Cutting 70mm cable......bolt croppers vs junior hacksaw?

[Paul C]

I've personally seen very old crimped connections fall apart, but never seen a soldered connection fracturing. On plenty of occasions, something's failed but it normally results in the copper strands taking more load than they should and gradually snapping one by one, the soldered "blob" remains coherent and doesn't fall apart.

[RLWP]

I've personally seen very old crimped connections fall apart, but never seen a soldered connection fracturing. On plenty of occasions, something's failed but it normally results in the copper strands taking more load than they should and gradually snapping one by one, the soldered "blob" remains coherent and doesn't fall apart.

Yes. That is exactly the problem - the way the rigidity of the soldered joint transfers the stresses onto the individual strands

 

Richard

[John V]

To put it this way.

 

The end of the soldered joint acts like a single bar of copper as opposed to individual strands, as a result when exposed to stress it breaks in exactly the same way.

In a properly made crimp joint the transfer of stress between the crimp and the individual wires is more gradual allowing them to react to fatigue individually

[FadeToScarlet]

Yes. That is exactly the problem - the way the rigidity of the soldered joint transfers the stresses onto the individual strands

 

Richard

So why doesn't a rigid crimp do the same? Is it that it's only rigid in the lug, where it has been crimped, whereas solder flows a bit further and makes a longer rigid bit?

 

Incidentally, I'm very happy with my eBay hydraulic crimpers- good for up to 300mm^2 cable!

[WotEver]

To put it this way.

 

The end of the soldered joint acts like a single bar of copper as opposed to individual strands, as a result when exposed to stress it breaks in exactly the same way.

In a properly made crimp joint the transfer of stress between the crimp and the individual wires is more gradual allowing them to react to fatigue individually

Exactly this

[Paul C]

So why doesn't a rigid crimp do the same? Is it that it's only rigid in the lug, where it has been crimped, whereas solder flows a bit further and makes a longer rigid bit?

 

Incidentally, I'm very happy with my eBay hydraulic crimpers- good for up to 300mm^2 cable!

 

Because the clamping force reduces and the wires fall out of the crimp connection, without snapping!

[WotEver]

 

Because the clamping force reduces and the wires fall out of the crimp connection, without snapping!

If the crimp has been properly made it cannot loosen because it has effected a cold weld within the lug.

 

Tony

[Guest]

If the crimp has been properly made it cannot loosen because it has effected a cold weld within the lug.

 

Tony

I agree. The old boys in the electrical game were highly suspicious of crimped lugs when I was an apprentice. I don't think it was realised then that the "cold welding" occurred.

[RLWP]

And away we go again. Soldering vs crimping is another of those debates

 

Richard

[WotEver]

And away we go again. Soldering vs crimping is another of those debates

 

Richard

So did you solder or crimp the power to your cassette loo?

 

Tony

[Paul C]

If the crimp has been properly made it cannot loosen because it has effected a cold weld within the lug.

 

Tony

 

So will a properly crimped connection eventually fail by the strands near the connector snapping?

[WotEver]

So will a properly crimped connection eventually fail by the strands near the connector snapping?

Unlikely. But if it did do so because of excessive and continual flexing then it would be a long, long time after a soldered one would have done.

 

Tony

[RLWP]

 

So will a properly crimped connection eventually fail by the strands near the connector snapping?

 

Probably - just a very long time after a soldered one

 

Richard

[Guest]

 

So will a properly crimped connection eventually fail by the strands near the connector snapping?

Never seen it happen. I amgine it could if the cable was inadequately supported, but that would be down to poor installation not the crimp.

[WotEver]

Is this the time to drag out the NASA report again?

[ChimneyChain]

So what shall we say 6 of 1 and 1/2 a dozen of the other ??

 

Darren

[Guest]

Is this the time to drag out the NASA report again?

It is interesting

[John V]

If you think of the connection to the lug of both methods......The crimp pressure area is inside the terminal with a small section of tube (un crimped) that prevents the stress being applied directly to the rigid section.......In a soldered joint the soldered (and rigid area) extends beyond the tube of the crimp so any stress applied to the connection is applied directly to the rigid section.

[RLWP]

So what shall we say 6 of 1 and 1/2 a dozen of the other ??

 

Darren

 

No!

 

Soldering was the way joints were made before crimping became the industry standard. Soldered joints are now specifically rejected in some safety critical industries becaus

 

Is this the time to drag out the NASA report again?

 

Oh, why not

 

Richard

e of the potential of failure

 

Richard

[Paul C]

Unlikely. But if it did do so because of excessive and continual flexing then it would be a long, long time after a soldered one would have done.

 

Tony

 

 

 

Probably - just a very long time after a soldered one

 

Richard

 

 

Never seen it happen. I amgine it could if the cable was inadequately supported, but that would be down to poor installation not the crimp.

 

Agree....I'm all for proper crimps and supporting wires/connections etc properly.

[RLWP]

As an alternative to the NASA document:

 

http://www.marinewireandcable.com/2013/11/crimping-vs-soldering-marine-cable-and.html

 

Richard

[Guest]

The higher resistance of solder is a point which rarely gets mentioned, but has been in that article.

Interesting it is still considered OK for batteries? We always soldered connections on fork lift batteries in th'old days.

Edited March 6, 2016 by Guest

[WotEver]

In this document, http://workmanship.nasa.gov/lib/insp/2%20books/links/sections/201%20General%20Requirements.html

 

NASA says:

Crimping is an efficient and highly reliable method to assemble and terminate conductors, and typically provides a stronger, more reliable termination method than that achieved by soldering.

Tony

[RLWP]

In this document, http://workmanship.nasa.gov/lib/insp/2%20books/links/sections/201%20General%20Requirements.html

 

NASA says:

 

Tony

 

Which would be all that was necessary - were this a technical debate. But it isn't, it's a debate between two proven technologies where one is displacing the other and is unlikely to stop until after the solderers have passed away. This is how technology progresses

 

Richard

[cuthound]

Is this the time to drag out the NASA report again?

It is interesting

 

It's not rocket science... Oh hang on, it is