Electrical crimps - your opinion on these, please.

[grumpy_o_g]

Here is what NASA has to say ....

...My opinion, a properly executed crimp needs no solder and heating it all up, smearing it with solder and flux is likely to do more damage than good.

That's not a good crimp - clear airgaps and delineation between strands. As for NASA, both they and the aviation industry use solder in aerospace applications all the time but NASA have a history of saying one thing and doing another. I'd have more faith in them if actually got the basics right (like checking if measurements are imperial or metric, absolutely fundamental in the aviation industry). A bad solder joint and a bad crimp are both bad joints and a good soldered joint and a
good crimped joint are both good joints. If you know how to crimp and know how to solder (and both are easy to learn) then both are fine. There are as many bad crimps around as they are bad soldered joints in my experience.

 

[grumpy_o_g]

Couldn't agree more :encouragement:

This suggests you don't know how to solder...

 

[grumpy_o_g]

Another problem with any solder joint is that sooner or later you're going to have to disconnect it, by cutting the wire. OK if there is spare length, but if not it means introducing two new joints. ...

Don't follow that at all I'm afraid. I can de-solder cables (done it thousands of times) though I wouldn't actually re-solder without trimming back unless I had absolutely no choice. I can't un-crimp a connection though - I have to cut that whether I like it or not.

 

[grumpy_o_g]

Maybe

Making Secure Connections
Which Is Better, Soldering or Crimping Terminals?
Most wire problems happen at the connections, and the experts are mostly in agreement on this one. Connections should be mechanically connected, not just soldered. Per ABYC (E-11.16.3.7), “Solder shall not be the sole means of mechanical connection in any circuit￾”. Further, crimping provides a solid mechanical connection resistant to “cold joints”￾ breaking under fatigue, and removes strain.


https://forums.sailboatowners.com/index.php?threads/is-electrical-soldering-allowed-on-boats.10445/

Boat Building Regulations | Boat Electrical Systems
newboatbuilders.com/pages/elect_a.html

Jan 10, 2017 - Wires should be supported using clips or straps, at least every 18 inches (45.5 cm), ... When you solder the wire it becomes essentially a solid single conductor wire. It forms ... Some marine wiring experts even advocate not using solder at all.

General wiring standards for boats in the US - an introduction to USCG ...
https://shop.pkys.com/wiring-standards.html

Nov 16, 2018 - Metals used for connections cannot be Aluminum or unplated Steel. Solder is permitted but cannot be the sole means of making the connection. ... Solder also tends to make the end of the wire into a solid wire as it wicks into the stranded conductors

WORTH READING THIS THREAD
http://www.ybw.com/forums/archive/index.php/t-446200.html

According to the link to the forum the ABYC regs actually say "Solder shall not be the sole means of mechanical connection in any circuit - which is perfectly true and also correct for crimped connections - this has nothing to with the electrical connection.

The stuff in that PKYS link is just drivel in places, dangerous drivel at that. It may be that person who wrote is simply a bad communicator but I would strongly suggest that you don't assume voltage drop is not a problem in AC circuits. It won't be if you've sized the cables and connections correctly for the load but that's kind of the whole point of the article. As for cable size and proximity not being important on a earth lead, that's like suggestion the buoyancy of a lifejacket isn't important. It isn't until you actually need it when it's all gone wrong. Ground or earth cables, when they do have to carry current, often have to carry a lot of it and can get very hot.


Solder is used extensively in the aerospace industry and I don't know of a single case of an incident, never mind crash, caused by the fact a joint was soldered - so why the marine industry thinks it's not good enough for it I cannot understand.

 

[Baggywrinkle]

That's not a good crimp - clear airgaps and delineation between strands. As for NASA, both they and the aviation industry use solder in aerospace applications all the time but NASA have a history of saying one thing and doing another. I'd have more faith in them if actually got the basics right (like checking if measurements are imperial or metric, absolutely fundamental in the aviation industry). A bad solder joint and a bad crimp are both bad joints and a good soldered joint and a
good crimped joint are both good joints. If you know how to crimp and know how to solder (and both are easy to learn) then both are fine. There are as many bad crimps around as they are bad soldered joints in my experience.

Airgaps and delineation between strands appear depending on how you cut throught the crimp, they are not very deep. The picture is to demonstrate the deformation of the wires and crimp and give people an idea of what goes on inside. Much more careful cutting reduces the appearance of airgaps and delineation considerably.

Saying one thing and doing another is rife in all industries, usually down to people being lazy or thinking they know better - see the soldered battery cable example from earlier - the company wouldn't allow it because it reduced the life of the cable - warranty - but the people making them loved it because it was quick, looked bombproof when new and they never saw the after-sales support side of the business.

I worked years on vehicle production lines, saw hundreds of occasions where the assembly workers cut corners, didn't follow the processes or thought they had a better idea. The older workers were always the worst.

 

[Lon nan Gruagach]

The cables leading to an electrical joint should be supported regardless or whether it's crimped, soldered or a terminal block. The crimp should never be the support.

For sure, and cables should be supported throughout their entire length. Personally, I think that cables should be trussed up tighter as a vicorian débutante.

One thought, though. The issue with solder wicking along stranded cores causing a boundary between rigid and flexible sections, introducing a stress point. The examples of a good crimp posted here will also produce such a boundary.


As for soldered joints never causing an issue in aviation, I wouldnt be so sure. One (irrelevant to wiring boats) issue with solder is the growth of tin crystals. They can grow sufficiently to bridge across to a nearby conductor.
http://www.circuitinsight.com/pdf/copper_tin_intermetallic_ipc.pdf

 

[PaulRainbow]

My opinion, a properly executed crimp needs no solder and heating it all up, smearing it with solder and flux is likely to do more damage than good.

Couldn't agree more :encouragement:

This suggests you don't know how to solder...

So you do think a properly executed crimp needs to be soldered too ? If that's the case, it suggests to me that a) you don't know how to crimp and b) you're happy bodging badly crimped connections with solder, surely not ?

You also think that it doesn't take any longer to crimp with uninsulated crimps, solder and then heat shrink all of the connections on a whole boat, rather than just crimp ? So the soldering and heat shrinking takes no time at all ? Be a neat trick to solder and heatshrink every connection on a boat without expending any time or costs, do you have the recipe for perpetual motion too ?

 

[ghostlymoron]

If they are not packaged it'd be hard to say. If they are packaged and from one of the big manufacturers you'd be safe. RS sell some good ones, as do CEF. The Ebay link i posted early is safe (no connection).

I've searched but can't find the eBay link. The only links are for wire cutters, strippers and crimpers. Could you repeat it please.

 

[lw395]

You check both the crimpers and crimp by doing a test on a piece of spare cable. Cut through the splice itself with a mini hacksaw and make sure the whole thing looks like a single of metal. There should be no airgaps in the joint and it should be pretty much impossible to make out individual strands of wire. Also, before cutting the crimp, check the insulating sleeve to make sure it's intact. It's not a 100% guarantee of a good joint but it's a pretty good check.

Most crimped connectors also have a pull test figure.
If you can pull out the wire from something intended to carry more than an amp with your bare hands, it was probably bad.

 

[PaulRainbow]

I've searched but can't find the eBay link. The only links are for wire cutters, strippers and crimpers. Could you repeat it please.

Apologies if i forgot to add the link, here it is ;

https://www.ebay.co.uk/sch/m.html?_...minals.TRS0&_nkw=crimp+terminals&_sacat=92074

 

[grumpy_o_g]

So you do think a properly executed crimp needs to be soldered too ? If that's the case, it suggests to me that a) you don't know how to crimp and b) you're happy bodging badly crimped connections with solder, surely not ?

You also think that it doesn't take any longer to crimp with uninsulated crimps, solder and then heat shrink all of the connections on a whole boat, rather than just crimp ? So the soldering and heat shrinking takes no time at all ? Be a neat trick to solder and heatshrink every connection on a boat without expending any time or costs, do you have the recipe for perpetual motion too ?

Needs to be? No. Does it it improve the quality of the connection? Yes. You don't seem to understand what "soldering" a crimped connection means. It means applying some solder to the cable before crimping. Many people refer to this as tinning though to me this is a little than just getting a coating on the wire. You then do a normal crimped connection and would use heatshrink or some other form of protection if the crimp does not have it built in. Lord knows why your talking about perpetual motion or uninsulated crimps as if this is the only way to do it. Having said that heatshrink expanders, the appropriate lube, good wire strippers, crimpers and a decent soldering iron and flux mean that the time taken to do even that is seconds. If taking seconds longer is that much of a problem I can't imagine why you'd be on a sailing boat anyway.

There's quite a large number of military and civilian aeroplanes still flying around with both my soldered joints and crimps on them (and boats sailing and vehicles driving too for that matter). It's possible there are better methods and there are definitely people who can do them both quicker and better than I but I, the civilian and military aerospace industry and the Armed Forces all are pretty happy with the technique I use - so happy that hundred sof thousands of aeronautical nd electrical fitters, engineers and technicians are trained to do this to this day. However, to go back to my original point that you seemed to have missed completely, it doesn't take long to do a soldered joint and any suggestion that the solder will damage the cable only applies if you "aren't that good" at soldering.

 

[grumpy_o_g]

Most crimped connectors also have a pull test figure.
If you can pull out the wire from something intended to carry more than an amp with your bare hands, it was probably bad.

Yes agree and it's worth doing. The only reason I don't like it too much is that a crimp can pass a pull test but still have a poor electrical connection. You're absolutely right about it proving that the crimp wasn't good if it fails though.

 

[lw395]

Needs to be? No. Does it it improve the quality of the connection? Yes. You don't seem to understand what "soldering" a crimped connection means. It means applying some solder to the cable before crimping. ....

No, I think it's you who is not using the accepted meaning of soldering.

 

[PaulRainbow]

Needs to be? No. Does it it improve the quality of the connection? Yes. You don't seem to understand what "soldering" a crimped connection means. It means applying some solder to the cable before crimping. Many people refer to this as tinning though to me this is a little than just getting a coating on the wire. You then do a normal crimped connection and would use heatshrink or some other form of protection if the crimp does not have it built in.

As is often the case, you have decided to post your opinion of everyones comments without bothering to read the thread properly. The post where you decided i didn't know how to solder was part of a discussion about using uninsulated crimps, crimping them and then soldering them.

The relevant comment was "a properly executed crimp needs no solder", that is correct, soldering after crimping is a waste of time. Using uninsulated crimps and then heat shrinking is a waste of time.

As for not knowing what "soldering" means, i suggest you look the meaning of the word up. Tinning wire is called....erm...... tinning wire, that's not soldering.

Lord knows why your talking about perpetual motion or uninsulated crimps as if this is the only way to do it.

You seem to think you can crimp a terminal, then solder it, then heatshrink it (this is what was being discussed) in the same time it takes just crimp one, that's clearly about as possible as perpetual motion. Your method of tinning (the already tinned cable) then crimping, then heatshrinking is also going to take longer than a simple crimp.

The only reason I don't like it too much is that a crimp can pass a pull test but still have a poor electrical connection.

It seems to me that a) your quality control is non existent and b) you don't know how to crimp properly. If it's properly crimped it will have a good electrical connection. Failure to pull test connections is bad practice. Perhaps you should stick to soldering

 

[grumpy_o_g]

As is often the case, you have decided to post your opinion of everyones comments without bothering to read the thread properly. The post where you decided i didn't know how to solder was part of a discussion about using uninsulated crimps, crimping them and then soldering them.

The relevant comment was "a properly executed crimp needs no solder", that is correct, soldering after crimping is a waste of time. Using uninsulated crimps and then heat shrinking is a waste of time.

As for not knowing what "soldering" means, i suggest you look the meaning of the word up. Tinning wire is called....erm...... tinning wire, that's not soldering.



You seem to think you can crimp a terminal, then solder it, then heatshrink it (this is what was being discussed) in the same time it takes just crimp one, that's clearly about as possible as perpetual motion. Your method of tinning (the already tinned cable) then crimping, then heatshrinking is also going to take longer than a simple crimp.



It seems to me that a) your quality control is non existent and b) you don't know how to crimp properly. If it's properly crimped it will have a good electrical connection. Failure to pull test connections is bad practice. Perhaps you should stick to soldering

OK, let's leave it at that. Obviously you have your interpretation/comprehension of the English language which seems a little at odds with mine.

 

[PaulRainbow]

OK, let's leave it at that. Obviously you have your interpretation/comprehension of the English language which seems a little at odds with mine.

No wishing to create an argument.......

We seem to be talking of different things. I'm talking about soldering after crimping, you're talking about soldering (tinning) before crimping.

 

[petem]

Please excuse my ignorance, but doesn't the colour coding denote the size of the connector and therefore you shouldn't have a red and a blue connector joining two wires?

Can someone tell me how you determine the correct size of connector for a specific wire?

Finally, how important is it to use a ratcheting crimper? I see loads of non-ratcheting crimping pliers (even from reputable tool manufacturers) so presumably they can't be that bad for the occasional repair?

 

[pvb]

Please excuse my ignorance, but doesn't the colour coding denote the size of the connector and therefore you shouldn't have a red and a blue connector joining two wires?

Can someone tell me how you determine the correct size of connector for a specific wire?

Finally, how important is it to use a ratcheting crimper? I see loads of non-ratcheting crimping pliers (even from reputable tool manufacturers) so presumably they can't be that bad for the occasional repair?

The colour denotes the wire size which can be used.

Red is generally up to 1.5mm2; blue is up to 2.5mm2; yellow is up to 6mm2.

Ratcheting crimpers are a good way of knowing that the crimp has had sufficient pressure - you can't open the crimpers until the crimp has been fully comprressed. The Draper ones mentioned by PaulRainbow in post 49 are good - I've had a pair for years and they make consistently sound crimps.

 

[penberth3]

...Can someone tell me how you determine the correct size of connector for a specific wire?...

I've got a pair of crimping pliers with the wire gauges for red, blue, yellow stamped into the tool handles. Problem is how do you identify the gauge of a random bit of wire?

 

[lw395]

I've got a pair of crimping pliers with the wire gauges for red, blue, yellow stamped into the tool handles. Problem is how do you identify the gauge of a random bit of wire?

I have wire strippers which have marked slots for multiple wire gauges. If the stripper slot for 1sqmm works well, cutting no strands, then a crimp for 1 sqmm will be OK.
For simple automotive style crimps, if the wire goes in then the crimp is big enough. If the wire goes in the next size down, use that.
Also, the AWG size is very often printed on the insulation....