Great tool to help solder two wires together.

[atikovi]

Originally Posted by George Bynum
Originally Posted by atikovi
Forming the ends into a hook and then soldering is awkward. Twisting them together and soldering leaves a bulky bulge.


I've soldered wires many times over 60 years. EVERY document I've seen "required" the joint be physically secure before soldering. Yours looks really nice, and with the amount of overlap may do pretty well in tension, but I'd not do it myself.

It's yours; do as you wish, but I discourage it.


If by some one in a million chance the wires somehow get pulled apart with such force that the solder joint fails, you think the wrapping together of the wires beforehand will do any better? An electrical connection's primary job is to transmit electricity, not to physically hold parts together.

 

[Dave9]

^ Yes it will do better to wrap/twist them, not only is there a much greater area of solder adhesion (unless you put a ridiculous overkill amount of solder on the joint which tends to create a bulbous sagging drop of solder), but there is also much greater proximity of wire conductors, with a LOT less solder, electrical conduction needed. The way you are doing it may work in some cases, but it is effectively weaker than the wire itself and an additional series resistance.

A solder joint is never a mechanical fixation in a good design. The wires being twisted together does not add much bulk if done carefully. Perhaps you just need more practice or different tools and technique.

There is a technique where the two wires are laid parallel to each other instead of twisting called a lash splice but it involves wrapping an addition length of thinner wire around the two parallel pairs. See the "Acceptable Lash Splice Inline"
example near the end of this NASA tutorial, and trust that they did extensive testing of different wire joining techniques:

https://workmanship.nasa.gov/lib/insp/2 books/links/sections/files/407.pdf

 

[Cujet]

Originally Posted by atikovi

Maybe for one or two wires in a harness that would work, but I was doing a 4 wire pigtail and those things would be way too bulky to fit in the loom.


Those are very, very compact. It won't bulk up a harness. They are common in aircraft.