[jgmick]

Thanks for the info but hydrochloric acid is kind of a non-starter. I have worked with it before and didn't ever like the experience. All kinds of hazards. Not in my job jar if I can ever avoid it. Sulphuric I can handle. (Battery acid.)

Also I am kind of looking for really black, not just tarnished. (I can get tarnished just by leaving it out in the weather for a couple of weeks.)

The "lightly sand" is kind of an interesting idea. I can get that with sandblasting. May give it a try and see if that makes things better.