Homebrew PCBs

Hi Adam- I was not feeling mislead, I just did not know what to expect.

The copper has only been in the acid for 18 hours. The acid still
looks  clear, as it did when I poured it into the water. The copper in
the air looks much as it did at the time of my last post. 

I hadn't measured the room temperature when I wrote the above, so I
went and did this. The etchant temperature is  about 65 deg. F. 

As I measured the temperature, before my very eyes on several spots on
the exposed copper wire a turquoise blue coating appeared. That was
quite amazing!  So I have every reason to believe that things will
unfold as they have for you.

The tank has been covered with its cover, which has a 9/16" hole in
it. Does this process need lots of air exposure at first? Or was it
just coincidence that when I took the lid off to take the temperature
the process evidenced itself?

I did put the entire 1.8 kg of copper in at the start.

Thanks for your continuing advice, information, and encouragement. I
will keep the list posted about the progress of the etchant.

Grant

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell
<adam_seychell@y...> wrote:
> You should put full 1.8kg of the wire in. I takes about 24 hours 
> for the acid to really start going dark and cuprous/cupric 
> chloride mix to be produced. The copper in the air should 
> eventually go bright blue Cu(OH)2 coating.
> Has the HCl still changed from its normal pale yellow to a dark 
> brown ?. If so then its working. This reaction is an accelerating 
> one.
> I'm sorry if I misguided you and you feel its not working as 
> expected. I've made 2 batches so far, using this technique.
> Eventually I would like to write a web page giving much more 
> accurate information than I have done so in these posts, 
> including pictures. I'm still experimenting myself at this stage.
> 
> Just add concentrated acid from now on, there should be enough 
> water for the moment. Don't hesitate to ask any questions.
> 
> Adam