Faraday Can (Better Than A Faraday Cage)

March 21, 2012 – 7:10 pm

After watching a few episodes of Doomsday Preppers, and building up my paranoia suitably, I decided to revisit my disaster preparedness plans. I had thought about my hard drive backups and other electronics often. I am more concerned about solar flares than nuclear EMP, but what works for one works for the other too. In the age of telegraphs there was a massive solar EMP that hit the lines and caused fires around the nation when sparks jumped from the wires. If that same EMP hit today, it would shut down most of the power grid and 90% of everything you own that plugs into the wall even if it is not plugged in at the time.

Final Faraday Can With Plastic Liner

I realized that I wanted some more protection for critical gear. I have a lifetime of software and documents that I do not want to lose either. I also have a nice solar powered radio which would work find after an earthquake but would be dead after an EMP.

What is the solution? No, not a Faraday Cage. That was what I thought at first. It seemed simple, protect electronics=Faraday Cage. Then I looked at the pricing for copper mesh. It is very expensive. That is when I realized I did not need a cage at all. The only reason people use mesh is to cover the walls of rooms with no gaps. If you want to protect electronics then you can simply surround them with metal that is grounded. The solution was obvious. I needed a metal can!

Some quick price checks showed I could get a metal trash can at Home Depot for $23 which is cheaper than a couple of square feet of any mesh.

I needed a liner to protect the things inside the can in case an EMP hit and the can was suddenly a high voltage skin. I already had a plastic trash can which was only about $25 when I bought it some time ago.

This was simple enough. I connected an old air-conditioner cord to the can by mounting the ground wire to the can along with a copper wire lug. I cut most of the power prongs off leaving only the ground prong. I left enough of the flat spades to keep the plug from spinning and sealed the hot wire ends so there was no chance of any current making it to the can.


I then connected the lug to the lid with a heavy guage wire as extra protection. Now I can plug this into any outlet or connect a clamp to any grounded water pipe or ground electrode easily.


That is all there was to making a Faraday Can. I can now put my backup hard drives, emergency radio, night vision, and an old laptop in the can. I will ground it to make sure it is protected and double check with a continunity meter.



I put in the old laptop because I have an old laptop I am not using and if my main computer is killed by EMP, it is likely everyone’s computer will also be dead and it could be months before more are available so I want a protected computer and an old one is better than none.


When any visitor who may be at my house and who does not know what a Faraday Can is sees it, they will think it is a regular electric garbage can.












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