lw395
Well-Known Member
Anyone who says their way is the only way is almost always wrong.
Electrical crimps - your opinion on these, please.
- Thread starter KompetentKrew
- Start date
Anyone who says their way is the only way is almost always wrong.
superheat6k
Well-Known Member
Whereas I understand the wicking theory, the improved electrical connection with a properly soldered joint is unarguable. Therefore if this is then linked with a section of adhesive lined heat shrink extending a reasonable distance either side of the joint (beyond the expected wicking area) the result will be a strong and sealed joint. The heat shrink will add considerably to the overall joint strength and will also act to some extent as a shock absorber against mechanical movements.
Incidentally larger crimps can be soldered, but require the flame torch of a gas soldering iron (up to 25mm2), or even a turbo torch for larger crimps. On AC motors used in semi hermetically sealed compressors we routinely use oxy-acetylene because the heat penetrates rapidly into the desired area of the crimp, without unduly heating the metal conductors beyond the crimp, meaning a clean soldered joint with no overheating of the coverings almost butting against the crimp. A well applied heavy soldered joint will not see the solder exiting the joint into the cable strands beyond the crimp at all, so the mechanical rigidity does not occur.
Incidentally larger crimps can be soldered, but require the flame torch of a gas soldering iron (up to 25mm2), or even a turbo torch for larger crimps. On AC motors used in semi hermetically sealed compressors we routinely use oxy-acetylene because the heat penetrates rapidly into the desired area of the crimp, without unduly heating the metal conductors beyond the crimp, meaning a clean soldered joint with no overheating of the coverings almost butting against the crimp. A well applied heavy soldered joint will not see the solder exiting the joint into the cable strands beyond the crimp at all, so the mechanical rigidity does not occur.
halcyon
Well-Known Member
Back in the distant times while designing fork trucks, our R&D engineers building up prototype power cables 25 / 50 sq mm, by clamping the terminal in a vice so it formed a cup. Heated it up and melted solder in it, then plunged the copper conductor into the solder bath, result perfect soldered joint.
Only problem it did not meet company standards, no soldered terminals due to fatigue were the solder ended.
Brian
Baggywrinkle
Well-Known Member
This is what the cross section of a good crimp should look like using correct terminal and crimp tool for the gauge of wire used.
Where exactly is the solder supposed to go? There are no voids in the joint to fill so it will flow over the surface of the terminal, heat the crimp and the insulation unnecessarily and perhaps wick up the wire creating a potential fatigue point.
Vehicle wiring harnesses which have hundreds of pins and connectors are exclusively crimped, and for good reason .... any solder on the outside of the pin or terminal may defeat the pin retention mechanism and cause pins in connectors to back out or only partially engage.
The only reason I can think of for soldering a crimped connection is if the wire is too small for the terminal and the crimp is full of voids .... so basically, to rectify a poorly executed crimp.
john_morris_uk
Well-Known Member
You said it before I did.
Indeed. As evidenced in lots of threads on these forums.
lw395
Well-Known Member
This is what the cross section of a good crimp should look like using correct terminal and crimp tool for the gauge of wire used.
Where exactly is the solder supposed to go? There are no voids in the joint to fill so it will flow over the surface of the terminal, heat the crimp and the insulation unnecessarily and perhaps wick up the wire creating a potential fatigue point.
Vehicle wiring harnesses which have hundreds of pins and connectors are exclusively crimped, and for good reason .... any solder on the outside of the pin or terminal may defeat the pin retention mechanism and cause pins in connectors to back out or only partially engage.
The only reason I can think of for soldering a crimped connection is if the wire is too small for the terminal and the crimp is full of voids .... so basically, to rectify a poorly executed crimp.
That is either not a very good crimp, or it has suffered in being sectioned.
Looks like a void all across the top of the wire. But cutting it in half can do that of course.
A good crimp will show that some strands have reduced area as metal has been moved around at high pressure.
doug748
Well-Known Member
PaulRainbow
Well-Known Member
Anyone care to hazard a guess how much extra time and cost would be added to a modern mid 30ft cruiser if the builders had to crimp, solder and heatshrink every connection throughout the boat ?
How about a modern car, with all of its electronics ?
How about a modern car, with all of its electronics ?
PaulRainbow
Well-Known Member
So, just how much would it cost the average DIY boater to set himself up to make reliable crimped connections ? It's been suggested that it's expensive, that's not the case.
The following are examples of reasonable quality tools, that will do a perfectly acceptable job and last the DIY user a lifetime. I haven't spent all day looking these up, just a quick and dirty look to give an idea of what is needed.
That's a reasonable set of tools and a good starter selection or terminals, total cost, less than £70.
If you can't make reliable connections with those, you need a kick in the bum. The stripper has a "depth gauge" so you can get consistently correct stripped lengths and it's hard to see how you could fail to get a proper crimp with those ratchet crimps.
Edit ; the Ebay link for the crimp terminals is for a company local to me, who i know supply good quality terminals.
The following are examples of reasonable quality tools, that will do a perfectly acceptable job and last the DIY user a lifetime. I haven't spent all day looking these up, just a quick and dirty look to give an idea of what is needed.
- Wire cutters, £5.99 >>> https://www.screwfix.com/p/magnusson-side-cutters-6/9330v
- Strippers, £12.99 >>> https://www.screwfix.com/p/magnusson-ratcheting-wire-strippers-8/5175v
- Crimpers, £17.49 (there are cheaper ones, but i know the Draper ones work well and last, i have had a pair onboard for over a decade) >>> https://www.ebay.co.uk/itm/Draper-3...m4d8fb57a2b:g:hZoAAOSwXNdckRfW&frcectupt=true
- Terminals, 50 each red and blue, spades, butt crimps and ring terminals, about £15. Plus £15 for 50 each red and blue glue lined butt connectors.
That's a reasonable set of tools and a good starter selection or terminals, total cost, less than £70.
If you can't make reliable connections with those, you need a kick in the bum. The stripper has a "depth gauge" so you can get consistently correct stripped lengths and it's hard to see how you could fail to get a proper crimp with those ratchet crimps.
Edit ; the Ebay link for the crimp terminals is for a company local to me, who i know supply good quality terminals.
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noelex
Well-Known Member
Both soldering and crimping can produce great marine electrical conections. I think there is generally little practical difference between the methods. Both methods can, and frequently are, poorly done.
The biggest drawbacks with crimping is that joints can be bulky and that a correct crimp involves the correct crimping tool and the correct crimp. Something such as connecting two different sized wires is possible but the correctly sized crimp needs to be sourced. Good quality crimps are not typical sold in local chandler or hardware store.
The biggest drawback with soldering is that it takes time. This makes it a poor choice for a marine professional. There is also more skill involved, whereas providing the equipment is correct anyone can crimp.
The biggest drawbacks with crimping is that joints can be bulky and that a correct crimp involves the correct crimping tool and the correct crimp. Something such as connecting two different sized wires is possible but the correctly sized crimp needs to be sourced. Good quality crimps are not typical sold in local chandler or hardware store.
The biggest drawback with soldering is that it takes time. This makes it a poor choice for a marine professional. There is also more skill involved, whereas providing the equipment is correct anyone can crimp.
rogerthebodger
Well-Known Member
To reduce production costs is one of the main reasons for the use of crimping of cable of all kinds.
The development of insulation displacement connectors was as a result of the cost of joining multi cables to connectors.
Even the DB25 RS 232 connector is available as an IDC connector.
crimp connectors are an advantage to some like Paul as time is money and the quicker the job can be done the higher the income. Also once he job is done its the owner we has to suffer any subsequent issues.
I do use insulated crimps with a ratchet crimp tool but some crimp pins used in some of the multi pin connectors are not insulated as then fit into a housing. These need a different crimp tool. Also some multi pin connectors require solder but do support the cable as should be done with any soldered joint.
There are many ways of doing a job and it depends on skills and equipment available and personal views.
Paul seems to think that its his way or the highway. Not so and when we can accept that different people have different but acceptable to the operator the better for the less experienced forma user the better.
Rocksteadee
Well-Known Member
The balance of quality suffering for price
https://uk.rs-online.com/web/p/solder-sleeves/8199874/.
£0.57 ea
https://uk.rs-online.com/web/p/crimp-butt-splice-terminals/0534648/
£0.09 ea
Apart from soldering, which can have a place to and a place not to, what else was nonsense?
PaulRainbow
Well-Known Member
PaulRainbow
Well-Known Member
Sorry, was there a point there ?
Your claim that crimping uninsulated crimps, then soldering them, then heat shrinking them being the only correct way of doing it was total nonsense. That can have no benefit and can easily lead to issues that simply using. If a good quality insulated crimp is correctly fitted, using reasonable tool, it is as good as any other method and for most connections on a boat it's perfect.
I did not say that solder does not have a place, any more than i said uninsulated terminals don't have a place. I carry a full range of insulated and uninsulated terminals, as well as soldering equipment. I use that which is appropriate for the job i'm doing. At no time will i crimp and then solder, it's one or the other.
rogerthebodger
Well-Known Member
ghostlymoron
Well-Known Member
I agree with most of what Paul says but would add that I have had crimped connections done with a Draper ratchet tool fail a pullout test. Admittedly the terminals were only Halfords automotive ones but I would expect (perhaps erroneously) Halfords to be reasonable quality. A friend of mine insists on laboriously soldering and heat shrinking all connections but I don't see that the more fiddly the process, the better the joint so I'll continue to crimp (but test each one). I also find it difficult to produce a good soldered joints in confined spaces whereas crimps are much more convenient and therefore produce reliable connections.
halcyon
Well-Known Member
The crimping tool I use cost £250 many years ago, it's done around 300,000 good crimps, you pays you money. In passing, we always attached the other end to switch panel via soldering to a PCB soldered, wired to avoid stress on cable joint, no problems after 30 years use on some.
As said there is a method to suit your use.
Brian
john_morris_uk
Well-Known Member
I think your mistake was to think Halfords produce or sell quality terminals. Halfords sell some quality items but they also sell some rubbish.
James_Calvert
Well-Known Member
And there was I thinking that maybe crimping with pliers onto Halfords quality terminals might be an improvement on the chocolate blocks....
Seems I need to solder them as well...might as well just blob solder on without the crimping.
Seriously, how do you tell when a crimped terminal is no good? Its probably one on those somewhere which screws up the car's computer.
Seems I need to solder them as well...might as well just blob solder on without the crimping.
Seriously, how do you tell when a crimped terminal is no good? Its probably one on those somewhere which screws up the car's computer.
noelex
Well-Known Member
This is one of the problems that you need to be aware of when crimping. A good quality terminal should be used and this needs to be matched closely to the wire. This is easy for a manufacturer using the same brand and type of wire in a limited number of sizes when producing a boat wiring loom. However, once you mix old and new wiring, metric and imperial wire sizes, different brands of terminal and crimping tool, the results can become less consistent unless a great deal of care is taken.
In practice in the real world, less than perfect crimps often work satisfactorily. I have even seen boats with multiple wires twisted together with some insulation tape added that has been surprisingly reliable, but modern boats often have a much more demanding electrical system. Sustained currents of many hundreds of amps are not unusual, at the same time navigational equipment is transferring large amounts of data via a multitude of fine wires.
Marine electrical practices that have traditionally worked acceptably need some review in light of the demands associated with modern yachts.
