Black marking on aluminium without cer/thermark

**Arjen Abbestee** · 03-12-2014, 12:09 PM

I'm sure this has been asked before, but my search returned no answer... What kind of laser (in terms of wavelength and power) do I need to make black (or at least very dark) markings on clear anodized aluminium like the back of an iPad? I have a CO2 laser that suits my purposes fine but the question 'can you make black markings on my ....' comes up quite often...

tnx, Arjen

**matthew knott** · 03-12-2014, 1:25 PM

Fiber laser or YAG is what you need, so around 1000nm, it will get you a very dark grey that most would be happy to call black. Much harder to get black on plain aluminium but clear anodised is ok.

**Arjen Abbestee** · 03-12-2014, 3:48 PM

Thanks, I figured it had to be around 1000nm, since yag/fiber and co2 are the most 'common' lasers used. If time is of no importance, what would be the minimum wattage to make dark mark (not the Harry Potter kind) on anodised aluminium?

**matthew knott** · 03-12-2014, 3:52 PM

10 watt would be fine for muggles like us !!

**Arjen Abbestee** · 03-12-2014, 4:19 PM

But I still feel like a wizard when I cut thing on my machine!
Now I'm starting to wonder if it is at all possible to 'convert' my machine to a YAG. I know Trotec has a machine that does both, but I assume you cannot use the same optics for both CO2 an YAG due to the very different wavelengths. But if I read it right a yag laser module plus power supply can be had for less than $1000,-. But I'm sure there is more involved than just replacing the CO2 tube with a yag module...

**matthew knott** · 03-12-2014, 4:29 PM

dont think you will get a pulsed yag laser for $1000 !! A fiber laser source is about $5k, then a whole load of work, you can use the same optics in both 'IF' you have the right optics, glass type (normally used for yag) is a no-no as the co2 will destroy them. In theory in can all be done but its fair from easy and you would need to know exactly what your doing plus all the safety implications to think off ! My advise don't try it Arjen

**Arjen Abbestee** · 03-12-2014, 4:35 PM

I may feel like a wizard but I know very well I am not one. So I won't try anything before I know everything there is to know about this stuff and as you may have guessed I have a long way to go...
I saw this page (don't know if posting links is allowed here): http://www.aliexpress.com/store/grou...252099148.html
Maybe this stuff in not at all usable, like I said, still a lot to learn but having so much fun doing it!

**matthew knott** · 03-12-2014, 5:06 PM

thats a good price for a diode side pumper head, i remember paying ££££'s for them. you still need to add a diode PSU, a q switch, a q switch driver, a water cooling system (+/- 0.1 deg), front and rear mirrors, beam expander, a load of machined metal work, wire, some electronics and you off and running, think about another 4k of parts to start lasering !!

**Arjen Abbestee** · 03-12-2014, 5:25 PM

So this will be something to consider when I look out the window and see a long queue of people all waiting to have their iPad engraved in black. Not anytime soon I guess, but one can dream...
It would be nice though to have a machine that can be converted from co2 to yag when needed. When the optics are the same you'd 'only' have to replace the tube (and connect the right supply and driver etc.) and you're good to go. Oh well, maybe some day.

**matthew knott** · 03-12-2014, 5:43 PM

Easier, better and probably cheaper just to get yourself a new fiber laser that's ready to go, then you have both that you can use at the same time! just stings the wallet a bit at first!!!

**Arjen Abbestee** · 03-13-2014, 6:15 PM

Ah, now you're being practical. Where's the fun in that?

**Chuck Stone** · 03-13-2014, 9:37 PM

can you overpower (remove) the anodized layer and color fill?

**Arjen Abbestee** · 03-14-2014, 3:42 AM

My clients mostly come in with iPads/phones/laptops they want engraved. That's why I don't want to use anything wet like cermark or paint...

Has anybody tried a 445nm laser on anodised aluminium?