I am new to this forum and I will pose this question
I have been using ferric chloride quite successfully to etch copper
jewellery, however it has been reclassified in New Zealand as a
dangerous good and my old supplier will no longer carry it and is
available only in commercially in large quantities through other
suppliers. So I had a look on the net for alternatives and found
computer circuit board etchers were people that needed the same
effect as jewellery etchersand had explored other options. ammonium
persulphate was one but what interested me was a mix of hydrochloric
acid and hydrogen peroxide that was reusable and looked like it gave
a very clean etch. however it seems to etch very fast which is never
good if you want to avoid undercutting. Has anyone tried this with
copper jewellery? and what depth of etch can you get?
I patinate the etched area with liver of sulphur and a clear
distintion between patinated (blackened) copper and plain copper is
needed, hence a the deeper the etch the better.