How to solder very thin leads?

Thread Starter

djsfantasi

Joined Apr 11, 2010
9,237
So I’m using a combination of tips y’all gave me.

The BluTack works great! And I use this Veleman PCB Holder.

E2F2B88D-44E6-4B3C-A3FD-BEF5E9988288.jpeg

As far as the thin leads, burning off the insulation did NOT work, as the burned wires did not hold solder even with flux. I found that using the back edge of an X-Acto knife blade removed the insulation without damaging the wire. Then a quick dip in the solder pot tinned the ends. I might try dl324’s toothpick trick as even with the BluTack, the thin leads slip out of position.

Thanks everyone for all of your suggestions
 

MrSoftware

Joined Oct 29, 2013
2,273
I'm not sure which wire you're using, but when using thin magnet wire I usually remove the insulation by sticking the end into a ball of solder on the tip of an iron. That usually removes the insulation right away, just be sure to clean the tip and use new solder for actually making a joint.
 

nsaspook

Joined Aug 27, 2009
16,339
I'm not sure which wire you're using, but when using thin magnet wire I usually remove the insulation by sticking the end into a ball of solder on the tip of an iron. That usually removes the insulation right away, just be sure to clean the tip and use new solder for actually making a joint.
It completely depends on the wire insulation. Some types are designed to be self-fluxing for easy soldering, others turn into a crust that's impossible to solder until cleaned.
https://ccoils.com/wp-content/uploads/WireInsulationGuide.pdf
 

Thread Starter

djsfantasi

Joined Apr 11, 2010
9,237
It completely depends on the wire insulation. Some types are designed to be self-fluxing for easy soldering, others turn into a crust that's impossible to solder until cleaned.
https://ccoils.com/wp-content/uploads/WireInsulationGuide.pdf
Here is picture of the thin wires I am talking about. I included an American penny for scale. They have vinyl insulation coating them. My digital calipers measure their total diameter at 0.33mm. Of course, the actual stranded wire is much thinner. Almost a thick human hair.
569C2E17-6D8E-460C-B77D-C59D74D19016.jpeg
 

Thread Starter

djsfantasi

Joined Apr 11, 2010
9,237
@dl324

Or stick a toothpick in the hole with the wire. Then reflow the joint to get rid of the hole from the toothpick.
The toothpick trick works great! While BluTack works for the through-hold components, using a toothpick works perfectly for the tinned fine leads. I did have to nip the extra toothpick off.
 

Thread Starter

djsfantasi

Joined Apr 11, 2010
9,237
UPDATE: When mass soldering the thin wires, the toothpick trick wasn’t working. And I had problems with the Blu-Tak. The wires (40awg or finer) with the vinyl insulation just slid out of place as my hands shook. Several soldered joints were insulated by burnt vinyl.

So here’s how I worked things out.

I cut 3/4” lengths of telephone wire and stripped both ends. I stripped the thin (40awg) wire 1/4” with my fingernail. I wrapped the bare fine wire around one end of the telephone wire and soldered it. Then I insulated the joint with small heat shrink tubing. This assembly was easy to solder onto the PCB.
 
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