Homebrew PCBs

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

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

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

--- 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 :))

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

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