Lasering "Hard" anodized aluminum

[Jack Harper]

Has anyone had any experience lasering "hard" anodized aluminum? I need to laser 430 seat numbers for a performing arts center. They originally requested dark bronze with white lettering but I am not sure how to do that without painting the letters. I thought it might be better to use a dark bronze anodized plaque and laser to create the white letter. When researching the anodized surfaces choices, I discovered hard anodizing will wear much better than regular anodized. Any thoughts or experience would be much appreciated. Thanks.

[Jerry Beltramo]

We have lasered hard andozied aluminum on a wood working fixture we manufactur for three years. The hard andozied aluminum holds up well with the usage of this equipment over time and the engraving looks great.

[Scott Shepherd]

Jack, I've not tried to laser it, but from a machinist standpoint, we used hard anodizing all the time. It's hard. I mean hard, hard. We used to specify "hard black anodize" and it always came back like they did it, but one visit to the anodizer years later, he confessed that the black took away from the "hard" properties. Hard anodizing is clear, pure hard anodizing. It makes the material very very very hard. You can take a piece of aluminum and hard anodize it and it'll outlast steel many times over.

Are you talking about clear hard anodizing, or colored hard anodizing?

Oops, looks like Jerry beat me to it!

[Jack Harper]

Thanks guys for the response. Actually I will need to do what is called architectural bronze anodizing. I'm told this is a two part process as compared to the single step process of regular anodizing. Apparently this is the only way to get a true bronze color. Overall it sounds like it should work fro my needs.