exxos's Atari, Amiga & retro forum

Sometimes I need to place a live powered board on a metal surface, sometimes on another motherboard. Some of those boards don't have any legs or encapsulation to isolate the circuit. The question is what to use to prevent any possible short. I'm talking about something temporary, for performing a quick test or measure.

I though that using that dark grey foam, that comes as packing material with many electronic devices, would be ideal. I have plenty of those in different sizes. But then I read that this foam might be treated to be conductive for anti-static purposes.

So what you normally use or recommend to use for isolating a bare powered board?

Anything rubber, or even cardboard.

Steve wrote: 04 Aug 2024 21:13 Anything rubber, or even cardboard.

Hi Steve,

Yes, I know that rubber is an excellent insulator, but seems it's not easily available in a convenient flat shape.
Regarding cardboard. I must admit I that for some reason I had the wrong idea and I thought cardboard is conductive. I was obviously wrong.

Thanks.

Is corrugated cardboard best because of the air gaps? (air being a good insulator iirc)

Cardboard is reconstituted wood pulp… Just how often do you use a cocktail stick as a bodge wire? ;-)

Cardboard for me, corrugated is best as the extra thickness prevents component legs from poking through, though I have a blue silicone soldering mat that I often use now as it's flexible and resilient, I just be sure to clean it thoroughly to be sure there are no bits of solder on it beforehand.

I use think card... Or a plastic chopping board.

I wouldn't place any high current or mains voltage type like PSUs etc on card though as it's a fire risk.

Cardboard for me. I use the estate agent flyers that come through the door occasionally or cereal boxes. I know they're only single ply, but they're very dense (of the order 200gsm) and readily replacable if puncturing through overuse is getting near.

I wouldn't go with corrugated cardboard myself unless it were the double wall type as the surface layer is very thin and easily penetrated.

I've seen plenty of people safely use anti-static bags, but I'd be concerned with those as the whole point is to be conductive or dissipitive, even if it's only on one side.

I would avoid rubber or plastics in general on account of the static charge potential.

A sheet of 4mm plywood may be the ne plus ultra, but is not very convenient!

BW

Badwolf wrote: 06 Aug 2024 09:34 I've seen plenty of people safely use anti-static bags, but I'd be concerned with those as the whole point is to be conductive or dissipitive, even if it's only on one side.

Well, anti-static bags aren't very conductive, they're in the megaohms range. They're conductive enough that static charge doesn't build up in one area but that's it.