circuit writer (silver conductive pen)

[tacobender]

Just wondering if anyone has built a pedal using this stuff. If its even a good idea, or is it one of those blasphemous words like "cold solder".

[R.G.]

I first remember this stuff from about 1970. It's been around longer, as the "printed" in "printed circuit board" was originally conceived to describe an additive process where conductive inks were used to actually print boards. IIRC, this additive process was actually first, before the subtractive process of coating a whole board and etching away the parts you don't want. I believe the reasons that industry doesn't do this today are:
1. Cost; that stuff is much more expensive in an industrial setting.
2. Durability; metal to metal bolding with solder is stronger than metal flakes or fibers in a binder.
3. Repairability; in general, it is very tough to UN-do a joint, replace a part, and then put a new part in. It may be possible, but it's harder to do that than with solder.

[amptramp]

I have seen this stuff offered as a conductive paint to repair rear window defrosters on cars.  You mask it to get the same thickness as the rest of the line.  You can use it to print circuits, but you will have trouble soldering to it.

http://9gag.com/gag/azb2jRm/conductive-ink

Printed circuits have come a long way from their first use in the BF-109 Messerschmitt.  (When the Brits first saw it, they assumed the Germans did this because they were running out of copper.)

[tacobender]

I was thinking that it would be a pain in the ass to solder to this stuff. I was considering installing the components to the board first, and then making the traces over the joints. I was mostly just wondering if it would have any effect on the sound, loss of frequency and whatnot. All considered i think it would be pretty convenient for DIY suff if suitable.

[duck_arse]

smurfberry has a take on this method .....

http://www.diystompboxes.com/smfforum/index.php?topic=101458.msg970386#msg970386

[PRR]

I do not understand the problem with soldering.

You don't solder it.

Blob some conducting ink around the joint, done.

For "un-soldering", use the main flaw: the stuff breaks easy. Bust the part out, put in new part, blob again.

No over-cooked traces. No toasted semiconductors.

It is super expensive in small bottles. It is weak, typically you need some other mechanical support (crimping or body-glue). It won't handle high currents. It will NOT bite through lead-tarnish like fluxed soldering does, you should scrub the lead just before blobbing.

But overall it is probably a fine alternative for small labor-intense DIY such as pedals.

[tacobender]

smurfberry has a take on this method .....

http://www.diystompboxes.com/smfforum/index.php?topic=101458.msg970386#msg970386

thats awesome,  but he should put it in a cardboard box and call it a "hobo drive"!