The hydrogen peroxide and saturated salt solution without the vinegar is doing a very good job of rusting a couple pieces of steel for me right now. I was going to do several more passes over the next couple days and then boil them to see if the rust turns black. You have answered that question, but I expected that it would turn black.
What I'd really like to know is if old barrels that have turned an even brown color could be degreased and boiled to reconvert the red oxide to black. I have been told that this will not work, but I don't see any good reason that it shouldn't. On some old guns that have a very deep and even patina, being able to reconvert the red oxide to black by doing a quick boil and if Damascus, an etch, might save a lot of time and effort to polish and re-blue. Anyone ever try this?
