dollar walmart galvo can is the most effective time and suffering solution!
just insulate the items inside. find you some aluminum duct tape, go over the handle lid holes
seal the edge on the perimeter .
carry by handles!
To help make your Faraday cage work more efficient, ground it to earth ground.
Best way is to have 8 foot ground rods in the ground,
Faraday cages do not have to be grounded. There was a long discussion on this very topic with comments by folks who are knowledable on the topic not very long ago. Go back about ten topics or so and you will find the discussions toward the bottom of the comments. Grounding accomplishes nothing and may be counter productive with regard to the type of electron flow which one is attempting to protect against.
Agreed. I have read all of Dr. Bradley’s material. He agrees with what you have written here. Mine are not grounded for that reason.
Always good to hear from you. I am less than 12 months from retirement. I will give you my contact info and you can use it if you choose to.
Another quick faraday cage would be a large metal ammo can. Just line the insides with some insulating material so the stuff your trying to protect isn’t touching any metal . After sealing the can wrap the lid with some metal tape for added insurance
Steve sorry to down vote you but consider this. EMP iis Electromagnetic not electric energy. As a young boy we would make germanium diode radios with a diode, antenna, a piece of coal and a safety pin. It only worked when it was connected to a ground. Energy only flowed to the antenna when it HAD a ground. Radio waves are a form of electromagnetic energy.
Using a ground rod makes the faraday into an antenna for the energy to flow to. Like putting up a lightning rod to attract electrical energy to focus on. Don’t ground the cage just let the energy find it’s own ground – not concentrate itself on your stuff.
Here’s a good article about grounding
According to Spaceweather.com last night the U.S. had Aurora Borealis visible as far south as Missouri. That’s significant inasmuch as the CME was only an M category CME and not an X category CME. I can’t say if it was visible in Europe, Russia and Siberia. If I understand their post correctly, Aurora may be visible again tonight for those folks in the northern states. There is a spot in Kansas which is purported to be halfway between the Equator and the North Pole. If that is the case, then the northern half of Earth was bathed with emanations from the sun. Fortunately for us, it wasn’t an X category bath.
This is a timely article given that we are in an eleven year solar maximum period when solar events are at their peak.
LCC: I’m reposting this in comments. Thanks for the tip, I’ve been reading them since you first mentioned space weather. niio
LCC: and, of course, it won’t allow me to copy your post.
It was supposed to be visible in south Scotland. Unfortunately it was overcast and we didn’t see a thing.
Interesting, my understanding is that electricity wants to follow the easiest way to earth ground.
That’s why I have three ground rods hooked to my radio tower.
That’s why I have my radios and repeaters all grounded to separate ground rods. I’ll keep on grounding.
I’ll dig deeper. Guess it’s time to get up on ARRL website.
Steve, I believe the ground will be super charged with the EMP. Your ground rods will allow a path to your container.
Just a couple of notes regarding a Faraday Cage. This idea comes from Faraday’s Ice Bucket experiment. Since an electrical charge will repel a like charge, any charge inside the bucket will go to the outside of the bucket. The interior of the bucket would be “field free.” Applying this to a Faraday Cage, there is no need to ground the cage. Likewise there is no need to insulate the cage from anything inside the cage. As long as there are no gaps in the conductive surface, there will be no charge inside the cage. I simply wrap electronics I wish shielded in aluminum foil. This include a spare key-fob car key. That way I can hide it in the car without leaving the car unlocked.
That is true, but have you considered the car itself would be affected by the EMP. Most cars today have a computer brain that controls 99% of the cars function including the spark that ignites the gas fumes to make the car go – and an electric car is 100% affected by an EMP
Note from LCC, subscribe (free!) to spaceweather.com to watch for possible CMEs. Again, LCC, thanks for the tip. Great site! niio
Red: I discovered spaceweather.com this past summer and I subscribed to the paid portion of the subscription. I consider it prepper money well spent.
I do wish this prepper website would learn prepper and not keep changing it to preppier or pepper or whatever other close word it feels like.
Spaceweather.com does offer free notifications and as preppers, I think it behooves all of us to follow its notifications. I may be selfish, but if I get a notification of an X category CME headed our way, I may just be too busy to take the time to post that notification on this site. I will also be notifying my children and grandchildren and the two or three friends still alive to batten down the hatches. Posting on this site may not even cross my one-track mind if I am hustling around unplugging stuff and turning off the main panel and whatever else may occur to me.
LCC: that’s why I posted the addy. If you think the site is good, all of us should at least check it. People are supposed to think, to be independent. Aside from that, it’s a great site just for browsing. Again, thanks for tipping us off. niio
Or, the perfect “Faraday cage”…. just store them in your microwave when not in use. Keep a junk one around, most thrift and junk stores have them cheap.
I am certainly not an expert in the field. In fact, I have not yet enrolled in Basic EMP/CME electronics 101 for Boneheads yet. That said, I believe there is a divided opinion about various household items acting as Faraday cages and a microwave is one of them. I plan not to use my microwave as such and have placed my electronic items in metals boxes and ammo cans duly insulated.
If anyone is planning on using their microwave, refrigerator, gun safe, washing machine, clothes dryer, metal shed as a Faraday cage, I would urge you to go on line and do some research. Be careful of the sites you take advice from. Look at the technical expertise of the person posting. If they don’t list their credentials, don’t give the site much credit. I would also add that OJT in the military or some other work-related experience more than 20 years old is like 20 year old cheap wine. It most definitely has not improved with age. Electronics and medicine have advanced so much in 20 years! Twenty years ago I had just switched from using a Packard Bell computer to a laptop running the first edition of Windows.
Along the line of using appliances, I read a tip that I hadn’t thought of and made a lot of sense to me. When the BIG ONE comes, in addition to filling the bathtubs in your house and every pot and pan you can scrounge up with water, consider filling your washing machine with water. Mine holds about twenty gallons of water. It will be clean and can be used to washing oneself, dishes, clothes, anything you might use water for other than drinking. I suspect that boiled, it would be fine to drink too.
Always remember if you have the old fashioned tank hot water heater it also will hold 30 or more gallons of water that is potable. Be sure to turn the gas off to the hot water heater before you start draining it. For folks who have switched to those on-demand hot water heaters, as with the just in time delivery system that we are decrying presently, you will find that the on-demand hot water heater doesn’t store more than a cup or so of water.
in regard to water heaters and emergency water >> regular flushing (done monthly using the water for a basement floor rinse?) is necessary to keep the sediment limited and actually keep the drain faucet clear enough to be used >> if nothing else it should be done as a maintenance routine for heating efficiency sake – sediment acts as an insulator between the water and heating element ….
Use 99.999 silver coin suspended or just placed in the water container to kill bacteria and viruses. Pioneers used to do that with their drinking water barrels.
Testing Faraday Cages – Do they really work?
Don’t know how my moniker got so mangled in the previous post, oh well………
Another way to EMP-proof your life is to have non-electric versions of the important stuff. . Ever hear of paper maps? Too hard to do? Spend some time watching the Amish. They are already EMP-resistant. I have paper maps of my local area, bug-out routes, state, etc in my vehicles and bags. I have cash on hand (no need for ATMs). I have a generator in a faraday bag and a manual siphon pump. I have two Propane stoves. . Try this exercise: spend two weeks with a notebook and every time you touch or use something electronic, write it down. Think about the things that are powered from outside you home. Then spend two weeks working on and documentation of non-electric or electronic work-arounds. Often you just have to think outside the box. Have an electric toothbrush? What about a regular manual toothbrush? Have radios in a faraday cage? What about a list of like minded individuals with radios?
For folks interested in what could happen in society from the effects of an EMP, I would suggest the fictional novel “One Second After” by William R. Forstchen. It was published in 2009. Definitely one of the scariest books I’ve ever read. Lots of good prepper information in it, as well.
Great Article and Comments for Preppers
Predicting the future is pure speculation…but the more experience and knowledge you have improves the predictive speculation.
Knowing that a huge solar event is going to take out the earth’s electrical grids ahead of time would be very good.
BUT…a powerful X-20 class solar flare causing an EMP has very little chance to hit earth. That type of flare happens very rarely, and almost ALWAYS goes into deep space. The last time one was to hit earth was the Carrington Event in 1859, it fried telegraph wires and equipment. HUGE X-Class Flares are very rare, and it is very unlikely it would be aimed directly at earth.
A solar Flare is not high on my list…
BUT…the same PREP is!!!
Experts say a surprise EMP is now part of China’s ‘Blitzkrieg’ strategy. Russians have had this for decades…but MAD (Mutual Assured Destruction) prevents them from using it. Our military would see who launched WWIII, and our subs would turn their cities into radioactive dust bowls. SO…Not Happening…
However, the following scenario has been discussed by those with much experience and knowledge.
The USA EMP attack:
A “rogue” nation or “religious terrorists”, secret friends of our enemies, with EMP nukes from a cargo ship in the Gulf of Mexico. VERY BAD, zero warning…In minutes airplanes will be dropping out of the sky, including in Mexico and Canada. You will know when you see that.
Do Not Under Estimate the Impact…This is a WORST CASE SHTF scenario. Our technology driven society will be gone in seconds. So many dangerous things will go wrong for the rest of your life.
There will be an eerie “Total Silence” in our world.
No light bulbs at night. We can see the stars again.
No cell phones. We will get to talk to our kids again.
If lucky, and if “hardened”, the 99 USA nuclear power plants will be able to safely shut down. And there will be much more danger all around us every day for the rest of our lives.
Life will not be the same as we go back 200 years to a time before electricity. Prepper Survivors will not live long enough to go 200 years “Back To The Future”. But your children might.
An EMP Nuke that kills North America will impact the rest of the world. Either our Sub Captains will counter-attack with EMP Nukes to keep the enemies busy in their own countries (for the next 50 years), or an economic collapse will be a severe disaster for the entire world.
In five years of survival, a world of 6 billion will be reduced to 1 billion, with 20 million preppers in the USA.
Most of the world population will be in China, India, Africa, and South America…in areas where technology did not rule their society.
Experts that say 90% of the American population will expire in one year. Possibly, but unfortunately, this deadly disaster will continue in “several waves over several years”.
– The big cities will quickly “burn” in the 1st wave. Starving armed survivors will migrate on foot to the country, killing each other for scraps of food as they go, but very few will last long against heavily armed country folks who are camouflaged (deer hunting) expert snipers.
After the first winter, estimates predict 90% of Americans and all big cities will be gone.
– Then the 2nd wave begins. Deadly city gangs of militaristic “pirates” using military tactics will start scouting for the loot owned by millions of preppers. Their numbers and firepower may be overwhelming.
The roaming gangs should be gone after 3 years, unless a Walking Dead “Neegan” shows up and controls local towns. But I believe heavily armed towns using defensive military tactics can stop the “Neegan” gangs.
I wish I was rich, cause an option for a wealthy prepper group with a couple million and a couple years to build it…
“It” being a small “hardened high-tech underground facility” set up like a 3-year Mars Mission. Stay underground 99% of the time with triple redundancy for all critical systems.
But seriously, no prepper wants any of this…
let us pray this all stays as Science Fiction.
But “Just In Case”, Keep Prepping.
All of the above situations are certainly possible. There is one other possible way to prepare for any such very likely events. Study Gods word,the bible, there is a war going on in heaven that is going to spill over onto the earth as fortold in the book of Revelation. Only those who have accepted Jesus Chirst as there commander in chief will be happy with the end results. Fear not who or what can kill your body but the one who can kill your soul, that old devil himself, Satin. Read all about it in Gods word.
That’s alotta readin’! I think I got the jist of it til later. ;o)
I have both (aluminum & stainless steel) pot. Sizes about 12 & 32 inches diameter. Can its used as an alternative of aluminum foil wrapped cardboard? TiA!