There REALLY are reasons...

[S/V Illusion]

The problem with crimping is
1. many don’t know how to do it properly,
2. Many don’t use the proper tools, and
3. It’s not possible to ensure a proper crimp without destructive testing.

Conversely, a proper solder joint with solid mechanical relief so as to preclude repeated movement is dependable.

Doing soldering wrong isn’t a good basis to exclude it’s use.

[Statistical]

Originally Posted by wyb2

A good example of conventional wisdom not really standing up to scrutiny for one reason or another.

Seems that lots of people with lots of experience have observed that solder joints fail at a higher-than-acceptable rate. That should be enough to accept that it is a problem. But figuring out why is a slightly different animal.

Encouraging fatigue right where the solder ends seems like a logical mechanism, except as you point out, it’s not clear why a crimp wouldn’t have the exact same problem. I don’t know the answer, but I’m wondering if it’s actually the solder that fatigues and begins to crack first, and the stress concentration/ crack propagation carries on through the copper strands.

Looking at the picture, it seems there is solder on both sides of the break.

It isn't just that solder is hard it is hard and fragile. Also solder will wick up the wire turning that high quality expensive high strand count flexible marine cable solid and fragile.

You now have this hard inflexible fragile cable segment which is unsupported. Worse it is unlikely this process is perfectly even meaning only some of the strands may be affected so you have numerous thin hard inflexible very fragile strands that were previously flexible.

Yes a crimp does turn the portion of the wire crimped into a solid mass but it is then protected by the connector itself which results in very high physical strength. The inflexible portion doesn't extend beyond the crimp connector in fact the crimp connector extends beyond the actual crimped portion providing some limited strain relief.

All of that well thought out engineering however is undone when someone tries to make it "better" by adding solder.

[wyb2]

Originally Posted by Statistical

It isn't just that solder is hard it is hard and fragile. Also solder will wick up the wire turning that high quality expensive high strand count flexible marine cable solid and fragile.

You now have this hard inflexible fragile cable segment which is unsupported. Worse it is unlikely this process is perfectly even meaning only some of the strands may be affected so you have numerous thin hard inflexible very fragile strands that were previously flexible.

Yes a crimp does turn the portion of the wire crimped into a solid mass but it is then protected by the connector itself which results in very high physical strength. The inflexible portion doesn't extend beyond the crimp connector in fact the crimp connector extends beyond the actual crimped portion providing some limited strain relief.

All of that well thought out engineering however is undone when someone tries to make it "better" by adding solder.

So it sounds like the problem does start in the solder, not the untouched copper.

Maybe I’ve always misinterpreted (and I’m not the only one it sounds like) the “hard spot” explanation. I had always understood it as the hard spot focuses any flex into the wire just outside it, and it fatigues there. Like bending a strip of aluminum or steel back and forth in a vise, it will break close to the jaws, not at some random spot in the middle.

But if it’s supposed to mean that the hard spot itself (the solder) is what’s breaking, then my theorizing was actually just the explanation all along. And that would seem to explain why it’s different from a crimp.

[S/V Illusion]

Originally Posted by Statistical

You now have this hard inflexible fragile cable segment which is unsupported.

.

Herein lies the real reason people conflate the longevity and efficacy of soldered joints with crimped.

Soldered joints aren’t intended to be mechanical connections free to move around.

[s/v Jedi]

There are two failure modes with soldered connections:

1. Stress risers due to hard spot. This is where the copper strands at the position where the soldered connection ends, work-hardens and eventually breaks off.

2. Melting due to high temperature coming from a nearby high resistance connection. The heat travels through the copper very well and melts the solder.

Both failure modes can be eliminated but this requires knowledge and experience.

That said, the stress riser failure mode also exists with a crimped connection and needs to be addressed similar to the soldered connection. Using quality crimp connectors with glue lined heat shrink and using a quality ratcheting crimper will provide that workaround easily for DIY’ers. For soldering it is more complicated.

[Statistical]

Originally Posted by S/V Illusion

Herein lies the real reason people conflate the longevity and efficacy of soldered joints with crimped.

Soldered joints aren’t intended to be mechanical connections free to move around.

For free wire on a boat often there is a no good way to mechanically support the other end of the wire. Supporting it 5 feet away isn't sufficient it should be supported within a few inches ideally an inceh of the joint. In the problem connection in the first post where would you do that. Even if you could will the vibration between the hose clamp and the terminal stud be the same? If they are that in time will lead to cracks in the solder.

Again it is a solution in search of a problem. Right tool for the job. Solder has a place it just isn't this place.

[Statistical]

Originally Posted by S/V Illusion

The problem with crimping is
1. many don’t know how to do it properly,
2. Many don’t use the proper tools, and
3. It’s not possible to ensure a proper crimp without destructive testing.

Conversely, a proper solder joint with solid mechanical relief so as to preclude repeated movement is dependable.

Doing soldering wrong isn’t a good basis to exclude it’s use.

Anyone who can't be assed to learn how to crimp properly sure as hell isn't going to learn how to solder properly. Anyone who can solder properly can crimp properly.

Sure with enough time, effort, skill, planning, and cost you can make a soldered connection that is almost as good as a crimped one from long term longevity standpoint. The question is why would anyone except those on a religious crusade do that?

[S/V Illusion]

Originally Posted by Statistical

For free wire on a boat often there is a no good way to mechanically support the other end of the wire. Even if you could will the vibration between the hose clamp and the terminal stud be the same?

Again it is a solution in search of a problem. Right tool for the job. Solder has a place it just isn't this place.

This is how perception bias both forms and is affected by misunderstanding.

Soldering joints aren’t intended nor should they be used for “free wire.. with no support”. No one here has suggested otherwise.

Rather, soldered joints are preferable where good, verifiable, supported connections are essential. I’ve seen too many poor crimp joints people thought they knew how to do.

[Statistical]

Originally Posted by S/V Illusion

Rather, soldered joints are preferable where good, verifiable, supported connections are essential. I’ve seen too many poor crimp joints people thought they knew how to do.

Yes and those people would have done better with soldering to include properly supporting both ends of the joint mechanically? I think not.

Your logic seems to be I can solder really well and some people crimp really badly so soldering is better. I would say if you care enough to solder really well including take the added cost and effort to mechanically support both sides of the joint well you can crimp really well too and do it with less time and effort.

[Lake-Effect]

Originally Posted by S/V Illusion

Doing soldering wrong isn’t a good basis to exclude it’s use.

I speak as someone who has been soldering all my adult life, mostly professionally, on all applications from circuit boards and surface mount to system and power wiring. All I'm gonna say is that in average hands, you are MUCH more likely to get consistent, repeatably-good results in wiire termination with crimping than with soldering. I've done, and seen (and repaired) enough soldered connections that I can say with confidence that there's much more variance in the quality of soldered connections than with crimped ones. Harder to do properly, harder to inspect, too.


(No-one, including the ABYC, has a problem with the soldering of small-gauge, signal-carrying wiring, btw. So this discussion is confined to power-carrying conductors on the average boat)


The case for not just soldering connections carrying significant energy is pretty clear, I hope. So, if you solder connections that have already been crimped, it's a belt & suspenders thing: if it makes you happy, do it, but it doesn't necessarily guarantee a better job. And sometimes it makes things worse, as in the first post.

Do I think that many people are capable of competent soldering? Yes, of course. But as a method endorsed or promoted by a standards body? Heck no. The materials, tools and workmanship in soldering vary much more wildly than with crimping.

Using quality lugs and a decent but affordable controlled-cycle crimping tool set up for those lugs, you need only average skills and attention to make dependable crimped connections, very consistently. You can't say the same about soldering.

[GordMay]

A proper double crimp tool crimps both the wire conductor, as well as the external strain relief, in one single motion.
The jaws/dies of a double crimp tool are unequal [asymmetric, or stepped] in size.
The wire conductor crimp area gets one [smaller/tighter part of die] crimp, and the strain relief barrel gets the second [larger/looser] crimp.
No "hard spot".

[sailorboy1]

I find this whole thread a a lot to do about nothing really. Crimps aren't magic and they probably fail at same rate as a solder connection done properly.

The saddest part of this whole thread is that in the original post the owner of a boat had spent "Much time and effort (and money) was put into diagnosing this before the boat was brought to me." for a pretty basic problem.

[Lake-Effect]

Originally Posted by sailorboy1

Crimps aren't magic and they probably fail at same rate as a solder connection done properly.

Looking just at DC connections in recreational boats:
- solder alone, on a lug, is unacceptable. Everyone knows why. All that's left then is soldering a crimped lug... and so you're not necessarily improving it. Often, you make it worse: melted insulation/strain relief, and making the wire more brittle at the lug.

- most people will produce an acceptable crimp, more often, than the same people would make an acceptable (or at least harmless) solder joint. Fact, not magic.

The saddest part of this whole thread is that in the original post the owner of a boat had spent "Much time and effort (and money) was put into diagnosing this before the boat was brought to me." for a pretty basic problem.

When connection faults are hidden, and unexpected (eg a connection fractured because of brittleness in a place where it really shouldn't have)... they're harder to find. Yes a talented pro can find them, and you can get $$$ instrumentation (eg TDR reflectometers) to locate problems, but this industry isn't that rewarding to talented pros.

[sailorboy1]

Originally Posted by Lake-Effect

Looking just at DC connections in recreational boats:
- solder alone, on a lug, is unacceptable. .

I never said it was!

[Cyrus Safdari]

Excellent post! Finally, empirical support to end this debate