Etching faceplates, was RE: [sdiy] Plexiglass panels

[Ken Stone]

>Ferric Chloride works great for etching copper, brass or any ferrous 
>metal. Here's a picture of a brass module faceplate I made using standard 
>PCB etching techniques:
>
>http://www.ccsi.com/~hanuman/modulator.jpg

Can you imagine a tube synth made using this technique. It would look
totally awesome.


>This was done with some nasty, depleted etchant I had on hand. Total 
>etching time was around an hour or so, which resulted in significant 
>relief depth in the metal without undercutting the resist too badly.
>Just for fun I tinplated the piece with a commercial PCB tinning 
>solution before removing the resist, then polished the tinplate.
>The results are striking.

I found that depleted Ferric Chloride could be used to etch iron, and
interestingly it released the copper as crystals when doing so. Obviously it
couldn't be used to etch copper again!

>Galvanic etching is done by suspending the workpiece in an electrolyte, 
>along with a waste piece of the same material. A salt of the metal being 
>etched is supposed to be the most effective electrolyte, but I used 
>a few tablespoons of ordinary table salt dissolved in warm water. 

Quite some time ago, I recall reading about PCB houses experimenting with
this technique for PCB etching. Obviously it was not able to completely etch
as PCB as connectivity was lost at some point (unless gold plating
techniques were used to maintain conectivity - i.e. have spare traces that
are cut later).

Too bad I never etch my own stuff any more!

Ken
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>