My First Enclosure Etching Experience... gone horribly horribly wrong

[jlullo]

I just thought I'd share my catastrophe with you guys tonight.  A little anecdote before bed!

I was overly excited to try and etch my first enclosure.  This afternoon, I completely tore apart my Caitlinbread Super Chile Picoso.  I didn't like the vinyl covering that came on it, and besides, the knob was completely stuck to it so that it wouldn't rotate.  I figured this would be a good chance to take a peep at how he built it, and try my hand at etching!  Cake, right?

Once I was down to a bare enclosure, I started to follow Mark's photo guide.  I had read this over a bunch of times, and felt ready to dive right in.  I wet sanded until it was shiny and clean.  I didn't have any PnP Blue, so I figured I'd try drawing across the surface with a Sharpie, since I had read that this works great as well.  I had a super simple design, with just "Super Chile Picoso" written across, then the entire face covered in Sharpie ink.  I then covered the sides and drilled holes with masking tape.  Just for good measure, I covered the majority of the face with masking tape, leaving only a box exposed around the text.  Mind you, that box was filled in with ink, except for the block lettering.

I dropped the enclosure in the etchant after heating the FC, and slowly rocked it back and forth as it fizzed away at the enclosure.  Quite a few times I pulled it out and rinsed it off so that it wouldn't get too hot.  I'd say it spent about 20 minutes in total in the etchant.

When the surface looked green around the area where I wanted it to etch, I pulled the enclosure out and anxiously peeled off the masking tape.

"Man, this whole entire thing looks black", I thought to myself.  "Whatever.  It's supposed to look like this."

Once the entire enclosure was peeled like a withered, rotten skin; I got to see the dirty fruit inside.  After sanding away at the surface to expose my beautiful artwork, I noticed that the etchant ate completely through the Sharpie ink in the exposed area where there was no masking tape.  A sloppy, black rectangle.

You'd think the story would end there, but of course I wouldn't be truly a part of the male sex unless I thought that I- inexperienced as I am, knew enough to fix it.

After wet-sanding the hell out of the face with 100 grit sandpaper I was slightly able to hide my nasty artwork.  I figured I'd save the whole design by scratching up and dry sanding the face with the 100 grit paper again, etching the entire face to get a pitted, "aged" look to it, wet sanding it, and then just paint the sides of the enclosure with a flat black paint (like in Mark's beautiful designs). 

After preparing the sides, again with masking tape, I dipped the face of the enclosure back into the etchant. 

As a side note, have any of you noticed that the gaseous by product of the etching process smells like rotten eggs?

I let it fizz and pop for around 3 or 4 minutes, because I saw how fast it worked the first time.  Smoke was actually pouring out of the container, and it got hot quickly.  I rinsed the enclosure off in the sink again, and started peeling back the masking tape.  This time, I noticed that since it got so hot so quickly, the tape started to peel away in places, and etchant seeped up along parts of the sides.  It also turned that big rectangle to a lovely copper hue.

This time, it took about 10 rigorous minutes of wet sanding with the 100 grit paper to make the face look even slightly presentable.  The sides- well, I've stopped caring for tonight.  I figure that I'll still paint them, and try to polish up the face as best as I can- battle scars and all.

For what it's worth, I learned a few things.  I know absolutely nothing about what I'm doing,  I am not artistically inclined with etchant and an aluminum enclosure, and that was a hell of a lot of fun for absolutely no gain to the outcome.

It's kind of like playing with my chemistry set when I was 10.  Let's hope etching my PCB will go over a little better.

[bean]

My first etch experience was so dissapointing I never tried it again. But, with all the buzz lately, I've decided to give it another try (tomorrow, in fact). I think the combination of sharpie and leaving it in way too long is where you went wrong, but I'm sure you already figured it out. Still, it's hard not to be inspired by the great boxes we've been seeing lately! Better luck next time.

[Snuffy]

Yeah, you'll get it soon no doubt... Probably would be best to pop a few bucks and go for the PnP
I've got some sheets myself but I've been putting it off... gotta get the right design, ya know

[markm]

 
Well then, Yeah, Sharpie pens are not really the ideal mask for etching enclosures.
Some guys like them and use a Sharpie with great success but, I prefer a better mask myself.
Sharpies are great for PCBs but not don't seem to be durable enough for enclosures.
BTW, 20 minutes is a very long time to be in the etchant, that's one of the problems too.
I hope you'll give it a shot again because it does work quite well and remember, the etch does not have to be
very deep on the enclosure, I have found lately that a shallow etch on the top of an enclosure gives the best results.
Good luck ! 

[MetalGod]

remember, the etch does not have to be very deep on the enclosure, I have found lately that a shallow etch on the top of an enclosure gives the best results.
Good luck ! 

That was my main problem - I etched for too long thinking that the etch wasn't deep enough.  I ended up with some pitting, but all in all I'd say mine is more of a 'second' than a complete nightmare.

[jlullo]

thanks for the tips guys.  i'm going to give it another shot when the PNP gets in on monday.  i guess that's what a whole lot of ambition and very little patience gets you