Suggestions? On what might be going wrong.

[Clark Pace]

I have a 40-50watt redsail machine. It's been really good to me for many year. And it still is, but I'm having a hard time engraving these anodized aluminum business cards. I've done them before several times for this customer, but I seem to be having issues this time? So a few issues. It's white in some places and seems to have gone right to the bare aluminum in other parts. Engraving in wood or cast acrylic, or just about any other material I use works just fine. Cutting, and engraving work fine on other substrates? Any ideas?

359948

[Gary Hair]

Usually that is caused by too much power, or too slow speed, but it could also be bad anodizing. Do a test grid and you should be able to figure out the right power/speed combo pretty easily.

[Kev Williams]

For sure it's too much power, but if you've had good luck before then you're dealing with an anodizing problem

FWIW, I almost NEVER have a problem with aluminum with any sort of sanded, grained or 'rough' finish, but when it HAS happened, it's been on anodized that's very glossy and smooth...great looking but too much laser and it's gone...