Solder vs. Crimp Connections

[chrisman287]

I really like non insulated butt connectors followed by heat shrink tubing. Super solid connection and foolproof.

 

[bastarddsm]

Remember OEM's don't do what's best they do what is cheapest that is good enough. It takes a lot more skill to solder than crimp.

I've seen plenty of solder in oem harnesses.

The biggest thing is strain relief. No strain relief = failure no matter what the connection type.

 

[92AWDHX40]

Ive done both more soldering when I wire I guess it's just a preference. I use Flux and of course insulated heat shrink .

 

[dwb]

If done properly, either method can produce quality results.
I also work in the aviation field. Contrary to what's been said previously, a solid crimp is all that's used for our new harnesses.
In the past I soldered all my wires (repairs) and I swore that's the only way to do it. I had OK results, but it was not always easy. Technique and work area has a lot to do with it. Sometimes I'd have the solder wick up the wire (poor technique/too much heat) and that's when the wire would become stiff and brittle. Other times, in tight quarters, I would accidentally shrink my heat shrink tubing before I was able to pull it over the joint.
Then I tried a GOOD non-insulated crimp and never looked back. Crimping has made my repairs easier, quicker, and cleaner. I took a tip from Jafro when he did his DSM wiring harness and I fold over the tip of the bare wire to give the crimp more to bite and prevents it from pulling out. Another benefit with a proper crimp, you get both an electrical crimp and an insulation crimp. This helps prevent the insulation from pulling away from the joint. I've had insulation pull away from a soldered joint.

 

[Capt Obvious]

Most motorsports harnesses are crimped, not soldered. A proper crimp has better vibration resistance than soldered (so I've been told by those who know better than me).

 

[danl]

If done properly, either method can produce quality results.
I also work in the aviation field. Contrary to what's been said previously, a solid crimp is all that's used for our new harnesses.
In the past I soldered all my wires (repairs) and I swore that's the only way to do it. I had OK results, but it was not always easy. Technique and work area has a lot to do with it. Sometimes I'd have the solder wick up the wire (poor technique/too much heat) and that's when the wire would become stiff and brittle. Other times, in tight quarters, I would accidentally shrink my heat shrink tubing before I was able to pull it over the joint.
Then I tried a GOOD non-insulated crimp and never looked back. Crimping has made my repairs easier, quicker, and cleaner. I took a tip from Jafro when he did his DSM wiring harness and I fold over the tip of the bare wire to give the crimp more to bite and prevents it from pulling out. Another benefit with a proper crimp, you get both an electrical crimp and an insulation crimp. This helps prevent the insulation from pulling away from the joint. I've had insulation pull away from a soldered joint.

This.

I adhere to the FAA best practices wiring guide. Their information is informed by investigations, typically involving loss of life. For them cost isn’t a factor, keeping pilots, crew, and passengers safe is.

I also reference a NASA document but their stuff is difficult and expensive so it’s a judgement call. Though they do have provisions for soldering which if it’s mandatory in my application, I adhere to their standards strictly.

 

[curt-s]

The fact is everyone has a strong belief in what they do for their own cars and generally will not be swayed by others forcefully.

We are the ones dealing with our own harnesses so I think we can all agree that whatever choice we make for our own car (not stealth airplanes) is the best choice for us, because we are the only ones having to deal with it in the first place.

And all of us do probably better work than what was on the car we inherited, amirite?

 

[CrackedDSM]

Everyone else is wrong, and only I am correct, so I'm not sure I know what you mean curt-S.


Unless you're telling me I'm right. In which case thank you, I know I am.

 

[jdxnc]

Something we can all agree on

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[zedicus]

saying one thing is better than another thing with out knowing all the variables is impossible.

if i am doing a repair on a 30 year old harness, i will probably select a different method than if i am building a new harness out of new materials. I have had jobs in automotive, I.T., and construction, the only thing that is a guarantee is if you use the right connector for the planned connection, it will last a lot longer. this goes for electrical, plumbing, HVAC, metal work, etc.

couple examples:
a lot of electric tools use crimp connectors because they pull high loads in burst situations. they would literally melt solder off connections.
Audio equipment a lot of times will have soldered and braced connectors as much as possible with high contact clip lock connectors to decrease interference.
computer and I.T. stuff usually gets the absolute lowest cost option regardless, because it will get replaced before it breaks.

think about this aspect in the world of plumbing? how many arguments break out over not just PEX vs PVS vs copper vs... but also crimp, vs glue, vs compression, etc.

there are different types of connection, not for you to favor one, but for you to use the correct one in the correct situation.

 

[CKOPOCT]

If done properly, either method can produce quality results.
I also work in the aviation field. Contrary to what's been said previously, a solid crimp is all that's used for our new harnesses.
In the past I soldered all my wires (repairs) and I swore that's the only way to do it. I had OK results, but it was not always easy. Technique and work area has a lot to do with it. Sometimes I'd have the solder wick up the wire (poor technique/too much heat) and that's when the wire would become stiff and brittle. Other times, in tight quarters, I would accidentally shrink my heat shrink tubing before I was able to pull it over the joint.
Then I tried a GOOD non-insulated crimp and never looked back. Crimping has made my repairs easier, quicker, and cleaner. I took a tip from Jafro when he did his DSM wiring harness and I fold over the tip of the bare wire to give the crimp more to bite and prevents it from pulling out. Another benefit with a proper crimp, you get both an electrical crimp and an insulation crimp. This helps prevent the insulation from pulling away from the joint. I've had insulation pull away from a soldered joint.

@dwb - Thank you for adding current information. I appreciate respectful professionals. My E&E (electrical and environmental) days were back in the 90's so it makes sense that methods and approved procedures have been updated. Sounds like I need to stop yelling at clouds and try something new and easier... but just as good.

 

[gsxitement]

Copper gets brittle from heat, which makes the fine strands break easier just past the point of the solder. Not to mention it makes a stiff spot. You'll never find a soldered joint in an oem harness for a reason.

Exactly this. Crimping forms a cold weld when done right.

 

[curt-s]

Shit, how much heat is being putting into the joint and for how long? General rules are on't use a dollar store soldering iron, use a proper tip that can transfer heat efficiently, and dial in your temperature for the solder you're using, the material you're soldering, and the gauge thickness. Don't just throw it up to 500F and go full-send making the joint hot enough to melt the insulation barely 1" from the joint. The copper will be inflexible at the joint, but no more than a crimp. A crimp with a touch of solder does not harm the copper or make it brittle. If your copper is snapping after being soldered, you're doing it entirely wrong and it's time to brush up.
Solder has a comparitively low melting temperature and while you lose roughly 20% of it's tensile strength at 250C during soldering (which is already much higher than the melting point of SAC solder), it does not remain so when it's allowed to cool.

 

[zedicus]

Don't just throw it up to 500F and go full-send making the joint hot enough to melt the insulation barely 1" from the joint.

so i am not supposed to use my MAPP gas torch on 18ga wire?

 

[curt-s]

The cutoff point is 16ga, sorry

 

[CrackedDSM]

So are we all against dollar store butt connectors then?


Semi-serious question. It's like 65% joke but I am also 35% serious.

I'm also like 23.6% unsure my math there was correct.

 

[dwb]

So are we all against dollar store butt connectors then?

Not even if you're 23 and reinstalling a stereo because thieves.
Wait. That was me. Move along. Nothing to see here.

In all seriousness, I've actually had pretty good success with them for low power/non critical applications. That stereo is still bumping 20 years later.
However, they WILL pull loose if not careful and I think they are aluminum which can corrode with copper wire (Galvanic corrosion).

 

[CrackedDSM]

Not even if you're 23 and reinstalling a stereo because thieves.
Wait. That was me. Move along. Nothing to see here.

In all seriousness, I've actually had pretty good success with them for low power/non critical applications. That stereo is still bumping 20 years later.
However, they WILL pull loose if not careful and I think they are aluminum which can corrode with copper wire (Galvanic corrosion).

Guess I need better crimp connectors for my wideband's logging wire to the ECU then. Doh. May just solder it. I've been spending so much on the car lately my wife gently asked me how much more money of our savings I'm gonna spend on it, so I'll refrain from buying connectors and a specialty crimper. Already got the solder and soldering iron.


I'll solder without flux and with the butane end of my soldering torch just open instead of with a tip, just for @curt-s .

 

[dwb]

In case you want to go with a better crimp solution, here's a cheap but functional crimping tool
https://a.co/d/7bQ9fYX

I also use this Terminal Connerctor Kit https://a.co/d/6Fpt9PH

Edit: don't forget heat shrink tubing as well.

 

[CrackedDSM]

In case you want to go with a better crimp solution, here's a cheap but functional crimping tool
https://a.co/d/7bQ9fYX

I also use this Terminal Connerctor Kit https://a.co/d/6Fpt9PH

Edit: don't forget heat shrink tubing as well.

I'll save those too. Gonna solder it for now though, all joking aside I'm pretty confident with it. I've got heatshrink and honestly don't see the wires at the ECU flexing that much. Plus interior/exterior harness needs replacing or at least re-wiring anyway.

 

[curt-s]

Guess I need better crimp connectors for my wideband's logging wire to the ECU then. Doh. May just solder it. I've been spending so much on the car lately my wife gently asked me how much more money of our savings I'm gonna spend on it, so I'll refrain from buying connectors and a specialty crimper. Already got the solder and soldering iron.


I'll solder without flux and with the butane end of my soldering torch just open instead of with a tip, just for @curt-s .

Don't threaten me with a good time.

 

[TerminalTalon]

As long as you're not a twist & tape guy I can respect that

I worked on a 775whp Evo. We don’t know how it made that or how it ever survived.
Twisted injector wires . As you can assume going through it all just turned up more and more and more.

 

[DimondStar]

Factory Ford and GM recommend to just use a crimp connector with heat shrink tubing. If you order pigtail connectors from GM, it’ll come with the crimp connector with heat shrink tubing all in one. Solder joints add resistance to the circuit. With 17 years experience working on GM and Ford diesel trucks, never had an issue.