making a mobile van faraday cage

Discussion in 'Physics' started by ambesilica, Dec 5, 2008.

  1. ambesilica

    Thread Starter New Member

    Dec 4, 2008
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    A real life situation exists where I'm attempting to turn the back of a van into a faraday/rf sheilded cage to transport 2 electromagnetic sensitive beings too properties where there is no microwave tower coverage in the hope they can live fuller longer lives (than are currently expected) in a supportive communal setting. They are presently confined to small parcels of land with a mobile faraday van their only salvation of traveling. Both have extreme reactions. I have personally witnessed my friend shrivelling skull like whilst driving past towers. The other, a Buddhist nun, has intense anaphylactic seizures with loss of breathing within range of towers/phones.
    Absolute certainty of the van's faraday sheild working is essential.

    If it is possible to make a completely sealed faraday cage from the back of a van:

    1: Does the vehicle need to be grounded whilst in transit?
    2: If so is a chain dragging from the chassis adequate?
    3: If a chain isn't adequate are there alternatives?
    4: Can a simple multimeter be used to check for any electric charges inside the cage indicating a breach?
    5: What would happen if a current was purposefully run through the body of the car (would it help reflect microwaves or be detrimental)?
    6: What material would 'soak up' any stray microwaves which might enter inside?

    I'm on a learning curve, simple explanations/links/diagrams to any of the above Q's would be greatly appreciated and shared with whomever may need it in the future..

    have posted this on:
    http://www.advancedphysics.org
    http://www.physicsforums.com
    http://forum.allaboutcircuits.com
     
  2. blazedaces

    Active Member

    Jul 24, 2008
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    I can't really help you, but I don't want you to think that my question is an attack or anything:

    Do you mean that these people are in danger of being hit by lightning from these towers, or are you implying they are being damaged by the EMF created by them?

    The cage wouldn't protect them from EMF, technically, but, to be quite honest, if you could explain it in such a way that it makes sense to them they would certainly make them feel much more secure. It would create a placebo effect, which can be extremely effective.

    Good luck, and sorry I couldn't help further. Though, I would assume that any cage made of a highly conductive material would work just fine (Aren't cars already then Faraday shield/cages? Someone who has more confidence they know what they're talking about let me know)...

    -blazed
     
  3. triggernum5

    Active Member

    May 4, 2008
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    A Faraday cage is about protection from charge/current, although a cage would partially block much longer waves.. You need a total metal enclosure, grounding would help..
     
  4. blazedaces

    Active Member

    Jul 24, 2008
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    How do you ground a moving vehicle?

    -blazed
     
  5. studiot

    AAC Fanatic!

    Nov 9, 2007
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    If you coated the vehicle in radar reflective paint, you wouldn't need to ground it.
     
  6. leftyretro

    Active Member

    Nov 25, 2008
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    Radar reflective paint :rolleyes: Why paint it at all, the underlining metal should reflective radar just fine I would think? Now if you meant radar absorbing paint, then that is something you can try and call your local military supplier and order up a quart or two. :cool:
     
  7. studiot

    AAC Fanatic!

    Nov 9, 2007
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    No I definitely meant reflective.

    The occupant don't want to be invisible, just have the EM directed elsewhere.
     
  8. triggernum5

    Active Member

    May 4, 2008
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    Metal does that on its own accord, grounding is important if you're trying to isolate a spark, probably not so much for controlled EM radiation..
     
  9. ambesilica

    Thread Starter New Member

    Dec 4, 2008
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    thanks everyone

    The main question/issue is whether I need to drag a chain whilst driving. I imagine this may create some form of grounding..

    I will back next Thursday night as right now I'm heading out to where my EM sensitive friend lives in a 'black spot' no mobile phone coverage. The location is good but lives isolated all alone and unable to go very far down the road - thus the need for the van to be able to transport them to somewhere a community can grow. I deliver food, clean washing and news of the world..

    cheers
    ambesilica
     
  10. triggernum5

    Active Member

    May 4, 2008
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    How are you going to put whatever you try to the test?
     
  11. ambesilica

    Thread Starter New Member

    Dec 4, 2008
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    hi triggernum5,
    I previously tested it with a mobile phone (trying to pick up a signal). It was not consistent - sometimes no signal and sometimes a very weak signal (1 bar out of 5. Whereas outside the van it was 5/5 so I was obviously acheiving something). Have seen someone with an old shipping container which has been sealed with aluminium flywire and foil. Absolutely no signal get's in.

    My friend who is sensitive and needs to travel felt very ill when I transported him in the back of the half finished van (have some holes in the floor and gaps where the metal doesn't connect all the way round). He felt that the microwaves were in fact intensified by the fact that they were getting in and then contained.

    It sounds like you recommend grounding of some type. The question remains 'how do you ground a moving vehicle?'

    Reflective paint is way out of my financial realm however found this in regards to mw ovens:
    http://howthingswork.virginia.edu/page1.php?QNum=1527

    Thought it may be possible to run a charge through the van's body which also may reflect microwaves away - any ideas?

    On a last note, heard about some absorption material made from carbon which soaks up any stray mw that may enter into a space - extremely expensive to buy could this stuff be made at home
     
  12. triggernum5

    Active Member

    May 4, 2008
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    Given the intensity you're dealing with regarding MW towers a distance away I don't know how much grounding would help.. Your chain idea is as good an idea as any I could come up with, but I really don't know how much it would accomplish.. What are your seams/corners like? Metal screen reenforcing the shield at points such as these might help.. Also you'll want to read up a bit on 'wave-guides' if you haven't already, to ensure that no metal objects are acting like an unwanted WG that does leak EM signal in and bounces it around..
    Its really easy to sheild 99% of unwanted EM, but the remaining bit will require some decent engineering to get rid of..
     
  13. ambesilica

    Thread Starter New Member

    Dec 4, 2008
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    Apologize for the delayed response triggernum5,

    Net access is quite a rare opportunity..

    Did some waveguide research which lead me on a winding merry path through many different areas..

    Are you able to name the 1% frequencies? (I presume they're high up in the spectrum)
     
  14. BillO

    Well-Known Member

    Nov 24, 2008
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    Mu-metal is a alloy of nickle and iron, and sometimes small quantities of copper and molybdenum. It has an extremely high magnetic permeability and is used for just this sort of shielding. I have used this before to shield experimental apparatus and it is quite effective. Not sure of the cost as the university usually had enough around for my needs.

    Try www.mumetal.com. They are a big supplier of mu-metal products and shields and could give you an idea on how much it would cost to shield the interior of a van.

    A regular steel van is not going to shield much at all, grounded or not.
     
  15. triggernum5

    Active Member

    May 4, 2008
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    I don't know the frequency specifics, or just how much it would even apply in the range the towers pump.. Leakage will happen across the frequency domain though..
    Billo does have a very valid point.. He probably has a much better understanding of this than I do.. I also thought about mu-metals, and specialized shields, but I just jumped to the conclusion that your need is too big to make that feasible.. I could be dead wrong on that.. I really don't know much about this application at all.. Its alot easier to understand how electronics will respond to EMFs like this than human beings..
     
  16. ambesilica

    Thread Starter New Member

    Dec 4, 2008
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    You have both been fantastic on this tricky subject and the rational support is appreciated

    Mumetals, tho at present time is out of my financial realm, is noteworthy and I have come to a greater understanding of the working structure of metals..

    For the present time I'll consider some options and tinker away, if the end product is successful I'll leave a note on this thread of the results.

    All the best for the New Year - blissings ambesilica
     
  17. duffy

    Active Member

    Dec 29, 2008
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    How about using a faraday tent inside the van?
    http://www.hollandshielding.com/faraday/shieldedtents.php

    If it's too awkward to erect, you could cut it apart (or obtain conductive cloth) and upholster the interior with it, using conductive epoxy at the seams.

    If all this stuff is too expensive, you may want to consider just giving the inside of the van a shot of copper spray paint. It won't do much to stop RFI, but I suspect it will stop the psychosomatic interference.
     
  18. studiot

    AAC Fanatic!

    Nov 9, 2007
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    It may just be that the cheapest (and most pleasant) solution is a Mickey Finn.

    Perhaps get your patient to drink that large bottle of Scotch you will receive for your transportation efforts, before your start.

    Or simply wait till the witching hour and transport her asleep.
     
  19. triggernum5

    Active Member

    May 4, 2008
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    Is it just harmless pain, or a very important warning to consider though? If its not psychosomatic that might be pretty bad..
     
  20. maitreya

    New Member

    Jan 10, 2009
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    Hi Ambesilica, I am also a new member, and found this site by searching the very thing you are trying to do. For different reasons, I also want to make my van a Faraday cage. Have you got any info from the other areas you posted to?
    Have you tried testing with the "chain ground"? An EMF meter could be useful in detecting leaks.
    Another question I have for everybody is; if I ground the chassis of the vehicle to the earth, will it affect my onboard electrical system? (stray current corrosion/drain on batteries)
    What about the windows of the vehicle? Are they also holes for emf to enter? could you shield them with expanded metal like in a microwave window?
    I am increasingly sensitive to EMF, fortunately not to the degree of your friends, but I get headaches and it is hard to breathe when emf is strong. I'd like to chat with you. e-mail me at maitreya.beast@gmail.com
    Best wishes, Maitreya;)
     
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