It is unclear to me if you had sucess finding the site since you iluded to the fact you noticed the detailed chemistry but also noted the site appears to be down.
You posted:
http://pacificsun.ca/~robert/pcb/cucl.htm Pretty good
> >>>>page on CuCl. Lots of precision chemistry.
And it appears to be down..
I any case here is the link.
http://members.optusnet.com.au/eseychell/PCB/etching_CuCl/index.htmlI think it explains the process of making it quite well but you need to read past the chemistry lesson. Just be aware that the concentrated HCL is very nasty and should be handled with a respirator and preferably outdoors. Inoors without an exhaust fan and you might notice steel things like tools in your shop rusting. It's quite alright once it has reacted with the copper which reduces it strength. I'm quite excited about it being re-usable. Sort of a green alternative (well almost) and also not having to dispose of expensive ferric chloride or buying ammonium persulphate which cannot be stored once mixed.
Sage