Hi,
  It seems my supply of ferric chloride etchant is utterly stuffed after =
all.
I've just tried to etch a board and it took a good hour and a half to etc=
h a
fiberglass PCB (1/2oz copper).
  While I was searching through the Farnell catalogue CD, I spotted this
interesting little document, from a company called CIF. It explains how t=
o
dispose of ferric chloride etchant in a more-or-less step-by-step manner:
  <http://www.farnell.com/datasheets/42946.pdf>

Seeing as CuCl etchant allegedly produces acidic fumes, that leaves FeCl =
and
the ammonium and sodium persulphate based etchants. I'm not too keen on t=
he
persulphate type etchants due to their short lifespan. Replacing the etch=
ant
every time I need to use it could get pretty costly.

Now... Sodium hydroxide looks like it should be easy enough to get - assu=
ming
I can find the stuff in the first place (and in fairly small quantities, =
i.e.
500g tubs). The problem is the pH paper - I've found a few USA-based sell=
ers,
but none of them appear to be willing to sell the stuff outside the USA. =
Does
anyone know if one of the Hanna Instruments pH meters that Farnell are
selling for =A318 +VAT each would work as a replacement?

I've also found ferric chloride etchant (again, from Farnell) at around =A3=
20
for 5 litres - seems to be a much better price than =A37.99 for a 500ml
bottle anyway...

If anyone wants to suggest an alternative to FeCl that has a decent shelf
life and isn't too hard to dispose of, I'm open to suggestions.

Later.
--=20
Phil.                              | Acorn Risc PC600 Mk3, SA202, 64MB, 6=
GB,
philpem@dsl.pipex.com              | ViewFinder, 10BaseT Ethernet, 2-slic=
e,
http://www.philpem.dsl.pipex.com/  | 48xCD, ARCINv6c IDE, SCSI
.... Journeys begin with a single step, and a decision to take it.
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