Bv,

I would agree with Jack Rowe after many various experiments with all types of blacking formula's over the years. I think nitric acid formula's are good for mild etching, but as a result they degrade the gloss finish.

Bv, I have a couple of my own formulas that I developed by trial and error years ago, with some old junk barrels, and they do not include nitric or hydrochloric acids.

Best Regards,


Doug