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Old 26-02-2018, 16:07   #1
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ESD Static bags for Lighting protection

Have wondered this for a while, but haven't see any technical answers...

Will an ESD bag protect electronics from a lightning strike on boat?

We all know that putting your VHF/GPS in the stove works because it is a Faraday cage. Would the ESD bag provide enough protection? It will act like a Faraday cage, but can it take the induced current without breaking down?

Does anyone have any thoughts?
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Old 26-02-2018, 20:20   #2
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Re: ESD Static bags for Lighting protection

I think not. The ESD bags are really designed to keep static from building up -- they are only partially conductive. I doubt if they would provide any help against the strong EMP (electro magnetic pulse) that a nearby lightning strike produces.

And for that matter, stoves are far from being a good Faraday cage. There are *huge* slots and gaps in the frame and around the door, and these will let the EMP right through. Even microwave ovens aren't good cages, since the door "seal" is designed to block the specific frequency used in the oven, and won't provide much protection against the broadband EMP field.

Using ovens and microwaves to protect against lightning probably can't hurt, and may provide some slight shielding, but I suspect that reports of lightning protection are circumstantial -- the device would probably have survived outside of the oven as well.
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Old 27-02-2018, 04:57   #3
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Re: ESD Static bags for Lighting protection

Definitely not. As Paul said, the bags are designed to prevent static build-up inside of them. They do nothing to protect the contents from a massive electrical discharge from the outside.
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Old 27-02-2018, 09:07   #4
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Re: ESD Static bags for Lighting protection

FWIW, I've seen two types of antistatic bags: the pink ones and the lightly silvered ones. Neither type is likely to provide lightning protection, for exactly the same reason.

If I wanted to protect a handheld GPS or VHF radio in a lightning storm, I would wrap a few layers of aluminum foil around it, making sure that there was good continuous contact all around. That might be a good way to store it in your ditch kit -- batteries removed if possible, and a ziplock plastic bag over the foil-wrapped device.
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Old 27-02-2018, 09:27   #5
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Re: ESD Static bags for Lighting protection

My bad, I thought the silver metalizad ones would work because I read this -

"Conductive antistatic bags are manufactured with a layer of conductive metal, often aluminum,[3] and a dielectric layer of plastic[2] covered in a static dissipative coating.[6] This forms both a shield and a non-conductive barrier, shielding the contents from static charge via the Faraday cage effect. These bags are preferred for more sensitive parts, but they also see use in environments where sparks would be hazardous, such as oxygen-rich areas in aircraft and hospitals."

-which says they provide a Farady cage effect. I also thought the danger to sensitive electronics wasn't the static discharge itself, but rather the EMP associated with it? Does anyone know for certain or are the opinions expressed just speculation?

Why your oven will not work -
https://en.m.wikipedia.org/wiki/Slot_antenna
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Old 27-02-2018, 10:35   #6
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Re: ESD Static bags for Lighting protection

Quote:
Originally Posted by Delancey View Post
My bad, I thought the silver metalizad ones would work because I read this -

"Conductive antistatic bags are manufactured with a layer of conductive metal, often aluminum,[3] and a dielectric layer of plastic[2] covered in a static dissipative coating.[6] This forms both a shield and a non-conductive barrier, shielding the contents from static charge via the Faraday cage effect. These bags are preferred for more sensitive parts, but they also see use in environments where sparks would be hazardous, such as oxygen-rich areas in aircraft and hospitals."

-which says they provide a Farady cage effect. I also thought the danger to sensitive electronics wasn't the static discharge itself, but rather the EMP associated with it? Does anyone know for certain or are the opinions expressed just speculation?

Why your oven will not work -
https://en.m.wikipedia.org/wiki/Slot_antenna
Speculation on my part.

But these silvered bags can't have much conductivity (you can see through them), and there has to be a big slot at the ziplock opening. They might provide some small degree of protection, but it can't be much.
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Old 27-02-2018, 10:49   #7
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Re: ESD Static bags for Lighting protection

Antistatic bags are mainly used for parts delivery and storage before installation.
The protection is mainly to make sure they survive delivery before final product assembly.
Also, they're not designed to be flexed over and over, rather a one time use.

Think of it this way:

Will my boat fenders protect me from damage by the dock if I'm T-boned by a ship going ten knots?
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