“Never solder vs crimp” logic?

[gregcope]

Hi

The other thread on joining wires has the often quoted “never solder as the wire can fail at the hard spot at the end of the solder”.

Also; “Good crimps form the strands into a solid copper join with no gaps”.

Logically both solder and crimps will form a hard spot, at the end of solid part, where they can both fail?

So why one over the other?

Is it that crimps have strain relief, and this has now entered legend?

Would a solder joint with heat shrink strain relief not be as good?

Interesting NASA allow soldering...

 

[RupertW]

I’ll be interested in the replies to this - I always crimp because I have thought that they allow much more movement without failing.

 

[noelex]

Both soldering and crimping can produce good marine electrical joints. There are advantages and drawbacks with both methods. On some joints one method is obviously superior, but in many cases either option is fine. Unfortunately, both methods are often poorly executed.

 

[rogerthebodger]

To me either solder of crimp both have their place but the important thing with hoth is to support the wiring close to the joint to reduce /eliminate ant flexing of the cable at the junction point.

 

[Spirit (of Glenans)]

My contribution would be to suggest that perhaps the heat of soldering would make the strands more brittle?

 

[Norman_E]

My contribution would be to suggest that perhaps the heat of soldering would make the strands more brittle?

You anneal copper by heating it red hot, but soldering does not come close to annealing temperature. It won't harden the copper of make it brittle either. What makes copper wire break is repeated flexing so support close to joints, and at regular intervals on cables that are not in ducts, is good parctice.

 

[noelex]

My contribution would be to suggest that perhaps the heat of soldering would make the strands more brittle?

Heating will anneal copper. That it is it will soften the copper, not make it more brittle.

However the heating time associated with soldering is too short at the temperatures induced (the melting point of good solder is 183° C and a typical soldering iron tip temperature is 330° C ) to produce any significant annealing effect.

 

[Lon nan Gruagach]

Interesting NASA allow soldering...

Have you seen NASA's soldering tome?

The bits I remember:
The solder is not the electrical or mechanical aspect of the joint, more like a glue to keep things in place. The joint is wire wrap technology whereby the wire is bent round a post for the mechanical aspects, the post has sharp corners which scrape the conductor for the electrical requirements. The solder merely stops it unravelling. All cables are supported near the joint to prevent stress.

 

[noelex]

A 1998 NASSA soldering handbook can be downloaded here:

https://protostack.com.au/download/NASA Student Handbook for Hand Soldering.pdf

 

[MikeCC]

Part of the problem is that poor soldering can lead to solder wicking up the strands and extending the solid section.

A good crimp using a ratchet tool and decent quality connectors should be harder to get wrong.

 

[gregcope]

Both soldering and crimping can produce good marine electrical joints. There are advantages and drawbacks with both methods. On some joints one method is obviously superior, but in many cases either option is fine. Unfortunately, both methods are often poorly executed.

Can you expand on the advantages of either please?

Specifically a permeant join?

Thanks

 

[gregcope]

To me either solder of crimp both have their place but the important thing with hoth is to support the wiring close to the joint to reduce /eliminate ant flexing of the cable at the junction point.

Exactly. The NASA guide I saw went into lengths on strain relief/support.

 

[noelex]

A good crimp using a ratchet tool and decent quality connectors should be harder to get wrong.

There is lot of truth in this post. Good crimping is dependent on good equipment. Technique is less important. The crimping tool needs to be good quality and importantly the crimp needs to be closely matched with size of the wire for the best results.

Good soldering is also dependent on good equipment, but also requires some skill for the best results, so these is more room for mistakes.

 

[Plum]

Hi

The other thread on joining wires has the often quoted “never solder as the wire can fail at the hard spot at the end of the solder”.

Also; “Good crimps form the strands into a solid copper join with no gaps”.

Logically both solder and crimps will form a hard spot, at the end of solid part, where they can both fail?

So why one over the other?

Is it that crimps have strain relief, and this has now entered legend?

Would a solder joint with heat shrink strain relief not be as good?

Interesting NASA allow soldering...

The first boat I completely wired every connector and joint was soldered and in the 15 years I kept it none of those joints failed and none of the wires broke. Another boat I rewired 18 years ago, also with all soldered joints. I still have that boat and so far no bad connections and no broken/fractured wires. On another boat where I made quite a few changes to the wiring, all my soldered joints are still good after 5 years. I am not saying crimpted terminals are bad, just saying that in my 12v experience soldering works for me.

Www.solocoastalsailing.co.uk

 

[jamie N]

Much the same as above; if you know how to solder, then do it. If you don't know, then crimping's the best option.

 

[noelex]

Can you expand on the advantages of either please?

Specifically a permeant join?

Thanks

Soldering typically produces a smaller neater joint and is more versatile. For example wires of different thickness can be easily accommodated. There is less need for the perfect sized connection.

However, soldering is is slow, very slow compared to a crimp if you are soldering properly and soldering requires skill.

Crimping is much quicker especially for example on a new build when using the same brand of wire in a limited number of wire sizes with carefully matched crimps. Quality control is easier. Test one crimp made with a particular crimper and terminal and every other connection is likely to acceptable even in the hands of an unskilled worker.

 

[ip485]

I have often wondered about both. I have tried tighly binding the bare strands together and then covering with glued hear shrink. It creates a flexible join with no hard spots. I have yet to have a problem with those I have tried.

 

[lw395]

I've seen a lot of bad crimps.
A fair amount of bad soldering.
Whatever the process it's never idiot proof.
Heatshrink can hide some real crimes.

We're not actually asking a lot. It's not like it's got to survive the vibration of a fighter jet or missile is it?

If it's done neatly and properly and the wires are supported, protected and not stressed, you are 90% of the way there.
A choc block in a nice little junction box will probably outlive a perfect crimp or solder joint flapping about in a loom.
Ideally, you don't join wires in the middle of nowhere. They run in a cable from A to B with proper muliway connectors or whatever.

 

[lw395]

I have often wondered about both. I have tried tighly binding the bare strands together and then covering with glued hear shrink. It creates a flexible join with no hard spots. I have yet to have a problem with those I have tried.

Either you are being a naughty little comic troll, or I'm tempted to send my favourite 'airframe' wireman to poke you with a soldering iron and attach ratchet crimp tools to your earlobes.

Nothing personal, but we have standards and traditions.

 

[ip485]

lw395 - strangely I do wonder what evidence there actually is that proves this form of joint is more / less reliable and if so by how much - https://www.youtube.com/watch?v=HTJ5kEzVvH4. I knwo we have always crimped or soldered, possibly before shrink wrap with a reliable glue core and tinned wire?