Homebrew PCBs

Stefan Trethan wrote:

> 
> (is my assumption correct that i need to dissolve 200gram copper to raise 
> the density by 0,2?
> in a 1l container...)
> 
> I'll try to get more copper in, and i also decided i need some of these 
> eyedropper bottles.
> then i can keep one filled with 1mol NaOH and use the other (equal-sized) 
> eyedropper for the etchant.
> 


Also add some hydrometers to your shopping list to cover the 
range 1.00 to 1.30  I find hydrometers with 0.10 range are plenty 
  good. Standard laboratory hydrometers have a range of 0.05.

Looking at the commercial CuCl etchant ( 
http://www.oxfordvue.com/TechInfo/how_does_it_work.html ), they 
run at  s.g 1.35 to 1.4 and have about 220 g/liter of copper.

I think this is too high, I found 1.25 to 1.30 better for room 
temp etching. CuCl2 etching without chemical oxidizers (H2O2, 
Cl2, NaClO3 etc) should etch 35um copper foil in 20 minutes at 
20\ufffdC with bubble agitation. Keep HCl plentiful.