Homebrew PCBs

At 2:21 pm ((PST)) Thu Nov 9, 2006, Stefan Trethan wrote:

>The plastic bags of dry FeCl i have show water going through the sealed
>plastic foil, that stuff must be pretty hygroscopic.

It's worse than that, it's deliquescent.

Then it dissociates and ferric hydroxide precipitates
leaving a strongly acidic solution.

So if your container of formerly anhydrous ferric chloride
should be leaky enough to let the liquor out, or its plastic
become embrittled with age, it can leave both iron stains
and acid burns.

That's what caught out my dad when he put a plastic pot
of my (double poly-bagged) ferric chloride on a high shelf
so the label couldn't be read to see what it was, then,
much later, lifted it down by the lid - which disintegrated.

It splashes quite a long way when dropped 6 feet onto a
concrete garage floor.

Best to store that kind of stuff low down on a catch-tray or
in an additional bucket -  and still treat it gingerly.


Regards, LenW