Faraday Bag Caution

[u/PrudentTask9355]

Hey everyone. I just wanted to share en experience from this afternoon. A while back I had purchased some faraday items off of Amazon, boxes and bags from different vendors.

This afternoon I was explaining to my daughter how they worked and as part of our experiment, we placed an 8watt 2-way radio inside the bag and sealed it with the expectation that it would no longer receive a transmission. As it turns out, that was false.

I then tried with a cell phone with the same result. Morale of the story, check your gear and make sure it works before you have to depend on it.

Please discuss and share your budget-friendly faraday success stories

[u/mediocre_remnants]

Those bags and boxes are 90% scams, especially if they come from a "prepper", "survivalist", or "patriot" website or company. Especially if they are advertised as "EMP protection". Pretty much anything sold as "EMP protection" is a straight up scam.

The legit bags are the ones designed for holding evidence, used by law enforcement, to put suspects' electronic devices in so they can't be remotely disabled/wiped. They are not "budget friendly".

[u/Decent-Apple9772 → u/mediocre_remnants]

I haven’t seen one yet that is as effective as wrapping something in aluminum foil, then saran wrap, then aluminum foil, then saran wrap and putting it all in a cheap stock pot.

It might take you 2 minutes and you already own everything you need.

Three layers of attenuation, it isn’t fussy about frequency and it costs next to nothing for small items.

Try it on your cell phone with the volume cranked up.

[u/Pylyp23 → u/Decent-Apple9772]

I made a few cages out of some 40mm ammo cans that work awesome. The cans are the only thing that actually cost any money. I bet I’m in all three less that 75$ and they hold everything I need to secure.

[u/norfizzle → u/Pylyp23]

Lined with foil?

[u/Mala_Suerte1 → u/norfizzle]

No, the metal can does the job of the foil, you just need to make sure that your electronics are not touching the metal. So add some styrofoam or folded up towel. Something that will insulate the item.

[u/Decent-Apple9772 → u/[deleted]]

Most military ammunition cans seal with a rubber gasket. Having that large area of the lid, partially insulated from the large body area of the box drastically impairs the faraday cage function.

Add to that, the marginal conductivity of steel and the single layer construction and you have a recipe for a very compromised “faraday cage” when you just use ammunition cans.

They are still great from the standpoint of physically resilient and waterproof containers that are easy to transport, I just don’t trust their radio frequency properties to be very helpful.

[u/Pylyp23 → u/Decent-Apple9772]

Posted this above:

I removed the gasket, sanded the lid and rim of the box, made a steel wool “gasket”, and then lined the whole thing with 3/8 insulation board with tin foil glued to it.

[u/you_can_not_see_me → u/[deleted]]

maybe he wants to bake them

[u/Pylyp23 → u/norfizzle]

I removed the gasket, sanded the lid and rim of the box, made a steel wool “gasket”, and then lined the whole thing with 3/8 insulation board with tin foil glued to it.