Finish etching damascus and maintaining contrast

[milkbaby]

So I made a couple of knives from damascus steel billets (from Alabama Damascus) before and just forged and ground another one out from some leftover ADS. As I was etching it in ferric chloride, it was really nice and dark until I scrubbed the oxides off with a scrubby. After a few rounds of about 5-10 minutes each to get a little topography, the last time I etched in the ferric chloride for only 2 minutes and neutralized with Windex. Then I took 2000 grit sandpaper with a hard backer to shine up the highs/15N20/nickel. The contrast is actually quite nice already at this stage.

I got to thinking that I did a coffee etch after ferric chloride etch previously because it seems to give very nice contrast with the dark steel very black. However, it doesn't seem to be long lasting as the black fades with use.

Is there any advantage to doing a coffee etch after ferric chloride etch other than making it look nice for a short time? What other techniques would be applicable for damascus kitchen knives? I know the coffee etch is supposed to be food safe, is there anything else y'all might recommend? I've read about setting the oxides by boiling as well as drenching with acetone and letting dry. Do these actually work for a user knife? Or is it just a fact of life that any high contrast black oxides will fade from use due to being only a surface thing?

 

[Kevin Cross]

Yes and yes. I've done the boiling many times (add a couple of tablespoonfuls of baking soda to the water). That set the oxides and gave greater contrast that lasts pretty well. That being said, it will still fade with hard use.

 

[weo]

I do both, set the etch with boiling baking soda like Kevin said and then after final cleaning/sanding do a coffee etch. I usually let the blade sit overnight after taking it out of the boiling water before before final cleaning with 5000 grit paper and a hard backer. I learned this from Dave Lisch, but I'm pretty sure he said he's not sure it's necessary to do the overnight thing, and just letting the blade cool to room temp is probably long enough for the etch to 'set'.