Acid for enclosure etching?

[Timko]

I've gotten decent at doing acid etches for my enclosures, but one of the things I've noticed is they don't see to etch very deep.  I've been using this (bought it locally)

http://www.mcmelectronics.com/product/20-5555?scode=GS401&utm_medium=cse&utm_source=google&utm_campaign=google&gclid=CNrtjre2jssCFQsPaQodk0YP8A

If I wanted to use something other that PCB etchant, what should I look into?  I'm looking for good, deep etches with sharp lines. 

[kgull]

I've tried muriatic acid once or twice, had some left over from cleaning a concrete floor. I don't do a lot of etching these days but that stuff will plow through metal at a terrifying rate. Think we've got a few chemists on here that can weigh in better but a lot of the super nice etches I've seen lately tend to be done with muriatic.

[m-Kresol]

muriatic acid (HCl) will work, but I would definetly not recommend using it as it's basically just a solution of a gas and thus releases stinging, corrosive gas. Neither good for you nor any metallic things around the house. I've also heard of people using sulphuric acid (even in combination with H2O2). Don't do it! just don't. way to aggressive and certaintly not something for hobbyists.

sodium hydroxide (NaOH) is what Graham is using and it works well (http://diy-guitar-effects.tumblr.com/etching). I've tried it too, but found that it is more agressive to the toner than FeCl3. It's cheaper though. I've been using FeCl3 lately (in a rather concentrated form), but will give NaOH another go for sure. Maybe your FeCl3 solution is just not concentrated enough to give a good etch before it eats away the toner.
I found that it is often deeper than it looks at first. You just neet to clean the gunk off thouroughly. Even if it's not that deep, it's most likely deep enough for painting and sanding it. What also works instead of sanding (especially with shallow etches and fine lines) is just scratching the paint of very locally with a spatula or fine screwdriver.

[daleykd]

The only thing I'm trying to figure out in regards to NaOH is what to use as a masking tape/spot-fixer.  With FeCl3, I could use nail enamel.  With NaOH, I can't seem to find anything, and therefore, the sides of my enclosure look yucky.

[Timko]

Perhaps I'm not letting the enclosure sit in the acid long enough?  I'm moving it back and forth, etching for between 5 and 12 minutes depending on the amount of exposed metal. 

My etches come through, but someone of the ones I see on here are noticeably deeper and more detailed, making sanding so much easier.  Is there a particular brand of FeCl3 you're using, or are you making your own?

[m-Kresol]

I'm using technical grade solid FeCl3 and make a solution from there. We have that stuff around, so it's convenient enough at the moment. I want to switch to NaOH since it's also easier to get...

I etch way longer than this. around 30-45 min sounds more like it. I do 3-5min dipping it in, then rinse with water and go over the whole surface with a sponge (not the scratchy part!) to remove some of the gunk.

The only thing I'm trying to figure out in regards to NaOH is what to use as a masking tape/spot-fixer.  With FeCl3, I could use nail enamel.  With NaOH, I can't seem to find anything, and therefore, the sides of my enclosure look yucky.

I use parcel tape for the sides. If it gets under the tape it will leave a mess for sure, but you can always sand this off. No solution for the nail enamel though.

[Timko]

I etch way longer than this. around 30-45 min sounds more like it. I do 3-5min dipping it in, then rinse with water and go over the whole surface with a sponge (not the scratchy part!) to remove some of the gunk.

Maybe that's my key.  So you do 30-45 minutes?  Do you shake/move it around, or just dip it, leave it, and rinse it ever 5 minutes or so?

[m-Kresol]

i constantly move it up and done in the solution as Cody does in his tutorial video.

[kgull]

sodium hydroxide (NaOH)

Yep, that's the one I was thinking of that everyone uses...somehow got linked with muriatic in my head.

Definitely a outside thing if you decided to try muriatic though.

[selfdestroyer]

Perhaps I'm not letting the enclosure sit in the acid long enough?  I'm moving it back and forth, etching for between 5 and 12 minutes depending on the amount of exposed metal. 

My etches come through, but someone of the ones I see on here are noticeably deeper and more detailed, making sanding so much easier.  Is there a particular brand of FeCl3 you're using, or are you making your own?

One thing to remember is the enclosure gets hotter the longer you leave it in the etchant. If you do it for to long it can get to hot and your toner transfer will lift. I do mine in 1-2 minute intervals with rinses in between. It extends the process but I find soothing. lol

Cody

[Timko]

I also do it like Cody has on his video, but perhaps I need to be doing it for closer to 30 minutes rather than 5-10?

[m-Kresol]

the initial reaction is definetly stronger/faster as you don't have the gunk protecting the bare aluminium underneath to get through.

Patience, young padawan, patience!

[Orbis_Ignis]

I've used muriatic acid with 30% hydrogen peroxide with decent results. I'm very new at it so they haven't come out very clean. I would do it outside and I would just put some of the acid where I wanted it with a q-tip. I might be messing up some of the toner with the q-tip. Not really sure. But it actually comes out really good. Just not clean lines like I want it.

I think I'm going to try lye with a pipette like the guy in that tutorial. I might try the ferric acid too.

[m-Kresol]

I've used muriatic acid with 30% hydrogen peroxide with decent results. I'm very new at it so they haven't come out very clean. I would do it outside and I would just put some of the acid where I wanted it with a q-tip. I might be messing up some of the toner with the q-tip. Not really sure. But it actually comes out really good. Just not clean lines like I want it.

I think I'm going to try lye with a pipette like the guy in that tutorial. I might try the ferric acid too.

Holy Smoke Batman! Please, please, please stop using that mixture. It will produce chlorine gas, which is poisonous. It will give you lung oedema and worse if you get a high enough dosis! a friend of mine had one as he thought it would be cool to handle chlorine gas as an adolescent, so trust me on this one. This really is not the thing to use as a hobbyist without proper fume hood and safety equipment. even than, I think it's way to aggressive for Aluminium which should work just fine without the Hydrogen peroxide.

Felix

[Orbis_Ignis]

I've used muriatic acid with 30% hydrogen peroxide with decent results. I'm very new at it so they haven't come out very clean. I would do it outside and I would just put some of the acid where I wanted it with a q-tip. I might be messing up some of the toner with the q-tip. Not really sure. But it actually comes out really good. Just not clean lines like I want it.

I think I'm going to try lye with a pipette like the guy in that tutorial. I might try the ferric acid too.

Holy Smoke Batman! Please, please, please stop using that mixture. It will produce chlorine gas, which is poisonous. It will give you lung oedema and worse if you get a high enough dosis! a friend of mine had one as he thought it would be cool to handle chlorine gas as an adolescent, so trust me on this one. This really is not the thing to use as a hobbyist without proper fume hood and safety equipment. even than, I think it's way to aggressive for Aluminium which should work just fine without the Hydrogen peroxide.

Felix

Believe me I don't inhale the fumes. I do it outside with no issues. I use so little of it too. I'm not a chemist but I am a pharmacist so I know about the dangers. I'm not very happy with it anyway, so I'm going to try the other bases/acids mentioned here (lye and ferric chloride. Not together though, lol)