does a steel building/shed constitute a Faraday cage?

[Duct Tape Man]

Have a friend who is into radio equipment, asked me to provide input into building a Faraday cage room for his gear because he is all worried about TEOTWAWKI, and wants his gear to be protected from an EMP pulse. Most of his gear is older-line 1950s and 1960s gear, not sure if EMP would even affect them, but he does have some recent high-dollar gear as well.

I understand the basics of a Faraday cage, having a cage or envelopment of conducting material around that which is to be protected, in order to dissipate an EMP blast without affecting the equipment inside. His radio shack is a small metal building already, not sure if that counts as a Faraday cage in and of itself.

Any input?

 

[laser3kw]

easy - just turn on a radio (with a built in antenna - like a home am/fm job) and see if gets reception.
No signal = Faraday cage.

 

[Speedy Petey]

Have a friend who is into radio equipment, asked me to provide input into building a Faraday cage room for his gear because he is all worried about TEOTWAWKI, and wants his gear to be protected from an EMP pulse.

Why does this mentality seem concentrated in the southeast quarter of the country?

 

[Duct Tape Man]

Why does this mentality seem concentrated in the southeast quarter of the country?

I don't know, but if the zombie apocalypse happens and the whole country is going to ****, but the South is doing just fine, perhaps we are doing it right!

 

[Alchymist]

Do the walls and roof have a metallic bond at every seam? Does it have a metal floor bonded to walls? Is the door equipped with metal fingerstock? Do windows have metal covers with fingerstock? Are the power lines shielded and filtered where they enter the building? No other openings of any size?

 

[theoldwizard1]

I have seen Farady cages up close. The use very fine mess copper screen and metallic seals on all joints.

A metal build is NOT a good Farady cage !

 

[DekeT]

I don't know, but if the zombie apocalypse happens and the whole country is going to ****, but the South is doing just fine, perhaps we are doing it right!

That's odd, I thought the zombie apocalypse was already prevalent in the southeast.

 

[APEowner]

If the gear is attached to an external antenna (so it's useable) then the cage isn't going to protect it at all. If the plan is to remove the antenna just before TEOTWAWKI and reattach it afterwards then he might as well just shut it off and unplug it which is all that's needed to protect it.

To answer your question; a well grounded, steel building with no windows (or windows with grounded wire mesh over them) is a fairly effective Faraday cage. It can be improved upon but it's a good start.

 

[Lotek]

That's odd, I thought the zombie apocalypse was already prevalent in the southeast.

You gotta stop watching Nascar.

 

[justsam]

As a retired RF engineer, I spent many hours in SCREEN ROOMS, which is what you are describing.

As the Wizard and Alchymist have pointed out, the metal building is a start, but far from a proper screen room. Everything, entering and exiting the room, must be electrically filtered, bonded, etc. A proper room is not cheap.

It sounds like your friend has equipped himself with vintage, tube type radio gear, assuming it is less prone to attack. He will need a large generator to power all this gear, which I assuming is vintage HAM radio gear.

 

[HAP]

An all steel building WILL have aeffect on some signals. Only the strongest radio sigs will make it in. Some cell signals will be affected. GPS signals/Sirius XM signal drops as soon as you get into building even with the door(s) open.

Hade to get a cell phone booster to get consistent performance with the doors closed.

R,
HAP

 

[Lightning rod]

I build faraday cages, small 20'x20 ' , rooms for electrical testing at the company I work for! Hence my alias

Most of the comments already stated are accurate

The metal room is a start and will filter some signals but there is a lot of detail involved to make it a true Faraday Cage. Lots of science and a bit of art

Faraday cages can be made from steel and copper and basically any metal but will have different performance curves


Alchymist got it the most correct. You must have built a few ?

 

[Duct Tape Man]

Okay, here's a follow-up question:

Is this project of my friend worth his effort, or is it a waste of time?

 

[kaffine]

If the gear is attached to an external antenna (so it's useable) then the cage isn't going to protect it at all. If the plan is to remove the antenna just before TEOTWAWKI and reattach it afterwards then he might as well just shut it off and unplug it which is all that's needed to protect it.

To answer your question; a well grounded, steel building with no windows (or windows with grounded wire mesh over them) is a fairly effective Faraday cage. It can be improved upon but it's a good start.

No it is not. EMP can damage equipment that is powered off. EMP is able to induce voltages even if all power to the equipment is removed.


They make a paint that contains a lot of copper that can be used. Trying to do an entire building would be very expensive. Depending on amount of equipment you might be able to get a 19" equipment rack that has been hardened. I have worked with a few however I never got to test the effectiveness. If I was going to try and protect a lot of equipment (more than a few racks worth) I would probably start with a metal shipping container. All wires, pipes or anything else the entered the box would go through bulkhead fittings. Cooling would be provided by a mini-split AC with the lines going through a bulk head fitting including the drain. Although it might be better to use geothermal HVAC this way all the AC equipment can be inside the faraday cage and be protected as well. Not sure what I would do for the door I have seen finger stock and also a metal compression gasket setup. Not sure how the compression gasket would do on larger doors. If really concerned all cables in and out should be disconnected and caps installed when not in use and use fiber optics whenever possible.

 

[wyliesdiesels]

Are large scale EMP generators still theoretical or are they physically possible? Now i know nukes create EMPs but what about a stand alone unit?

 

[Gerald O]

Okay, here's a follow-up question:

Is this project of my friend worth his effort, or is it a waste of time?

Seriously? You're asking if doomsday prepping is worth the effort? It's like religion. You're either a believer or you're not.

 

[Duct Tape Man]

I'm not a believer - and I told him it's probably not worth the effort. Just wanted some opinions from the "peanut gallery" so to speak.

To explain the type he is: one time I went by his house and he was putting aluminum foil on the windows (no, I'm not joking). He said he heard on the shortwave radio, one of his "programs", that told him there was a secret government program that used satellites to read the brain waves of people. He said he was putting the foil up to prevent his brain waves from leaving the house. Nope, still not joking.

 

[laser3kw]

.....that told him there was a secret government program that used satellites to read the brain waves of people

I know the type......
some are sitting mere feet away here at work.....

 

[Speedy Petey]

Okay, here's a follow-up question:

Is this project of my friend worth his effort, or is it a waste of time?

I'd venture to bet 75% of what this looney does in his life is a waste of time.

 

[nehog]

It is difficult to stop an EMP.

The first letter 'E' is for electro. That is a tension or electrical field much like a powerful radio wave. Easily stopped with a Faraday cage, shielding or even careful bypassing.

The second letter 'M' is for magnetic. Oops, much harder to stop! That shielding for the electro component is only marginally effective against magnetic fields. What happens is that the magnetic field induces a voltage in a circuit or device and that voltage then destroys the device. Think of it as a gigantic transformer!

The problem is that a steel building, even a Faraday shield made of copper wire, does little to block magnetic fields. What can stop them is something called Mu-metal (expensive, very hard to work with) or using components that are designed from the ground up to not be sensitive to magnetic pulses (military rated components, for example.)

One of the easiest ways to limit your exposure is to use old tube type equipment which is much, much less sensitive to EMP risks.

 

[Alchymist]

Wrap and seal your building with this:

http://custommagneticshielding.magn...sheet-and-foil/mumetal-stress-annealed-sheet?

To avoid this:

http://www.wnd.com/2014/09/a-giant-magnetic-explosion-on-the-sun/

 

[Rookie2]

I'm not a believer - and I told him it's probably not worth the effort. Just wanted some opinions from the "peanut gallery" so to speak.

To explain the type he is: one time I went by his house and he was putting aluminum foil on the windows (no, I'm not joking). He said he heard on the shortwave radio, one of his "programs", that told him there was a secret government program that used satellites to read the brain waves of people. He said he was putting the foil up to prevent his brain waves from leaving the house. Nope, still not joking.

You can't be serious ! I would walk away !

 

[megalo]

Are large scale EMP generators still theoretical or are they physically possible? Now i know nukes create EMPs but what about a stand alone unit?

http://www.boeing.com/Features/2012/10/bds_champ_10_22_12.html

 

[MBfreak]

Nehog is right on magnetic shielding, ie to stop an EMP from entering a metal clad volume. It is difficult

Have been involved in some designs and calculations in the vicinity of high current equipment to reduce the field ( Wb/m>2 or T) to levels that were not above the limits for a residential building.

We ended up with large coils of copper cables that were series circuits and tuned to resonance with series capacitors. It worked quite well. However we got the field down from 650microT to below 200microT.

An EMP from a nuclear blast is quite something different. And my take is that it will not happen, ever, and if I am wrong, the least worry would be destroyed electrical and electronic equipment.

Ola

 

[Rookie2]

Mutual assured destruction
If there is ever a EMP , we'll all go by way of the dinosaurs.

 

[BFBOB]

... so you're saying that in the event of an EMP the vises I've stored in a steel roofed and sided building may turn into magnets, but they'll still work?

 

[wyliesdiesels]

http://www.boeing.com/Features/2012/10/bds_champ_10_22_12.html

Thx for the link. Interesting info!

 

[Cruzingoose]

Any equipment using vacuum tubes is safe from EMPS with no special precautions. Everything else will be fried unless protected. The easiest and cheapest protection is to wrap the device in aluminum foil. Just put the device in a plastic or paper bag, and wrap until completely covered. Put into another bag or box, store it away and wait 'till it happens. IF you survive, you might get to use it, otherwise, someone else scavenging will get to use it. Wrap lithium, NiCads or NiMh batteries and solar panels also. You will want power to run the devices after the fact. There wont be any commercial power for at least a year as every transformer and substation will be also destroyed or severly damaged. A gasoline (points and condenser ignition) or better yet, diesel genset will survive if the output terminals are shorted together to the frame. No other precautions required. Fuel will be available as there will be lots of cars and trucks on the side of the road dead, and all are potential fuel sources.

 

[FLgirl]

I have a related question: I have read that since electro magnetic waves do not bend, they can't go around corners. So, in regards to protecting the electronics in a vehicle or Bobcat mini excavator, if you store them in a steel and galvalume building with no windows, and build a steel wall between the equipment/ vehicle and door, and put plate steel on the concrete floor under them, will it protect them? Does the floor and walls need be welded together? And grounded separately from the building? Lighting rods affect EMP at all?

 

[Alchymist]

They do bend - it's called waveguide. And magnetic fields move them. In theory a metal building would work. In actuality, there can be no holes, not even a pinhole. Access doors must be sealed with "fingerstock". There can be no discontinuities in the structure whatsoever. And steel is not the best choice for shielding.
https://www.techopedia.com/definition/13159/radio-frequency-shielding-rf-shielding

 

[Marctrees]

DuctTapeman - I'm not at all saying this applies in your Friend's case, it probably statistically does not, but it is possible.

I have dealt with it for years in my family, so I'm pretty familiar with it.

Basically, if his life is pretty normal otherwise, he's just eccentric.

Very well done list of Schizophrenia symptoms -

http://www.schizophrenia.com/earlysigns.htm Marc

 

[sberry]

Brain fart.

 

[Ole Slewfoot]

Okay, here's a follow-up question:

Is this project of my friend worth his effort, or is it a waste of time?

Depends if he gets nuked or not.


Lots of talk about door sealing....I think an airlock type arrangement may be more efficient.

While RF waves may or may not bend, they certainly bounce. Ive seen guys send a pulse at the moon and get it back a few seconds later.

 

[nsula_country]

That's odd, I thought the zombie apocalypse was already prevalent in the southeast.

I have been watching them survive zombies for years on AMC...

CT

 

[Lelandwelds]

I have been watching them survive zombies for years on AMC...

CT

That's in Georgia.

 

[Lelandwelds]

I'm not a believer - and I told him it's probably not worth the effort. Just wanted some opinions from the "peanut gallery" so to speak.

To explain the type he is: one time I went by his house and he was putting aluminum foil on the windows (no, I'm not joking). He said he heard on the shortwave radio, one of his "programs", that told him there was a secret government program that used satellites to read the brain waves of people. He said he was putting the foil up to prevent his brain waves from leaving the house. Nope, still not joking.

I had a high school friend drop by. I hadn't seen him or heard him discussed since the mid 1980s. I did not realize he had a drug problem until he came out of my bathroom with all my compact fluorescents in pieces. He had taken them apart and was EXTREMELY excited because the government had bugged his house and now they were bugging mine.

Thank God the wife was not home!

My metal roof kills cell reception. I have made sales calls in concrete structures which killed all cell and radio reception. I bet a cage in a cage in a cage would fail by a smaller margin. Don't all self respecting tin foil hatters insist on an underground concrete bunker?

Ever see " Enemy of the State"?

 

[shteii01]

I don't know, but if the zombie apocalypse happens and the whole country is going to ****, but the South is doing just fine, perhaps we are doing it right!

It is the other way around.

Up North zombies will freeze to death in the winter. So the rest of us have to survive the Spring-November period.

Down South your people will be fighting them all year around or until you run out of ammo. Considering that zombies will start drifting from the North as the weather gets colder, people down South will run out of ammo before they run out of zombies.

 

[shteii01]

As far as faraday cage. Don't forget the floor. It needs to be metal too.

One interesting option is metal paint. This way you can take even a regular building, spray metal paint and turn a room into a farday cage. Much easier to work and much lighter than metal sheets. Probably costlier. So it becomes convince vs cost.

 

[apollo11]

Why does this mentality seem concentrated in the southeast quarter of the country?

 

[PNWguy]

He said he heard on the shortwave radio, one of his "programs", that told him there was a secret government program that used satellites to read the brain waves of people

Well, I'm going to make a guess that he's not really a critical thinker or has a good grasp on science. You could tell him anything (true or false) and he'll believe it if he wants to. Does the Faraday cage even matter?