We do both rotary engraving and laser marking, but I have not had good luck marking black on a clear anodized piece of Al. I know that it can be done because I have had other vendors do it for me, but I don't know the complete process.

1) I was told that you have to do a chemical treatment to the top of the material to turn the marking black. I have seen mention of using Flow Master?

2) I have found a website describing the manipulation of power and speed to produce black marking instead of white. But I have not been able to make this solution work successfully.

http://www.synrad.com/search_apps/application_briefs/13-2.htm

BTW I have an Epilog Summit - 25 watt laser.




Any input would be greatly appreciated.


More info found:

I have been looking around a bit more and came across:
http://thermark.com/web-content/Thermark_Proc/how_apply_inks.htm
they advertise a couple of products that are spray on chemical treatments to produce black or colored (many colors avail.) marking with a laser. This product comes in a paste form (paint on), aerosol (spray on), and tape. I am having a hard time deciding between aerosol and paste. Does anyone have experience with these or similar products?

I use the Thermark LMM-14 in a spray can once in a while on clear anodized alum., works OK. Mostly use it on steel.
Using a 25 watt Mercury Laser-Pro at 100% power and 30% feed.
They have other products that might work better with the alum., but being this is "general purpose" you can use it on various metals and it's quick and easy to use as a I get it in a spray-can.
*One note, after lasering, the best thing I have found to wash the excess spray off is to soak in COLD water for a few minutes and it rinses off nicely. Avoid rubbing the lasered area and NEVER TRY TO RINSE OFF THE EXCESS WITH WARM OR HOT WATER!! this will activate the spray and turn the entire area dark. Good luck!
Don

You should not need Theramark. I sell Marking Equipment and with the Laser I sell. You use 95% power, put your Frequency at about 50,000, and your scan speed @ 1250 and use about 3 passes. This should put a mark on any anodized Aluminum.

Will this leave black marking on Clear?

Yes it should be. You may have to change a few of the settings a little, but it should be black.

I've been using Cermark for about 4 years now. I've done SS, Bare Alum, Chrome plating and Titanium.

I initially bought the aerosol can; however, the pressure ran out quickly. I punch a whole in the can and dumped it into a glass jar. I now use an airbrush to apply the solution to the item to be engraved. I highly reccommend this approach. You'll get better results and not waste as much of the solution; which is like the price of gold. I haven't tried the colors yet. None of our customer's have requested color.

I believe I bought mine from Laserbits.com. Pretty much the same price as anywhere else at the time.

A better option would be to see if Epilog carries a high density lens for your machine. I recall something about a flying lens, similar to their new Helix model. I run a ULS 30 Watt machine and Universal sells their metal marking C02 lens for around $2500. Obviously you'll need to have a good demand in order to justify the cost.

Best of luck!
-Ed

Does this kind of marking on aluminium plate lasts long ? It will do it for outside? I need it for parking plates sticked to the floor.
Luis