Has anyone had any luck etching copper? I’ve read that CO2 lasers either don’t work due to copper conductivity/reflection or that you have to have at least a 100w laser… Like the new Thunder 
A friend wants help etching a bunch of mugs, and I’m trying to avoid having to buy and deal with that much ferric chloride
To do any etching of the surface of metals you need a peak power over 130 watts. Also the optics need to be specifically configured to keep beam reflections from entering back into the cutting head. Ours does not, please don’t try cutting metal on the new laser.
They do make a CO2 & Fiber combo to do metal marking and wood cutting in one unit.
Don’t worry, I was never planning on testing before asking and I knew cutting was out from the basics class (thanks again for teaching the class @talkers!)
I figured without a fiber laser that I would need to start learning chemical etching… That’s just a headache I was hoping to avoid
You could probably cut vinyl mask and sandblast as an option. I use a product called spray mask that is easier to peel than sign vinyl, and withstands at least surface etching levels of sandblasting. They also have more robust materials for deep cutting that are thicker and more rubbery.
I was planning on testing using a painted brass surface on the laser. You use the laser to etch/burn away the paint (low power, so I believe this is safe and approved), then chemically etch the bare metal with a electrolysis process involving a conductive wand soaked with a mixture of vinegar and salt.
Higher power CO2 lasers (over 1 KW) actually use copper as mirrors. So, don’t even try lasering copper - it could damage the laser.
in addition to vinyl stencil and sandblasting you could use the electrolytic metal etching process.
Several folks on youtube and instructables use this method for metal. there are several variations, but this is the simplest setup: https://www.youtube.com/watch?v=lTInRaM2eTw
Solution: salt water or salt & vinegar
Power source: 9v batteries or battery charger
marker: qtip
mask: vinyl OR for greater detail
→ apply masking tape/transfer paper on the metal. Etch the design on the mask with the laser.
@Haley_Moore can tell you more (sorry!) about copper & brass electro-etching.
I have successfully done the laser paint etching part of this. I used muriatic acid and hydrogen peroxide as etchant though without electrolysis. It worked well once I got the laser power and speed right. I think I posted results in one of the monthly project show and tell topics.
I found lower speeds better since I was cutting traces for a pcb and features were small enough that vibration of the laser head at high speeds affected the results. Multiple passes at lower power worked better (2 passes at 10% I think but I’m sure this depends on a lot of variables).
