Proper way(s) of soldering two wires together?

[ericohman]

Been watching a few YouTube videos and there seems to be many ways to do it, some of them looked pretty ugly... Thought I'd ask here.
If you're sharing your technique, please write if you are referring to solid or stranded wire joining...

As for stranded wire joining, I noticed 4 techniques:

1. Twist both wires, Tin both wires, put them parallel to each other and start twisting to make a mechanical connection. Then heat up with the iron.
Tinned wires get's pretty stiff though so I'm not sure how easy it is to use this technique on small wires?

2. Twist both wires, no tinning, then, hold the wires like an X, twist the right side of the X clockwise and left side counter-clockwise to make a mechanical connection.
Put a blob of solder on your iron tip, hold the tip UNDER the wires and let it travel up and into, once that blob has been absorbed by the wires, keep iron where it was (under the cables) and come in with the solder and apply some solder on top of the wires til the whole connection looks like a tinned wire.

3. No twisting, no tinning. Push the end of the wires to each other so that the strands randomly joins and look like one untwisted thick stranded wire.
Give it a light twist, quarter of a turn or less, apply solder like the technique described on method 2.

4. Twist both wires then tin them. Put the wires parallel to each other, kind of like this symbol  =  
Then take your iron and heat up the solder, wires will join sitting parallel to each other.

What are your preferred method?
#4 seems sketchy, the #2 X thing seems good, but I'm a beginner so I'd really like to hear your opinions.

Also, if you have tips from solid core wire joining of 2 wires, please share.
Almost forgot, USE HEATSHRINK TUBE for all methods

[ayayay!]

First, slip some heat shrink tubing over one of the wires and keep it at least an inch away.   

#2 would be closest, I think.  Twist them tightly so they appear to be one solid wire that's hardly different than just a piece that's missing insulation.  Then heat it up and let it flow.  If it's twisted nice and tight, it should flow easily.  Dunno what that blob stuff is you're talking about, but blobs should only be used in plots of campy movies.  

I'm a big fan of making the mechanical connections the strongest link.  You should only count on solder to make a solid electrical connection, not a mechanical or load bearing one.  

[ericohman]

the blob was used in 2 videos I saw

I have never joined 2 wires together, but I'm about too...
#2 without the blob might be what I go for

[R.G.]

The old rule in soldering, pre-SMT, was that solder is not glue.  If you want a reliable joint, make the joint reliable by twisting, etc. before soldering, and only then solder.

To join wires, there are a few variations, but for reliable joints they all involve twisting the wires so they withstand a decent amount of pull before soldering, and only then soldering. The "Western Union" splice is a named example.

However, the real answer is to not do this unless you're forced to. The best splice is replacing the wire. Only splice when you can't do anything else, or if the splice is very temporary, for testing perhaps. In that last case, any joint will do, because you'll replace it.

[Hides-His-Eyes]

Well, we all know that PCB joints are considered fine, so what you do is make a mini PCB (complete with standoffs) with two pads and a trace on it, then mount one of those in the enclosure.

Easy.

[Derringer]

To join wires, there are a few variations, but for reliable joints they all involve twisting the wires so they withstand a decent amount of pull before soldering, and only then soldering. The "Western Union" splice is a named example.

yup ... that's how I tend to do it

and what ayayay! said ... don't forget the shrink wrap!

[CodeMonk]

The way I was taught, oh so many years ago....
Tin both wires.
Create a loop on both wires like you would for a turret terminal or maybe a pot lug.
Loop them together.
Squeeze gently together.
Then solder.
This gives you both a mechanical and an electrical connection.
Similar to this:



That was Mil spec (Whatever number), back in the mid 80's
Standards may have changed since then though.

[R.G.]

Well, we all know that PCB joints are considered fine, so what you do is make a mini PCB (complete with standoffs) with two pads and a trace on it, then mount one of those in the enclosure.

Easy.

I like it. Hey, here's a new market for yet another flower to bloom: make PCBs for wire splicing with two pads, one trace between them.  

Except that the reliable way to solder wires to PCBs is to then mechanically restrain the wires outside the solder joint. One way that is used in layouts for higher reliability is to drill another blank hole adjacent to the PCB pad for the wire, then to stick the wire through the blank hole, and then turn the stripped end down into the hole with the pad. The insulated wire passing through the blank hole prevents much of the mechanical stress from reaching the solder joint.

And even in SMT, mechanical stresses on the solder joints are an issue. A fair amount of the literature on SMT layout and packaging is concerned with flex and stress cracking joints or components. Even minor board bending can break caps loose.

[CodeMonk]

Well, we all know that PCB joints are considered fine, so what you do is make a mini PCB (complete with standoffs) with two pads and a trace on it, then mount one of those in the enclosure.

Easy.

I like it. Hey, here's a new market for yet another flower to bloom: make PCBs for wire splicing with two pads, one trace between them.  

Except that the reliable way to solder wires to PCBs is to then mechanically restrain the wires outside the solder joint. One way that is used in layouts for higher reliability is to drill another blank hole adjacent to the PCB pad for the wire, then to stick the wire through the blank hole, and then turn the stripped end down into the hole with the pad. The insulated wire passing through the blank hole prevents much of the mechanical stress from reaching the solder joint.

And even in SMT, mechanical stresses on the solder joints are an issue. A fair amount of the literature on SMT layout and packaging is concerned with flex and stress cracking joints or components. Even minor board bending can break caps loose.

I have done it that way quite often.
Whats your opinion of two holes, run the wire between the holes and run a zip tie through the 2 holes to hold in there (With proper strain relief of course).
I have actually only done that a few times, and then only on my own stuff, test equipment mainly.

[petemoore]

  It depends on which wire, for HV/High tension stuff, I like to start with the right length workpieces and install them.
  For 9v stuff I get a bit more cavalier approach because I know it won't deck me.
  Any of these techniques can be made to work, even combinations of them...I've been known to use various "cheats", they're only violations if ya get caught, I know this from having done a fair bit of 'cheating.
   Third wire: strap clamp, a longer de-insulated end, looped, then twisted around the two other wires that would wanna come loose when heated...a cheat that needs to be 'offset'...ie isolated by structure [kept away from other traces, best when near a 'stay' lug or pad, not floating around the middle of a clothesline situation. Running the solder up nearer or into the insulation makes the bare wire hold shape.
  It's all about preparing and shaping the wires prior to 'glomming', once soldered they don't shape so well, 'add on' solder isn't bad if the joint is twisted.
  For HV stuff I like everything strap-tied or twisted-luglocked since some of these things get hot enough to melt the solder, some stuff might want to come off too...just enough twist to more than hold it's own weight, not so much as to rip the lug out of a socket etc. Everything 'clamped by plier', 'pulled or leaned on' so physical copper to copper contact is good.
 

[familyortiz]

+1 on the heat shrink where desired, e.g., wire to wire joints.

[petemoore]

Whats your opinion of two holes, run the wire between the holes and run a zip tie through the 2 holes to hold in there (With proper strain relief of course).
  Based on experience, should be very good for strain relief, as long as crosswire inductance isn't an issue. Very similar to drilling 1 hole near the edge of the board for the ziptie loop except 1/4 turn...the wires naturally will point out from the edge of the board with the 2-hole technique.

[jplebre]

I just finished a big studio complex installation where a lot of this was involved.
We'd either go for CodeMonks technique if there were components involved or for sliding the conductors from the 2 cables together and twist them together.

Worked like a charm.

In the beginning I actually had a go at some of the other alternatives and they proved fiddly and time consuming. Some would make soldering the cables to the blade trickier (one of the cables would slide out when the bond with the solder blade happened).

For those that had a go soldering B-GPO patchbays (smaller bantams) you'll know what I'm talking about, specially doing this stuff over a couple of studios with tons of these.