Old Etching solution

[Nico Coesel]

Utter nonsense.

Its not. Eventually the copper will leach out. It is much better to
have it disposed of properly so the copper can be extracted. BTW the
copper price has never been higher!

 

[[email protected]]

Its not. Eventually the copper will leach out. It is much better to
have it disposed of properly so the copper can be extracted. BTW the
copper price has never been higher!

More, but different class of nonsense.

 

[YD]

It is much better than ferric chloride. It also has a great advantage that
it won't etch nickel or solder plated traces that allows for making
plated-through holes.

Unfortunately it has one _MAJOR_ deficiency -- the etching solution don't
last. It is OK for manufacturing when solution is discarded at the end of
day but for a hobby use when one board is etched once a month or so it is a
big waste.

The best one for hobby use is cupric chloride. It is cleaner than ferric
chloride and the solution lasts forever. Dunno how it works on nickel/solder
plated copper but usually it is not an issue in hobby use because it almost
never involves PTH that requires much more chemicals and those chemicals are
quite expensive and not all of them are readily available for a hobbyist.

Yes, CuCl2 is real neat once you get it going. Mine's lasted for a
couple of years by now, with an average of one board a month without
needing reactivation. It even seems to be working better now than when
new. After use store it covered with enough air space to reoxygenate
by itself. The cover is to avoid evaporation and release of HCl fumes
that will corrode anything in their sight.

http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/index.html
for one, use your favourite search engine for more.

- YD.

 

[Jasen Betts]

That's just stupid, though wouldn't expect otherwise from the weenie left
(coast). There is *nothing* in paint that will harm a landfill, particularly
once dried. Nothing to spill on the way to the dump, either.

All sorts of interesting chemicals are present in paint, aside from the
flamable resins and solvents some of the pigments are toxic.

Over here some paint retailers will take leftover paint (for recycling), as will the
hazmat people at the runnish transfer station.

Refusal of dried paint me be due to cases where the paint isn't tried all
the way through.

 

[[email protected]]

All sorts of interesting chemicals are present in paint, aside from the
flamable resins and solvents some of the pigments are toxic.

Water is toxic.

Over here some paint retailers will take leftover paint (for recycling), as will the
hazmat people at the runnish transfer station.

Sure, why waste it.

Refusal of dried paint me be due to cases where the paint isn't tried all
the way through.

The alternative is worse. People will flush it down the sewer and then throw
away the can. Same deal as the disposal of appliances. Make it "free" and
people dispose of them in a "green" manner. Make it impossible and they'll
become scenery.

 

[bud--]

If you use ferric chloride as etchant you can reactivate it by adding
HCl (hydrochloric acid). You never have to dispose it until you want
to get rid of your etching gear.

Hobby quantities here can be disposed of at the county recycling site.

I thought there was something you could add that would precipitate the
copper and make the rest safe to dispose of. What I remember was lye,
but I heard it a real long time ago.

 

[Rich Grise]

Hobby quantities here can be disposed of at the county recycling site.

I thought there was something you could add that would precipitate the
copper and make the rest safe to dispose of. What I remember was lye,
but I heard it a real long time ago.

I think it was Spehro Pefhany who suggested washing soda, sodium carbonate,
which turns the ferric and copper chlorides into ordinary salt and iron
and copper carbonates, which are essentially dirt.

Cheers!
Rich