Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Grant, I took a 500 ml beaker. Added 20 ml of 8M HCl (20%
wt) + 20 ml of water and pieces of scrap copper sheet 0.7 mm
thickness. At this stage about 1/2 of the copper was
above the liquid level. Over a 54 hour period I measured the
progress.


time HCl Cu mass appearance
(hours) (Molar) (grams) of solution
---------------------------------------------
0 4M 12.3g clear
12 ? ? pale brown
23 ? 10.0 Coca-Cola brown
-> added 20 ml of 8M HCl + 5 ml water.
-> started bubbling air through solution.

23 5.45 10.0 " "
34 3.77 3.8 dirty brown liquid
46 2.4 0.7 dirty brown liquid
54 1.67 0.0 deep green


Note: The bubbles were created from a air hose immersed in
the solution. If an airstone had been used to create smaller
bubbles then the reaction would of been much faster.

regards,

Adam.