After watching you tube videos I decided to attempt to make my own nitric acid to dissolve my Sterling silver. I used the bubble method using standard muriatic acid 100ml Sally's volume 40 hydrogen peroxide (12%) 25 ml distilled water 50ml hi yield stump remover says 95-99% potassium nitrate 80grams and pure elemento copper 35grams. For some reason the final product has a light blue color and I know it's not bubbling over. But it will react with copper but when I tested it on a small piece of silver it wouldn't dissolve it even after 6 hours no reaction. Really need some guidance here