Will the K40 remove plating from metal? I know it can’t engrave metal directly but if I do a brush plating of say a dark ruthenium over a metal would I be able to engrave off the plating?
not sure. I haven’t tried ruthenium. But it does engrave ipad/imacs/etc. It also will engrave painted metal and burn off the paint & powder coatings as well. It will fuse moly to metal.
So, probably can only tell if you try 
I have done annodized aluminum and it takes it right off… sometimes there is a bit of residual staining depending on the color
Once my plating gear shows up, I’m going to try to plate 24k over polished steel and see if I can laser engrave on that. I don’t have high hopes, but you never know. I do know it works with anodizing and powder coat, but what I’m engraving you can’t do that to.
24k gold? I wouldn’t even bother… the stock mirrors that come with the machine are gold plated
Ok, good to know. I’ll play with some of the other platings then. I have my eye on a flat black plating as well and its’ cheap to experiment with.
Moly on steel will engrave black. And a spray can of CRC Dry Moly Lube is only $11 on Amazon.
I do know that, but since I’m going to be playing with brush plating anyway I thought maybe it might work. No harm in asking right