Etching Holes ...

[Haible_Juergen#Tel2743]

>Hey. I just thought of another way to do the slots - etching. The
>reason they tell you not to pour ferric chloride into aluminum pans to
>etch circuit boards is that it eats aluminum MUCH faster than it eats
>copper. (Some day you can hear the story of how I know that...)

Hey, I like this idea!
But would it really work? I think Aluminium panels have a thick oxide
on its top that makes etching difficult (?)

> This process releases some really nasty fumes, perhaps even chlorine
> gas, really bad news;

Hmm, I don't think so. You can etch aluminium (if the oxide is removed ...)
with simple Hydrochloric acid (HCl). In this case, there is just some H2
gas (explosive, but not toxic).
If the Fe2O3-Method works, there should not be much gas at all.

And, just for your amusement: Guess what I used for my very first attempt
to make PCB's ? (In my innocent youth, just exploring chemistry, never
heard of Fe2O3 ...)
Well, nitric acid (sp? - HNO3 that is) did the job quit fine, but *that* was 
a
nasty gas I produced !

JH.