Slow Monster rebuild

[utopia]

Originally Posted by 350TSS

7. If soldering as well as crimping, do not pre- tin the cable end before crimping and use the bare minimum of solder – common sense.

I would definitely agree with that.
Also I find that, since the connectors are ready-tinned, there is no need to use any extra flux if using multicore solder.
And if its not stating the obvious, crimp the bellows seal AFTER the soldering is done.
In fact, having initially crimped the wire, I then bend the remaining cable slightly away from the metal of the terminal to avoid any heat transfer to the insulation (as far as is possible anyway).
The key to soldering them though is to use a very, very thin bit on the soldering iron, so as to get concentrated heat precisely applied to exactly where you want it.

I have recently done extensive mods to two bike looms using Superseal connectors.
My advice would be .. be wary of any crimped connection.
In theory it may be the best connection but without the exact proper tools and perhaps also a little experience, there will almost certainly be a fair few connections which don't end up being totally secure.
This can easily scupper your efforts .. and rectification is not straightforward as you have already burnt bridges. It can get very frustrating at that point.
I don't want to labour the point too much but I would definitely crimp AND solder all the terminals .. once you've practiced the technique.

For me, the breakthrough was lightly clamping the crimped terminal/wire assembly to a plywood board before soldering (via a soft, rubber pad to prevent damage).
Thus everything is held firm, leaving one hand for the soldering iron and the other for the solder.

There are some very detailed assembly instructions for superseal connectors on the net somewhere.
These have lots of very handy cross-section drawings.

A sharp knife is an excellent tool for scraping away any excess solder .. but with practice you'll get neat enough to rarely need to do that.

Oh come on utopia - crimping is the industry standard and soldering as well is not necessary.

Ok if you haven't got the right crimper then do solder as a 'make-do' in an emergency but why not get the right gear?

You're an engineer!

[Mr Gazza]

Crimping is only the industry standard because it's cheaper, does not use heat or expensive metals.
It can be performed by less skilled operators, in quicker time.

That doesn't mean it's a better, durable, electrical connection.
You just can't beat a properly soldered, cleaned and sealed connection.... A little bit more time and skill involved. The industry just wants BANG. Done.

[slob]

a soldered copper wire is potentially more brittle and may not survive as well as a properly crimped connector in service

[Capo]

Crimped connections are the industry standard, they pass the criteria for conductivity and security, simply a cheaper and better job than soldering. An engineered reliable solution.
Are there any manufactures who solder the electrical connections on their products?
Punch down blocks prevail in the telecom industry, no crimp, solder or screws, an engineered solution.
I have crimped many connections none of which have failed. The secret is using the correct crimping tool. A ground down pair of pliers is never going to do a good job.

Originally Posted by Mr Gazza

Crimping is only the industry standard because it's cheaper, does not use heat or expensive metals.
It can be performed by less skilled operators, in quicker time.

That doesn't mean it's a better, durable, electrical connection.
You just can't beat a properly soldered, cleaned and sealed connection.... A little bit more time and skill involved. The industry just wants BANG. Done.

It is prohibited to solder connections on any aircraft. Crimping is mandated. Soldered connections will not withstand vibration. Hence the prohibition in aircraft manufacture and maintenance. Cost has nothing to do with it.

[Mr Gazza]

All the connections were soldered on all my aircraft, and I'll be sticking with it. (<Pun there.. )

Crimp away gents. I won't be joining you.

[Luddite]

Originally Posted by slob

a soldered copper wire is potentially more brittle and may not survive as well as a properly crimped connector in service

Expanding a little on what slob says, there will be a tendency for any solder to wick along the wire under the insulation due to capillary action. That part of the wire won't be as flexible as the remainder so any stresses caused by movement in the loom will tend to concentrate where the solder begins, potentially causing a break.

On a separate point, the addition of solder will increase electrical resistance in the connector.

There are, of course, plenty of plusses and minuses for both crimped and soldered connections. I remember reading on the NASA site that they use both crimped or soldered connections, depending on the exact application. I can't imagine a more extreme environment than that in which NASA's equipment operates. I don't recall them saying that solder and crimping being used on the same connection though.

[350TSS]

Why will it increase resistance ? because lead is a poorer conductor than copper?

[Luddite]

Originally Posted by 350TSS

Why will it increase resistance ? because lead is a poorer conductor than copper?

You can't beat copper as a conductor!

This chart shows the conductivity of various solders as a comparison with copper.



The first column shows solder conductivity between around 9% - 16% of copper, depending on its composition.

As a baseline, the standard resistivity of (annealed) copper is 1.7241 x 10-8 ohm-metre.

Whether the difference is worth worrying about is another question. You could always do a quick test - measure the resistance of a length of unsoldered wire then add some solder part way along its length and measure the resistance again.

[Nasher]

Originally Posted by haloguy628

It is prohibited to solder connections on any aircraft. Crimping is mandated. Soldered connections will not withstand vibration. Hence the prohibition in aircraft manufacture and maintenance. Cost has nothing to do with it.

As above.

I'm the Strategic Procurement Manager for a Civil and Military Aviation electronics company down here on the South coast.
A little add on to my position involves me working very closely with Boeing quality engineers to conform sample products we've designed and built before they can be put through qualification testing for use on aircraft.

I can confirm cost has nothing to do with it, crimping a 'Crimp' to a cable, when carried out in accordance with the manufacturers instructions using the correct tooling, is considered better in all respects for consistency and longevity of the joint.
Vibration as mentioned is the killer of soldered joint at the point the tinned bit of conductor ends.

The only soldering of cables we carry out is when joining a cable assembly(pigtail) directly to pads on a pcb.
Then it has to be carried out by an IPC Class 3 certificated operator.

Nasher.

[Darren69]

Originally Posted by Darren69

Have you tried without tinning the wires, just crimping the bare wire? I don't know but maybe the solder is making the wire too thick for the crimp to close down enough? I don't think you need to for those sealed connectors anyway.

As Dukdesmo and I said originally no need to solder those superseal plugs, just crimp the bare wires with the proper tool and all will be good well actually better. Can of worms now officially closed!

[Pedro]

I’ve worked in the connector industry for nigh on 30 years now, crimping is low cost and perfectly suited to automotive applications, but you gotta have the right tools or the crimp integrity will be compromised either through poor conductivity, long term corrosion or poor pull off forces.

Super seal connectors can be crimped using pliers/cutters if you know what your doing but not recommended. Pukka tools are not cheap, normally ratchet type as the repeatability is built in.

Happy to discuss further If needed, drop me a pm

Ped

Ps nasher - out of idle curiosity who do you work for? You might be a customer of mine - I work for Smiths Interconnect

[utopia]

Originally Posted by BLUNT

Oh come on utopia - crimping is the industry standard and soldering as well is not necessary.

Ok if you haven't got the right crimper then do solder as a 'make-do' in an emergency but why not get the right gear?

You're an engineer!

Such a loud criticism demands a response.
Sorry for the thread clutter.

1) The crimping is merely incidental to the soldering process but it actually IS necessary to do or the terminals won't fit the housings.
2) If I bought the "right gear" as you call it, every time, my shed would be bursting with expensive and seldom used crap .. which would do nothing to verify my engineering status.
I'm guessing you're familiar with that in your shed.

You seem to be missing the point and assuming that I claim my soldering method to be better than industry standard.
If you read my comments properly you will see that I make no such claim.

[utopia]

Solder and crimp isn't a "belt and braces" thing.
The crimping is necessary for the terminals to enter the housings correctly.
It also happens to be a handy way of holding everything tightly during soldering, as well as minimising the amount of solder in the joint.
It's just the sensible way to solder them.


For Superseal connectors, I have found that any stiffening due to solder "wicking" up the strands is extremely minimal and is in any case confined well within the semi-rigid terminal, with the wire and insulation being further supported by the body of the connector itself and the seal .. thus in my judgment the critical area is protected from vibration induced failure.