So I had this membrane keyboard assy from a Swiss machining center in for repair as a couple of the switches had failed, and intended to replace the two with mechanical NO switches as the membrane is NLA from TESA. I couldn't trace one of the printed switch conductors back to the main circuit, so I had to peel the membrane apart to see what happened. One of the printed traces had opened, so I picked up some Bare conductive paint from Radio Shack to repair the trace.

http://www.amazon.com/Bare-Conductiv...nductive+paint

This product sold on the premise that it could be used to replace or fabricate circuit traces or use to attach components without solder. On the back of the package, they show a painted circuit connecting an LED to a battery.

Since this is just low voltage/low current key matrix, I figured that this would work fine. Before painting it on, I drew a two inch trace (maybe an eighth wide, about the width of the printed traces) on a piece of plastic and measured the resistance the next morning. The two inch trace read over 1K. That's right, 500 ohms per inch on a fairly wide circuit trace. The small blob I would need would read between 50 and 75 ohms. Maybe it would work, maybe not, but I'm not taking a chance.

I can't imagine any use for this stuff whatsoever.

Has anyone used this stuff and measured the resistance of it? :

http://www.amazon.com/CircuitWriterT...nductive+paint