How to make an EMP or faraday cage.

[savageagle]

HOW TO BUILD A FARADAY CAGE
What is a Faraday Cage? In a nutshell, a Faraday Cage is s container that protects sensitive
electronics from an Electromagnetic pulse generated from a nuclear detonation high in the
atmosphere, or from a massive solar flare. A massive EMP will render anything that uses
chips, resistors etc. (basically all electronics) useless ... forever. (They will be "fried".) This
article will instruct you on How To Build A Faraday Cage (cheaply) that will protect your
valuable electronics and batteries.
A simplistic explanation of the construction of a Faraday Cage is: any metal box, or cage (it
doesn't have to be solid) that completely surrounds the contents with a "metal
shield"(including the top and the bottom) metal. The EMP will pass over and around the
Faraday Cage rather than through it, thus protecting any electronic (and batteries) that have
been placed inside the cage. Your microwave oven is actually a Faraday Cage. If you look
closely at the glass door, you'll see a mesh embedded within the glass. That same mesh is
also between the inner and outer skin. If there was no metal mesh, the microwaves would
burn your face when you peeked into the oven to see if your burrito was done.
You can spend a kings ransom for a custom built Faraday Cage, but it's absolutely not
necessary.

Below are 2 examples of EMP cages, or faraday cages. They are easy and inexpensive to
make and protecting your electronics will put you in the minority when and if the power
grid comes back to life.
The one made with the screen is closest to what I built. Mine is much larger and I started
with 1" x 1" spaced x 1/8" thick steel mesh then used the screen to cover everything. The
inside has 1" x 1" pine boards creating an inner framework then covered by thin plyboard to
offset the inner walls, floor and cieling by 1 inch.
I used 6 feet of standard guage battery cable (black) with the insulation cut back off the
copper inner wire 2 full inches. I seperated the inner copper wire so it was kinda flat then
layed it over the 1/8" thick steel mesh (cage) and soldered it in place. The other end will be
attached by a cable clamp to a six foot ground rod that will be buried 5' 6" inches deep.
It sits on a platform made of 2" x 4" boards. It is also covered with a heavy duty cardboard
box just to keep dust and debris from getting to the contents.
Your list of things you want to protect will give you your first idea of how big you need to
make your cage. If you have anything solar, your panels, charge controllers and anything
electronic will need to be protected. Cell phones would be the last thing you'd want to
protect as cell towers will be impossible to protect from an EMP, either from the sun or a
aerial nuclear blast.

The most important thing is to cover sides, top and bottom and to ground this box to the
earth. It can be a solid box with a lid but the lid, when closed must be in full and constant
contact (all sides) with the bottom section. Any areas that do not have a good contact will
allow the pulse to leak in and could destroy the contents. The grounding is critical as the
pulse being absorbed by the cage needs to be bled off to ground (earth) and the larger the
ground wire used the better the transfer of this pulse current is to ground.
There are plenty of examples online which give you many options of size and materials.
Just pay close attention to the details and adhere to these details when making your own
cage. See any "warnings" or "notes"? READ THOSE CAREFULLY, they could be very
important to the effectiveness of your cage and maybe keep you from injuring yourself.

 

[Gazrok]

Something else to consider...

1. Accessibility. Can you get to these items inside easily? Are they used often?

2. Constant Protection. Are these items always kept and put back here?

This is why my plan is building a Faraday Cabinet. Something I can keep the items in all the time, so passive protection. Something I won't have to think about.

 

[savageagle]

After these cages are secured they will stay there for who knows how long. I don't plan on having it somewhere where it can be found and all my goodies get taken away. As I said before when they come to take your weapons they will not leave any PC's or communications devices. They will at least destroy everything so as to make sure you'll never be able to use it or fix it.
This stuff will be accessed at a later date after TSHF and even then will have to be guarded from those who think they need it more than I do. It's all too valuable to take a chance and have it taken by anyone. I've got extras of most things so if some does get taken I'll be assured that at the right time i'll still have access to those which they thought they took.

 

[Gazrok]

An interesting point on seizing communications equipment. Rather than having dupes, sealing them, then burying them though, no real ideas on hiding such stuff. I'm banking on them doing a rather cursory search, finding a couple firearms I WANT them to find, fully cooperating and then being satisfied that I still have what I need, while they cross me off their list.

Simply put, it's a man hours and logistics issue. They likely won't waste time and resources on folks cooperating and turning over their stuff.

 

[jontte]

now I know what to do when finished my garden dutys.
it has to be that very fine mesh??

 

[jimLE]

im wondering if said items can be put into pvc pipe that's large enough for the items.then sealed closed with pvc cement and caps..then wrapped in wire mesh or window screen.then buried 1 to 3 feet into the ground..im thinking.that'll not only hide your stuff.but protect it from a emp at the same time..only thing is.burying it someplace where there's lots of metals in the ground already

 

[Gazrok]

So far, I've seen it said that 2' of dirt is a good EMP insulator. However, remember that a LOT of EMP effects are speculative, or based on rather dated experiments. My advice = Wrap the PVC pipe in a couple of layers of aluminum foil, and then some thing to keep the foil on, and it wouldn't matter how shallow it was buried (and a lot cheaper than that mesh)....it would be protected.

 

[newbieprep]

I am going to display my ignorance here, but I have been looking at making a faraday cage. I am still trying to figure out the uses so I can figure out the size. So here are my questions. If I load a Kindle with survival guides and keep it in the cage, will I still be able to retrieve these manuals? If an EMP happens I assume cell phones will be useless even if it is in a faraday cage, so walkie talkies would be better? What else do you keep in them? Hope I am not hijacking this thread.

 

[jimLE]

yes to cell phones being useless if a emp took out the power grid.seeing how there'd be no cell phone towers and all..and as for the kindle and walkie talkies will be very useful.and so will hand held CB'S.im sure you thought of this.you'll also need a way to recharge what you'll have that runs on batteries..and as for showing ignorance.no you havent.sometimes the best way to learn is to ask..i heard a saying that goes like this.the only ignorant questons is the ones that dont get asked.

 

[newbieprep]

Thank you Jim. I have a million questions, so you can watch the forums for more!

 

[jimLE]

oh yeah..if it'll help out any on what a EMP will do..do a search for the EMP of 1859..it took out telegraph lines..telegraph poles caught on fire.etc etc.plus,some telegraph keys were operational for a while without the batteries.

your welcome

 

[Gazrok]

I am going to display my ignorance here, but I have been looking at making a faraday cage. I am still trying to figure out the uses so I can figure out the size. So here are my questions. If I load a Kindle with survival guides and keep it in the cage, will I still be able to retrieve these manuals? If an EMP happens I assume cell phones will be useless even if it is in a faraday cage, so walkie talkies would be better? What else do you keep in them? Hope I am not hijacking this thread.

Yes, you'd still be able to retrieve the manuals. Get the solar-powered Kindle. As for cell phones, depends on the locality of the EMP mostly, but yeah, probably not going to happen. Walkie talkies are fine if you are talking about close range contact, but otherwise, you'll want something with more range. You can even get handheld HAMMs for under $100. While you need a license...you won't need one if the SHTF now will ya?

As for what else (in addition to your list):

Flashlights
Rechargeable Batteries
Solar Battery Charger
Spare Electronics for Car
Spare Car Battery
Any Electronic Medical Equipment
Spare Electronics for Generator
Electric Power Tools

My plan is doing this as a metal cabinet where I'll normally keep these things anyhow, so they will be always, passively protected. Just trying to find a good deal on one big enough (and that closes tight enough) to fit the bill. Just above where the cabinet will be, I also store my spare metal sheeting in the garage rafters, so that will provide a good shield against any airburst EMP as well.

I have an existing smaller metal cabinet with some of this in it, but the goal is to get a bigger and better one.

 

[newbieprep]

I heard that an EMP won't affect older vehicles since they don't have computers. Are you saying it could still affect the batteries? Thank you for the list of items and I will google the past EMPs.

 

[jimLE]

yeah newbie..if i remember right..that'll be from 1987 on back.on acount they dont have the computer boards and all in them..but yet.im wondering if the wireing and all can be effected in some way or not..and if i remember right,yes to the batteries...

 

[Gazrok]

To be honest, the last tests they did, most cars weren't even majorly affected. In essence, an all metal car is a leaky Faraday cage. I'd have to look up the exact percentages, but the Diesels were certainly untouched, and only a small fraction were unable to drive, whereas only a slightly larger percent had just minor electrical issues, but still started and could drive. Granted, the last scaled tests were years ago (2002) and weren't even on a lot of cars. I wouldn't bet much on cars that are more fiberglass or have sophisticated e-brains. Those could be a problem.

Ah, found it. Here's an excerpt to help disprove the myth a bit:

We tested a sample of 37 cars in an EMP simulation laboratory, with automobile vintages ranging from 1986 through 2002. Automobiles of these vintages include extensive electronics and represent a significant fraction of automobiles on the road today. The testing was conducted by exposing running and nonrunning automobiles to sequentially increasing EMP field intensities. If anomalous response (either temporary or permanent) was observed, the testing of that particular automobile was stopped. If no anomalous response was observed, the testing was continued up to the field intensity limits of the simulation capability (approximately 50 kV/m).

Automobiles were subjected to EMP environments under both engine turned off and engine turned on conditions. No effects were subsequently observed in those automobiles that were not turned on during EMP exposure. The most serious effect observed on running automobiles was that the motors in three cars stopped at field strengths of approximately 30 kV/m or above. In an actual EMP exposure, these vehicles would glide to a stop and require the driver to restart them. Electronics in the dashboard of one automobile were damaged and required repair. Other effects were relatively minor. Twenty-five automobiles exhibited malfunctions that could be considered only a nuisance (e.g., blinking dashboard lights) and did not require driver intervention to correct. Eight of the 37 cars tested did not exhibit any anomalous response.

Based on these test results, we expect few automobile effects at EMP field levels below 25 kV/m. Approximately 10 percent or more of the automobiles exposed to higher field levels may experience serious EMP effects, including engine stall, that require driver intervention to correct. We further expect that at least two out of three automobiles on the road will manifest some nuisance response at these higher field levels. The serious malfunctions could trigger car crashes on U.S. highways; the nuisance malfunctions could exacerbate this condition. The ultimate result of automobile EMP exposure could be triggered crashes that damage many more vehicles than are damaged by the EMP, the consequent loss of life, and multiple injuries.

 

[TheShadowKnows]

Nice article Gaz. Who did these tests? Just out of curiosity; I kinda want to know who has contained, scalable EMP tech without getting too deep into the subject.

 

[newbieprep]

Great article Gaz. Thank you. Our BOV is an 81 diesel, though we plan to bug in, so hopefully we will still have wheels until the diesel runs out! A lot to think about, but a faraday cage seems like a simple step that wouldn't cost much.

 

[Gazrok]

The EMP Commission did the tests. Here's a link to all of it:
http://www.empcommission.org/docs/A2473-EMP_Commission-7MB.pdf

I got the excerpt from another article, you can read it here:
http://jalopnik.com/5937778/how-to-prepare-your-car-to-handle-an-emp-and-why-you-shouldnt-bother

 

[GeoffreyLevens]

Hi all, new to these forums. Kind of newbie to electronics and unclear about one thing re: Faraday cages.

If I want to harden my solar electric against EMP, isn't it true that not only will I need to have cage surrounding the compnents themselves i.e. panels (which will somewhat reduce the amount of light they receive), charge controller, inverter...but I also need to have them essentially in the same cage so that all wires/cables connecting them are caged as well. Also any appliances (refrig etc) that are connected must also, along w/ the cords, be essentially in the same cage? If not, won't the exposed connecting links just carry the pulse to that which I am trying to shield from it?

Thank you!

 

[jontte]

ok ladys and gents, this is something I wanna know too, so pls you who understand about things of this nature tell us??