Natriumperoxidisulfate not working on alu?

[JimRayden]

Etching a Hammond alu box but the stuff doesn't seem to leave any dents on the surface, leave alone etching. It does work on copper of PCBs though.

-----------
Jimbo

[TELEFUNKON]

the box etchers use the yellow stuff.

but  10g/l NaOH solution (the kind you use to develop photo-PCBs or clean your sinks)
will work aggressively on aluminum.
especially when warm.
WATCH OUT - DO IT OUTSIDE - DON`T BREATHE !!!

[JimRayden]

I'm not sure I have NaOH at hand right now...

But the box is starting to look a bit dull... after about half an hour etching...

---------
Jimbo

[markm]

I use Ferric Chloride from the Shack.
Five bucks a bottle.
It's all I use 'cause it's all I have found locally.

[JimRayden]

Yeah I'm following your pictorial.

Hmm, did you make an extra-strong mix for box etching? Anything you forgot to mention?

Oh well, I guess these two substances are just so darn different. Proved by their colour too: yours turns brown, mine turns blue.

------------
Jimbo

[markm]

Yeah I'm following your pictorial.

Hmm, did you make an extra-strong mix for box etching? Anything you forgot to mention?

------------
Jimbo

Mine is straight out of the bottle, room temperature.......a "man's" etchant

[JimRayden]

Just found the NaOH at the local store. Oh the world of cool finishes, here I come!


---------
Jimbo

[markm]

That's not Ferric Chloride
Let me know how it goes.

[Peter Snowberg]

Ferric Chloride = FeCl₃•6H₂O (ferric chloride hexahydrate)

[markm]

 

[TELEFUNKON]

WATCH OUT - DO IT OUTSIDE - DON`T BREATHE !!!

TAKE PRECAUTIONS! WEAR A MASK !

IT`LL GET WARMER/HOTTER WHEN REACTING !

It`s aggressive to your lungs and hands. but it doesn`t make yellow stains.

Some white stuff (al-dioxide?) will fall out/dilute.

[JimRayden]

Thanks for the warnings, I'll make sure to take it on the balcony.

The white stuff is propably Al₂O₃ as I remember from the chemistry class. Haven't had one in a while.

----------
Jimbo

[TELEFUNKON]

I don`t think the NaOH and the white stuff that falls out is very dangerous for the environment.
(at least not as dangerous as the yellow stuff is for your metal water-pipes).

btw: the "blue" from the peroxid-etching is VERY poisonous for yourself and the environment,
and stems from the copper-content.

can`t explain it properly, but the one thing is "AGGRESSIVE",
and the other is "POISONOUS".

[no one ever]

the box etchers use the yellow stuff.

but  10g/l NaOH solution (the kind you use to develop photo-PCBs or clean your sinks)
will work aggressively on aluminum.
especially when warm.
WATCH OUT - DO IT OUTSIDE - DON`T BREATHE !!!

10M?

(molarity)

[markm]

Aggressive is right.
Do not, I repeat, DO NOT heat the etchant.
It works fine at room temp.
Also, do not consume it either, could have adverse effects.

[JimRayden]

btw: the "blue" from the peroxid-etching is VERY poisonous for yourself and the environment,
and stems from the copper-content.

Damn Europe... on one hand they restrict lead as a 'hazardous substance', on the other hand, Northern Europe's main electronics supplier (ELFA) *only* supplies the blue stuff (natriumperoxidisulfate). Go figure.

------------
Jimbo

[TELEFUNKON]

the box etchers use the yellow stuff.

but  10g/l NaOH solution (the kind you use to develop photo-PCBs or clean your sinks)
will work aggressively on aluminum.
especially when warm.
WATCH OUT - DO IT OUTSIDE - DON`T BREATHE !!!

10M?

(molarity)

10 gramme (0.01kilogram) per liter of water (about the same concentration that is used for developing photosensitive PCBs - in fact you can use "used" developer-solution).

yes, I noted "warm", as opposed of "hot"...

after I warmed it up to 50°C once (as opposed to 10° from the tap),
I moved the stuff to open-air adventures... (with lots of rinsing water available)!

[JimRayden]

I don't think I've seen any tips for the disposal of the etchants... Anyone?

-----------
Jimbo

[TELEFUNKON]

"SEARCH"-button!

[Satch12879]

Why don't you do your etching mechanically with an air eraser?