Homebrew PCBs

> Copper is toxic in large quantities. Runoff from a roof goes into your
> yard and is filtered (and diluted) by the soil. In the US, it's
> illegal to run your roof gutters directly into the sewer.

That's strange. In Austria 90% of all roof runoff goes into the same sewer 
as
the household wastewater. Now that you say it i am really suspicious how 
the
wastewater plant processes this huge amount...

Only in the last years people startet to let rainwater seep away in the 
garden because
they charge you more sewer fees if you run the water from the roof down 
the drain.
(depending on sq. meters of the house)

But then you have the farmers who put copper sulphate (i think) on the 
plants, to
keep the bugs off. (See it is obviously poisonous). maybe you should 
dilute it and
spray your garden with it ;-).


I think it is a good idea to set up electrolysis electrodes and see what 
happens,
so far the copper content in my etchant is much too low and i can't try 
them out
but i will let you know what happens when i can finally try.
I'm very curious what will happen with the HCl molarity, because i do not 
fully understand
the chemistry involved. i hope the electroplating takes the second copper 
away from the CuCl2 and
this way generates CuCl which etches again, not sure. If this is the case
and there is no clorine gas escaping then you should not need any 
chemicals to keep it
going. (chemical process: copper in at the pcb, solid copper out at the 
electrode,
no gas escaping -> great. Disadvantage: stop dreaming, it isn't going to 
be that easy)

ST