Brass Tag

Laser engraved and electro etched brass plaque

Hey guys, welcome back to the Bill & Rae show

I wanted to do a rundown on the process I used to make this brass product tag

I have been trying for weeks to get this figured out

I had seen and read about this idea that you can spray paint metal, laser engrave your design and then etch the metal either with acid or electro etching

In my case I am using thick brass sheet and a 5.5w diode laser, the Atomstack M40

I tried several black spray paints and a few brush on paints but without good results until I ran across a post in Reddit specifying Lacquer paint and cleaning the laser burned residue with Naphtha.

Finally, this was the trick that made it work

The black Lacquer paint I used was Rust-Oleum and my laser was running at 90% and 600 mm/min

Once engraved, it looked like the metal was exposed but I believe there is still residue

The next important step is to clean any residue without damaging the rest of the paint

This is where my other attempts failed. Scrubbing the residue would take off some of the paint and ruin the design detail

With Lacquer paint I was able to use lighter fluid and remove residue without bothering the rest of it

I am running the electro etch in a weak copper sulfate solution with a coil of heavy copper wire for the Cathode

I am using heavy aluminum wire secured to the back of the brass sheet with tape since aluminum does not react in the process

First I ran 1.2 volts with very low amps around 50ma trying to see if the design was clean enough to etch

Not much seemed to be happening at this level so I raised it to 3 or 4 volts

After 10 minutes the brass looked darkened so I removed it to get a look

At this point I was able to clean off the design in hot water and stiff brush revealing bright bare metal (Just cut a cheap paint brush short for a good scrubber)

I think the first bit of etching attacked the remaining residue

I continued the etch at 10V drawing around .6A for about an hour

During this part the design remains looking like bare metal

This produced a nice deep etch and the remaining paint comes off with acetone

Next I need to color in the design

I tried some Brass Black but was not able to get the deep black I was hoping for

Then I just used black paint to fill the design and squeegee off the excess

When dry a bit of sanding removed the excess paint while preserving the design

Some liver of sulfur gave it a bit of tone and character for the final result I have been looking for