Hi guys. I’ve always used my CO2 laser + rotary to engrave (actually burn off) the powder coat on stainless steel mugs and bottles.
Right now, I’m in the middle of a rather large job and tried to split the work load with my 30w galvo. Sadly, can’t find a good setting that would burn the paint away with marking the steel below.
Has any of you found a sweet spot for this task?
Thanks in advance.
It takes a lot of experimenting with a galvo and every color, and every coating material is different. Seems like orange is the worst, black is the easiest. A lot of coatings are not powder coat but seem more like a latex, some more like ceramic. It is really hit or miss.
It seems to me that the best solution will be to “invest” in some material testing to find the best definitions suited to the purpose. 
I have a Galvo 50w JPT laser. I just finished 75 PINK tumblers which added 5 years to my life.
This is what I’ve always done with new colors when I run across one. I create a 6mm x 6mm square. I engrave it, and note the settings. PWR, SPEED, and FREQ. I adjust from there rinse and repeat until I have what I want. My latest battle with these HOT PINK tumbs made me go to AI to educate myself on Wobble, SCAN angeles, and why pink and aqua are harder to engrave than let’s say BLACK.
My PINK tumbs took 9 minutes. I probably tested around 3 hours total before I got it right. I didn’t like the fact that I had a 9 minute engrave but I have to get them done. My black tumblers from the same supplier? 2 minutes flat.
Do that small square test. You can get more testing done before scrapping another tumbler. I have a shelf of sacrifced tumblers that I always setup with, even though I have libraries of settings. Hope that helps some. These guys here have saved my bacon more than once.