Laser engraving metal

[nottingham82]

I think I have a way to etch metal.... stand by for a run down if it works...  Got a tip from a guy on facebook that i'm gonna try today. 

[ThothLoki]

Oh, please share when you test!!!!

[nottingham82]

well it didnt go entirely as planned.  Need to buy some replacement stuff.  More details later.  But as a proof of concept.... I'm getting there!

[Zax]

Not bad for a start. I was expecting an additive process (black mark) but it looks etched so you must be doing something else. 

[nottingham82]

An additive process!!?!? What do we look like? a 3d printing forum?  It's all about the subtraction of materials! actually i didnt expect it to turn goldish.  I will try again today and see if i can get this process working.

[mrehmus]

If that is a Zippo, the underlying metal is brass so what you did is remove the chrome finish.

[nottingham82]

It's not a Zippo but it is a Zippo like device. So it must have a similar construction

[Stonemull]

Activating a chemical like an acid or alkali i reckon.

[Tonyaloney]

I made a few test runs at metal. Gonna upgrade my 2.8w laser to a 10w and try again.

I did find that an additive helps the etching process when I was using a 2.5w laser. Haven't tried it with my 2.8w laser.

I took a Sheetrock mud spatula (shiny chromish look) and sprayed chrome moly lube on it. Let the spray dry completely, then burn away. It leaves a dark etching on the surface once you wash the lube off after you burn it.

I did manage to get good results on anodized aluminum business cards. I just have the 1 picture I took, which is attached below....

[nottingham82]

got it!  Ok so the results werent amazing because I need a rotary axis.  Here is the process


Paint your piece
remove the paint with the laser creating a mask
get an old ac to dc charger.  5-12 volts 1-3 amps. 
wire the negative to a piece of copper
Wire the positive to the piece
wrap the copper in in cotton and dip in salt water
dab the cotton wrapped copper on the mask for 5 seconds at a time
when done remove paint.

[nottingham82]

I hit the schneider one with some ac after the dc.  it arcs like crazy and is supposed to darken the etch.  I think it did.  The ranch one should have been smaller.  It got too out of focus.

[ThothLoki]

DUDE!!!! STOP!!!!!

Now I have to do this as well. First wood, then slate, then glass/acrylic, NOW METAL!!!

Seriously, that is friggin SWEET. Thanks for sharing. I too am looking at rotary designs. The wife wants some wine glasses etched. Now I can etch my stainless coffee mug!!!!

[nottingham82]

haha first a 3d printed cap now a laser mask electro etch.  Your coffee cup is all modded out.

[nottingham82]

fyi you may electrocute yourself.... thats why you need to use low volts and low amps.  If you electrocute yourself that is your fault so no blaming me!   Oh and the most of the new dc converters wont work because they are smart and wont let you short circut them.  I got mine for $.60 at goodwill.

[ThothLoki]

I have already electrocuted myself way too many times. I am in construction, it's part of the job (at least thats what they tell me). I have a huge box of wall-warts of various voltages and amps. I am sure I will find one that works.