[Bosk]

Just wondering, is there an especially good method used to solder two wires of different gauges together?

By that I mean soldering wires directly to each other, not through a PCB or terminal.

 

[Lil' Knight]

One of good ways to solder 2 wires is tin to both wires first and then put them next together, melt the solder from one of them and they will stick together easily.

 

[VncentValntine]

you could hook them (well i guess it depends on the gauge), after tinning of course

 

[NightOwl]

The basic for any solder joint is to have a good mechanical/physical connection before soldering. If it's solid core wire I twist it together and solder. If it's stranded wire I tin it first then twist together because otherwise the heat from the iron will separate the strands of untinned wire and trap air inside the join. Soldering wires together is not great for an audio signal but not so bad for a power conductor as long as your thinner wire is a suitable gauge. Don't make your twist so tight that you're stressing the wire.

 

[Uncle Erik]

Tin stranded wire first, twist together and crimp them with pliers. Then solder them and put heatshrink over the joint.

However, I make a point of never joining two wires this way in my work. Instead, I always use a tie point. Maybe a little overboard, but I don't like unsupported joints, no matter how cleanly made. Every solder joint should be supported by the chassis.

 

[MoodySteve]

I think you're better off crimping them together with a ferrule. That is a far stronger mechanical bond than any solder joint.

 

[SiBurning]

A NASA technical standard that has splicing on page 82 and on.
NASA Recommended Methods of Splicing

There's a historically interesting debate between the Western Union splice and Bell Systems. Here's the best I could find about it:
Home telephone wiring - dslreports.com
See the 5th post from Splitpair at 2008-10-21 18:41:17

More stuff I found
Soldering Splices
Wire Splicing and Soldering

And one just to show that splices are not created equal, and the wires you're splicing is an important consideration in choosing.
Splices for High Tensile Smooth Fencing Wire

 

[Mr Incredible]

I was taught to use the western union joint for soldering two wires together. Of course its for solid core wires, but its VERY strong.

Twist them together according to the pic then add solder.

 

[n_maher]

I always try to create a mechanical joint in addition to the solder joint, similar to what is shown above.

 

[Juaquin]

+1 on the mechanical connection. Don't just place them together and solder. I learned by making each wire into a hook, hooking them together, then twisting the ends of the hook. Then solder.

 

[compuryan]

I use the method Mr Incredible posted. It creates really clean, strong connections.

 

[TimmyMac]

Creating a mechanical joint makes things much harder to desolder. I usually use the lap splice shown in the NASA thing. If your solder is wetted properly to all surfaces it's plenty strong.

 

[Juaquin]

Plenty strong, maybe (look at NASA's tests - the line did not break at the joint, yes, but the force at which it broke was quite a bit lower), but there's isn't a whole lot of contact area going on like in one of the more complicated joints. If it turns out you need to desolder it you can always just cut out the joint and start with fresh ends of the wire, assuming you left a bit of slack.

 

[DKJones96]

The fact that when they did break it didn't happen at the solder joint is good enough for me. But, I might be different, I don't put much of any real stress on my wires.

Plus, all of the wires with joints failed lower than untouched wire and the difference between lap and even western union was only 3 pounds. In my opinion, if you're running the wires that close to the breaking point you should really take a look at how you're treating your wires.

 

[olblueyez]

Quote:

Originally Posted by Mr Incredible /img/forum/go_quote.gif I was taught to use the western union joint for soldering two wires together. Of course its for solid core wires, but its VERY strong. Twist them together according to the pic then add solder.

This method will look nice under some shrink tubing when your done, no need to tin the wires first.