I have just tried to engrave something in an aluminium plate (50x20 mm).
I was not very confident on having a good result, but to my surprise it finally came out quite good.
I used a black edding 500 permanent marker pen to paint the surface to engrave first, let it dry for 1/2 min (yes, I hace no patience at all 😅) , then engraved and to finish I used solvent and a soft cloth to remove the black paint.
black edding 500 permanent marker pen
As you can see in the photos below there is not much difference when using different speeds. I also tried with 2 passes and still not much difference.
Hope it helps for your future engravings!!
@alvar0.ga That looks really good, it's amazing what you can engrave with these low power diodes.
Well, i done this today and when i remove the black paint, the engraving disappear easily.
Secondo me è solo vernice del pennarello bruciata, basta pulire bene e tutto scompare
Wow, It surprised me....
I thought I couldn't engrave ANY metal materials with 2.5W laser.
Thanks a lot for REALLY good information.
@MightyBear It's not really engraving the metal but it does add pigment to the surface. There are commercial products like Cermark / Thermark that do this but they are expensive, using acrylic paint or markers is a cheap alternative but a bit hit-and-miss on results. I make a solution from brasso cleaning fluid and alcohol that seems to work well with my CO2 but not so good with the diode laser.