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My company's business is stretching and armouring cars. In the former process we must also lengthen all the wires. We've just come across aluminium cables, which pose a problem — until now we used to cut and solder the cables together with the extension.

The sections we have to deal with are (in mm²):

  • 0.5
  • 0.75
  • 1
  • 1.5
  • 2.5

I'd like to know what [industrial] options are available to stretch aluminium cables. There is one possibility that is out of question: replacing entire cables with longer ones. We don't have all the connectors since not every single of them is available, some are proprietary and brand-specific. So we're left with actually "stretch" the cables.

So what are the available options?

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    \$\begingroup\$ Stretching the cables will reduce the cross-section leaving them undersized. Try cutting them and fixing crimp terminals to the ends. \$\endgroup\$ – pjc50 Sep 5 '16 at 15:43
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    \$\begingroup\$ I would think by saying "stretching" he means "lengthening". \$\endgroup\$ – Tyler Sep 5 '16 at 15:57
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    \$\begingroup\$ You can look into Burndy aluminum compression fittings. Seems like they MIGHT work. E.g., burndy.com/docs/default-source/cutsheets/… \$\endgroup\$ – mkeith Sep 5 '16 at 16:46
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    \$\begingroup\$ Are they definitely aluminium and not simply tinned copper? \$\endgroup\$ – Andrew Morton Sep 5 '16 at 18:39
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    \$\begingroup\$ Well, if Toyota and Mercedes are doing it, they have probably done enough research to determine how to overcome the inherent problems with Aluminum. Most interesting! \$\endgroup\$ – mkeith Sep 5 '16 at 20:38
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You can solder aluminium, or at least certain grades. I can solder to cooking grade aluminium foil for instance.

The trick is to buy a specialist multicore solder, with a particularly nasty aggressive flux in it. I find it easiest to 'tin' all the surfaces, then use conventional solder to complete the joint. It needs some practice to get the solder to take, especially getting the temperature right. I don't know whether it is still available, I bought mine 3 decades ago, and still have some left!

One alternative is screw clamps, another is crimp. I'm not sure either would be too robust against possible corrosion of the mating surfaces, unless scrupulously encapsulated after joining. Both would be larger profile than soldering.

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    \$\begingroup\$ And under no circumstances should you attempt to connect aluminum to copper using either method unless you are using connectors specifically designed for such. \$\endgroup\$ – Ignacio Vazquez-Abrams Sep 5 '16 at 16:34
  • \$\begingroup\$ Even those "approved" for aluminum can be less than reliable. Anything you use should be researched first. \$\endgroup\$ – Robert Endl Sep 6 '16 at 2:28
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This is another solution:enter image description here Tulsonic

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    \$\begingroup\$ Does your distinctly short and non-descriptive answer refer to the bonding method of this company? \$\endgroup\$ – user2943160 Sep 6 '16 at 2:57
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The problem with aluminum wire is that the conductor "cold-flows" when crimped with standard crimp splices.

The most reliable splice that I use is a standard electrical Marrette splice cap. This has a conical spring inside that tightly grips the conductors. These are reliable for decades.

Although I regularly solder aluminum using specialty solder and Flux, it just doesn't seem to be as reliable as a Marrette splice cap.

The downside of Marrette splice caps is that they are physically large.

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  • \$\begingroup\$ Twist-on splice connectors are probably not rated for use in high-vibration environments. \$\endgroup\$ – user2943160 Sep 6 '16 at 3:22
  • \$\begingroup\$ Marette splice caps definitely don't apply here. They've been used in the past and proven totally unreliable. Most of all they don't circumvent the problem of humidity on the exposed wires. \$\endgroup\$ – user59864 Sep 6 '16 at 13:56

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