With an ever-growing dependence on digital technology, it is becoming more and more important to be prepared for potential disruptions in our electronics.
Electromagnetic pulses (EMP) are a genuine concern, as they can cause a devastating amount of damage to sensitive electronics, such as computers, phones, and other devices.
Preppers and survivalists must be aware of the potential harm of EMPs and take necessary steps to protect their electronic equipment.
Is The Threat Real?
Electromagnetic pulses (EMP) are intense bursts of electromagnetic radiation that can cause severe damage to sensitive electronics. Various sources, such as nuclear explosions, solar flares, or electromagnetic weapons, can cause EMPs.
When an EMP passes through an electronic device, it can cause permanent disruption or even destruction of the device.
Electronic devices such as laptops, mobile phones, and two-way radios are particularly vulnerable to damage from EMPs, making it nearly impossible to reach out to other people. However, here you can learn the only way to communicate after an EMP.
An EMP will disrupt the device’s delicate circuits, causing it to malfunction or even fail. In addition, an EMP can also cause permanent damage to the device’s memory, making it impossible to recover any data stored on it.
For this reason, preppers and survivalists who rely on these devices should be aware of the potential risk posed by EMPs and take steps to protect their equipment.
Faraday Cages
A Faraday cage is a metal enclosure that protects electronics from an electromagnetic pulse (EMP) and derives its name from the English scientist Michael Faraday, who discovered the principle of electromagnetic shielding.
Faraday cages shield objects from electromagnetic waves using a metal enclosure to block external static and non-static electric fields. Electromagnetic shielding is due to the metal reflecting and redirecting the electric field lines, thus creating a neutral potential inside the cage.
Related: 10 Faraday Cages You Can Make at Home
To construct a Faraday cage, the metal enclosure should be completely covered with a conductive material and have no gaps or openings.
Additionally, the metal should be thick enough to block the electric field but thin enough not to absorb too much energy.
Depending on the strength of the EMP, different types of metal will work for a Faraday cage, such as aluminum, copper, or steel.
Effective Faraday Cages
The following five attributes are present in a practical Faraday cage:
- Electrically Conductive: The faraday cage must be made of an electrically conductive material, such as aluminum or copper, to be effective at blocking EMPs.
- Shielding: Shielding the Faraday adequately to block the electromagnetic waves from entering. Shielding can be done using correctly grounded metal sheets, a metallic layer, or a combination of both.
- Seamless: The faraday cage must have no gaps or seams through which EMPs can enter.
- Air Tight: The faraday cage must be airtight for it to be effective at blocking EMPs.
- Durability: The faraday cage must be durable enough to withstand the force of the EMP, meaning that the material and construction of the faraday cage must be able to withstand the force of the EMP.
Using A Microwave Oven As A Faraday Cage
Some preppers believe microwaves can be used as a Faraday cage to protect electronics from EMPs.
The belief centers around the fact that they have a metal housing.
The metal housing, in theory, should keep electromagnetic waves out.
Related: 11 Things You Believe About EMPs and Faraday Cages That Are Actually Wrong
However, it is essential to remember that a microwave oven may not provide complete protection from EMPs, as the extent of protection can vary depending on the size and power of the EMP.
The effectiveness of microwave ovens as Faraday cages is compromised by the fact that there is a gap between the door and the microwave’s body through which an EMP could enter.
Using A Refrigerator As A Faraday Cage
Refrigerators are a better Faraday cage for protecting electronics from EMPs because they are airtight and made of metal.
The metal exterior of the refrigerator will act as a shield, blocking electromagnetic energy and preventing it from entering the device.
Additionally, the insulated interior walls of the refrigerator will serve as a buffer, helping to absorb the energy and further protect the electronics.
The fact that refrigerators are airtight will also help protect electronics from outside environmental factors, such as dust or moisture.
Sealing the refrigerator completely by insulating all gaps and cracks is essential. Overall, the effectiveness of a refrigerator as a Faraday cage for protecting electronics from EMPs depends on how well it’s sealed and insulated.
Related: A Step-by-Step of What to Do Immediately After an EMP Strike
Which Is Better? Microwave Versus Fridge
Refrigerators are generally a much better choice for Faraday cages than microwave ovens for a few reasons:
- The metal content of a refrigerator is much higher than a microwave’s, making it a much better conductor of electricity and, therefore, better at shielding the electronic equipment inside from an EMP.
- Refrigerators are much larger and have much more interior space, allowing more equipment to be stored inside. A refrigerator’s insulation also helps absorb the energy from an EMP and further protects the equipment inside.
- A refrigerator door’s airtight seal helps prevent any leakage of electromagnetic energy and further protects the electronics inside.
It would be better to use older refrigerators as they are generally made with thicker metal and provide more shielding from an EMP.
In addition, refrigerators that are buried underground or in a subterranean bunker are generally a better choice as they are better shielded from an EMP due to their distance from the surface and the other earth covering them.
Some Guidelines On Metals For Faraday Cages
The minimum thickness of metal that can be used to construct a Faraday cage will depend on the type and size of the cage. Generally, the thicker the metal, the more protection it will provide.
For most Faraday cages, a sheet of aluminum or copper with a thickness of at least 0.0625 inches (1.6 mm) is recommended.
Copper is the best option for a Faraday cage because it is an excellent conductor and very durable. It is also relatively easy to find and relatively inexpensive.
Aluminum is also a great choice for a Faraday cage because it is an excellent conductor, lightweight, relatively easy to find, and inexpensive.
Steel is a good choice for a Faraday cage because it is durable and can withstand extreme temperatures and pressures. It is also relatively easy to find and relatively inexpensive.
You can also buy metal fabrics or Faraday fabrics online that can shield or cover gaps in your current Faraday cage.
For the Faraday cage to work as intended, it needs to be grounded. Grounding is done by running a copper wire from the cage to a copper rod driven into the ground, providing a path for the electric current to flow through and protect your electronics from the EMP.
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Check online for details of using a large galvanized steel
garbage can lined with cardboard connected with aluminum
tape.We store our cordless chain saws withe bars removed
and the chargers in the steel can.
Radio’s and solar generator are in a solid steel gun safe.
Will it work? I hope so but none of us know for sure
One way to check effectiveness is to put a cell phone in it turned on and seal the cage then try calling the number. If you can hear the phone ring it’s not sealed or grounded or some other problem. I use the metal can lined with cardboard to keep the items from touching the can directly and it works just fine.
Not even true
Not picking a fight.. but for those that might be new to this concept.. could you please elaborate as to why BBB’s comment is incorrect?
before cell phones it was a portable radio >>> allllll the way back to an early 60s AM transistor radio >>> an extreme NOOOOOO1111
EMPs are not the same as phone microwaves. If the phone microwave is blocked, the other frequencies of EMP may be strong enough too get through.
I use a ground coffee bag to block signals. It may not work on 5G. I don’t know.
The five stated things that a faraday cage needs are accurate, the problem is a current day refrigerator doesn’t do well at meeting them. The air tight seal at the door is actually a defect at stopping EMP. It is rubber or plastic, both insulators in regard to electrical continuity. The door hinges ride on nylon bushings, another insulator. The whole door may be isolated and not bonded to the main body. A 1950s model might have been a starting point but todays stuff has more plastic then metal in its construction. I would consider a metal trash can with a wire permanently attached between the body and the lid with the whole thing grounded to earth. Then a layer of insulation inside and each unit in its own protected envelope. And yes being below grade would help. (disclaimer, these are just my views from reading other material I have done no testing).
How about steel drums?
The rubber gasket that makes a good seal for cold, moisture and air will do nothing to stop EMP waves. You would need to seal it with metalic tape to some other metallic part of the freezer to make that part EMP proof. Also air tight has no bearing on EMP waves. They travel through space just about as well as through air. There is also no ” force” associated with EMP waves. It can’t move anything on its own.
saving your electronic devices is predicated on there still being electricity available. perhaps saving some battery operated devices is feasible but for how long and has any thought been given to recharging said devices.
If you have a regular gas generator you are limited to what gas you have stored, not to mention the noise created by running it. If you have a solar generator have you protected it from said EMP?
Just something to think about.
Get a solar generator for charging your small electronics like a flashlight, radio, etc. Some solar panels even have batteries built into them to store the charge.
Protect your solar panels and solar generator from the EMP by going to
disaster preparer dot com
and getting broadband ferrites to attach to the cables next to the device to absorb the power surges and TRAPs to insert into the plugs on the solar generator to also absorb the power surges. I put the direct product links in, but my comment went into moderation.
The grid will go down for months possible years that’s everything what good is anything electric and that is everything even if you save your things from being fried in a cage its nothing but a paper weight when towers an power station are off line
That is not exactly correct with the Advent of mesh networks and meshtastic Radio Networks that can be set up there’s lots of uses for cell phones besides paperweights after a grid down event including when cell towers go down. Zello will still work, any tactical software you have on there will still work and of course any Bluetooth or wireless mesh system will still work.
Is a grounding wire required if the aluminum can contents are covered with aluminum foil and the top placed on can and can sealed all the way around with Faraday tape? Sits flat on concrete?
Far from me to be ridiculing this article but preparing with food and independence from the grid is far more important than preparing for a EMP attack. Even if you save your electronics with who will you be communicating. Radio, Tv and internet stations including microwave towers will be out.
Ham radio operators that protected theirs… any point to point comms, like the 50 mile radius radios my brother-in-law and I have, etc…. Cell phones when comms are restored at some future point, etc….
The EMP event will most likely not be worldwide. Having a receiver (shortwave) would allow one to get news from a non-affected area.
Your typical hometown AM/FM stations would almost be guaranteed to be affected.
Consider getting walkie-talkie devices, but remember that the stated range of ‘up to’ is wildly optimistic.
Remember that a grounding wire of any appreciable length could also be described as an antenna, reaching out for an EMP instead of protecting your devices.
And yes, food and drinks trump electronics.
I agree that prepping with food is important but think that it is only part of the team. We need to be prepared in more than one way and for more than one thing if possible. Food and water must be priorities but defense and security have to be right with them. Several small two way radios could help with the security which would help with the defense. If you protect >2 of the small FRS radios then you can communicate to your associates. If you protect a couple solar charge controllers and Inverters and if it is true that and EMP will not hurt solar panels then you have a source of power to keep the batteries on those FRS radios charged. If we were hit with either a SME or an EMP there may be a great number of lead acid batteries available for someone to scrounging.
GOOD GOD – they’ll allow just about any hockey who to be published here – it’s already been said >> a refrigerator is total crap as a Faraday cage – the bottom of the frig is wide open for the mechanicals – it’s nothing but plastic insert held in a questionable sheetmetal box ….
Note to the newbies >>> don’t learn your prepping watching TV & movies – Indiana Johns wouldn’t have survived a nuke blast even with a 1950s frig …..
An EMP should have no effect against the efficiency of smoke signals or drum signals. Ok, that was tongue in cheek, but protective measures for chainsaws is crucial for staying warm 3 winters down the line. Two years worth of cordwood is minimal. Having a good ax or three and sharpening files along with 10 to20 gallons of premixed gas buried 6 feet under in an aluminum garbage can could save the day. Make sure you have an armed lookout when running your saw, and gather your supplies early rather than later.
The problem I can see is knowing when to store them in the faraday cage,because you don,t know when an EMP will hit.
No idea as to the effectiveness, but a company called “Mission Darkness” makes faraday bags of varying sizes. Do they block EMP? Who knows. They do block EMF, RFID, cellular, WiFi, walkie-talkie signals, etc.
They’re fully lined and sealable with a rolling closure.
Good to store redundant powered gear, maybe? Only one real test if something is EMP proof, lol.
Redundancy. The saying one is none and three is one comes to mind. If you have >1 of electronics, protect one, if you have three, protect two of them but in different ways/places/levels. Check Dr Arthur T Bradley, he has done a great deal of research on EMPs and CMEs. I read EMP Attacks and Solar Storms when he first published it and read much of his other research. Look at his and other sources such as this article and go from there. In the end we have to make the choices that protect us. I feel confident in what Bradley puts out but at the same time only time will tell. Without a “live” test does anyone really know how things will work? I think Bradley is as close to a “live” test as one can get, but… That is why I almost asked Frenchy (above comment) if he is including a two man logging saw in his preps.
I do have a two man/one man and one woman saw.
Dr. Bradley, PhD (his website), I think it probably the most authoritive site Iv found. For those who dont know of him he is first an Electrical Engineer but his PhD is in .. noise shielding if I recall (EMP is a type of noise).. and he works for NASA.
Personally, Iv written a few things on this website related to EMP and Faraday cages.. and Iv had a few chats with the Dr. Bradley about EMP, its effects… and Faraday cages/boxes and protecting from the effects of this destructive “noise”.
My interest has always been for people to know how to be prepared, and protect their electronics (for one, communications is a vital KEY to recovery from such a catastrophic event [as is fuel], protecting electronics is VITAL). My background… decades of electronics, Extra Class ham radio, commercial/industrial electrician.. and a few other “assets”. Anyway, I would absolutely, HIGHLY recommend some time watching his experiments. Would answer MANY questions I see on these pages.
Oh! I not only keep all my important documents, pics, papers, manuals… even a large selection of movies.. all on a 2 terabyte drive in my faraday cages… along with an extra laptop, printer, camera, portable automotive ham radio with auto antenna tuner, TNC unit (so I can transmit digital images such as maps or documents for one) solar panels and associated pieces to charge my equipment.. I use 12vdc laptop and printer; printer uses REFILLABLE ink cartridges.. in larger faraday cages. I also keep a good store of printing paper, with extra ink, in ammo cans and desiccant). What good is the digital files if you cant pull them up?
I also keep several UV5R hand held radios and affiliated components in the faraday box. I have found the FRS type radios typically have a VERY short range, have permanent antennas that are not easily altered, are limited to 1/2 watt.. UV5R’s are CHEAP and cover at least SOME of the FRS range. You can adjust the power and with full voltage batteries will run 5+ watts. Antennas can be EASILY changed from rubber ducky to a easily built .. and hung in a tree.. antenna that will multiply the range if desired.
While storing food and supplies is great, you need to be prepared to defend those supplies or you will not have them long!
OK. Im always longer than I intend!
Honestly folks, dont trust a microwave for a Faraday cage. Or a refrigerator. Even a gun/other safe isnt a good idea. Iv explained Faraday cages many times before on this site.. Perhaps it sounds better coming from a PhD. Works for me!
Been working on home fuels and chemistry .. again.. lately. Maybe see ya there!
Just expect it, when you least expect it.
Yep. Kinda like 9/11…
if a frig is better wouldn’t a metal safe be even better
You would have to seal the door with metalized HVAC tape.
Fire resistant safes have a gasket that is supposed to expand and seal during a fire which creates a gap for the EMP to enter.
Non fire resistant safes don’t have consistent enough metal to metal contact at the door to protect it either.
Gun safe?
Is this discussion not quite well resolved by the fact that electricity chooses the path of least resistance, and if you capture that, even with a grounded metal screen with not overly large holes in it, then you are pretty safe from having your electronics fried? The complexity of this discussion starts to sound like voodoo to me, rather than physics, but perhaps I am missing something. What is this idea about a metal needing to be thin enough not to absorb too much energy? I would think that electric potential completely intercepted by metal, of whatever thickness, would be prevented from reaching devices and entering into their circuitry to overload anything. I thought I understood electricity pretty well, until now. For example, why would an electromagnetic pulse want to pass between a metal door and a metal frame, pushing through a rubber or silicone insulator, in order to specifically target metal circuit-filled items that might happen to be sitting inside that metal box? EMPs must have a really evil intent. Is there experimental data to show this electrical preference to follow circuits rather than direct shorts?
For any home made Faraday cage, TEST IT.
I used a metal trash can with metal lid and borrowed a cell phone.
I put the phone inside the cardboard lined van, replaced the lid and had someone call the phone.
The phone RANG!.
Reason? The kid did not totally seal against the metal can.
When I wrapped a layer of aluminum foil tape around the lid, the phone still rang!
Why? Because the handles were not taped!
Taped the handles and no more ringing.
My two cents.
I have done considerable research on EMPs and Faraday cages, because R&D and technology fascinates me. I’m not a prepper, but I am a good boy scout / prepping enthusiast.
1. AM radios are a better test than a cell phone, due to their operating frequency.
2. The need to be grounded is up in the air. No one knows for sure, so it’s best to do so if possible.
3. I have some communication devices and other sensitive electronics, with batteries separate for ease of maintenance, in a banker box wrapped and sealed in aluminum foil. That cardboard box is in a little bit larger cardboard box to protect the foil wrap.
I guess I’ll find out if it works or not if and when D-day strikes in my lifetime!
I agree with what you said, especially the good boy scout part! I musta been a sponge at that time in my life, as I try to live my life that way 58 years later, I think I was 8 when I went into scouts. What about a conex for storage and some items wrapped as you stated in #3, stored inside the conex. Next on the to do list is a steel drum with plywood shelves and dividers to store items isolated from the drum and further isolated from the conex. These would probably be items I already have 2 or 3 of, part of my thought of a different place/way/level. Have your duplicate items in different places, packaged in different ways and protected at different levels. Be prepared!
Read a paper about 10yrs ago about the testing the gubmint did on emp using cars. They left them running and it knocked only SOME of them out. When they tried to restart the ones that died almost all restarted. The few that didn’t only needed minor fixes to get running. The real problem will be getting gas to run them. Wonder what it would do to an EV? No I don’t recall who did the paper I read but there were lots of references to the gubmint testing. It was 10yrs ago and I have trouble recalling what I had for dinner last night. Was any of it true? No idea. But I do know if you take a metal trash can and cover the inside with cardboard including the lid and seal all the cracks with metal tape, put a phone in it and call the phone AFTER sealing the can really good the phone won’t ring. THAT I TRIED MYSELF MR Milfno Hunter. BTW calling someone a liar in a roundabout way is the same as doing it to their face where I come from. Not cool.
They also specifically dialed back the intensity of the EMP so the cars wouldn’t lose all their value after the test, so they could sell them. This is one instance where the government was frugal with our tax dollars.
So the test was interesting, but unlikely to be replicated in the real world, except for a more distant EMP where the intensity has dropped.
Love your comment about not remembering what you had for dinner. An old friend of mine used to tell me that memory is the second thing to go. Myself, I have a severe case of CRS.
You are correct. Multiple reports for many varied test efforts on everyday objects found and still find everyday items exposed to EMP are fine with no effect as primary and turning off the most common secondary effect.
I’ll chip this in since I don’t see anywhere it fits as a “reply” >>>>
when you are considering the Faraday cage options – remember that both an EMP & CME events will be ongoing – possible some of the subsequent follow-ups will be more severe than the initial – and it could last days/weeks/months and even years >>> your electronic device usage out of the cage needs to be “use & scoot” – that dictates a renewable Faraday cage – the foil wrapped and other one-use devices just won’t cut it …..
I do have a two man/one man and one woman saw.
OMG! Grounding the Faraday Cage? This idea has been dismissed long ago.
There are several errors in this article. For actual authoritative information concerning Faraday Cages and EMP, watch YouTube videos by “EMPDoctor,” Dr. Arthur Bradley of NASA.
EMP is real but the hype of what it will do is extreme. Yes it will destroy the grid because of the long transmission lines that absorb lots of EMP energy. Everything else has a high probability of no effect. In the 1980s AT&T put an electronic switch (1970 era delicate chips) in semitrailers and sent it to a military HEMP (High Energy Magnetic Pulse) facility for exposure testing just like tanks, planes, small ships. The switch was processing communications signals while while it was hit multiple time over multiple days with EMP bursts. It worked perfectly fine with no damage through all the testing. Microchips and electronics are far more robust today. Protecting some items is a conservative plan but main focus should be on a robust non-grid dependent electric generation system that can also save you on month bill expenditures right now before SHTF. If an EMP is ever used the grid will be down five to ten years for 90% of the country assuming some form of overarching government survives.
microwave = NO
refrigerator = NO
a faraday cage must be 100% sealed and the contents must be 100% insulated from touching any part of the “cage”
do some real in-depth research before depending on any type of urban myth information or wasting a lot of money on overkill.
I found that snack tins work very well as an inexpensive faraday cage for smaller items.
Radiation moves in a straight line. It doesn’t go around cracks in a door.
I have a question??? Will Mylar bags save crackers from growing stale??
Microwave ovens do not even come close to being a Faraday cage. You’d think they should be being that they are supposed to confine the 1000+ watts generated by the magnetron.
As a demonstration to other people, I have placed my cell phone inside their microwave oven then told them to call my phone. They are surprised when it rings and I tell them the cell tower is less than 5 watts. NEVER stand in front of your MW oven.