Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

One explanation I was given is that the vinegar reacts with the chloride in salt and produces a very weak hydrochloric acid.  I tried it but it took forever to see any effect on the copper.  Much easier to go and get a gallon of muriatic acid for $10. I only use about an ounce at a time  along with 3 oz of peroxide and get boards etched in about 5 minutes.