Laser Engraving Copper

[James Cogbill]

Looking to engrave / laser mark some Copper with my Trotec Speedy 300. Never tried it before. Can anybody recommend some tips, or Power and Speed settings for me? Thanks!
Best,
James

[Tony saunders]

Not good I'm afraid... Even with a fibre laser , it's slow and not a good mark. Copper is a great heatsink and very resistive to CO2 lasers.

However, using Cermark you can get a result. You've not said what power your 300 is though?... On my 80W I still had to go quite slowly in order to really make the Cermark fuse properly but it did have nice contrast.

T

[Dan Hintz]

Tony's right (and we're both assuming you have a fiber laser in that Speedy as a CO2 won't touch it)... you will have a heck of a time getting a mark with much less than a 50-70W fiber, and ideally it should be 100W+ to really get something useful. Copper is just too reflective to work with low powers, even at 1 micron wavelengths... a 532nm fiber is better.

[Mike Null]

James

Don't know if this will work for you but JDS offers a copper finished aluminum which can be marked with sublimation or color laser transfer. It is suitable for plaques and decorative applications.

Cermark has a new item called LMM 6060 (Johnson Plastics) which you might possibly use on bare copper but I have my doubts.

[Joe Hillmann]

Depending on the mark you want you could cover the copper with a mask, engrave through the mask then use a sandblaster to do the marking.

If the copper is at least somewhat polished sandblasting will leave and easy to see mark.

[Hannu Rinne]

Here is my test on brass and copper:

Picture 1. test file
Picture 2. blank plates
Picture 3. Thermark LMM14
Picture 4. thick layer of Thermark added
Picture 5. washed plates
Picture 6. polished plates with Autosol Metal Polish
Marking on brass is permanent after polishing, but copper is not so good. I think lower speed and higher DPI settings will make more permanent marking.

Regards,
Hannu

[Gary Hair]

Picture 4. thick layer of Thermark added

If you look at the lines in your coating you can see that they follow the lines that are missing on the copper piece. You really need to spray it on in a thin coat to get marks that are consistent. Since you have 60 watts you can get away with more than I can with my 30 watt machine, but I bet you'll get better results if you spray on a very thin coat. It may be different with Thermark vs Cermark, but I don't think so.

[Hannu Rinne]

If you look at the lines in your coating you can see that they follow the lines that are missing on the copper piece. You really need to spray it on in a thin coat to get marks that are consistent. Since you have 60 watts you can get away with more than I can with my 30 watt machine, but I bet you'll get better results if you spray on a very thin coat. It may be different with Thermark vs Cermark, but I don't think so.

Gary, I only have a large paintbrush to do this... - ok, I will try a thinner layer!

Best Regards,
Hannu

[Dan Hintz]

I bet you'll get better results if you spray on a very thin coat

Seconded... thick coats do nothing to enhance the mark, and generally prevent a good adhesion to the substrate.

[Mike Null]

Hannu

While I prefer an airbrush I have a couple of regular jobs where I can't use it. There I use a small sponge brush and get excellent results.

I also prefer a thin solution.

[Nick Mauer]

We engraved copper mugs recently. Kept our speed as usual but had to turn our power up quite a bit. When we use LMM14 on stainless, we use 20-30% laser power, on copper we needed to go to 40-50%, if I remember right. Ended up with a really dark mark that adhered just as well as stainless.

[Gary Hair]

Gary, I only have a large paintbrush to do this... - ok, I will try a thinner layer!

Best Regards,
Hannu

Even with a paintbrush I would try thinning it down quite a bit - so thin that it's like milk. It will run all over the place, but you can put a good sized drop in the middle and tilt it around to spread it. You'll see how thin you can go and still get a good mark.

[Dan Hintz]

When we use LMM14 on stainless, we use 20-30% laser power

Trotec SP1500 400-watt

I hate you, Nick

400W must be all kinds of fun...

[Hannu Rinne]

I made Thermark as thin as possible and I added also as thin layer as I could, as Gary and Mike suggested. Is there a rich, black mark after engraving ? No, it went inside to the material approx 0,14mm! Now the copper plate is like etched or engraved with blade… I don’t have a suitable gauge to measure it but the marking truly is deeper than 0,1mm.

Am I some kind Nobel candidate now ?

Regards,
Hannu

[Nick Mauer]

I hate you, Nick

400W must be all kinds of fun...

Sir, it is a blast! We're still trying to find that mythical glass ceiling.