Etching the aluminum box

[Beach_bum]

Hi,

I am new here. This is my first post. I built a harmonic percolator and put it in an aluminum Hammond case.

To label the controls, i just painted IN, OUT, BAL and Harm with Testors model paint and a small brush. But I would like to print the labels more professionally.

I wonder if a laser engraver would do the job. The box is unpainted aluminum. I thought about buying a 10w diode laser, more than 10 watts and it gets too expensive for me. Does anyone here use a laser engraver on their boxes?

My guitar playing buddy said my harmonic percolator sounds pretty good and encouraged me to build more boxes.

Thanks,
Erik

[stallik]

Welcome.

I don't have a laser but I do know that painting an enclosure then using a laser to etch away the paint to create the labels gives a very good effect and requires a lower powered laser than the one required to etch away deep enough Chanel's in the plain alloy.

[deadastronaut]

if you want to actually etch, heres my tutorial on how i do it.....

[R.G.]

I wonder if a laser engraver would do the job. The box is unpainted aluminum. I thought about buying a 10w diode laser, more than 10 watts and it gets too expensive for me. Does anyone here use a laser engraver on their boxes?

Sadly, no, the common laser engravers will not do the job.

The low end lasers are either diode lasers at about 5-10W, or CO2 lasers from 20-50W. Aluminum reflects high-90s percent of the light from these lasers and what does get into the aluminum gets conducted away too fast to heat the aluminum much. Essentially, the aluminum just kind of sits there and laughs at the laser.

As mentioned, both might be able to burn off paint or powder coating.

[Mark Hammer]

Ferric chloride will etch your plumbing, just like it etches the box.  So it's a good idea to keep a plastic container with baking soda in it, to shake off the excess etchant into, before running it under the water and letting the etchant go down the drain.  When baking soda and etchant meet, foam is created.  The foam is harmless and can be put into the trash once it dries and hardens.  Baking soda is also recommended for disposing of well-used etchant.  Just be forewarned: the foam reaction is quick, hot, and big.  Unless done a bit at a time, you may find yourself with a big foam blob quickly spilling over the sides of the container and permanently staining whatever surface it lands on.

There are many occasions when an etch is taking a little longer than I was hoping for.  On those occasions, I keep a hair dryer handy, hold the board face up and blow hot air on the still-wet board.  You can see the chemical reaction speed up and the etchant turns black as it eats away the metal.  I don't etch patterns on my enclosures, but I see no reason why a 20-30 minute etch couldn't be reduced by 5-10 minutes by occasionally turning the box face up and applying a little heat directly, before turning it over and putting it back into the etchant.

[ElectricDruid]

A *laser* engraver might not work, but a *normal* engraver would. A X-Y routing table with a engraving bit would manage soft aluminium with no problems.

[amptramp]

If you don't like chemical etchants like ferric chloride, a good alternative would be electrolytic etching where the item to be etched is connected to the positive side of a DC supply and a plate made of the same material is connected to the negative.  A salt of the same metal is used as the electrolyte.

[Beach_bum]

Thank you everyone for the information. I purchased a 10W laser engraver for $350.00 and it does not leave a mark, lol. I am still learning to use it however with laser GRBL software and it is cool and fun for other things. When they say use it in a well ventilated area they mean it, it smells bad and sets off smoke alarms. 

Here is  a picture of my HP-2 clone and the laser. I am giving the box to a guitar playing friend for evaluation. I can not play a single cord. 


Erik

[R.G.]

If you've already bought the laser, try spraying the box with a covering of (preferably black) lacquer, then lasering off the places you want etched. Once that's done,  put the etched surface face down in etchant. It should etch only where you've lasered off the lacquer  - and only to the degree that the laser actually removed the lacquer, as others have found.