Posted by Sarup Chopra on May 12, 2008 at 17:27:27:
In Reply to: etching of pure copper posted by Julia Wiecken on May 12, 2008 at 06:51:43:
The concentration of the hydrochloric acid is between 36.5% and 38.0%. You could also try a 10% aqueous solution of Ammonium persulfate ( prepare a fresh solution before use ).