Homebrew PCBs

John Popelish wrote:

> --- In Homebrew_PCBs@yahoogroups.com, "dl5012" <dl5012@...> wrote:
> (snip)
> 
>>What is the proper way to dispose of used ferric chloride?
> 
> 
> Other carbonate based chemicals can also be used (sodium bicarbonate,
> calcium carbonate or lime, even portland cement).  But sodium
> carbonate is very cheap; the liquid residue is just salt and any extra
> washing soda, and sodium carbonate also serves as a developer for many
> kinds of positive resist, so it is handy to have some around.
> 

I experimented with difference neutralizing chemicals for copper 
chloride etchants (containing > 150g/L of ionized copper!!!). Safest, 
cheapest and easiest was neutralizing with lime. See my page:

http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/index.html#Disposal