If you ever have a delicate electrical project where you are afraid that the heat of soldering will damage tiny components or melt nearby materials, you should try out this electrically conductive Wire Glue. It isn’t terribly easy to work with, being runny and inflexible. but if you are in a delicate position, or you are trying to solder to things that solder just doesn’t like to stick to, it becomes an invaluable addition to any geek’s toolbox, and it is lead free.
Update: The stuff is water based, but after using it to glue together the leads for the under water portion of an electrolysis unit pulling around 80 volts, it has held up fine for weeks of under water load (as long as you let it fully cure first). It worked as advertised for our uses, but we haven’t tried replacing the ink in our inkjet and printing out a circuit board or anything. We leave that bit of fun to you.
The cheapest place I’ve found it is through ThinkGeek Gadgets
Amazon also carries Wire Glue, and it is still cheap enough you could just toss it on your next order and not feel like you spent anything.
Update: Chemtronics also has a line of electrically conductive epoxy and pens. After trying both in some pretty harsh and corrosive environments, I’ve found the Chemtronics stuff to be more durable. Amazon carries their stuff too.