I have a project that involves making plaques for some outdoor sculptures. I’m thinking of laser engraving the plaques, which will vary in size (18" x 18", 8" x 10", 11" x 14"), and they’ll be made out of stainless steel 1/4" thick. Which class would be more appropriate for this project? Small lasers or big lasers? Thanks!
-Raul
Both small and large lasers are CO2 lasers. CO2 doesn’t cut metal.
However, it is possible to mark stainless by spraying with moly dry lube. That’s pure molybdenum disulphide powder and a propane propellant that evaporates out, no oil or binder. It binds to metal but can be wiped off with rubbing alcohol and a paper towel.
But if you laser at the right power level, it will fuse the molybdenum to the metal and create a durable, deep black, and the unexposed part can be cleaned off.
There’s a limited exposure window where this works. It’s not a really narrow window, but if you give it too much power it will just bubble and burn it off.
This is also a case where the net exposure (power divided by speed) isn’t the bottom line. Lower speeds and lower power may be needed to give it enough time to fuse thoroughly.
A diode laser can do these really well, too. Better, actually. But we don’t have one of those
If you haven’t purchased the plaques, look into Chromaluxe plaques and use sublimation. Get the outdoor quality. Excellent results as it was designed for that purpose and you can do color. But if laser has to be use the back side of one of the plaques to run a powergrid. I say probably 100 power, around 90 speed and high quality, 600 dpi on pearl. Is the one that has given me the best results.