Generally, crimping makes a more mechanically sound joint in wiring in vehicles, and it is just as electrically sound as soldering. But it has to be done correctly and with the proper tools. Soldering irons in the hands of the inept are just a disaster.

In some situations though, like splicing a wire into an existing harness, it is easier to go with soldering, and if done correctly is quite OK. Dual wall (glue lined) heat shrink can be used can be used over either and is good for keeping out moisture.

Solder and heat shrink . Must say most electric wires to your house are crimped. With 12 ton crimping tools ..

A general rule (before we invented Auto electricians) if the joint was FIXED (anchored securely) it could be soldered and if the joint was subject to movement/vibration (ie not supported) it should be crimped.

From experience (and from others on a very long thread here ages ago) soldered joints (like welds in steel that fail next to the weld) tend to fail at the edge of the solder run.

This rule has served me well since taught this in 1969 mechanics training in the RAAF.

 

When I did the NASA course we were told that hand soldering was superior in every way to any other method of connection.

However we don't need to go to the moon so nowadays I use a very high quality crimp set and hardly ever solder any more.

Just saying...




ZCheers

Well...I do both...when I,m around my workshop at home anyhow.

But out in the wilds....a really good quality ratchet crimper and decent terminals does the job for me. And while we are on the subject of soldering ...I have never had a soldered joint give any sort of trouble in 30 odd years of DIY and rattling around this great land. I might add that all joints are shrink wrapped with thick wall tube too.

 

Cheers  Keith

Tinning wires before crimping, or before securing under screw down terminals, will always allow the joint to loosen with time because of the malleable properties of the solder. If you want to protect wires when using screw down terminals, use a crimped bootlace ferrule.

dorian wrote:

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What about first crimping the joint and then flowing solder into the crimp afterwards? Would that be OK? In fact that's what I do.

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 Actually, you do see that sometimes in OEM vehicle wiring where they have light weight, open barrel crimps, on heavier wiring, especially in power wires. I have seen it mainly on fusible link wire terminations. And from memory, one of the Motor Body Builders Manuals we used says to do that on fusible link wiring. I'm not sure why though, maybe a belt and braces approach, and as long as the solder is only under the crimped section, and doesn't extend into the support section of the crimp, I can't see a problem. But with normal wiring using standard crimp terminations, and done with the correct tools, it isn't necessary and only introduces possibilities of a poor joint where the solder wicks up the wire past the support section of the crimp.

Edit: typo doh!

-- Edited by 03_Troopy on Thursday 19th of November 2015 11:27:58 AM

Hylife wrote:

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Depends on the connector type.

If it was for automotive use it will be most likely a crimp fitting. These should NOT be soldered. As has already been mentions the joint is less secure than crimping alone, IF, you use a proper crimping tool. If you just try and mangle the lugs together with some pliers it will be worse than just doing a twist tie joint.

 

If you are concerned with poor connections due to higher resistances (dry joints), then purchase a small tube of dielectric grease.

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 Sorry, but dielectric grease does not improve connection conductance. By it's very nature, it is an insulating compound. It may be helpful for lubrication and keeping moisture out of connectors once they are done up, but is far more likely to attract impurities that will damage threads and sockets. And definitely don't put it on a wire before you crimp it.

Servisol Electrical Contact cleaner would be far better for using on connectors. It cleans the surface and leaves a thin film of light lubricant which is likely to attract debris.

Reading the OP is helpful when giving advice.

 

Edit: Actually I will give you a bit of lea-way on using it on a crimp connection. Provided the crimped connection is well formed with quality crimping tools, it is probably not so detrimental. Given that a properly formed crimp connection will have squeezed the grease out from between the metal surfaces anyway. It may also help to keep moisture from wicking into the wire, outside the crimp connector. Or you could just use dual wall heat shrink over the joint.

-- Edited by 03_Troopy on Thursday 19th of November 2015 06:00:44 PM

Electrical compound grease is basically high graphite grease . Used in outside crimp joints to keep moisture out .,
Very important when crimping copper to alloy wire .. The sleeve or crimp is after friction welded to prevent corrosion..
There is a difference between 12v and 240 / 415 v also.. When solder is used on LV it de rates cable as it won't hold the heat..
Years back cables where bound at the ends .. But due to some live disconnections the bound wire caught in meter or switch causing an electrical flash.. Why do it under load ? PC correct way is to do away due to dumb asses..
Stereo systems are better soldered .. Nothing worse than a crackling speaker..
Boats or near salt water have different rules where tinned wire should be used..
I would say I have paid half my house off servicing houses with out supply on the coast..
New screw crimps where you tighten through insulation is much safer ..

Three things in the OP.

1. As I have said a properly made solder joint OR a properly made crimp joint WITH THE CORRECT crimp tool, not the Bunnings pretend tool, will last forever.

2. Heatshrink will protect and insulate a connection 10 out 10 for that one.

3. Neutral cure silastic will do the job, I suspect (as the same in my van) that all the underneath has this silastic on it, works a treat if worked correctly.

Cheers

I put a dob of hot glue on a small board , then as the glue starts to set i roll the soldered connection in it , making like a cigarette, build up if necessary, never failed yet

-- Edited by Petermernamc on Friday 20th of November 2015 06:39:26 PM

Aus-Kiwi wrote:

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Depends on the quality of fittings . Strange as it may seem my quality ( ???) Yamaha speakers had little solder on speakers coils and become semi detached .. After soldiering properly they have lasted some quite heavy work..
To much solder in this area would make the wire too stiff .
In most cases limited flex or saddling wires limits any movement ..
Again it's a horses for courses application ..
Either done well with no dry joint is fine ..

The crimps I was referring to is what is used on single HV cable joints now ..
Where they used to heat alloy and weld cables together ..
Used on house service wires, often bimetallic alu service and copper consumer mains..
Such a wide variety out there, in s many fields..

---

 So not really relevant to the OP...

Solder on speaker coils??

03_Troopy wrote:

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Aus-Kiwi wrote:

---

Depends on the quality of fittings . Strange as it may seem my quality ( ???) Yamaha speakers had little solder on speakers coils and become semi detached .. After soldiering properly they have lasted some quite heavy work..
To much solder in this area would make the wire too stiff .
In most cases limited flex or saddling wires limits any movement ..
Again it's a horses for courses application ..
Either done well with no dry joint is fine ..

The crimps I was referring to is what is used on single HV cable joints now ..
Where they used to heat alloy and weld cables together ..
Used on house service wires, often bimetallic alu service and copper consumer mains..
Such a wide variety out there, in s many fields..

---

 So not really relevant to the OP...

Solder on speaker coils??

---

 Yes wire to speaker .. They don't come with connectors ..

depends on application ..Ego.. 

Sorry that you thought your post had been treated in a dismissive way Hylife, my reply wasn't intended that way. But some of us also have extensive experience in these areas as well. For example:

I was an Avionics Tech on military aircraft for 30 years, 22 years in the RAAF where I completed many different courses in wiring termination and connections, including connector best practices, High Reliability Hand Soldering and mechanical terminations and tooling (crimping). I also spent a couple of years investigating failures due to poor installation practices. And yes in aircraft, connections are almost always crimped for higher reliability.

I had my own business repairing consumer electronics and computer systems for 7 years, this was mainly soldering but occasionally crimped terminations.

I worked on 240V and 415V industrial electrical equipment such as inverter and large amperage welders and plasma cutting equipment (2 yrs). Here again, connections between internal components, input and output connections were crimped or screwdown connections (sleeved or wrapped cable ends).

I worked for a large company for 4 years, rewiring Blast Hole Drill Rigs, building mine service vehicles (utes and trucks) and also wiring and terminating electrical switchrooms (32VDC, 240VAC & 415VAC). Here I worked with a team of Auto Electricians and Electricians from various backgrounds. The Drill Rigs were almost always crimped terminations, except inside junction boxes where bootlace ferrules and push in terminal blocks are also used. The mine service vehicles had mainly crimped connections using insulated and non-insulated crimp terminations. Where it was necessary to splice into a wiring harness, strip and solder terminations were used.

Qualifications: RAAF Radio/Avionics Technician, Cert IV Avionics Maintenance Engineering, Advanced Certificate of Electrical Engineering, Advanced Diploma of Electrical Engineering.

In summary, yes crimped terminations do prove more reliable for vehicle interconnections, as I stated.

As for the Dielectric Grease, it does have a voltage breakdown point, which is high and in the order of 1100V/mil so that is probably not relevant to automotive use. The point I was making though, was in relation to this statement
-----------------------------------------------------------
Hylife wrote:

If you are concerned with poor connections due to higher resistances (dry joints), then purchase a small tube of dielectric grease.
-----------------------------------------------------------

Dielectric Grease will not lessen the possibilities of high resistance joints. It is an insulator. It will aid in lubricity of contact surfaces and moisture exclusion decreasing corrosion. However, it will also allow particles to be embedded into the grease and to stick to it causing increased damage to connectors. A fine light coating, as left by something like Servisol Contact Cleaner, on connector mating surfaces is much less likely to cause the same thing to happen. And I would not use it on cable ends prior to crimping because of it's insulative properties. This practice would be totally forbidden on aircraft crimped connections also, where any traces of contamination on cable ends must be removed before crimping.

A "Dry Joint" is a poorly made solder joint, where the solder has not wetted the metal surface (therefore not bonded) causing a high resistance joint, as opposed to a fractured joint, where the solder between the metal surfaces fractures and becomes high resistance. Where connectors have loose, dirty or corroded contacts, it is simply a high resistance joint.

To the OP, sorry that this has gone a bit off topic.