Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi all,

i was thinking the whole HCl H2O2 business is just for
getting Cl into the etchant to attach to the Cu, right?

So i thought maybe there are other ways to get this done.

Pool clorine.

There are two types, anorganic and organic.

the organic version is for long-term, it is cyanuric cloride.
(it is a acid).
I had that so i put a few shavings of a tablet in a small amount of used
CuCl.
No regeneration could be observed but there was severe gassing and clorine
gas smell.
I diluted that and disposed of it. (was only a tiny sample).

The anorgainc clorine used in pools is calcium hypochlorite.
it is used to quickly kill everything if the water is already half green.
It is not used for long durations (it doesn't stay in the water).
I'm not sure if i have that variety somewhere to try. I would guess
it is potentially better useful for CuCl etcants, because using another
acid seems
not the solution to simplify the process.


I do not have the chemistry knoweledge to find out what is going on there,
but i'd like to know what you think of using other forms of clorine than
HCl
as clorine source.

Could calcium hypoclorite potentially work? could sodium hypoclorite
(bleach)
potentially work? Why not?

Could someone summarize the chemical reactions in CuCl / HCl / H2O2
etchants
in simple terms, so that i might understand it too?

Well, thanks a lot.

ST