I've played around a lot with etching damascus...tried quite a few different methods...some with better success than others. When it comes to etchant solutions, stronger is not better. The etchant attacks each metal in the damascus at a different rate of speed...that's how the pattern is revealed. A strong solution will tend to eat all the metals at a similar rate. A slower etch (with a more diluted solution) is generally a nicer, more crisp etch.
Muriatic solutions are notorious for their ability to creep under finger nail polish resists. If you want to use muriatic, make sure you allow the nail polish to cure overnight...better still, one or two days.
I've gotten best results by "dunking" in short, 5 minute bursts. Then rinse in purified water and TSP (or Baking Soda...two heaping tbsp). Then rinse in straight water, then back into the etchant. (BTW, both the etchant and the TSP solution work best if the water has been first heated up a bit...I "nuke" the water for under one minute in the microwave prior to adding the acid or the base). When finished, I let the steel soak in boiling water and baking soda for about 10 minutes...this helps to set the black oxides. Finally, "hose down" the steel with acetone or alchohol...this immediately removes all moisture.
Like anything else in knifemaking, there are many ways to skin a cat,...
the above method has been working well for me...so far.
Dennis Greenbaum
Yeah Baby!
BTW: 3M's polishing papers are fantastic after the etch. Lightly "sand" with the finer papers (they go up to about 7000 grit). The result is almost instantaneous... and quite nice.
