Etch resist for aluminum?

[JKowalski]

Does anyone know of some material that can be manually applied to aluminum (i.e. drawn by hand) as an etch resist?

I've tried acrylic paint, sharpie and etch resist pens (which all work perfectly on copper), but the ferric chloride just goes right through them with no trouble at all when I use them on aluminum.

[MicFarlow77]

Try some acrylic spray paint.... just spray a little into the cap and you can brush that on.... or tape off and then spray....

[John Lyons]

Enamel and acrylic should be fine.
Maybe the paint wasn't totally cured
and the acid broke it down and got through.
Fingernail polish works as well.
Just make sure it's dry first.

[darron]

never have problems with acrylic paint or polyurethane.... didn't hand apply but spray painted. i always leave it at least overnight though and don't bake it to try to speed things up.

[JKowalski]

Hmm, that's odd.

I've been having ridiculous amounts of trouble with this one enclosure:

http://www.diystompboxes.com/smfforum/index.php?topic=78759.0

This is a continuation of those problems.

I finally got a decent amount of toner to stick, enough so that I felt comfortable painting in the parts which were missing (alot of painful work). I left the paint dry for two days - was busy for a while, didnt get around to etching. But still, when I popped it in the ferric chloride it just went right through the paint. All the toner areas which actually stuck did not let anything through. 

This happened similarly with my last etch, before this one, where I filled in a small amount of non-toner areas with an etch resist pen which did nothing either.

Is it possible that the enclosures (those two were from the same shipment) which I got had some special property that is making my life a living hell? 

Some strange mix of metals, or something? Considering the seemingly random and inconsistent problems, I don't know what to think.

[Nasse]

http://en.wikipedia.org/wiki/Hard_water

I was getting grey hair with some copper pcb etching and read something that sometimes with copper something in the water can do the trouble

[darron]

i use either of those sprays whenever i do an acid etch of a pcb or an enclosure, but i spray the whole area, not touching up. i used the hydrochloric+peroxide last time and it was week and stayed in there all day without problems.

THAT being said, i never found a good way of touching things up when i was using PNP. I tried art paints and liquid-paper (whiteout, correction paper, whatever), sharpies, etch resist pcb pen. any tiny, tiny chance the acid got to get through it would find a way and touchups wouldn't work. i can understand your frustration.

[chi_boy]

Is it possible that the enclosures (those two were from the same shipment) which I got had some special property that is making my life a living hell? 

Some strange mix of metals, or something? Considering the seemingly random and inconsistent problems, I don't know what to think.

Anything is possible.  With this being a non critical application there would be no regulations regarding the composition of the material.  I work in a metals testing lab and we see products from some countries that vary all over the place.  Almost like they will ship anything that looks close.


Cheers,
George

[differo]

Old thread but still... Last night I did (again!) a rather unsuccessful etching of enclosure. Too shallow, dots where toner/nail polish was etc. The only thing so far that resists FeCl really good is masking tape I used it on sides as slade does in his tutorial and that actually kept sides perfectly clean from dots. Resolution is pretty bad and I'm struggling with transfer too. Slade uses photo paper and it seems to me that paper also gets stuck on enclosure when he peels off back side of it. Does anyone else notices that? His transfer is not black but rather light in color which suggests it's actually paper. And analogy from masking tape tells that paper (together with blue/toner) is a good resistant.  Will try again with some photo paper instead of pnp.

[deadastronaut]

yep i use photo paper too....as good as pnp..lot cheaper...

i found when the toner cartridge is new it gives a nice thick image on the paper...at best quality..

but as i do more n more the toner doesn;t cover as thick....

ive used that sticky brown parcel tape too..thats a good side resist..leaves a bit of sticky behind

but if you cover the sticky residue with mayonaisse and leave for half hour it comes off  easily,...(starnge but true)...



as for the paper white left on the box i genrly rub off as much as poss with a sponge...but im pretty sure the ferric will bite through that anyway....

it is quite aggresive....

[Hides-His-Eyes]

yep i use photo paper too....as good as pnp..lot cheaper...

i found when the toner cartridge is new it gives a nice thick image on the paper...at best quality..

but as i do more n more the toner doesn;t cover as thick....

ive used that sticky brown parcel tape too..thats a good side resist..leaves a bit of sticky behind

but if you cover the sticky residue with mayonaisse and leave for half hour it comes off  easily,...(starnge but true)...

I expect (you'd have to test it) that it's the vinegar in the mayo that's having the effect and not the eggs; try it with just vinegar for something a bit cleaner

[deadastronaut]

yep i use photo paper too....as good as pnp..lot cheaper...

i found when the toner cartridge is new it gives a nice thick image on the paper...at best quality..

but as i do more n more the toner doesn;t cover as thick....

ive used that sticky brown parcel tape too..thats a good side resist..leaves a bit of sticky behind

but if you cover the sticky residue with mayonaisse and leave for half hour it comes off  easily,...(starnge but true)...

I expect (you'd have to test it) that it's the vinegar in the mayo that's having the effect and not the eggs; try it with just vinegar for something a bit cleaner

i could lick it off ..lol....

[therecordingart]

I have an extremely difficult time getting toner to stick to enclosures. I never liked doing toner transfers with an iron, and for me it is probably user error because I get perfect transfers to copper clad using a laminator.

I'm going to give Lazertran (the version for a laser printer) a shot because the package says you can use it as an etch resist on metal.

http://www.lazertran.com/techniques/etching.htm


You use rubbing alcohol to break down the decal paper which leaves just the toner sitting on the enclosure surface.

[deadastronaut]

I have an extremely difficult time getting toner to stick to enclosures. I never liked doing toner transfers with an iron, and for me it is probably user error because I get perfect transfers to copper clad using a laminator.

I'm going to give Lazertran (the version for a laser printer) a shot because the package says you can use it as an etch resist on metal.

http://www.lazertran.com/techniques/etching.htm


You use rubbing alcohol to break down the decal paper which leaves just the toner sitting on the enclosure surface.

sounds interesting....

when i do toner ironing on aluminium i use a coarse 180 grade paper on the top of the box..with washing up liquid..this
cuts through and also removes any grease at the same time...then dont touch the top at all..dab dry with kitchen roll....slightest bit of grease/oil from even fingers seems to bugger it...also it has to be a nice thick best quality image too...then i use hottest setting on iron..linen setting..
works for me this way...

[mikemaddux]

but if you cover the sticky residue with mayonaisse and leave for half hour it comes off  easily,...(starnge but true)...

I have to ask........how did you find that out?  Eating a sandwich while etching? lol

[deadastronaut]

but if you cover the sticky residue with mayonaisse and leave for half hour it comes off  easily,...(starnge but true)...

I have to ask........how did you find that out?  Eating a sandwich while etching? lol

yeah sort of!....lol...no i saw it on a crappy house cleaning tips prog on tv!..works tho..i hate having to peel off sticky labels
that leave crap behind..ha ha..

[differo]

I have only one sheet of (real=) photo paper at home so I have to ask, do you print on glossy or dull side?!

[KazooMan]

Glossy side, otherwise any paper would suffice.  Some use glossy magazine stock, but I have never tried it.  If you have only one sheet you had better make your trial a good one.  If possible, print multiple copies of the transfer on the sheet to give yourself multiple tries.  Barring room to do that, perhaps you can fit in a smaller layout to practice with to get the details like how long to iron "ironed out".  Also, you should jack up the darkness on your laser printer to get more toner on the sheet.

[railhead]

I sand my shells FLAT with 400 grit paper, then use InkJet gloss photo paper with my laser printer. Cut to fit, use a household iron on the "cotton" setting for 2-3 minutes, and the world is happy.

[Slade]

If your paper is not High Glossy try washing it after the transfer and scraping it with your fingers , not taking it out like a PNP. Use nail enamel to cover the surfaces where the toner doesn't cover.