Homebrew PCBs

morriso2002 wrote:
> 
> --- 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.

The only airation i do is with the small fish-tank air pump during etching.