Etching faceplates, was RE: [sdiy] Plexiglass panels

[The Peasant]

Thank you for an excellent and informative post Robert, your panel etching 
looks great! I'm definitely going to have to try this myself.

Take care,
Doug
______________________
The Electronic Peasant

www.electronicpeasant.com


Quoting Robert Kent <hanuman at ccsi.com>:

> 
> (I'm surprised with all this Plexiglass talk that nobody seems to have 
> mentioned Lexan, a hard-but-flexible polycarbonate material that's supposed
> to be much easier to drill, cut, etc. Somewhat more expensive and less 
> available, but the local home improvement place sells sheets of it as
> window-glass replacement.)
> 
> On Tue, 5 Jul 2005, Tim Parkhurst wrote:
> > By the way, has anyone tried using standard PCB etching techniques to put
> > legends/labeling on face panels? Does this work with aluminum? You
> wouldn't
> > need (or want) to etch all the way through, just a little bit would work.
> > How about etching a thin copper sheet, and then putting that on top of a
> > thicker panel (and then protecting the copper from oxidation with a few
> > shots of clear coat)?
> 
> 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
> 
> 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.
> 
> Due to the weight of the brass I used a thin sheet of stock mounted over 
> an aluminum L-channel for rigidity. The whole process seemed like a lot
> of trouble, and I really wanted to etch aluminum instead. Ferric Chloride
> is absolutely not recommended for use with aluminum, as others have noted.
> I tried a few experiments with lye, but the violent reaction destroyed 
> convential iron-on toner and permanent marker resists. Then I found out 
> about a technique called galvanic or electrolytic etching, which works
> with any conductive metal including aluminum.
> 
> 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. The 
> workpiece (anode) is connected to the positive side of a low-voltage, 
> high-current power supply (I used 13.8VDC at 5-10A, a car battery would
> work as well). The waste sheet (cathode) is connected to the negative side 
> and current is applied. After 15 minutes or so the bare areas of the anode 
> are etched into sharp relief. I used toner-transfer etch resist which 
> didn't transfer to the aluminum very well, requiring some touch-up with a
> paint pen, but held up pretty well in the bath.
> 
> Below are the anode and cathode ready to etch:
> 
> http://www.ccsi.com/~hanuman/bass-preetch.jpg
> 
> And the results after cleaning, filling in the relief design with enamel,
> brushing, and assembling the module:
> 
> http://www.ccsi.com/~hanuman/bass.jpg
> 
> Although moderately work-intensive, I am very happy with this process. The 
> resulting front panel markings will never fade or wear away in the normal 
> course of operation, and will probably outlast me.
> 
> Here's a site I found very helpful in explaining the chemistry and 
> practice of galvanic etching:
> 
> http://greenart.info/galvetch/
> 
> --Robert
> 
>