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Unprotected electronics will be fried and useless in the event of an nuclear/emp attack.

A Faraday cage can protect electronic devices.

Copper mesh is what is used by governmental entities (apparently, FEMA headquarters is wrapped in the stuff) in constructing, essentially, Faraday cages.

Here's a comprehensive source for copper mesh.

http://www.twpinc.com/twp/jsp/product.jsp?type=3
 

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Mucho mucho gracias!!! :thumb: Isn't there a minimum size mesh? 1/4 inch IIRC?

What's folks opinions about deep well pumps? I'm not talking about the peripherals on the surface (have spares put up in ammo cans), I mean the pump itself. Figure 200 feet down and inside a metal pipe is probably going to have you covered? Thoughts on this?

Fixing to work on a deep well hand pump and make some changes to the pump house to hopefully help with the EMP issue as well.
 

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If RF/EMP shielding is your aim, and a faraday cage you intend to build, eliminate the windows you must. :)

Essentially, any large gap in your cage will render it much less effective.
unless someone knows of a source of conductive glass that can be used. the emp protected federal buildings have windows also.....
 

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Guss Chiggins
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farday cage

most every body has a farday cage already.. its your microwave.. copper may work but any wetal will as well as long as the equipment is insulated by non conductive materials. I went to a class were the nuke specialist said he recomends metal garbage cans with rubber bottoms and metal tape to seal the lid ounced closed.
 

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Copper mesh is what is used by governmental entities
I wonder why that is, any conducting metal would do. It just has to be finer than the wavelength its stopping, which is why a metal enclosure should work.
An external static electrical field will cause the electrical charges within the conducting material to redistribute themselves so as to cancel the field's effects in the cage's interior. This effect is used, for example, to protect electronic equipment from lightning strikes and other electrostatic discharges, which is also why it must be grounded below and away from you.

What if instead of using a ground you use it to power a motor to generate electricity? It would only work with an external electrical field. Even then, in an EMP it would be like trying to capture lightning.

Also may i remind you that led lining your bunker or whatever will have little effect on electricle fields. Its not very conductive and will not redestribute its charges.
 

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I wonder why that is, any conducting metal would do. It just has to be finer than the wavelength its stopping, which is why a metal enclosure should work.
An external static electrical field will cause the electrical charges within the conducting material to redistribute themselves so as to cancel the field's effects in the cage's interior. This effect is used, for example, to protect electronic equipment from lightning strikes and other electrostatic discharges, which is also why it must be grounded below and away from you.

What if instead of using a ground you use it to power a motor to generate electricity? It would only work with an external electrical field. Even then, in an EMP it would be like trying to capture lightning.

Also may i remind you that led lining your bunker or whatever will have little effect on electricle fields. Its not very conductive and will not redestribute its charges.
You have some good points here, "It just has to be finer than the wavelength its stopping"

Higer Frequency means shorter wavelengths, the real question is how small does the mesh need to be on the faraday cage? Difficult to say, this is determined by the design of the EMF generating device, Nuclear or otherwise.

The downside here is that, even if you have the "perfect" faraday cage, A nuclear event may be able to induce current in the cage, without using EMP.

An example would be: induced electron flow from other sub-atomic particles, not the actual EMP.
 
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Sorry About Your Feelings
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Thank you!!
I'll bet this is where the Mythbusters bought their copper mesh.

I wonder what the minimum fineness is required to defend against a large EMP attack?
 

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Thank you!!
I'll bet this is where the Mythbusters bought their copper mesh.

I wonder what the minimum fineness is required to defend against a large EMP attack?
Fineness,(hole size), needs to be smaller than the wavelength the EMP gives off, (or secondary EMP given off by the Earth's magnetic field etc.) I dont recall if the PDF on one of these threads gives the frequency.

If you find the frequency, you can use it to find the wavelength. The formula is:

Wavelength = rate of travel(300,000,000 m/s) divided by the frequency.
 

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Mesh size, more

I came across this forum as part of my search for construction ideas on a Faraday cage.

Let me share what I've found, between the conflicting information out there.

http://www.twpinc.com is a fantastic location for sourcing mesh.
The stainless steel mesh they sell is suitable for application on windows. Order a swatch and see for yourself.

The 16 mesh copper .11 wire diameter is just fine for a Faraday cage. It's equal to higher grade mesh up to 1 Mhz. Even then, you can spend 4x the money for a tiny margin of improvement. They sell it up to 72' in width, so you could conceivably do a room with it.

It seems the frequencies you are trying to protect against are longwave in the range of 3 to 30 KHz. Between reading about what NASA says (twpinc.com has a pdf) and information about the 1989 Candadian blackout and various articles relating to the 1962 Starfish testing and Russian #184, #187, #195 tests that's what I've gleaned.

So buy the lower density mesh without worry. Runs about $3.50 a SQ foot, which isn't terrible. You can build a pretty good size chest or line something fairly well for not too much coin.

-Axehead
 

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Gone Galt
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What about old microwaves? Garage sale finds, or even scrap-yarded ones that don't work. Just set one in you garage and run a ground wire to the ground on the plug. Pop oven the door and stuff in the electronic goods.

?
 

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I have spent quite a bit of time talking about Faraday cages with a physicist, he says that the simplest way is to use a file cabinet. Insulated the items you place in the cabinet so that they have no contact with the metal of the cabinet. The small gaps around the drawers should not be a problem. . He says that the gaps around the drawers in a normal file cabinet should present no problems.

He also says that a broken microwave makes a good faraday cage. Just cut the cord off.

There is lot of discussion about what will and won’t survive. I plan for the worst and hope for the best. Anything I will really want to depend on I will protect.
 

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I worked with cages when I was in the USAF and NASA.copper window screen is what they are with metal grounding fingers around the doors.
a garbage can( metal) would work fine or a big window screen envelope. to test it tune a radio to a strong station and put it in your container,if you can still hear the radio station you are doing sometthing wrong.
 

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Ok I'm going to try the garbage can so do you put rubber on the bottom seal up the lid with metal tape and then run a ground wire from the can to what?
 

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you would run the ground cable to ground. it can be the 3rd plug of a household plug, a metal spike driven into the ground, your water lines if they are still metal pipe (and are properly grounded themselves). I would suggest the metal spike in the ground it is probably the safest way to ground it out in an emp type of situation.
 
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