Re: HCI h2o2 issue

Posted by Silver Blues on Sep 13, 2020; 10:20pm
URL: http://guitar-fx-layouts.238.s1.nabble.com/HCI-h2o2-issue-tp49160p49164.html

Right okay, yes the green colouration is normal and in fact beneficial to the etch - the acid alone cannot etch copper (which is why you add the peroxide in the first place). You can "strengthen" the etchant by just dissolving a bit of copper wire in the fresh solution.

Household peroxide is only ~3% hydrogen peroxide, which is not very much. It's stored in dark bottles because it is light sensitive, and regardless isn't extremely stable so will decompose over time. If the peroxide you used was old, it might explain inefficient etches as well.