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Katmandu
12th October 2012, 06:24 PM
The main point below is to use a few layers of nested Faraday cages.

This article reads easier at the original webpage:
http://thesurvivalmom.com/2012/10/09/skill-of-the-month-make-a-faraday-cage/



Skill of the Month: Make a Faraday cage

When it comes to worst case scenarios, it’s hard to beat the Electromagnetic Pulse (EMP).

I’m not ashamed to say that reading One Second After by William Forstchen scared the living daylights out of me. For weeks, I didn’t want to travel more than 15 or 20 miles from home. The novel details life in a small North Carolina town following an EMP, an electromagnetic pulse. An EMP can be caused by the detonation of a large bomb, nuclear or otherwise, in the atmosphere, miles above land. Its pulse wave can easily cover a continent and destroy electronic components in computers, engines, power plants, and solar panels alike. An event like this has never happened on a large scale, and there are differing opinions as to the exact consequences, but one thing is certain: In a matter of moments, life as we know it would be gone forever. Our closest star, the sun, could also do extensive damage in the form of a Coronal Mass Ejection (CME). The results would be similar.

One of the latest hit TV shows, Revolution on NBC, portrays life 15 years following some type of EMP/CME event, and it isn’t a pretty picture. Life without modern technology would be deadly for tens of millions of people. Again from Survival Mom:

Some might describe a post-EMP world as going back to the nineteenth century, but I think in some ways it would be far worse. We no longer have the tools, skills, knowledge, and, in some cases, raw materials to make the most basic tools for survival. How many blacksmiths do you know? Do you happen to own a pair of oxen and a wagon for transportation? You might know how to sew, but can you create cloth from raw cotton or sheep’s wool? The moment of an EMP burst freezes time. The food, medications, supplies, and tools in our homes may be the only ones we have for a long time. If you have 9 bottles of Advil, that’s all you may ever have.

There are so many unknowns when it comes to EMP/CME, but one way to prepare is to build one or more containers to shield important items from the effects of 50,000 volts of power. These containers are called Faraday cages and they’re pretty simple to make.

My friend Rob Hanus of The Preparedness Podcast has spent a good deal of time researching the facts and myths of EMP/CME, and here are his simple instructions for making your own Faraday cage:

The hardest part about protecting your equipment is simply doing it. A few rolls of heavy duty aluminum foil, some cardboard boxes and a galvanized steel trash can are enough to create your own Faraday cage and protect your electronics from EMP.

The simplest and cheapest way to build your own Faraday container is to use heavy duty aluminum foil. By completely wrapping an item in several layers of foil, you can protect that item from damaging effects of EMP. Keep in mind that every side of the item needs to have a minimum of three layers, so by the time you’re done wrapping it in the foil, some sides may have more than three layers. This is fine, so long as you have no less than three layers of HD aluminum foil between any part of the item and the open air.

By itself, these three or four layers of foil are probably enough to protect your electronic gear, but when dealing with an EOTWAWKI scenario, there are no replacements, nor second chances, so it pays to do it right the first time. Simply adding more than four layers of foil to the device is probably overkill and may not add anymore protection than the initial three or four layers. However, you can increase the the effectiveness of your Faraday protection by layering, or nesting them.

For example, place your foil wrapped device into a shoe box or other cardboard box that is wrapped in foil, then place that box inside a galvanized steel trash can with a tight-fitting lid. With your devices protected by three layers like this, they’re likely to survive even an enhanced EMP attack with a stronger electromagnetic pulse.

To get started on your own Faraday cage/container, you’ll need these supplies:

Heavy duty aluminum foil. You’re going to be using a lot of this, so be on the lookout for coupons!
Either plastic wrap (Saran or something similar) or plastic bags for each electronic item you want to shield.
Pieces of cloth that will be used to wrap items.
Cardboard boxes of assorted sizes
Small, essential items that contain an electronic component, such as a clock radio, weather radio, walkie-talkies, ebook/Kindle, mp3 player, etc. Make sure these aren’t things you’ll be wanting or needing in the near future. If you don’t already have duplicates, make a list of what you want stored in your Faraday container and then look for them at garage and estate sales.

The procedure is very simple. First, wrap an item in cloth. This will add a layer that will isolated the item from the foil and will also help to keep any sharp edges or corners of the item from puncturing the aluminum foil. Next, wrap the object with plastic wrap or place in a plastic bag and then wrap with at least 3 layers of foil. Use your hands to gently mold the foil each time, making sure there are no holes or rips in the foil. Every bit of the item’s surface should be covered with at least 3 layers of foil.

Place your wrapped items in the cardboard box and then wrap the entire box with two layers of foil. Layering for EMP/CME is just as important as layering for winter weather! Be sure that no foil used to wrap the outside of the box touches any of the foil within the box. When your box is wrapped and finished, store it off the ground.

If you want to store large items or have numerous items to store, completely line a galvanized steel trash with cardboard. Make sure there are no gaps. The foil wrapped items cannot touch the metal of the trash can. Make sure the lid of the can fits tightly, and you’re good to go.

zap
12th October 2012, 06:38 PM
I have replied to these type threads before, trying to figure out if my house was protected.... since it is all metal from the studs to the roof, doors. (ya everything except the window.) So I guess it really isn't, I don't know if I mentioned before that we wrapped it in astro-foil.

http://www.astrofoilint.com/stage/residential.html (http://www.astrofoilint.com/stage/residential.html)

Aluminum foil reflects 97% of radiant heat and only emits 3% making it an excellent material to reduce radiant heat transfer and meet your residential insulation needs. ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html)reflective insulations and R+HEATSHIELD radiant barriers are made with 99% pure aluminum foil. Using these residential insulation products in the applications below will provide extra energy savings:
http://www.astrofoilint.com/stage/images/ie_webhouse.jpg



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Put ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html) or R+HEATSHIELD as a radiant barrier in your attic to prevent heat build up during summer months and reduce heat loss during winter. Your air conditioner and furnace will thank you!


http://www.astrofoilint.com/stage/images/2.gif
Either wrap your house with R+HEATSHIELD or install ASTRO-TAB (http://www.astrofoilint.com/stage/products.html) in your sidewalls to enhance the performance of mass insulation by reducing drafts, providing a thermal break and creating a more thorough building envelope.


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Use ASTRO-TAB (http://www.astrofoilint.com/stage/products.html) or ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html) to insulate below your radiant heat floor and you will reduce hot spots, prevent downward heat loss, and decrease boiler loads.


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Our ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html) Garage Door Insulation Kit will keep your garage temperature more comfortable throughout the year. Don't forget that you can also install it in the walls and on the ceiling.


http://www.astrofoilint.com/stage/images/5.gif
Whether you wrap your ducts with ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html) or line them with Astro-Safe (http://www.astrofoilint.com/stage/products.html), you will minimize energy consumption by keeping the air flowing through the registers not escaping into unwanted areas.


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Line your crawl space with ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html) to insulate the floor and eliminate ground moisture from transferring to your living space.



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Insulate your water heater with ASTRO-FOIL (http://www.astrofoilint.com/stage/products.html) to save energy by minimizing water temperature fluctuation, reducing cycle time.



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Install ASTRO/BARRIER under your floating wood floor to gain cushioning and a moisture barrier with one easy-to-install product.



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We've got the stuff! TUFF-STUFF under radiant heated slabs will greatly reduce downward heat loss and prevent moisture transfer. Installers jump up and down over our STUFF. Can't do that with foam board!

osoab
12th October 2012, 06:42 PM
Anyone tried these bags.

Just an example.

http://www.amazon.com/EMP-Cover-Bags-Kit-Electronics/dp/B0081V8YOE

Dogman
12th October 2012, 06:45 PM
If everything is bonded together electrically, and if you have several grounding points around the house that are true earth grounds. You are Huge steps in the right direction. The only weak points would be your windows/doors (if not metal) where emp energy could get into the house. Even then what would get in would be much less than if you had a normal wood/masonry house.

Plus you have your mountains/hills that surround you that add great bucketfuls of protection for your house.

I would guess you have better protection than the top 90% or better than most people.

IMHO!

steyr_m
12th October 2012, 07:04 PM
The easiest & cheapest Faraday Cage I've came across is taking the electronic device you want to protect and wrap with aluminum foil [I don't think it's necessary; but it was recommended where I read it] then wrap it with saran wrap, then a final layer of Alu foil. Finally, ground it. I use the 3rd prong of my outlet by running a wire to a plug with only the ground and a clip on the other end. Don't do that if you don't know what you're doing.

You can also take that item and set it on a PC and if there is electrical contact [metal to metal] it will do the same thing since all PC's have the 3rd prong attached to the chassis.

Katmandu
12th October 2012, 07:30 PM
Zap, the Faraday cage can have holes in it. For example, a metal mesh can be used, as long as the mesh is smaller than the wavelength of the radiation that it is trying to keep out.

For example, microwave ovens have the mesh in the window so that you can see inside, but keeps the microwave radiation inside. Microwaves work at a frequency of 2.45 GHz, which corresponds to a wavelength of about 120 mm, or about 4.5 inches. And the holes in the mesh are much smaller than 4.5 inches, so it serves as an effective shield to keep the microwaves inside the oven. I don't know this for sure but based on the above description of a microwave oven, for really effective blocking, the mesh hole size may need to be SEVERAL times smaller than the wavelength that it is trying to block. Keep that in mind for the discussion below. [An old unplugged microwave oven IS a faraday cage. Metal on all sides except for one side that is metal mesh].

Getting back to and EMP pulse, I looked for some graphs that show the EMP frequency spectrum:

http://i50.tinypic.com/20gfw9z.png

The EMP spectrum is most intense up to about 1 MHz (wavelength = 300 meters), and then decreases in intensity down through 10 MHz (30 meter wavelength) and still weaker at 100 MHz (3 meter wavelength). There is still even some energy beyond 100 MHz, but it is much much weaker.

So you can see that if your house was completely metalized except for the windows (let's say the window are 1-2 meters tall) it would appear that you would get blockage of the lower EMP frequencies (1MHz, or 300 meter wavelength), and that you would nearly be at risk of the higher frequencies (10-100+ MHz, or 30 meter to 3 meters wavelength) leaking through.

But if we consider from the microwave example that the hole size may need to be SEVERAL times smaller than the wavelength, you can see that a metalized house with un-meshed windows could be quite leaky to an EMP pulse.

I think the conclusion here is that you would get some EMP protection from a metalized house with open windows, but I would not rely completely on that for protection of your valued electronics.

By the way, here is one poster who was thinking along the same lines as you about a Faraday house.
http://www.hipointfirearmsforums.com/forum/f302/emp-living-faraday-cage-263637/

Cheers,
Kat

Katmandu
12th October 2012, 07:35 PM
Anyone tried these bags.

Just an example.

http://www.amazon.com/EMP-Cover-Bags-Kit-Electronics/dp/B0081V8YOE

These should work just fine as one layer of a multi-nested faraday cage. Many electronic components are stored and/or shipped in these bags to protect from Electrostatic Discharge (ESD). They are an expensive version of putting your device in a ziploc bag or shoebox covered in alum foil.

freespirit
12th October 2012, 07:49 PM
what about one of these? some metal tape around the lid to seal it, something to ground it, and should be good to go, should it not?

3820

...they're pretty affordable, and have considerable space inside.

zap
12th October 2012, 07:53 PM
In the link the guy is saying that a emp would fry your well pump? How if it isn't connected to electricity, Or a old china diesel generator, no computer/ electric parts there, windings?.

Katmandu
12th October 2012, 07:54 PM
what about one of these? some metal tape around the lid to seal it, something to ground it, and should be good to go, should it not?

3820

...they're pretty affordable, and have considerable space inside.

They are mentioned in the article above. Make sure your electronics are not touching the inside of the can (e.g. line the can with cardboard).

Katmandu
12th October 2012, 08:04 PM
In the link the guy is saying that a emp would fry your well pump? How if it isn't connected to electricity, Or a old china diesel generator, no computer/ electric parts there, windings?.

If there are any electronic components associated with the well pump, they will likely fry; it would be good to have spares of any of the electronics or have a spare motor. Even if it is not plugged in, the AC cord will act as an antenna to EMP energy. Not sure if the induced currents would be enough to fry windings. If it doesn't have electronics and/or is mechanical only, then that would be a much better scenario.

Neuro
13th October 2012, 12:44 AM
Get yourself a wind up gramophone. There is no point in trying to live in the past with this one.