--- In
Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@...> wrote:
>
<snip>
> >
> > Oh, and if anyone knows where I can get a kilo or two of solid FeCl3 (hydrated or anhydrous, but prefer the latter) in Melbourne Australia, I'd be very grateful.
>
> I bought a 40 Litre bottle of liquid ferric chloride years ago from Orica (iirc)
> in Melbourne. I use it diluted 1:1 with water and a bit of HCl in a Kalex
> bubble etcher:
>
> http://kalex.net.au/index.php?module=Website&action=Text&content=1098429165312-0019&parentContent=1098424907968-1192
>
> After etching a pcb, i put a lump of wood on it to stop evaporation.
>
> If i use it a few months later, i put some HCl in it.
>
> After a year of doing this, it went more green than brown, but still
> etches in 15mins (no heating).
>
> The same etchant seems to be lasting forever (CuCl etching).
>
> Moral of story: don't throw away your etchant if you use airation bubble
> etching.
>
> Let me guess, you've been throwing away kilos of the stuff
> over the years;)
>
Guilty as charged :-( I can see I will have to get into the regeneration thing. I do have some HCl here for the money pit in the backyard and will think about how to oxygenate it - I don't have a big bubble tank and don't really want to go down that path. I usually get very good and quick results by swabbing the board continuously to remove the insoluble oxide deposit that forms on the copper. I use a sponge swab from an art supply shop.
Thanks to everyone who replied - particularly with the news that Farnell still sells FeCl3. It looks like the hexahydrate, but that's OK. It seems I will be able to continue using my favourite etchant for a while yet.
Morris