Homebrew PCBs

rolanyang wrote:
> Do you have a digital camera? Can you take a photo
> of your solution? When you have something that looks
> like http://www.techfreakz.org/cucl2/?slide=5
> the solution is probably right.
> 
> If you're getting brown or sludge, then first bubble
> air through it or add H2O2. If that doesnt help, then
> start adding HCl until it turns blue-greenish.
> 
> Adding too much HCl won't slow down the reaction
> but not having enough CuCl2 will.
> 
> Here's another idea: 
> does anyone know if copper powder is cheap?
> The reaction would likely go a lot faster
> since the suface area of powder is drastically
> greater than when using plain old scrap wire
> or boards.
> 


You can get copper powder from some art supplies, but its VERY 
expensive for what we are doing. I think they use it as pigments 
in paint, or coating surfaces. Its almost fine as flour and thus 
dangerous to breath in.

You can react either, copper carbonate, copper(II) oxide (black 
pigment powder) or copper(II) hydroxide (bright blue powder for 
fungicides) with HCl and instantly get copper(II) chloride 
solution. The problem is none of these are easily/cheaply 
available as scrap copper in the quantities we need (1 kg of 
copper). Maybe they are, but I don't know of any.
You can get few hundred grams at very high $/kg or buy 25 kg bag 
from an industrial supplier at low $/kg but you'll have *way* to 
much. Unfortunately there is no in-between.

I'm going to have a better play around with getting copper metal 
to react with HCl and do it fast as possible.