Need balck engraving on anodized aluminum

[Merv Yoder]

I have the potential of doing a very large project where a guy is wanting his logo and text put on a anodized aluminum. The coating on this aluminum must be very hard looks almost like chrome. When I use ther-mark LMM14 it tends to laser silver or gray and not black. If I take the pc. on the belt sander and grind the surface it will produce the desired results. If I laser without thermark at very low speeds and high power it will laser white. Any Help will be appreciated. I have an Epilog Legend 75 watt laser

[Dan Hintz]

Are you sure this is anodized? I'm not aware of any anodizing that looks like chrome. Could it be highly polished aluminum with a clear powder coat?

[Chris DeGerolamo]

Depending on the amount of detail, you could mask the entire piece, etch through or cut out mask and then spray with Krylon Fusion...not sure if it's as durable as what you or your client wants but you would definitely have it black.

[Mike Null]

It's possible that laser sublimation might do the trick depending on the coating.

[greg lindsey]

JDS has an aluminum sheet that is silver that engraves black. If that helps you.

[Merv Yoder]

I am only going by what the client is telling me. I have never worked with anodized aluminum so I am not sure what is typical. If it is what you think it is. What do you suggest I try to get it to be black.

[Gary Hair]

I am only going by what the client is telling me. I have never worked with anodized aluminum so I am not sure what is typical. If it is what you think it is. What do you suggest I try to get it to be black.

If it is polished and clear coated, either paint or powder coat, then the only options you really have are a rotary engraver or stencil, sandblast and cermark (or paint fill). I had to mark a 36" x 36" x 1/2" piece of aluminum that was mirror polished. I tried regular Cermark as well as the stuff made for highly polished surfaces - neither worked for me. I ended up applying sandblast stencil, cutting it with the laser, sandblasting the polish off and cermarking. It turned out really nice and the sandblasted areas really looked amazing with the texture from sandblasting. You could try to laser off the coating but you'll get better, more consistent, results with sandblasting.

Gary

[Dan Hintz]

I am only going by what the client is telling me. I have never worked with anodized aluminum so I am not sure what is typical. If it is what you think it is. What do you suggest I try to get it to be black.
We can't make a proper suggestion until we know exactly what you're dealing with... a pic would help.

[Gary Nicholls]

Recently I did a bunch of anodized aluminum parts for a shop that also wanted a logo on the parts. I first engraved the logo with a high setting to burn off the anodize, then removed parts from the fixture I made and blew them off with compressed air, sprayed cermark (diluted with DNA 5 to 1) on with airbrush, locked back into fixture and engraved again. Worked really well. I tried without engraving off the anodize first, did not work. Hope this helps.