Laser Engraving on Polished Aluminum Host?

[scumbagatheist]

I've had a client ask inquire about having a logo/name laser engraved/etched into the host for the build. The host is polished aluminum.

Is this something that is possible at a reasonable expense? Does the forum know of companies that are capable of such work?

Thank you in advance for your answers.

 

[Cyparagon]

Yes, that's possible. If I remember correctly, they'll put some sort of temporary coating on it to help absorb the heat. There are a few members here that own engravers that might even give you a better price than any marking company.

 

[scumbagatheist]

That would be an ideal solution! I look forward to hearing from someone. Frankly, if it's that difficult, I'm not terribly interested, myself.

 

[Livinloud]

i was thinking of engraving a few of my hosts and the only thing i thought of was a shop called "things remembered" not sure if you know of them but they basically sell a ton of silver and metal stuff that women would buy i.e. jewelry boxes and that stuff. bought my mom something from them a while back and they did a great job engraving it. iirc they engrave in store so my thought was to bring them the battery tube section and see if they could engrave it. it may be a long shot but check it out. afaik they are nation wide but may be wrong. ill be checking with them in the next month when i get home, dont think there is a shop in tampa but if there is ill check this week

 

[scumbagatheist]

I'm familiar with Things Remembered. But, my client does not want a mechanical engraving. I guess I should specify Laser Etching is needed.

 

[Livinloud]

oh i see, well there is a machine shop in my town back home that could do it easy but they are a multi-million dollar company and would probably charge a decent amount for a one off job. they have every machine under the sun and i know they have a laser engraver sitting next to their million dollar CNC. i know the owner really well so i can see if he can do mine flashlights and if he says yes i would "slip" yours in as mine. if you dont get someone here to do it then i will be back home in two weeks. ill keep checking in to see if you got the job done or not. now that i think of it, i may have him make me a few dozen heat sinks maybe brass or titanium

 

[scumbagatheist]

Thank you, LL. That is very kind of you!

 

[Livinloud]

i cant promise he will even take my work but i figure its worth a shot to ask. ill check back in two weeks and see your status and then ill ask him if he will do this for me

 

[Phryan]

I am new to the LPF community but would be more than happy to help out with any custom laser engraving. I have been doing it for a while and can engrave about anything. Send me a PM if your interested.

 

[hwang21]

By no means an expert, but would a CO2 gas laser be enough? Just to mark aluminum? There's a few powerful gas lasers owned by LPF members here

 

[Phryan]

To mark most bare metals a cermark spray is used. The heat energy created from the laser fuses the cermark to the metal creating a durable black mark. This method is used on a lot of aircraft and military parts for serial numbers. It gives a good contrast with the black on metal compared to blasting wattage. High power does have a cool looking effect if dialed in tho, I am not exactly sure the science behind it but it can give the metal a rainbow oil slick effect. It is hard to see unless held in sunlight, i assume it is from super heating the metal. Too much power dents and burns unevenly. Cermark coating has a clean professional look and similar durability to anodized finishes.

 

[Livinloud]

have any photos for examples of this process and finished work?

 

[Phryan]

I dont have any personal pics or videos of this yet but here is a few youtube links, i searched "cermark spray." I do have experience with the product tho and it works great. Last winter I did a full set of Snap-On tools for a mechanic in trade for some auto work. I will get some pics posted of some random items ive done over the years.

CerMark Colored Metal Marking Paste - YouTube

v=Nq8rwpZopJk"]http://www.youtube.com/watch?v=Nq8rwpZopJk[/URL]

 

[Spooky]

Utoh,

Cermark, Thermark etc make an polar covalent bond between the coating and base material and while very strong it can depend on the base metals (a lot of hosts are some pretty dirty alloys that don't like chemical bonding). I do a LOT of engraving and won't touch the Cer/Thermark stuff where possible.

Plain gas CO2 lasers can be destroyed by trying to engrave aluminium, the index of reflectivity for Al is close to 90% and few lower quality lens's have an anti reflective coating both sides. Backscatter running back through the optical train can easily destroy tubes and lens's (usually the output coupler on the tube and final lens) so I would seriously recommend not trying it on anything less than a big industrial CO2 (even then it requires specialist set ups to process properly)

Yag is a different matter, they direct engrave on Al very well (and at quite low power) they can achieve a surface (sub 0.05/0.1mm depth) on Al quite easily and can run to 3mm depth for colour filling if really required using higher powers.
Fiber will also work on Al but the beam quality can be a little "off" on the cheaper Fibers if you want clear , very small engraved areas.

Compared to Yag/Fiber, cermark/thermark is expensive, the solutions or tapes cost quite a bit and the process is long winded for what you get.

To give some idea, a picture/text of 10 mm by 25mm on my Yag Galvo would usually get change out of 10 cents an item if I was doing a few and likely change from 2 bucks as a one off.

Engraving on anodised aluminium is totally different, a normal pretty low power CO2 gas laser will work from 25 watts upwards. All it does is leeches the colour from the hydroxide surface leaving a pale white on background look.

best wishes

Dave

 

[Phryan]

In my experience the finished product has always turned out well. I completely agree on avoiding the spray when possible, as it is more expensive and time consuming.

 

[Spooky]

It is indeed great stuff Phry but the variation in Chinese aluminium alloys can cause a lot of problems. I used to use it before getting the Yag but now I won't touch the stuff especially at what it costs and the cleaning up afterwards

cheers

Dave