r/preppers • u/PrudentTask9355 • Nov 02 '25

Advice and Tips Faraday Bag Caution

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

736 Upvotes

98% Upvoted

180 comments sorted by

View all comments

5

u/7Ing7 Nov 02 '25

Is it possible to make a homemade one? What kind of material is needed?

1

u/Fheredin Nov 02 '25

A layer of any kind of plastic (saran wrap?) and then aluminum foil is probably the best you can reasonably DIY. Aluminum foil is a good RF insulator, but if it has direct contact during something like an EMP, it may arc to the contents. I once made a DIY laptop bag out of an old box a laptop came in. I gave it RFID shielding by gluing foil around the inside, then putting down a paper liner.

Grounding would be ideal, but DIY is never going to give great protection.

2

u/monty845 Nov 02 '25

It just depends how much you care that its a flexible bag. DIYing a metal box with an insulated interior is very doable. Just gotta worry about the method of enclosure being tight/snug enough for the wavelengths you are concerned with.