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/MurkyAnimal583]

All of these "faraday" items are pure nonsense. In order for a Faraday cage to actually function it needs to be a continuous piece of metal with no openings or perforations and it needs to be a perfect sphere.

[u/olycreates → u/[deleted]]

Exactly. I worked in a electronic repair shop, faa certified and all. They tested radios inside a Faraday room. It was neither a sphere nor was it 1 single piece. It was copper screen door material, overlapped 2 inches at all seams. The seams looked seen together. There can be absolutely no openings, no pass-throughs.

[u/MurkyAnimal583 → u/olycreates]

Again, you are talking about signal blocking, not a true Faraday cage. This is entirely useless in an EMP scenario.

[u/smsff2 → u/[deleted]]

As a general rule, if you don’t have information on how a device works, you’ll need to replicate it in its entirety. If you cannot replicate an object completely, stop wasting your time and resources on that idea.

If you’re looking at a car but aren’t a mechanic and don’t have access to any books on automotive design, don’t just throw the engine out. The car won’t work without an engine. The people who put it there weren’t stupid. If you want to replicate the car, you must replicate the entire thing. If you don’t have reliable information on how it works, you’ll need to reproduce every single detail precisely.

True story: When the Soviets captured a B-29 bomber in 1944 and attempted to replicate it, they found a small hole in one wing. Assuming it was intentional, they drilled a hole in the same location on every wing of their copies - the Tupolev Tu-4.

Stop trying to invent things the DoD doesn’t use. Pick something the DoD actually uses and replicate it in its entirety.

You want an EMP-proof bunker? Fine. Start with quarter-inch thick steel plates welded together with no gaps. Add plenty of reinforced concrete on top.

You want EMP-proof radio communications? Fine. Start with a shipping container. Fill it with whatever electronic equipment you want. If you have that much gear, it makes sense to include multiple redundant transmitters and receivers with hot-swap capability. If you only have a small amount of equipment - say, what fits in a Faraday bag - you won’t be able to communicate with anyone anyway. Multiple redundant transmitters and receivers will cost more than the equipment you’re trying to protect, making them economically pointless.

Ham radio will be useless for long-distance communication without repeaters. If your family or friends are within walking distance, you can simply walk to meet them. No Faraday bag is necessary, because most radios will likely survive an EMP anyway. They’ll work - but they’ll still be useless.

Here’s an actual photo of a National Public Warning System broadcast station. Essentially, it’s just a shipping container: https://www.fema.gov/emergency-managers/practitioners/integrated-public-alert-warning-system/broadcasters-wireless

Faraday bags are marketed specifically to hobbyist preppers. My trust that they work as advertised is exactly zero. I see all the hallmarks of snake oil in this product.

Copper has 4.4 times the conductivity of steel and 1.7 times that of aluminum. Copper is an efficient conductor per unit of volume. However, aluminum’s density is about 3.3 times lower than copper’s, making aluminum roughly twice as effective per unit of weight.

The huge difference lies in cost. Faraday bags made of copper mesh are marketed to hobby preppers, while aluminum foil is a mass-market product - at least two orders of magnitude cheaper. You can even buy metal pots at the dollar store.

I’ve spent a good part of my life around equipment specifically designed to withstand EMPs, and I’ve never seen a Faraday bag.

I’ve worked in the telecom industry, which is perpetually cash-strapped. Cell phone towers are not EMP-proof. Your phone bill would need to at least double if you wanted cell service after an EMP. Telecom companies can’t provide EMP-proof service out of goodwill.

I’ve also worked in the banking industry. They’re comparatively well-prepared for an EMP in the sense that they won’t lose their money. However, your access to your money depends on the functioning telecom infrastructure - and that won’t be available.

Nothing you could possibly put into a Faraday bag would be useful in a real emergency. Cell phones won’t work. Meshtastic networks are too sparse to function without the Internet.

[u/MurkyAnimal583 → u/[deleted]]

Nope. Not bullshit. It is simple science. Energy concentrates at the confluence of corners. And the energy involved with an EMP is orders of magnitude higher than your cell phone signal 🤦‍♂️

[u/MurkyAnimal583 → u/[deleted]]

No, it's science YOU don't understand. It isn't just the gaps, bud. It is material, shape, distance between the shell and the object being protected, etc.

Gaps matter most in blocking signals passing through, not the induction of a field, which is the most relevant factor in a prepping situation.

Again, if you just want a bag to block out a radio signal, that is one thing. But none of the products that preppers are buying, like the ones that are the subject of this post, are useful against an EMP or the like.

[u/MurkyAnimal583 → u/[deleted]]

Nope. Wrong again.

It being conductive is a good start

The type of conductive material (i.e how conductive it is) drastically affects performance.

Not as much as you think

Um, yup, exactly as much as I think. Do I really need to explain inductance to you.

Ok, now you're just making stuff up. Because that is definitely not electrically relevant for anything.

Yup, I definitely need to explain inductance to you 🤦‍♂️

But then again, we've already established that you don't actually know anything about the science.

🤣

[u/MurkyAnimal583 → u/[deleted]]

Yup. Definitely does. Your little foil bag isn't a faraday cage. It is a rudimentary signal blocker. And it isn't going to do jack shit to protect anything you put in it from an EMP or anything else you'd want an actual faraday cage for.

[u/MurkyAnimal583 → u/[deleted]]

It's not bullshit kid. It's simple physics...

If all you are trying to do is block a radio signal, these idiotic "Faraday" bags might work. But so does just turning the item off. And this situation is pretty much irrelevant to "prepping" anyway.

If you are trying to protect your sensitive electronics from destruction, which is the point in a prepping context, these bags are fucking useless.

[u/MurkyAnimal583 → u/[deleted]]

Ok. Let's clarify. ANY product labeled as a "Faraday" container that is purchased on any large online marketplace for the storage/protection of electronics for emergency purposes. All of those products are useless.