Letter Re: Advice on EMP Protection for Electronic Gun Vault Locks

I haven’t noticed this discussed on your blog, or any other for that matter. Is there anyway to protect a gun safe that uses the electronic key pad instead of the standard dial combination lock from electromagnetic pulse (EMP)? I wasn’t thinking along those lines when I purchased it several years ago. I enjoyed “Patriots” immensely and will be re-reading it soon. Thanks for the terrific blog. – Bruce H.

JWR Replies: I mentioned this about a year ago in SurvivalBlog, but it is worth repeating: A steel gun vault body itself makes a decent Faraday cage. (Although a mesh RF gasket at the door perimeter would make it even better.) All that you really need to add is a flat steel can (such as a peanut can or Danish butter cookie tin) to cover the keypad assembly. Taping the can on works fine, but it will look tacky. A hinge attached to a square or rectangular tin with epoxy (allowing the can to swing to the left or right) might look better. Ideally, the tin should be grounded to the vault body. (Again, this looks tacky, but there is no way around it if you want a fully effective Faraday enclosure.)

If EMP is a major concern where you live (i.e. if you live within 250 miles of a major nuclear target), and your vault has an electronic lock then you should use silica gel rather than a Golden Rod dehumidifier in your vault. This is because the power cord for a Golden Rod can act as an unintentional antenna that might “couple” EMP to your vault’s electronics. (One of the major “no-no’s” with Faraday cages is to have any conductor that can carry RF penetrate the cage/container body.)

And, needless to say, to have a vault lock that is absolutely safe from EMP, the next time that you move, you should sell your current vault as an included “bonus feature” with your house. Then replace that vault with one that has a traditional mechanical combination lock. (I prefer S&G Group II locks.) Oh, and speaking of moving, I prefer Zanotti Armor brand six piece gun vaults that can be disassembled for ease of transport.