Hi,

I'm soon going to start messing around with designing circuits again, either
with breadboard type things or making PCB's with UV sensitive boards and
Ferric Chloride. I'm concerned about the toxicity of this evil looking
stuff and how best to dispose of it and the dissolved copper.

A good many years ago I made some PCB's and, trying to solve the disposal
problem, discovered that if I put a bunch of nails of a certain type into
the used Ferric Chloride solution, they would become coated in the dissolved
copper, which I could then wash off with water, recovering the copper by
letting the wash dry outside. The remaining ferric chloride looked pretty
much like the virgin solution and I'm pretty sure etched boards again.

Doing some Googling throws up the answer "you can't really recycle Ferric
Chloride". (I really don't want to have to use electrolysis). Well what was
my
experiment showing?
And also, what about the UV developing solution - I
believe it's a bleach, but can you just chuck it down the sink?


Cheers,

Gareth.

...the toxicity of this evil looking stuff
and how best to dispose of it and the dissolved copper.
Gareth Magennis

If you like looking thru mud to see what you're doing,
ferric chloride is the stuff.
Otherwise, look into Ammonium Persulfate or Sodium Persulphate.

In another group, we decided that in typical one-off efforts
you won't produce enough to worry about.
If you're not on a septic tank, just flush it down the toilet.
For the sake of water conservation, wait until you are going to flush anyway.