My Hydrochloric acid and Hydrogen peroxide etchant goes red without any copper in it. How come?
I recently tried making acid cupric chloride etchant; however, my batch always goes a darkish red colour as soon as i mix the two together even when i haven't added any copper. I've been using 3% hydrogen peroxide from a pharmacist and 30% HCl From Bunnings. All the stuff was fresh and in dark plastic bottles. The container i put it into is plastic. It still etches but it's nearly impossible to see if the copper is etched away without pulling it out. Can anyone tell me what's in the mixture that's making it red and how i can correct it. Thanks