CO2 Laser Marking Metals

Some quick notes for ways of marking metals with a CO2 laser.

Commercial

Cermark LMM-6000, supplied from Trotec (engraving-supplies.ca)

They also have LMM-14 Black. It maybe an older product? Not so popular? - https://sawmillcreek.org/showthread.php?241326-Thermark-LMM14-vs-LMM6000

There is also a Cermark marking tape (Black Marking Tape 1" x 50 ft roll) but I remember reading people weren’t happy with it (would need to re-check that.)

Molybdenum Based Alternatives

Stainless Steel Only - Calcium/Chromium Substitution

Plaster of Paris for Stainless steel (only?)

People report that this effectively etches where the laser hits. One theory: "I believe this is working due to the chromium content of the stainless steel. Stainless has a passivation layer that is thin and completely transparent; Chromium oxide. When combined with calcium sulfate (plaster) along with the heat from the laser and potential water from the surrounding air, you end up with calcium oxide and chromium sulfate. Chromium sulfate creates the mark and the calcium oxide washes off. Again this is my basic premise and understanding of what’s occurring here. “ (http://frankieflood.blogspot.com/2014/12/laser-engraving-stainless-steel-w.html)

Some links:

Dijon Mustard (Stainless Steel only?)

Cerkote

Super hard paint/spray on ceramic that can be laser engraved- https://www.cerakote.com/project-gallery?htids=Laser%20Engrave

Electrical Etching

Mask + teaspoon of salt… can use the laser to make the mask (eg tapes (non PVC vinyl!), engrave off spray paint…)