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@melka
So here's an update for the "gilding" process. I tried to do some electro-etching and see if I could get a deep enough engraving to make a brass insert.
I made a stencil using electrician tape, and then applied a saturated solution of common household salt. Part is plugged into positive, a little sponge into ground. Let's see what happens.
I'm no chemist, but salt containing Cl and water H, the vapors should be HCl, or Hydrochloric Acid. Take your precautions if you want to try that little trick.
The engraved piece. Being an exothermic reaction, the tape I used started to peel off the steel, maybe the reason for the jagged edges. Kapton tape should be a better stencil material. Depth of the engraving is around 0.2mm after a solid 10 minutes. Should work.
Part is brazed with flux-coated brass rods, and it flows quite nicely. I then brush and sand until I remove all the excess brass on the outside of the engraving.
And finally, I apply a phosphoric acid solution (rust remover) reacting on the surface of the steel, but not on the brass. This darkens the steel and creates contrast.
It's the same process used a couple months back on my finish tests, but I guess the rust remover lost a bit of punch or the plate I used to test this time is just not reacting the same, I couldn't get the same tan / brown tint.