How to Solder (Stainless Steel) Conductive Thread

I got the idea for this from Leah Buechley's LED sequins made with crimp beads. I wanted to solder thread connections instead of sewing. I like the flexibility and durability of stainless steel thread but it doesn't solder.* So I developed a "work-around."

I couldn't solder to the thread, but I could solder around it. The trick? String a crimp bead onto the thread, then melt solder into the bead hole. If there's enough solder, the bead stays put. It's easy, and you can add a soldered bead even if you don't have access to the end of the thread (i.e. because the thread is already attached to something).

Materials:

a needle threader

conductive thread - I'm using Adafruit's 3 ply stainless steel thread.

crimp beads - Choose a size that leaves a bit of a gap between the thread and the bead. For this thread, I'm using #2 beads.

tweezers

soldering workstation

solder (thin enough to fit inside the bead)

stand for holding soldering iron

*For info on other conductive threads, including ones you can solder to, check out Hannah Perner-Wilson's overview or Lynne Bruning's series of thread reviews.

Step 1: To Solder the End of the Thread

Use the needle threader to thread the crimp bead onto the stainless steel thread.
Clean the tip of your soldering iron, then place it in a stand so you can use it without holding it. (I place mine in its holder upside down.)
With one hand, use tweezers to pick up the threaded bead.
With the other hand, pick up the solder. Wet the tip of the iron with it. Press the bead against the wet tip and feed a generous amount of solder into the middle of the bead. It will stick to the bead, but not the thread.
Once you've filled it up, move the bead away from the iron and let it cool. (Careful! it will be super hot.)
After it's cooled, tug on it to make sure the bead is held in place.
Now you can solder anything you like to the bead and it will be connected to the thread.

Keep in mind, when you heat the bead up again, the solder inside will melt. If it leaks out, you may need a "refill".

Step 2: To Solder in the Middle of the Thread

If your thread is already stitched into something, you can still solder it, if you've left a little slack.

Bend a thin piece of bare hook up or bus wire around the thread, and hold the ends together. Thread them through the bead.
Using the wire, pull the thread itself through the bead.
Holding the wire with pliers, melt solder into the hole in the bead.
Let it cool, and tug to check that it's solid.
Once you're done soldering, cut the long wire leads short.

And that's it. Easy peasy.