Faraday Bags

[fenster]

Anyone know if these are worth having?

Not promoting this company, but here is a link in case you don't know what I'm talking about:

EMP Faraday Bags

[woodyz]

My mail order prescriptions come in a Mylar coated bag, some of them 12x12. I use those bags for stored electronics.

[thywar]

Ok.. glad you brought this up. I heard the other day that you can store electronics in an old microwave and it will protect it from EMPs. I have no idea if that's true or not.. is it?

[fenster]

Jul 20, 2012 13:27:31 GMT -7 thywar said:

Ok.. glad you brought this up. I heard the other day that you can store electronics in an old microwave and it will protect it from EMPs. I have no idea if that's true or not.. is it?

I've heard the same as long as the seal is good. You can test the seal by placing a cell phone inside and calling it. If it rings you don't have a good seal.

Disclaimer: I can't remember where I got that information. ;D

[woodyz]

I don't know about the micro waves I have heard the same, but unable to confirm.

The bags that my scripts come in are not MILSPEC but if a line my butt pack with a big one and put the electronics in a smaller one inside the bigger one it should work.

But if it won't some one let us know.

[hitec4you]

Jul 20, 2012 13:36:24 GMT -7 fenster said:

Jul 20, 2012 13:27:31 GMT -7 thywar said:

Ok.. glad you brought this up. I heard the other day that you can store electronics in an old microwave and it will protect it from EMPs. I have no idea if that's true or not.. is it?

I've heard the same as long as the seal is good. You can test the seal by placing a cell phone inside and calling it. If it rings you don't have a good seal.

Disclaimer: I can't remember where I got that information. ;D

I read that I think on the ST site. I went home and tried it and it rang. It was a brand new microwave too. Only had it a week when I tried it. Maybe it was a bad one. That would be my luck. It cooks great though.

[orly152]

Maybe CWI can share some light on the subject

[Cwi555]

I've been contemplating how to be polite about this.. then I remembered that I've sworn off PC so here it goes. Skip to the bottom if you wish to avoid the technical verbiage.

It may in fact be "Mil Spec"(Which I seriously doubt)

The specification they are quoting is MIL-B-81705C

The other quoted standards do not even go with MIL-B-81705C.
The title of that specification is "Barrier materials, flexible, electrostatic protective, heat sealable".

Operative words there are "electrostatic protective". It is nothing more than an upgraded version of the same kind of bags you get for a laptop, computer parts, etc.

Interesting name they have for the leading protect.
"Alex Jones EMP Faraday bag".
Dunno maybe it is meant to be alien brain wave protection? What say you CW?

As to it's 'milspec'
You can read it for yourself here:
www.everyspec.com/MIL-SPECS/MIL-SPECS-MIL-B/MIL-B-81705C_10385/
It's a free download.
Now once you've downloaded it, go to this page:
www.disasterstuff.com/store/pc/ALEX-JONES-EMP-Faraday-Bag-8-x-8-128p1552.htm

The 'alex jones' bag. Go to the bottom and read the specs listed.

EMI Shielding - (MIL-B-81705-Rev-C): >40 db Between 1 & 10 GHz
Resistivity-Conductive Metal Layer -(ASTM D-257): <2 Ohms/sq. in. avg.
Surface Resistivity - (both surfaces) (ASTM I-257 @ 12% RH): <10 12 Ohms. sq. in.
Static Decay - (FTMS 101C, Method 4046.1 5000 to 0 Volts): <0.05 Seconds
Capacitive Probe Test - (High Voltage Discharge) - (EIA-std 541/Appendix E-1 KV): <8 Volts
Charge Generation - Nominal (Modified incline plane Avg. nC/sq.in.):Teflon: -0.09 Quartz: +0.10 Physical Properties
Total Thickness - 7.0 mils
Light Transmission - (ASTM D-1003-77) <.01%
Tensile Strength - (ASTM D882-83 Method A) 735 lbs.
Tear Strength - (D1004-66 - Notched) MD: 5.8 lbs.TD: 7.5 lbs.
Burst Strength - (FTMS 101-C Method 2007 1a) >130 psi
Puncture Strength - (FTMS 101-C Method A) >38 lbs.
Elongation - (ASTM D822-83 Method A) MD: 40%TD: 74%
Heat Seal Strength - (ASTM D-1876-72 Vertrod Sealer) >11 lbs./in width MVTR (ASTM F-1249 @ 100°F 100sq. in./24 hrs) <.0006 gms OTR (@ 100% Oxygen 100 sq. in./24 hrs) ASTM

Edit: try to find those ASTM specs in the listed Mil Spec while your at it.

Now pay attention to 'thickness listed. They list 7 mils. 1 mil =.001"
which makes their bag .007" thick. Now go to page 7 table one of the milspec, toward the bottom of it "thickness". It list Type II and III being .006" with Type 1 being .015".

If you go to page 28, they have the 'types' and service for those types listed. If you had a type I bag, with some inner shielding added, you may have something that would work for very mild EMP (40-50 Decibels), but it may not even good for that.
As was discovered in in table 1, the bag is only .007".
Therefore it can only qualify for Type II or III, (if it qualifies for that)
Paragraph 6.1.2, and 6.1.3 on page 28/29 of that specification gives you the description. None of which gives me a warm fuzzy for EMP protection.

For those who get the idea of double wrapping it, you should look up the term resonance cavities, wave guides, and what constructive and destructive interference is.

Summary for those who skipped to this point;
Your money would be better spent on food, water, or a new pair of underoo's. That is unless you buy into the whole Nibiru alien invasion conspiracy. Even then a roll of aluminum foil may be better, depending on what frequency the alien overlords use.

[garret]

think i'll stick with buying the underoo's (lol CWI)

[thywar]

I'm buying Aluminum Foil Underoos though.. and lots of baby powder

[fenster]

Thanks, that's why I asked. It seemed like the easy way out, but I'll stick to my plan to build my own faraday cage.

Any thoughts on the microwave CWI?

[Cwi555]

Jul 20, 2012 18:20:35 GMT -7 fenster said:

Thanks, that's why I asked. It seemed like the easy way out, but I'll stick to my plan to build my own faraday cage.

Any thoughts on the microwave CWI?

Yes, it will not work for a nuclear EMP.

[woodyz]

Good to know, thanks for clearing it up. I think the info was on the other site, but that does us no good here.

[Cwi555]

Jul 20, 2012 18:53:39 GMT -7 woodyz said:

Good to know, thanks for clearing it up. I think the info was on the other site, but that does us no good here.

Which info is that?

[mountainmark]

This is an interesting site that (I think) was referenced by you, cwi, on the old board. They do mention the use of an older microwave for smaller items, but I'm curious what you think about there use of foil then plastic wrap, then foil, then plastic wrap, then foil etc.... I was thinking about using this method for a short wave radio.

www.futurescience.com/emp/emp-protection.html

Don't come down too hard on me, I admittedly don't know much about this stuff.....