Best way to etch the box?

[rockhorst]

What's the best process for etching alu enclosures like a Hammond 1590? Any restrictions on etchant to use, sanding the box down, etc.?

Especially directed at people like Markm. It surfaces once in a while in the pictures thread, but I couldn't find a real thread about it.

[Snuffy]

I think this might be what you're looking for:

http://aronnelson.com/gallery/album24/FXsign

[MartyMart]

http://aronnelson.com/gallery/album24

It's all here

MM.

[darron]

tips for things that held me back:
- make sure your transfer is as close to perfect as possible. don't use too much/little heat from the iron.
- don't buy the ferric chloride powder. get the liquid stuff! it's mixed to the perfect ratio.
- agitate while etching. it loves it
- if you are doing things with fine detail, etch deep enough so that when you paint and sand you ewont sand the paint out.
- for the paint (if you want to use it), i found a spray can that's designed to painting steel and aluminium car wheels and it is chip resistant. PERFECT if you can get something similar.
- spray the paint in very thick so that it fills all of the holes. the correct way to do this would be lots of light coats, but i find it's better to lump it in one THICK spray and wait extra time. less effort.

i'm interested... what are people's thoughts on spraying with a clear or similar afterwards? i havn't tried it.

please send us pics in this thread when/if you finish an etch!

[rockhorst]

AH! So there it was! Apologies!
As for the etching: I ordered some powder stuff (oops?), but thinning it down to a decent concentration (suggestions) shouldn't be too hard. I'm gonna have a first go on both PCB and on box-etching, expect results early next week.

[rockhorst]

Question: Around step 24, the box is pulled out of the etchant after about 3 minutes in total, and checked. After that follows a final rinse step. Has the box been in the etchant again, or does the whole etching take just those 3 minutes?

Additional Q: is it unwise to re-use the same etching solution that was previously used for a copper PCB and then for an aluminum box? I can imagine that there is no real problem as long as the etchant solution is still strong, but I'm not sure. It's a long time since my last chemistry class.

[markm]

Question: Around step 24, the box is pulled out of the etchant after about 3 minutes in total, and checked. After that follows a final rinse step. Has the box been in the etchant again, or does the whole etching take just those 3 minutes?

This is a wishy-washy answer but, it depends.....
In that particular instance, it was in the etch 2 times. the best thing to do is keep checking it frequently. The 3 minutes is really the total time because once the FC starts working, it doesn't take long at all.

Additional Q: is it unwise to re-use the same etching solution that was previously used for a copper PCB and then for an aluminum box? I can imagine that there is no real problem as long as the etchant solution is still strong, but I'm not sure. It's a long time since my last chemistry class.

I don't know the answer to this as I have only used new etchant however, you can use it "watered down" a little bit to make it less aggressive but, it will take much longer.

- if you are doing things with fine detail, etch deep enough so that when you paint and sand you ewont sand the paint out.

Not too deep though....I've found the best results are not always that deep at all.
If the surface of the enclosure is completely flat, this shouldn't happen.....at least it doesn't to me.
Good Luck and have fun,
  MarkM

[zjokka]

hi, will be etching my first box somewhere soon after I'v learned to invert black/white in illustrator. but do have some questions

1) have used HCl + hydric peroxide to etch pbc which worked fine and clean. Don't know about the hammond boxes? Has anybody tried this before?
2) only etched with photopaper and found that you cannot overheat the paper. Is this a danger with pnp? have some lying around, haven't used it yet. Will try it for etching the box if it's easier.
3) MarkM, I understand how the lettering turns black from etching but in the photoessay you spray it with silver paint all over. Then you sand and the letterings colors black again?!? I thought the whole point was that you could sand off paint on the lettering, because it's into the box.

here it is covered in silver paint


here the lettering is black again



Do you have to stick with the color you originally coated the sides with? I mean, you cannot leave it bare metal?

thanks for so much pioneering work
zj

[markm]

 

I'm a bit confused as, I didn't paint anything silver in the tutorial.

[Pushtone]

1) have used HCl + hydric peroxide to etch pbc which worked fine and clean. Don't know about the hammond boxes? Has anybody tried this before?

Do you have some on hand? Give it a try and let us know how it worked!

2) only etched with photopaper and found that you cannot overheat the paper. Is this a danger with pnp?

I find that if the iron is too hot the toner smears and bleeds.
Instead of the PnP sticking in one place it slides around smearing the transfer.
The backing can take a lot of heat. Its the toner turning to a thick melted liquid.

I use the polyester setting on my iron to do PCBs but an aluminum box top seems
to need a little more heat. I always stay under the cotton heat setting though.

[zjokka]

I'm a bit confused as, I didn't paint anything silver in the tutorial.

metallic then? http://aronnelson.com/gallery/album24/FXzzz3a?full=1
sorry didn't work to embed the pics. It is some paint still, as you say yourself

"couple of light coats of paint to the top. Any color could be used really but, lately I've been doing the "brushed aluminum" look with black lettering. Sometimes it's best to keep it simple."

this covers the embossed lettering, right? I suppose if you smear shoe polish or paint and sand you could bring out the lettering again, but that's not how you did it.

1) have used HCl + hydric peroxide to etch pbc which worked fine and clean. Don't know about the hammond boxes? Has anybody tried this before?

Do you have some on hand? Give it a try and let us know how it worked!

I do and I will. Just trying to find out the best way. Never used ferric chloride, but from the reports this method is produces less harmful fumes and can be disposed in the sewer if diluted with plenty of water. Even the chemist was surprised when I told him why I wanted it. He mentioned ferric chloride and the old days.

I use the polyester setting on my iron to do PCBs but an aluminum box top seems
to need a little more heat. I always stay under the cotton heat setting though.

I always used the highest setting when doing pcbs, and if I'm not mistaken, polyester (because it can melt) will be a very low setting. Never had problems with smearing toner, but that's maybe just because I only did pcbs and not yet large toner-surfaced boxes

[markm]

That was BLACK paint that I sprayed on the top to fill in the lettering. 
I doesn't have to be black, just what I chose to do it with.

[darron]

when i first read your tut markm, i thought the paint was silver also! i just assumed that the photo made it look that way.

[zjokka]

thanks mark, now it makes sense, do have some other questions for every etcher out there:

what software do you use to design the layout that can do the inversion to have white on black lettering.
i've started to use illustrator trial version which works great for designing the lettering at the right scale, just because of that it's vector based drawing more that picture program.

should i download photoshop too then?
any great freeware available for mac  that's a simple as ms paint?

[darron]

illustrator would be absolutely fantastic if you kept all of your work in vector! it's probably  the best tool that you could have. i use flash because it's easier for me to draw vecotrs in, then send them to illustrator later. i don't know much about illustrator, i know alot about photoshop.

by inverting the image, do you mean inverting the colours? or flipping it around? if you want to invert the colours then just  change the background of the image to black, select all your vector work then change it to white. to flip the image you'll have to find something along the lines of "flip horizintally" in one of the menus.

if nobody response, i'll help you out in detail when i get back home in a few days from this tour.  i'm in perth, have a couple of gigs, then im goign to melbourne.

[markm]

what software do you use to design the layout that can do the inversion to have white on black lettering.
i've started to use illustrator trial version which works great for designing the lettering at the right scale, just because of that it's vector based drawing more that picture program.

I myself use photoshop.
Here's a little "trick" I use....
Scan the enclosure you're going to etch into photoshop.
This way you have an exact size with which to work with! You can then add all the graphics to it using different layers and everything will fit onto to it perfectly and you won't have to mess with the sizing at all.
I usually work in just Black and White for enclosure designs to be etched.
You have to keep in mind that whatever is black in your image is NOT going to be etched. All white lines will be etched.
Have a look >>>>>>>>>>>>

Now the finished enclosure>>>>>>>>
I hopes this helps you.