You can use the acid to etch damascus pattern steel. It's used by the knife makers all the time.
However they are generally after a deep 3D etched out pattern coming about from the differences in the 2 steels used in the blades composition/
The acid used in very strong soln in those instances carves out the damascus pattern. Then the surface is lightly polished again. The deeply etched surfaces retain their darker eaten away color and that's where their color differences come from.
They do not usually finish the blades with the same rust browning/rust bluing and then very light etch to remove that color from one component of the damascus and leave it on the other to obtain the finish and contrast.
Ferric chloride is Ph acidic around 2, right up there close to what some common fruit juice register, but it isn't an acid in itself.
It works perfectly for loosening the fragile oxide from one component of the composition steel bbl.
If you do use Muriatic, mix it to a very weak soln and experiment with it before doing that H&H bbl set.
I only use around 2% Ferric Chloride for etching soln and with that the bbl is into and back out as fast as I can dunk it. Then rinsed off with water and carded under running water.
Any stronger than that and I will loose too much of the color I'm trying to build.
I suspect any Muriatic soln concentration won't have to be much at all.
I have also heard of using acidic acid in the form of vinegar, but never have tried it. Seems like it may do the job as well. But again experiment to get results.
Protect the bores when using any of these.
