What's the correct way to solder twin and earth cable?

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They were never popular here for mains wiring (at least, when compared with US). I have a few UK wiring books going back to about 1930, and they aren't used during that period for mains. There is something which looks similar but actually contains a blind brass terminal with a grub screw in the side, and that seems to have been popular in that era. There's also something else today which looks similar and made me do a double-take on a couple of occasions, and that's a blind (one-sided) crimp.
They were popular for things like aerial, bell, speaker, etc connections, and you can still buy them for that sort of use.
Of course, you will sometimes find someone has put one on mains wiring. I moved into a house in 1986. It had been professionally rewired in 1974 to a good standard, but then less professionally modified in a couple of places, probably in 1984. After about a year, a socket in the kitchen stopped working. When I came to strip out the kitchen, I found that the neutral was connected to where the socket had been before moving it with a wirenut, which had burned out. So that was installed in about 1984, and looked new, but didn't conform. You will undoubtedly find such cases going all the way back to their invention, probably more so when regs were less strict, but they don't seem to have been in use for mains back to at least 1930.
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Andrew Gabriel
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    clangers snipped-for-privacy@yahoo.co.uk writes:

I'm not aware of any connection boxes explicitly designed for soldering. Very few electricians are competent to solder, so there would be no market for them.
17th edition doesn't tell you how to solder, crimp, or braze connections. It's covered by requirement for good workmanship.
I will however comment on the special inaccessible connection terminals which have sprung up. They seem to me to be to be completely unsuitable for the job, indeed much worse than using screw terminals. It's as though the designer didn't understand _why_ inaccessible connections are specified to be handled differently, but just designed something which doesn't use screw terminals because he knew they aren't allowed. I've only seen pictures though, not had one in my hands.
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Andrew Gabriel
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Only problems I've ever seen with screw terminals on a domestic installation is where others have done them up - or rather not. I've never had any come loose or give problems so personally would be perfectly happy having an ordinary JB in a totally inaccessible place.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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Harry Bloomfield wrote:

dangerous advice. Soldering works fine, but has one weakness that catches people out: the solder is very soft and weak, and cant tolerate movement. It is therefore essential that the wires to be soldered are completely immobilised. You cant achieve that by wrapping them with fusewire, twisting is the logical thing - BUT - twist them twice as long as looks solid, else they're liable to fail.
TBH if you need instructions on soldering, dont do it. Its a fine method if done right, but its so easy to screw up and leave a dangerous joint behind. I've seen so many failures, thankfully at low powers.
NT
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After serious thinking snipped-for-privacy@care2.com wrote :

I agree that solder cannot tolerate movement, which was why I suggested binding them with wire rather than twisting.
Trying to twist a single solid core would harden the copper making the joint weaker, plus produces extra stress where the joint ends - than leaving the cores straight and over binding plus soldering. There was nothing dangerous in the advice, I have done it successfully many times and it is a standard method used for many decades.
In the 1960's there was an IEE regulation taught method of solder jointing the then used 7/.029 cable. It involved binding the two ends then tinning at two points along the length of the joint, rather than tinning the entire length. It was fairly similar to a splice in a rope. The point being to provide a joint which was not only sound, but had some built in flexibility.
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Harry (M1BYT) (L)
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Harry Bloomfield wrote:

I'm a bit surprised that you can isolate the solder joint from all movement and force by binding it. It would need to be 30A fusewire rather than 5A, and presumably have a fair length of binding.
NT
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Tell the GPO that - twisted connections were the norm for many a year.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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On Mon, 11 May 2009 23:47:14 +0100, Dave Plowman (News) wrote:

Can't say I've been aware of plain twisted wires. Solder tag blocks, block terminals with screws, IDC, gel filled IDC "nuts".
Wire wrapping I guess but that didn't seem to last long or become widespread, I wonder why? B-)
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On Tue, 12 May 2009 10:10:16 +0100 (BST), "Dave Liquorice"

cables - no doubt millions of such joints are still extant. Indeed, long before that, twisted joints in various forms (Britannia and copper-sleeve) were in use for overhead open wire spans. Considerably more skill (and time) is needed to perform a twisted joint than crimps and other 'modern' types.
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Underground cable joints - twisted then paper sleeved before being sealed.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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John Rumm wrote:

http://wiki.diyfaq.org.uk/index.php?title=Electrical_Circuit_Faults#Wire_resistance_table
Thanks John, this is exactly the way I would have tackled it, being an electronics engineer. However what concerned me is that the heatshrink sleeving is normally very thin, certainly much thinner than the cable sheath. I'm concerned that this would fail an electrical inspection. Any thoughts?
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clangers snipped-for-privacy@yahoo.co.uk wrote:

Heatshrink IME is a little thinner - but also a bit tougher. It certainly withstands 500V testing with an insulation resistance tester. If you are particularly concerned there is nothing to stop you using two layers. The main thing is to ensure the joint itself does not have any sharp protrusions like wisps of solder or wire ends poking out.
Presumably if you are soldering, then it is in a place where it can't be inspected in future anyway!
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Cheers,

John.

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wrote:

http://wiki.diyfaq.org.uk/index.php?title=Electrical_Circuit_Faults#Wire_resistance_table
What kind of solder? There seems to be more choice in this post lead era.
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Graham.

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Graham. wrote:

I always use 60/40 tin/lead solder. Something with a flux core, and a eutectic melting profile. I usually get a fairly fine solder for electronics work (say 22 swg) and hence would use that - however if I were buying it for the purpose, then would go for a heavier gauge.
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Cheers,

John.

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this to say:

It's only places like Maplins that no longer sell real Pb/Sn solder. Even B&Q sell the real thing...
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Frank Erskine

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Soldering iron and solder. Was it a trick question or are you genuinely stupid?
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