Dull wiring question

elton said:
Several reasons for my choice:

  • I have a boat, not an aircraft.
  • I wouldn't trust an unknown electrician to use the right tool for the crimps.
  • Every piece of electronic equipment I own has hundreds of components soldered together. None of them are crimped.
  • I can visually inspect a soldered connection and verify its integrity. I can't do the same with a crimp.
  • Factory assembly employs a strict QC regime, which does not apply to in-service add-ons and modifications.
I do wonder how many of those expressing an opinion on this subject have any practical experience.
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Heres my 2 cents worth

Both boats and aircraft are in a high vibration extreme enviroment so the requirements are similar.

In a radio or gps the electronic components are kept rigid by the circuit board so solder is used (smaller and cheaper)

If crimps are done correctly by a trained electricain with tools that have been periodicaly tested they will be very good.

If you are worried aboout the competence of an electricain go somewhere else.

It is easier to do a bad solder joint than a bad crimp

The physical strength of a crimp vs a solder joint will be at least double .
I have personally done this test using a strain gauge.

Solder joints are recognised as BDR (Battle Damage Repair) and have the be replaced ASAP.
 
elton said:
Several reasons for my choice:

  • I have a boat, not an aircraft.
  • I wouldn't trust an unknown electrician to use the right tool for the crimps.
  • Every piece of electronic equipment I own has hundreds of components soldered together. None of them are crimped.
  • I can visually inspect a soldered connection and verify its integrity. I can't do the same with a crimp.
  • Factory assembly employs a strict QC regime, which does not apply to in-service add-ons and modifications.
I do wonder how many of those expressing an opinion on this subject have any practical experience.
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Yes, but I'm using aircraft as an example of high quality engineering - why would you want less for your boat? I can't afford to use aircraft grade components on my boat, but I certainly can apply good engineering principles and use good quality terminations.

Have a look at your average new build yacht / mobo / cruise liner. There will not be any scotchlok connections, but plenty of crimping.

Maybe my standards are too high - I was referred to as being "a bit OCD" by two fellow boat owners two days ago... :)

Would you trust an 'unknown' electrician for anything? On the other hand, if they are established and professional surely you have to assume they know what they are doing.

We're talking cabling - you can't scotchlok / IDC / crimp components onto circuit boards - let's not move the goalposts.

You CAN visually ascertain the integrity of crimped connections - I would be bold enough to suggest that in fact you have a better chance with crimps than soldering as you cannot see inside a soldered connection. It can look good on the outside and be dry as a bone inside due to multiple factors.

practical experience: I used to be a certified aircraft engineer. I used to be a certified avionics senior development engineer. I used to work part time as a marine engineer. I now concentrate on my own boat and helping friends with problems on their boats.
 
I think that I'd like to see some good data re the assertion that soldered joints suffer worse from vibration/ fracture faults then crimped joints. The generally stated idea is that because the solder may 'wick' up the conductors then the 'wire' becomes a solid mass and rigid and hence likely to fracture through vibration!....... strikes me that the wicking would make for a 'phased' transition between soldered mass and separate conductors and hence relieve any specific 'stress point. The crimped fitting on the other hand would have a very demarcated transition from hard worked, crushed and deformed conductor to separate conductors. And hence a very specific stress point. All an intuitive view by the way and the reason as to why I'd love to see some real facts.
 
rosssavage said:
Yes, but I'm using aircraft as an example of high quality engineering - why would you want less for your boat?
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It's not a matter of wanting less; it's about pragmatism.

rosssavage said:
Have a look at your average new build yacht / mobo / cruise liner. There will not be any scotchlok connections, but plenty of crimping.
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As I've said already suggested, we aren't talking about a factory environment with factory resources, factory skills, and factory equipment.

rosssavage said:
Maybe my standards are too high - I was referred to as being "a bit OCD" by two fellow boat owners two days ago... :)
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Well there we have it :rolleyes:

rosssavage said:
Would you trust an 'unknown' electrician for anything?
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No.

rosssavage said:
We're talking cabling - you can't scotchlok / IDC / crimp components onto circuit boards - let's not move the goalposts.
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My point is that solder is used to make countless tiny connections in all electronic equipment, subject to stress, vibration, thermal cycling and humidity, and can function flawlessly for decades.

rosssavage said:
You CAN visually ascertain the integrity of crimped connections
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How?
rosssavage said:
- I would be bold enough to suggest that in fact you have a better chance with crimps than soldering as you cannot see inside a soldered connection. It can look good on the outside and be dry as a bone inside due to multiple factors.
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I've never seen that. I wouldn't say it's impossible, but less likely than getting 6 balls on the national lottery.
rosssavage said:
practical experience: I used to be a certified aircraft engineer. I used to be a certified avionics senior development engineer. I used to work part time as a marine engineer. I now concentrate on my own boat and helping friends with problems on their boats.
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I think you'll find the overwhelming majority of boat owners are not certified aircraft engineers, so have to deal with electrical problems using hobbyist skills at best.
 
elton said:
I think you'll find the overwhelming majority of boat owners are not certified aircraft engineers, so have to deal with electrical problems using hobbyist skills at best.
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As the OP I would like to thank you all for your contributions.

I'm certainly a hobbyist when it comes to boat wiring. However from what I learnt from this thread and this website I have become a confirmed crimper.

I bought a reasonable crimping tool and some heat shrink terminals and am now quite proud of the results.

I did try soldering but with no mains electricity available on the boat, with getting older eyesight, no decent vice and not the steadiest of hands I found the results using a butane powered soldering iron unsatisfactory.

So its crimping for me.
 
Fascadale said:
I did try soldering but with no mains electricity available on the boat, with getting older eyesight, no decent vice and not the steadiest of hands I found the results using a butane powered soldering iron unsatisfactory.
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Don't mess around with butane irons. Antex do a 12V verson of their standard 18W one which is the dog's danglies for car and boat soldering.
 
elton said:
Several reasons for my choice:

  • I have a boat, not an aircraft.
  • I wouldn't trust an unknown electrician to use the right tool for the crimps.
  • Every piece of electronic equipment I own has hundreds of components soldered together. None of them are crimped.
  • I can visually inspect a soldered connection and verify its integrity. I can't do the same with a crimp.
  • Factory assembly employs a strict QC regime, which does not apply to in-service add-ons and modifications.
I do wonder how many of those expressing an opinion on this subject have any practical experience.
Click to expand...

I have 15yrs + personal & professional experience. Is that enough? FYI soldered connections frequently fail in high vibration environments. Thats why many soldered components for boats are potted, or high risk components will have a glue on the pcb to reduce the strain on the joints.

I work with performance engine management systems and frequently have problems with 3rd party fitted 'scotch locks' bodge-ons in dry environments let alone on a boat. In fact recently I had troubles with my own towing elec due to previous owner having had it fitted again with scotch locks. I now need to take that all out and solder it properly.

BUT ALL automotive cable terminations are now crimped as above usually with waterproof AMP connections. Even 20+ years from being built many will be as good as new and are incredibly strong. (i.e. the wire will break before the crimp does)

All the above is practical FIRST HAND experience. By comparison, I have seen open crimped non waterproof connections behind a dash on a small speed boat fail within a year of being fitted. Scotch locks would not last 5 mins in this environment.
 
Pragmatism, yes. But my point is there is no shame in aspiring to produce the best result you can, given the time / money / skill level etc. I would suggest that crimping well is easier than soldering well, and hence would be the preferred choice? Especially over Scotchlok, which was the original question.

As for factory production - again, agreed. But they DON'T use scotchloks!!

I would also agree that soldering has it's place, and almost none of today's micro technology would work without it. I would just hesitate in a non-protected environment as I believe correctly crimped terminations are better than twisting and soldering wires together. I have actually a soldered joint in my VHF co-ax, done by me, and I think in the circumstances I have used it, it was the most suitable connection. Haven't got ANY scotchloks or chocolate block anywhere on my boat though.

As for my background, no, most boat owners are not engineers, HOWEVER I still think there is nothing wrong with using best practise. The OP wanted an opinion on crimping - I'm guessing he (she?) is not an engineer by trade, so I want to give the best advice I can based on what I know.

That would be: Don't use scotchloks!!!!

Anyway, it has been a lively debate - I wish there was a hand-shake icon. Have a smile instead :) All the best.
 
Elton

You seem to hold factory assembly in high regard. They don't all deserve that, even from some of the better builders. The boats I work on are often 10,20, or more years old and from good respected builders. It's an eye-opener! One 32' powerboat's AC panel was a custom etched piece of aluminum with the breakers installed in it instead of a commercial panel. The neutral and ground wires, all 7 of each, were twisted together and soldered - badly soldered. During my rewire I installed buses for each with a heat shrink eye on each end.
I have seen scotchlocks on some boats but not often - and I never use them. Never use wire nuts or electrical tape either but many builders have.

For an amateur who wants to work on his own boat and is inexperienced in wiring a crimped connection with the proper crimper and connectors can do a very good job after a bit of practice - the link that Fascadale used is an excellent one to use as a guide. I very much doubt a beginner can create consistent solder joints without prior experience.

In addition to the hard spot a soldered joint creates the thought is if the wire heats up the solder may melt. Those are the reasons that ABYC requires that a soldered connection not be the only means of connection. Your own BSS guide discusses crimping but makes no mention of soldering except for battery cables which are allowed to be soldered by ABYC as well.

I am a marine electrician. Not ABYC certified but I wire to their standards.
The creator of this website http://www.pbase.com/mainecruising/wire_termination
is ABYC certified.
 
Rosssavage, I don't know where you did your aircraft maintenance course but one thing you say is simply wrong. Aircraft most definitely do use solder in critical components. On many MIL-spec multi-pin sockets there's absolutely no way you can crimp the pins. Are you suggesting all the connections on a fly-by-wire such as a late model Boeing or Airbus are crimped? I can assure you they are not. The military also use soldering extensively.

I suspect like yourself, I've been doing this a long time now (about 40 years:eek:) on everything from aviation and boats to houses and data-centres so I am speaking from a good base of experience.

There's also talk of cold-welding and creating homogenous lumps of metal after crimping. If you have managed to create a homogenous lump of copper when you made the crimp then you have definitely over-crimped and should cut it off and start again.

Regarding hard points created when soldering, whether you crimp or solder you will have a hard point where you transition from the connector or terminal to the cable somewhere. Both solder and crimp terminals are made of fairly soft metal and need supporting beyond the terminal and fairly well up the insulation by a semi-rigid device anyway. Adhesive-lined heat shrink is the best option as it also provides environmental protection, but it's not the only option and the cable should still be supported even if it has got a heat-sleeve on it, especially if you are using ring or fork terminals.

If you've managed to get solder that far up the cable that there's a hard point beyond the support of the heat-shrink or whatever you've used then you've soldered very badly. It's easy enough to check where the tinning ends by simply flexing the cable anyway.

As for the wire heating up to the point where it will melt the solder I think I'd want the connection to fall apart as quickly as possible if the wire got that hot. The most common solders melt at over 180C so you've got other problems if you're running your wires that hot.

There's little difference between a well crimped and well soldered connection these days, certainly not enough to worry about. If people feel more comfortable crimping than soldering no problem. Soldering is a skill that should be possessed by anyone who wants to be self-sufficient though.

I agree Scotchbloks are not to be recommended but they do provide a good temporary fix and the gel-filled ones are much better then the older types. Should still be replaced ASAP though unless you don't mind losing the connection.

Personally I wouldn't use a cheap domestic "chocolate block" even temporarily unless it was life or death. In some circumstance (not on a boat) the leaf style terminal strips are OK to use but there are better alternatives definitely.

I'd DEFINITELY agree that the manufacturer is not a good baseline to use. Even in the aviation industry that's sometimes the case. In the marine and other industries there are some pretty horrible things foisted off on the poor punter.
 
Ubergeekian said:
Don't mess around with butane irons. Antex do a 12V verson of their standard 18W one which is the dog's danglies for car and boat soldering.
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Thanks, I'll try and find one of those: the butane thing is hopeless for soldering, but it does double as a heat gun so is very useful for the heat shrink crimps

rosssavage said:
Pragmatism, yes. But my point is there is no shame in aspiring to produce the best result you can, given the time / money / skill level etc. I would suggest that crimping well is easier than soldering well, and hence would be the preferred choice? Especially over Scotchlok, which was the original question.

The OP wanted an opinion on crimping - I'm guessing he (she?) is not an engineer by trade, so I want to give the best advice I can based on what I know.

Anyway, it has been a lively debate - I wish there was a hand-shake icon. Have a smile instead :) All the best.
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A "he", not an engineer but aspiring to produce reasonable work, and yes crimping is easier than soldering and if crimping is good enough for modern planes then it should do for my 26ft 38 year old MAB.

Thanks for the debate and advice
 
Rosssavage, I don't know where you did your aircraft maintenance course but one thing you say is simply wrong. Aircraft most definitely do use solder in critical components. On many MIL-spec multi-pin sockets there's absolutely no way you can crimp the pins. Are you suggesting all the connections on a fly-by-wire such as a late model Boeing or Airbus are crimped? I can assure you they are not. The military also use soldering extensively.



Three year apprenticeship with BA, when they did that sort of thing. Two years at Brooklands technical college, a further two years at Farnborough technical college.

PACE rework certified.

Experience as an avionic technician on B737, B747, B757, B767, A320 family, L1011, DC10 and Concorde.

Then CAA avionic design sig on B737 and A320 family.


Without thread drifting, we are talking about wire terminations. I stand to be corrected, of course, but you show me where Airbus or Boeing use soldered connections in their FBW cabling. They don't.

I've never once mentioned anything about cold welding in any of my posts.
 
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