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Etchant recycling

Etchant recycling

2003-12-28 by dkesterline

Hello,

I've been experimenting with toner transfer for a while now, and I'm
starting to see acceptable results. This group has been a great help
in my endevors.

I read some posts in the archives about recycling (revitalizing might
be a better word) Feric Chloride etchant.

As I read the instructions, using two iron nails as electrodes, run
about 1 amp through the solution. (more details would have been
helpfull)

I tried this and my results were less than stellar. The negative
terminal collected particulate copper (kinda looked like a sponge,
but just dust, wiped off easily) and the negative terminal did erode
some (about 1 hour). In the end my etchant looked like brown mud.
Then I tried etching with it and it seemed slower than before I did
it.

Perhaps sombody could advise?

Thanks,
Denny

Re: Etchant recycling

2003-12-28 by felixdkat2002

not sure what material your electrode needed to be made out of,
but there are MANY different kinds of nails.... i would advise to
find your source on the proper electrode and then get a nail that
matches as closely as possible... if you got some copper on the one
nail it sounds like your idea was working, but you may have been
depositing other chemicals into your etching solution depending upon
what the container, wires, and nails were actually made of...

im not a chemist, but i know that these are all factors to
consider....



--- In Homebrew_PCBs@yahoogroups.com, "dkesterline"
<desterline@t...> wrote:
> Hello,
>
> I've been experimenting with toner transfer for a while now, and
I'm
> starting to see acceptable results. This group has been a great
help
> in my endevors.
>
> I read some posts in the archives about recycling (revitalizing
might
> be a better word) Feric Chloride etchant.
>
> As I read the instructions, using two iron nails as electrodes,
run
> about 1 amp through the solution. (more details would have been
> helpfull)
>
> I tried this and my results were less than stellar. The negative
> terminal collected particulate copper (kinda looked like a sponge,
> but just dust, wiped off easily) and the negative terminal did
erode
> some (about 1 hour). In the end my etchant looked like brown mud.
> Then I tried etching with it and it seemed slower than before I
did
> it.
>
> Perhaps sombody could advise?
>
> Thanks,
> Denny

Re: Etchant recycling

2003-12-29 by dkesterline

Everyday Iron nails, polyethelene container, and the wires weren't in
the solution.

Trick is the coper was on the negative nail, and was just powdery
sludge. I'm no chemist either, but it didn't look like any
electroplating I've ever seen. Besides, I thought the coper should
plate onto the positive electrode?

-Denny


--- In Homebrew_PCBs@yahoogroups.com, "felixdkat2002" <ebay@s...>
wrote:
> not sure what material your electrode needed to be made out of,
> but there are MANY different kinds of nails.... i would advise to
> find your source on the proper electrode and then get a nail that
> matches as closely as possible... if you got some copper on the
one
> nail it sounds like your idea was working, but you may have been
> depositing other chemicals into your etching solution depending
upon
> what the container, wires, and nails were actually made of...
>
> im not a chemist, but i know that these are all factors to
> consider....
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "dkesterline"
> <desterline@t...> wrote:
> > Hello,
> >
> > I've been experimenting with toner transfer for a while now, and
> I'm
> > starting to see acceptable results. This group has been a great
> help
> > in my endevors.
> >
> > I read some posts in the archives about recycling (revitalizing
> might
> > be a better word) Feric Chloride etchant.
> >
> > As I read the instructions, using two iron nails as electrodes,
> run
> > about 1 amp through the solution. (more details would have been
> > helpfull)
> >
> > I tried this and my results were less than stellar. The negative
> > terminal collected particulate copper (kinda looked like a
sponge,
> > but just dust, wiped off easily) and the negative terminal did
> erode
> > some (about 1 hour). In the end my etchant looked like brown mud.
> > Then I tried etching with it and it seemed slower than before I
> did
> > it.
> >
> > Perhaps sombody could advise?
> >
> > Thanks,
> > Denny

Re: Etchant recycling

2003-12-30 by roel_cnc

--- In Homebrew_PCBs@yahoogroups.com, "dkesterline" <desterline@t...>
wrote:
> Everyday Iron nails, polyethelene container, and the wires weren't
in
> the solution.
>
> Trick is the coper was on the negative nail, and was just powdery
> sludge. I'm no chemist either, but it didn't look like any
> electroplating I've ever seen. Besides, I thought the coper should
> plate onto the positive electrode?
>
> -Denny
>
hi,
it isnt a plating bath so dont suspect a nice and shiny nail he'

why do they call it (+)anode's in a plating bath -
-we talk about etch fluid now-
the (-) cathode get plated with the copper and the nails metal

the one who said that it speed up after pulling cu out isnt right-
ferric Chloride can etch up to a maximum of 100g of copper per liter
of solution and should be disposed.
this wholly setup is intended as trying to pull some copper out so
that it can be replace with new cu from the pcb to give it a longer
live and save some money.

thats the way i think it is, so correct me if i'm wrong :))

Re: [Homebrew_PCBs] Etchant recycling

2003-12-31 by Adam Seychell

dkesterline wrote:

>
> I tried this and my results were less than stellar. The negative
> terminal collected particulate copper (kinda looked like a sponge,
> but just dust, wiped off easily) and the negative terminal did erode
> some (about 1 hour). In the end my etchant looked like brown mud.
> Then I tried etching with it and it seemed slower than before I did
> it.

If you have potential too high then your change all your ions.
I.e. you get hydrogen ions (+1 charge) and copper ions (+2
charge) attracted to the negative terminal because that's where
electrons are being feed. Simultaneous deposition of hydrogen gas
and copper metal make you a messy sponge.
Lower the cell potential so hydrogen no longer evolves and you
get only copper.

On the opposite side your anode will attract negative ions
(anions) i.e. chloride (-1 charge) and hydroxide (-1 charge).
But you have iron anode material, and electrons are being sucked
away from the surface. The result is iron becomes iron ions (+3
or +2 charge). The chloride ions don't get a chance to give up
their electrons because the iron does it so much easier. The
hydroxide may do it a little bit and so you might get some oxygen
gas evolving.

Electrochemistry is a nightmare to understand.

I wouln't expect results, at best you can plate out all the
copper and finish up with saturated ferrious chloride solution.


Adam

Re: [Homebrew_PCBs] Etchant recycling

2003-12-31 by Adam Seychell

dkesterline wrote:

> Hello,
>
> I've been experimenting with toner transfer for a while now, and I'm
> starting to see acceptable results. This group has been a great help
> in my endevors.
>
> I read some posts in the archives about recycling (revitalizing might
> be a better word) Feric Chloride etchant.
>
> As I read the instructions, using two iron nails as electrodes, run
> about 1 amp through the solution. (more details would have been
> helpfull)
>

Another possibility is to use carbon anode, and it may reduce
your ferrous ions to ferric ions , but don't put too much voltage
that chloride gets reduced and chlorine gas. If you smell
chlorine at any time, then reduce the voltage.

Adam