# 7 ml Mylar bags for radios?



## RNprepper (Apr 5, 2014)

Paul, I know we have discussed Mylar not being thick enough to protect electronics from EMP, and I fully understand the rationale for foil wrapping with insulation between layers. However, is there ANY weight of Mylar that would work? I am looking for an easier way to keep the stuff protected, but still be able to open the packages for battery recharging. Would this extra heavy, 7 ml Mylar still be too thin, even if layered with insulation inbetween layers? Just asking.

Extreme Duty, 7 mil thick, 5 gallon mylar bag for food storage.


----------



## 8301 (Nov 29, 2014)

double bag using mylar bags for extra protection.


----------



## RNprepper (Apr 5, 2014)

Any other input on using Mylar that is twice as thick as the regular food storage Mylar?


----------



## Kauboy (May 12, 2014)

They would be optimal for storing dehydrated water.
Just add water to re-hydrate, and you're good to go!


----------



## paraquack (Mar 1, 2013)

It's not the Mylar, it's the aluminum coating. Might be ok for static electricity but doubt for a nuke generated EMP. I followed the advice from 
Electromagnetic Pulse Protection - EMP - Futurescience.com
Here is the text I found. To read it in entirety search for aluminum foil on the article.

"For small portable electronics, though, completely covering the
electronic equipment in heavy-duty aluminum foil makes a good faraday cage around the
equipment. The foil covering needs to be complete, without any gaps. Wrap the device
in plastic or put it in an insulated box before wrapping the covered device in foil.
(Otherwise, the foil may simply conduct the EMP energy into the device more
effectively.) A single layer of foil may not be adequate. In order to enclose the
equipment in a nested faraday cage, place the foil-covered device in a plastic bag, such
as a freezer bag, and wrap that bag completely in aluminum foil. If you really want to
protect the equipment against a large EMP, add another layer of plastic and foil. The
layer of plastic needs to be the thickest plastic bags that you can easily find. (They don't
need to be terribly thick, but do try to find some heavy-duty bags.)
If you have done an absolutely perfect job with the first layer of aluminum foil, the
"nested faraday shield" is not needed. As a practical matter, though, the "nesting"
procedure helps greatly in protecting against both inadvertent gaps and possible later
accidental punctures through the aluminum foil that may severely compromise the
shield."

I've been putting my electronics in a small cardboard box and then wrap with aluminum foil with seams folded over 3 times and pressed down tightly, a layer of HD plastic sheet, and the same with 2 more layers of foil and plastic.


----------



## RNprepper (Apr 5, 2014)

I understand the foil. That is how I have my electronics currently stored. I am looking for something that would be easier to UNwrap and REwrap so the batteries can be recharged regularly. The idea of a box that is wrapped, insulated, and wrapped again is a good one. Several items could be stored together instead of wrapping them all individually.


----------



## Quietsurvivalist (Apr 26, 2015)

Put the radio in a box, then a Mylar bag.

Then put the whole thing in a galvanized garbage can, so its not sealed away for eternity


----------



## paraquack (Mar 1, 2013)

RNprepper said:


> I understand the foil. That is how I have my electronics currently stored. I am looking for something that would be easier to UNwrap and REwrap so the batteries can be recharged regularly. The idea of a box that is wrapped, insulated, and wrapped again is a good one. Several items could be stored together instead of wrapping them all individually.


The batteries don't have to be EMP protected if they are removable. I have the same problem but for other reasons and think I will go with the small garbage can "Faraday cage" or something like it, described later on in the article I linked. See below.

"A locking-lid galvanized metal trash can, though, can be a very effective electromagnetic shield. Although it can be very effective, it is less than perfect, so the interior of the body of the galvanized metal trash can should be lined with some material to electrically insulate items stored inside the container from the metal exterior. (Cardboard probably works better than any other inexpensive material for this. Liners such as plastic trash bags may be too thin for this because of the momentary high voltages that could be induced on the exterior of an imperfect faraday cage during an actual EMP.) Do not place any insulation at a point where it would interfere with the electrical connection between the metal lid and the metal body of the trash can. It is also important to wrap any very sensitive items placed inside the metal trash can with a layer of aluminum foil (preferably in the "nested faraday cage" manner described above).
It is important to remember that a galvanized trash can, by itself, is usually an imperfect shield. It may be good enough for many purposes (such as for storing items that you use frequently or for less sensitive items), but the extra layer of shielding provided by aluminum foil on equipment that is stored on the inside may be a critical factor in a severe EMP. On a galvanized trash can, the electrical connection between the body of the can and the lid is critical. For this reason, use only a new galvanized trash can for this purpose. Dents and distortions in the roundness of the lid and the upper part of the galvanized can severely deteriorate the high-frequency shielding effectiveness of the can. Also, the lid must be kept very firmly in place for a galvanized trash can to be an effective shield."

The electrical engineer who gave a talk on EMP also used a copper foil tape with conductive adhesive to seal the lid.


----------



## GTGallop (Nov 11, 2012)

Can you store radios in mylar? Yes.
Will mylar protect them? Yes.
From an EMP? Depends on how close.
Can mylar bags be enhanced to provide more protection? Yes, but it is more work than just about any other alternative.


----------



## PaulS (Mar 11, 2013)

Make three envelopes from paper or plastic that will fit inside each other and cover each with heavy duty aluminum foil. Seal each envelope and then put it inside the next and so on. A steel trash can, even if you could line it completely with an insulator will not protect your electronics from an HEMP. Steel is too poor a conductor and the pulse will penetrate the steel before the pulse can travel around it. Mylar bags do not have a thick enough aluminum layer to keep the E1 pulse out. You need at least heavy duty aluminum foil as your conductor or something with less electrical resistance. In order from the minimum protection to the best it goes like this:
minimum: Aluminum in three isolated layers
Gold in at least 5 mil thickness with at least three isolated layers
Copper in at least 4 mills with three isolated layers
Silver in at least 3 mils thick with three isolated layers
The thicker the conductor is and the better the electrical insulation is the fewer layers you need to use. A hole in your conductor or your insulation of just .1 mm will cause leakage to the next layer. (1/10 of a mm is about half the diameter of this period or the dot on this "i".


----------



## azrancher (Dec 14, 2014)

hmmm Ammo can, or ammo can with steel wool, or tinfoil wrap the radio and then the ammo can, or tinfoil wrap the radio, ammo can and then garbage can, with steel wool as the conductor on the lid, then buried 10' underground with a steel reinforced concrete roof, or corrugated steel ceiling, or just bend over and kiss your goodbye.

*Rancher *


----------



## PaulS (Mar 11, 2013)

The E1, E2 and E3 pulses from an HEMP will easily penetrate more than 40 feet into the ground. The ground itself becomes a conductive path due to ionization.You have to build a capacitive resistance between your device and the E1 pulse.
That is why layers of conductive material and insulation is so important. The more conductive the material the faster the pulse passes by. The less conductive the material the more pulse goes through because it takes too long to go around. Some of the pulse will always get through but after three layers of good insulation and good conductors the pulse is weak enough that it won't harm the sensitive electronics.

An HEMP produces no radiation that makes it to the surface, there is no blast wave, and the heat wave is used up in the atmosphere before it can be any danger. Only the electromagnetic effects make it through the atmosphere because it is the interaction with the atmosphere that causes them. The only thing that will effect people on the ground is the light in the sky (above the atmosphere) that might cause temporary "flash blindness".

Wrapping a radio in tin foil is a good way to be sure that it is destroyed fast. Wrapping that radio in an insulator and then in tin foil (and doing the same two more times is a great way to protect it. Having your radio in a safe deposit box in a bank vault will not protect it from an E1 pulse. Three zip-lock bags and a few feet of heavy duty aluminum foil is very good protection for your radio.

People are at no danger from the direct effects of an HEMP. What will kill people is the loss of emergency medical gear, lack of water, food and emergency transportation. These secondary effects will kill millions.


----------



## Prepadoodle (May 28, 2013)

"EMP is composed of both electrical and magnetic energy, and any conducting metal can shield against electrical effects. Iron and steel provide good protection against magnetic EMP energy. _Other kinds of shielding are unlikely to be effective and/or practical for field use_." (Emphasis mine. Source:Army FM 3-3-1 2, Appendix C)

This FM is "Nuclear Contamination Avoidance," so is mainly concerned with man-made EMPs. The full version (in .pdf format) is available HERE.


----------



## RuthKMB (7 mo ago)

Good day gentlemen, 

I hope I can offer you a much easier solution - from a lady's perspective (out of the kitchen). 

One Christmas I was given a nice tin full of cookies. It is a thick tin. After finishing the cookies, I laid out the tin with cardboard on the bottom and sides. I then put my cell phone in it and called ... nadda, zero, zilch ... which I understand means it is then "sealed" sufficiently. It seems the cookie tin serves as a Faraday Cage for smaller electronics.

I am keeping my hard drives stored in them and it is easy to access. My main back-up external is inside a home made foil bag, inside a cookie tin.

Still looking for a cookie tin big enough for my notebook, hahaha. 

As a point of interest, I believe EMP's can be produced by other means, OTHER than nuclear devices. I am not a pro on this, my knowledge is limited, however I suspect devices that mess around with the ionospheric electrons, such as HAARP systems, can cause EMP's. Possibly globally or large parts of the globe in one go, with not as much collateral damage to infrastructure as nuclear devices would cause - besides electronics. Roads, railways, buildings etc will remain in tact, but for the electronics. A solar flare will probably be blamed when - I personally believe - it will be a man-made expedition. A movie such as The Book of Eli (Denzel Washington) give a good portrayal of that.

Hope this helps.

Regards, 

Ruth


----------



## Back Pack Hack (Sep 15, 2016)

Using a radio or cell phone to 'test' the effectiveness of a Faraday cage is an exercise in futility. You are only making a test within a very narrow band of the electromagnetic spectrum. 

Other frequencies may penetrate the enclosure with ease. A simple way to demonstrate how this concept works is to look into your microwave when it's running. 

The clear holes in the door block the lower microwave frequencies, but allow the higher frequencies of light through.


----------



## justinsane (4 mo ago)

Back Pack Hack said:


> Using a radio or cell phone to 'test' the effectiveness of a Faraday cage is an exercise in futility. You are only making a test within a very narrow band of the electromagnetic spectrum.
> 
> Other frequencies may penetrate the enclosure with ease. A simple way to demonstrate how this concept works is to look into your microwave when it's running.
> 
> The clear holes in the door block the lower microwave frequencies, but allow the higher frequencies of light through.


While I certainly agree that test is extremely narrow in it's scope there's a glaring issue with your explanation of the demonstration, which is that at approximately 2450GHz the average microwave is nearly 6 times higher than the frequency of even UHF(420MHz) and 17 times higher than VHF(144MHz).
One other thing I don;t believe I saw in this entire thread was any mention of grounding, except kind of the guy that said the ground(earth) would become a conductor. I've never seen a Faraday cage for this purpose mentioned without being grounded, but if his statement is true then perhaps grounding is a bad thing???


----------



## Back Pack Hack (Sep 15, 2016)

justinsane said:


> While I certainly agree that test is extremely narrow in it's scope there's a glaring issue with your explanation of the demonstration, which is that at approximately 2450GHz the average microwave is nearly 6 times higher than the frequency of even UHF(420MHz) and 17 times higher than VHF(144MHz).


What does the frequencies of UHF and VHF have to do with the example? It was a comparison between microwaves and visible light.



justinsane said:


> One other thing I don;t believe I saw in this entire thread was any mention of grounding, except kind of the guy that said the ground(earth) would become a conductor. I've never seen a Faraday cage for this purpose mentioned without being grounded, but if his statement is true then perhaps grounding is a bad thing???


Are autos grounded when their only contact with the ground is rubber tires? Are airplanes grounded when they get struck by lighting when flying?


----------



## justinsane (4 mo ago)

Back Pack Hack said:


> What does the frequencies of UHF and VHF have to do with the example? It was a comparison between microwaves and visible light.
> Yes the comparison was between microwaves and light, but that's not relevant to radios and similar electronic equipment which was the actual topic at hand. That's why I referred to the frequencies of radios. I'm pretty sure no one is worried about the EMP affecting things in the visible light spectrum. If they should be please enlighten us(pun intended)
> 
> 
> Are autos grounded when their only contact with the ground is rubber tires? Are airplanes grounded when they get struck by lighting when flying?


Autos are grounded to themselves, as are airplanes, this is not really relevant to the EMP discussion as most theories have both failing immediately.
The question I was asking, or at least referring to, is whether the Faraday cages require earth grounding. And that question was complicated by the statement I'd never heard before, that EMP would penetrate the ground significantly, and the ground would act as a conductor. On this I have way more questions than answers, in large part because I'd never heard that postulated before.
My understanding of the Faraday cage is that the cage gives a path of least resistance around that which is encased in it. However, that path requires a place to go. Electrical energy travels from one place to another, if it has no other place to go then the "path of least resistance" is not a path at all. Again, more questions than answers.


----------



## Back Pack Hack (Sep 15, 2016)

justinsane said:


> Autos are grounded to themselves, as are airplanes,


Say what?



justinsane said:


> this is not really relevant to the EMP discussion as most theories have both failing immediately.


Huh?




justinsane said:


> The question I was asking, or at least referring to, is whether the Faraday cages require earth grounding. And that question was complicated by the statement I'd never heard before, that EMP would penetrate the ground significantly, and the ground would act as a conductor. On this I have way more questions than answers, in large part because I'd never heard that postulated before.
> My understanding of the Faraday cage is that the cage gives a path of least resistance around that which is encased in it. However, that path requires a place to go. Electrical energy travels from one place to another, if it has no other place to go then the "path of least resistance" is not a path at all. Again, more questions than answers.


Try about half-way down on this page:









Faraday Cages: What They Are and How They Block EMF Radiation : DefenderShield


The Faraday cage, which blocks all EMFs, was invented by Michael Faraday, the 'Father of Electricity' & pioneer in Electromagnetic Fields.




www.defendershield.com


----------



## justinsane (4 mo ago)

Back Pack Hack said:


> Say what?
> Autos are grounded to themselves that is it that's the whole thing noting more nothing less. They are not grounded to anything else just themselves, as are airplanes.
> 
> 
> ...


I already understand how they block EMF there was a post by someone else suggesting that the EMP would penetrate the earth and the earth would act as a conductor. I have ALWAYS seen Faraday cages being grounded to earth, so obviously if the earth is energized equally by the EMP the grounding is of no value and there is no "path of least resistance" because there is no "path" it's all the same. When a Tesla coil is used to generate million volts and strikes a Faraday cage with a person inside who is unaffected, it is because the voltage goes "around" them via the path of least resistance, if that cage weren't grounded the "path" is interrupted, the voltage has no "path" to follow. Again I'm referencing a post made by someone else in this thread which I will find and quote after I post this reply


----------



## justinsane (4 mo ago)

PaulS said:


> The E1, E2 and E3 pulses from an HEMP will easily penetrate more than 40 feet into the ground. The ground itself becomes a conductive path due to ionization.You have to build a capacitive resistance between your device and the E1 pulse.
> That is why layers of conductive material and insulation is so important. The more conductive the material the faster the pulse passes by. The less conductive the material the more pulse goes through because it takes too long to go around. Some of the pulse will always get through but after three layers of good insulation and good conductors the pulse is weak enough that it won't harm the sensitive electronics.
> 
> An HEMP produces no radiation that makes it to the surface, there is no blast wave, and the heat wave is used up in the atmosphere before it can be any danger. Only the electromagnetic effects make it through the atmosphere because it is the interaction with the atmosphere that causes them. The only thing that will effect people on the ground is the light in the sky (above the atmosphere) that might cause temporary "flash blindness".
> ...


@Back Pack Hack this is the post I'm referring to:
"The E1, E2 and E3 pulses from an HEMP will easily penetrate more than 40 feet into the ground. The ground itself becomes a conductive path due to ionization.You have to build a capacitive resistance between your device and the E1 pulse." his words not mine


----------



## Back Pack Hack (Sep 15, 2016)

I don't understand where you're coming from. You say faraday cages are always grounded, but cars and planes are grounded 'to themselves'. You can't have it both ways.

As to the post you're referring to, I can't speak for whoever posted it. I recommend you ask that user.


----------



## justinsane (4 mo ago)

Back Pack Hack said:


> I don't understand where you're coming from. You say faraday cages are always grounded, but cars and planes are grounded 'to themselves'. You can't have it both ways.
> 
> As to the post you're referring to, I can't speak for whoever posted it. I recommend you ask that user.


When I say Faraday cages are always grounded, I mean, that devices I have seen that were built for the expressed purpose of serving as a Faraday cage to protect electronics from EMP, which is the topic being discussed. 
When I say cars & planes are grounded to themselves I mean that their electrical systems reference to ground is only their own chassis.


----------



## Back Pack Hack (Sep 15, 2016)

Should You Ground a Faraday Cage Against EMPs? - Survival Sullivan


Should you bother grounding your Faraday cage that protects your electronics from EMP? I think not, here’s why.




www.survivalsullivan.com


----------



## justinsane (4 mo ago)

Back Pack Hack said:


> Should You Ground a Faraday Cage Against EMPs? - Survival Sullivan
> 
> 
> Should you bother grounding your Faraday cage that protects your electronics from EMP? I think not, here’s why.
> ...


This is the kind of info I was seeking thanks


----------



## WineGuy (3 mo ago)

U line also sells Faraday bags for electronics. I put my electronics in them seal them with faraday tape and then put them in a Mission Darkness bag. May be overkill, but....


----------



## Back Pack Hack (Sep 15, 2016)

Actual _faraday_ bags... or just to prevent electrostatic shock?


----------



## WineGuy (3 mo ago)

Back Pack Hack said:


> Actual _faraday_ bags... or just to prevent electrostatic shock?


This is how they describe it. It is also why I put it in a mission darkness bag to be safe.

*STATIC SHIELDING BUBBLE BAGS*

*SELF-SEAL*​Complete protection from static discharge and rough handling.
Aluminum "Faraday cage" layer shields product from electrostatic fields inside and outside the bag.
3/16" anti-static bubble absorbs shock, dampens vibrations and provides ESD protection.


----------



## Back Pack Hack (Sep 15, 2016)

The fact that they put quotation marks around 'faraday cage' should be a red flag


----------

