Need Help!- Laser Engraver Leaving Streaks when Engraving Mirrors! Any Suggestions?

[Mitsuboy]

Hello all,

I just got comfortable running my new Laser Engraver. I started Engraving the back side of mirrors. The first few turned out very nice. I'm starting to have a problem with streaking. You can see by the pictures that I am posting below. Something is wrong! I'm not sure if it's my settings or what! All of the optics are clean! My focal length is correct as far as I know. The only thing that I can think of next is maybe doing a beam alignment, But I don't have the tool that was supposed to come with the machine. I've contacted the Manufacturer of this machine, and although I have gotten several responses from them in the past, No response yet regarding this issue. Any help would be greatly appreciated.

[Barrys place]

Working with mirrors can be a real pain. Inconsistent "coating" thickness is one of the biggest challenges I've found so far. In fact I don't like to do mirror work for just this reason.
I don't believe it's an alignment issue but one never knows.. What machine are you working with?

Are you running this dry or are you using the wet paper mask? I know I had streaking/edging issues where the paper dried when I failed to keep it consistently wet.

Barry