Front panel material

[Theo]

----- Original Message -----
From: Mike Granger <mgranger at greenville.infi.net>


> I believe Terry was correct. I have done etched graphics on black anodised
> aluminum panels like the Moog ones. The material is common anodised
aluminum
> which is a matte black oxidized surface on aluminum. The process is very
similar
> to making a copper PC board in that it uses a photosensitive resist
coating over
> the blank panel which is exposed with UV light through a negative image of
the
> panel graphics. Where the UV passes through the negative, the resist
coating is
> hardened, and remains when the developer is wiped over the panel. The
> exposed/developed panel is then etched in a very diluted solution of lye
which
> eats away the anodisation where the silver graphics need to show through.
The
> etching process happens fast and generates heat. If you try it, be very
careful
> with the lye. It is nasty, dangerous stuff.
>
> Mike Granger
>

Seems I am the one who didn't understand.
Never heard of this etching method before.
The method I use works with blank anodized material.
A photo resist coating provides a mask where color should bond.
(you can do multiple colors in one run)
The material is sealed afterwards by boiling in hot water.
It works well but the base material is rather expensive.

I will certainly try this etching method next time I need a black panel with
alu lettering.
Just one, err.. two questions what  is the chemical name for lye and
what concentration is used??

Cheers, Theo