The material is machined using a copper-zinc alloy wire, and the remelt material contains some copper and zinc.
Any insight is appreciated.
You'll have to experiment a bit with the concentration and immersion time, but it should be doable. If all you want to do is remove Copper and Zinc from Platinum and Irridium any number of etches for Copper should be able to do the job. And remove the Zinc almost incidently. I want to post a question or inquiry of my own. I am a supporting advertiser and want to reach the inquirer privately .