Gold/Platinum Engraving Methods and Techniques

[Daniel Lum]

Hi team,

Long time visitor but finally became a member. Had some questions on gold and platinum engraving and learned a few things on this board. My hope is to build a thread that answers these questions more definitively. I'm a total newbie, and such that others can partake in my research, here are the threads/experiences on Sawmill Creek I've seen:

Threads covering this topic I've read here on the board:
Engraving on 14kt gold
Engraving on silver and gold
Engraving on silver

What I've learned:
+ Some have said that 40W YAG and larger can do a permanent job. I haven't seen too many settings associated with this claim.
+ Ted of Laserscribe is a go to authority on some aspects of engraving precious metals [ maybe all of them ]. I will try to speak to him in the near future. If I find something interesting, I'll try to report it back clearly.
+ *For silver* Keeping the power at near 100% about 8 khz and 200mm/second. I am unclear if this will work on gold or platinum.
+ Read that diamond drag is the only method that really works. Would love to hear more thoughts and opinions here.

What we could use:
+ Any real world examples, equipment, and precise settings folks have had success with on gold or platinum.
+ Whenever possible, pictures of the work is greatly appreciated.

Of course, I've never tested any of the methods mentioned here so your mileage may vary/caveat emptor. However, the whole point of compiling this research is to see if we can create a thread that has more real world examples and tests.

Thanks all for your contributions,
Daniel

[Dan Hintz]

I'm not quite sure what you're trying to "compile". If you want to engrave precious metals, you need to move to the fiber/YAG wavelengths. A 10W fiber will gladly engrave using a 100mm lens, but it will be very slow with very shallow passes. A 30W fiber will get you a bit more speed, and a 50W will get you some very respectable engraving speeds (5+ mm^3/min).

From a frequency standpoint, the lower frequencies (20kHz) will do the main hogging out of material, and the higher frequencies(100kHz+) are good for smoothing/finishing.

[Daniel Lum]

Hey Dan,

Regarding what I'm trying to compile, I've seen a # of folks ask how to successfully engrave gold/silver, and I've seen conflicting takes on what's doable and what isn't. So I'm trying to compile real world examples and the specifications/techniques associated.

Recapping what I mentioned earlier:
+ Any real world examples, equipment, and precise settings folks have had success with on gold or platinum.
+ Whenever possible, pictures of the work is greatly appreciated.

Thanks for your input.

Best,
Daniel

[Ross Moshinsky]

Um, mechanical engraving?

[matthew knott]

We do lots of engraving on the precious metals, read Dans post, its spot on, or do a google search under images for 'laser engraved gold' or laser engraved silver , the photos you get will be what can be achieved, anyone who says you can't engrave precious metal with a laser is simply mistaken, you just need the right wavelength and power,

[Bruce Boone]

I engrave titanium all the time, but do gold and silver with the same settings. I do full power at 80 watts YAG and do lots of passes. I don't recall the frequency off hand, but Dan is likely spot on.

[Dan Hintz]

I'll also add that if you're doing "precious" metals, like silver/gold (not just metals in general like SS, aluminum, etc.), you're better off with UV wavelengths (particularly with silver). A 355um laser would be a huge improvement over 1000um as its reflectance drops like a rock around that frequency. Gold will be highly improved at that wavelength, just not as much as silver. If you're trying to keep a wide range of materials in mind, stick with the standard 1000um fiber and just suck it up for the less-than-optimal speeds for gold/silver.

[matthew knott]

532 (green) works well on gold, you can mark as apposed to engrave with a green laser, Personally I prefer a YAG over a Fiber as at a similar power laser the peak of a YAG is higher, you can get high peak power fibre lasers but the beam quality is not all that m2 of around 1.7 or something. But that's just my preference on the choice of lasers i have here to use.
If you want a UV be prepared to get the cheque book out, they are unreliable and EXPENSIVE !!!

I'll also add that if you're doing "precious" metals, like silver/gold (not just metals in general like SS, aluminum, etc.), you're better off with UV wavelengths (particularly with silver). A 355um laser would be a huge improvement over 1000um as its reflectance drops like a rock around that frequency. Gold will be highly improved at that wavelength, just not as much as silver. If you're trying to keep a wide range of materials in mind, stick with the standard 1000um fiber and just suck it up for the less-than-optimal speeds for gold/silver.