First box: etching attempt

[Reelo]

Hi everyone.
I'm currently building my first "stompbox" (the Noisy Cricket amp, so it's not really a stompbox) and I've tried etching my hammond box. Since I kept reading Caustic Acid (NaOH) works well on aluminum I went that way and tried it. I used a 30% solution (strongest I could find). My verdict: Don't bother trying. After more than 30mins I guess I got as far down as 1/2mm which is nowhere as deep as I'd want it to be.

So now I will try to get my hands on FeCl3 since you guys say it works well on the boxes too.

My question would be: How exactly does the etchant need to be:
Say, if I had FeCl3 in solid form, how would I need to dilute it to get the right acidity? Do I absolutely need peroxide as well to etch?

[glops]

I have good results using a good press n peel transfer to a well sanded box:

I put the box in a plastic container face up on some scrap wood.  I applied ferric
chloride (from Radio Shack) with a huge syringe.  A good amount of ferric and keep
applying by using the syringe and the run off.  This keeps the solution agitated.

I do this for awhile and try not to let the box get too hot and then dunk the box
in a plastic tub of water regularly to inspect the progress.  I repeat this step
until satisfied.  Here's my last two etches for a couple of Shin-Ei Companions made for friends.  Had originally
painted the etched parts black but had too much dust on the clear coat so I used acetone and a toothbrush
to remove the clear.  Was going to completely strip it and start over but liked remnants of the black mixed with the
ugly etched parts.  Cleared over it this way and they came out really great to me...

[Reelo]

Ok, got m'y hand on some FeCl3 pellets, but how "strong" should the solution be? I read something about 10% is that enough?

[glops]

I would use the search function for that query or if you live near aradio shack you could take a look at the chemical breakdown and go from there. Trial and error is something you want to avoid as much as possible since it's too expensive on boxes.  My first two boxes came out great but the 3rd and 4th came out horrible.  I tried to etch using glossy magazine paper but it didn't work well on enclosures but fine for PCB.  Bestresults using pnp and not letting the box get too hot while etching...

[Kearns892]

Just got a bottle of the stuff from radio shack, however it does not give a breakdown of the dilution of the chemicals. Sorry I can't be of more help.

[Reelo]

Well, here's the final result of my fiesta attempt. I used ferric chloride. Please tell me what you think, also of the design itself.

[Earthscum]

Looks better than my first attempt! I found that the more "spent" (won't etch PCB's) the FeCl is, the faster it etches aluminum. As a matter of fact, I have stuff that is totally spent that will actually cook off the edges of my mask. That seems to be the problem I was having. Now I have it down that I can etch a pedal in under 10 minutes.

My first one ate away through the mask so bad that I wasn't able to sand down far enough to take out the pits... but it looks kewl anyways! I'll get pics up in the gallery one of these days.

And gratz on your first etch!

[glops]

Your noisy cricket looks great. Good graphic design. I like when the acid bleeds through and you get some pits.  Great job, man