Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@y...>
wrote:
> Anyone here etch with CuCl2 but only rely on air for regeneration ?
Just 
> wondering what other peoples experiences are with this etchant.
> 
> I'm using HCl + CuCl2 at S.G = 1.36 and etch speed appears to be about 
> 70% of fresh FeCl3 (S.G 1.4) at room temperature. The HCl concentration 
> I'm running at is approximately 1N (or 40g/l HCl or 1 Moles/liter or 
> 4%). I found S.G of CuCl2 dramatically effects etch speed. e.g CuCl2 at 
> S.G of 1.15 was about 10 times slower etch speed than at S.G of 1.35.
> Commercially, CuCl2 etchant operates between S.G 1.35 ~ 1.45.
> 

My CuCl is about 1.2 SG and is still pretty slow.  no amount of
bubbling regens it.   H2O2 make all the difference but its still
taking abourd 40 minutes to etch a board.  The literature I've seen
seems to say 1.17 is the target SG.  I guess I should dump some more
copper in.