Another way of etching?

[CodeMonk]

Saw this posted on another forum.

Anyone tried this for enclosures yet?
Seems like a negative image printed on laser then ironed on to an enclosure may be a good way to do this is it works.
I have an extra small enclosure, that I may submit to this torture in the next few days.

If it works, well, I'm doing an octavia clone for a friend of mine and I think I may do this to it.

[octfrank]

This is electro-etching, a good example for doing larger pieces is at http://www.instructables.com/id/How-To-Electro-Etch-a-Solid-Metal-Plaque/

[Seljer]

I've done it

12V PC power supply + 12V automotive turn signal lamp wired in series to limit the current to about 1.5A + ice cream tub full of salty water

Ignore the wire colours here, the positive wire should go to the piece that you're etching


I wasn't impressed with my results because there was a lot of pitting, but thats my laser printer's fault and not the etching method's (though it may work better at a lower current). I got a rather deep etch after 10 minutes at this current. I didn't do any further experiments but I think 5 minutes would already by more than enough at this current (I had my multimeter hooked up to measure throughout).

I also tried it to etch a PCB but the problem there is once the copper is etched away between the traces, theres no longer a conductive path for the process to continue. Might work better with a localized approach, etching the copper away piece by piece by using a cotton ball soaked in electrolyte hooked up with an alligator clip.

[duck_arse]

@seljer - how big is the electrode not connected to the box, what's it made of, and does it erode/sacrifice?

[Seljer]

@seljer - how big is the electrode not connected to the box, what's it made of, and does it erode/sacrifice?

Had to rig up the setup again to verify everything as it's been a while since I've sat in a chemistry class

The cathode was bare stripped copper speaker wire. About 15cm of it (new addition: add a clothespin so it stays put). It doesn't erode,  it stays clean as a whistle

The aluminum anode etches away into aluminum oxide (a gray/white powder that mucks up the water). On the copper electrode the electrolyte bubbles away into gas. This time I used baking soda which leaves you without any poisonous gases but it may be a bit slower than using table salt (which leaves you with chlorine gas that isn't that healthy   ). I believe the gas on the copper electrode would be hydrogen

And prepare whatever you're etching well because if it's been sitting around for a while it while have formed the aluminium oxide layer on it own from just being in the air and won't conduct!

[PRR]

The reaction in water *will* produce Hydrogen AND Oxygen.

At reasonable current, not a problem as long as they can float-away as fast as they are produced.

If you close the container and trap the H and O together, all you need for an EXplosion is a spark. And we know where to find that.

[GibsonGM]

A little ventilation is a good thing....the kind of project I'd do in the garage in front of the door

Got pix of the finished product?   Typically I do *stuff* like that with muriatic acid and no electrolysis....if this works, it would be a much nicer solution!    This is how you un-gunk (cosmoline) things like WWII gun barrels, etc....hadn't thought to etch a box this way.

[Seljer]

For a proof of concept, I tried the slightly older method of making the etch resist layer out of hot wax (heated the enclosure up with a heat gun and smothered the block I have for potting pickups on like butter) and scratching the design in with an awl.

Etched in a tub of baking soda and water for about 4 minutes. I held it in by hand though I could have easily put some kind of riser underneath. The etched lines are deep enough to catch your fingernail though they are so thin you can barely feel them with the fleshy part of your finger.



Should have used more wax  because it ate through on the edges on some places. Also, more sanding. Baking soda is a worse conductor than salt so I could have probably let it go for a bit longer.

[allesz]

Thank you Code Monk: I finally etched a pedal (my drive easy) with the method you posted.

Nothing fancy: V (for volume) and a capital gamma letter (for gain, of course) and a small thunderbolt drawing; I used eletrical tape for masking, a 20V adapter, a solution of vinegar and salt and some q-tips.

I always hated using paint (never had good results, but maybe I am just too lazy ) for the finish and acids for etching boards and pedals (I only build on perf). I don't sell pedals btw, so I never had to get something professional looking.
I always went with tape, stickers and markers... this is a revolution.

THANK YOU