To put the HCl fume problem in perspective - I had been bubbling the
etchamt solution with an open tank for over a week without any HCL
damage, even on steel a few feet away.
It was only when I started aerating with a much higher volume pump
that the problem appeared. The etchant surface was so agitated that it
was spitting some etchant out of the tank - and into the air. And the
bigger compressor got warm enough that the air was being warmed, and
increasing the temperature of the etchant. I understand a higher
temperature alone may cause fuming.
I believe the CuCl approach can be used without any fume damage, even
without a fume exhaust.
As to the slow process, this is in part due to my air sparger making
largish bubbles. If I got an aquarium air stone the process would
probably be much faster.
Grant
--- In
Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
> i really believe with this cost / etch i won't start the bubbling
campaign.
> this seems much to high effort (concerning the corrosive fuem
discussion also).
> regards
> st