Anti-Static Bags

[ArmorAlley]

I'm not sure if this the right forum but it seems as good as any to ask this question.
Electrically sensitive devices should be kept inside anti-static bags.

I was informed recently that electrically sensitive devices should not be placed on the outside of bags on the grounds that the outside surface is not anti-static, indeed it is just the opposite.
Should I be concerned when I see cards on top of an anti-static bag in online auctions?
Is it a bad practice to leave electrically sensitive devices on top of anti-static bags?

The Wikipedia article (below) suggests that it isn't a problem although I will have to read it again.

Antistatic bag - Wikipedia

en.wikipedia.org

 

[Corgi]

I don't have a clue scientifically, but anecdotally: I always put cards atop the anti-ESD bags they come in to visually inspect them before installation. I haven't had a card (NuBus, PDS, CommSlot, ISA, PCI, PCI-e) fail on me due to this practice in the past 24 years I've been installing cards in computers.

 

[cheesestraws]

Anecdata: never had a problem myself. But the design of them is asymmetrical and the outside and the inside do not have the same properties.

Also, not all antistatic bags are the same and the risks differ depending on what kind of bag it is. I don't know very much about this. Here's a source that seems to say reasonable things but it is also from a antistatic packaging supplier, so apply your corrections for marketing bias:

https://www.gndzero.com/techdocs/Shielding/Sheilding%20Bags/Choosing_the_Right_Bag.pdf

 

[LaPorta]

Then again, running things on plastic anti-static bags might not be a good idea, but ive done it. Case and point are cheesestraws beta hardware AirTalk units: i tested them running on my rug with the bag between the two .

 

[Skate323k137]

I believe it's the ones with the visible patterning that carry a level of risk, though it's never bit me either, I avoid setting boards on those particular anti-static bags.

Never had a problem powering up [bare arcade] boards on anti-static bubble wrap either. I've done that more times than I care to admit.

 

[jessenator]

Yeah, I've always just avoided it because of what others—whom I've assumed were more knowledgeable—have told me.

Seems there are different types, which makes sense, based on the sheer number of bag appearances.

Antistatic Bags & Conductive Bags

Ever wondered what antistatic bags are, what it is used for and where to buy antistatic bags for low prices. Find answers to all your questions on antistatic bags or static sheilding bags here.

www.packagingknowledge.com

Seems that some are dissipative, etc.

Edit: that source is just one I've found; not sure of the veracity of its claims

 

[cheesestraws]

I should clarify: when I said "I've never had a problem" I mean with just placing things on top of anti-static bags. I have never powered anything up on top of one, and I'd be very cautious about doing that.

 

[LaPorta]

I should clarify: when I said "I've never had a problem" I mean with just placing things on top of anti-static bags. I have never powered anything up on top of one, and I'd be very cautious about doing that.

Yeah, I know, we took it a lot further!

 

[stepleton]

I should clarify: when I said "I've never had a problem" I mean with just placing things on top of anti-static bags. I have never powered anything up on top of one, and I'd be very cautious about doing that.

Is the concern that the bag's ability to conduct current might affect the proper functioning of the electronics? In that respect I don't think it should be much different than operating a bare circuit board that's sitting atop an antistatic mat. Both the mat and the bag are conductors but with such a high resistance that I would expect no real impact on virtually any digital logic circuits. Your fingers will be much more conductive than either of those things (and to be fair sometimes a finger poke can be disruptive).

I'll confess: I can't be bothered to make or buy a bracket or an enclosure for SCSI2SDs that I have for my NeXTs... or the Gesswein MFM HD emulator I have in another machine... or the bare board Floppy Emu that I use with my Lisa 2. I just throw them into an anti-static (silver) bag and let them be loose around inside the case covers (or outside for the Floppy Emu). Cables usually keep the things pretty still. The bag is mainly to keep the pins from shorting on the metal case; it's an anti-static bag to discourage static buildup from my own handling. I've had things this way for years and have never had any issues. YMMV, at your own risk, etc.; maybe someone else knows why this should be bad?

 

[Skate323k137]

Oh I never power them up on the bags, only set them on them temporarily. Anti-Static bubble wrap on the other hand I don't really have qualms about it.

The arcade community has told me the ones with visible patterning on the outside can cause a short... Just what I was told.

 

[cheesestraws]

Is the concern that the bag's ability to conduct current might affect the proper functioning of the electronics?

I can't talk for anyone else, my concern is that they obviously are conductive and it's always been easier to just not do it than to work out whether it's OK or not . My concern should, perhaps, not be taken very seriously.

 

[jessenator]

I just continuity / resistance tested the swath of bags* I have here, and none of them showed continuity … not to say all do or don't, but test yours out and be wise.


*Pink, blue, mylar-esque stiffer ones, the line pattern gray ones