Homebrew PCBs

the bubbler running will provide for some of the needed O2.
perhaps a little more HCl is needed, it also fumes out...



--- On Tue, 6/17/08, DJ Delorie <dj@...> wrote:
> I've got a somewhat new tank of HCl etchant that
> I've used a few
> times, but it's mostly been sitting for a while. 
> It's only pale
> green, but it's emerald not brownish.  My test boards
> (one just
> scrubbed copper as a control) have been in it for 40
> minutes now.
> It's warm and the bubbler is running, I even added a
> shot of peroxide
> ten minutes ago.  It etched real quick the first time I
> used it, when
> it was fresh.
> 
> What's the most likely cause of this sluggishness? 
> What could I try
> doing?  Things to test?
> 
> I was thinking of making some copper oxide (the wire+heat
> trick) and
> try to get the solution darker, but I'd rather not put
> too much copper
> in if there are simpler ways.