Soldered wiring joints, buried in plaster

Last time I needed to remove a socket from its backbox (was having an soundproofing wall constructed in front of it) I used butt crimps to maintain the ring (done with a ratchet crimper and gorilla tested) individual shrinkwrap plus overall shrinkwrap.

Electricians are not trained in soldering, which is why you won't see them doing it, although soldering is a permitted method of making inaccessible cable joins.

A properly soldered joint with tin/lead solder should last longer than a crimp. (Lead-free solder doesn't have the same long life.)

Solder isn't intended to be a mechanical connection, but you have maybe ensured a good mechanical connection with your loops. I have soldered inaccessible connections in the distant past by using a regular screw terminal bakelite junction box, and soldering the terminals/conductors afterwards. I'm not so sure your cable join without an enclosure is quite as acceptable. You could argue another reason for soldering not being used regularly is the lack of cable connectors designed for it on the market.

T&E PVC insulation isn't well designed to handle soldering temperatures, and melts someway up the wire, and might not meet insulation spec after it's solidified again. This area would need to be sleeved. The copper needs well protecting from plaster/cement and any moisture which gets into it.

I personally don't regard Wagos as acceptable for inaccessible joints.

Lay the stipped ends, side by side, then bind them tightly with thin gauge copper wire. 5amp fuse wire, works well, for binding, then finally solder and insulate.

I makes a strong joint, with no lumps or bumps, which heatshrink will easily slide over.

I think that's what the guidance *used* to say, but it doesn't give a good mechanical joint (which is essential) and is a pain to do

I'm surprised. Soldering is not exactly a highly skilled task! Clean the wire, make a mechanical joint, clips on the wires to reduce heat transfer, solder with Pb/Sn flux'ed solder, don't disturb for a few seconds (until chilled), insulate.

I've occasionally used a "barrel" from a chock block (without the screws) to contain the wires and then soldered, but the additional thermal mass needs more heat, so more risk to insulation.

Clips on the wires can act as heat sinks to reduce the risk.

They're very useful but I certainly wouldn't bury them. They're OK in the appropriate box underneath floorboards

I do as you do.

I am better with solder than crimps. Try and waterproof everything before you plaster it

If you have all that it is a lovely way to do it. Back in the day everyone had fusewire.,..

Yup page 3 of the wiring regs, 1st edition:

Yup and acceptable way to do it...

Probably a combination of factors; Soldering can be harder and slower to deploy in real world situations. It carries a burn risk, and may even count as "hot work" on your insurance. It also often needs power, unless you also have a catalytic gas iron etc.

Typically insulated butt crimps and two layers of heatshrink (individual wires, and overall sheath).

Solder is not a mechanical solution. It's not supposed to have tension applied to it, for tin-lead at least.

Even as a hobbyist, I learned the hard way, to not do it this way. If the solder fails for any reason, the two items come apart immediately.

----------- ----------------- [Your first hobbyist method... until you have a failure] ^^^^^^ Dribble solder here

Here is a video of a clever technique.

There should also be a technique for stranded wire, but it is unlikely to look like the hobbyist way of handling stranded wire.

Technicians at work, are all sent on a soldering course. Why ? They were already taught how to solder, while getting their education. But the soldering course establishes a common baseline for the work, so all the techs can refer to that course when discussing "the right way" to do stuff. It avoids arguments over the virtues of peanut butter versus solder.

Paul

That's interesting, it's a slightly tidier version of what I've always done (for 45+ years)

Coincidentally, look what I found today behind a piece of nailed-on hardboard:

Hmmm, that link doesn't seem to work. What image hosting site do others use?

ok here

looks like 7/029

Hmm, it's OK for now too. The "wire nuts" (is that the correct name?) brought back vague memories from childhood, in the late 50s, of them still being around.

B&Q Lyons farm, Worthing had at least 30 packs of 30/15/5 fusewire on sale only a few days ago.

Works fer me

Oh sure, but who just has some? back in the day it was as necessary as super glue is today but now?

Well something that we don't have a problem with these days;)...

I. THE DYNAMO MACHINE.

1. The dynamo machine should be fixed in a dry place.
2. It should not be exposed to dust or flyings.
3. It should be kept perfectly dean and its bearings well oiled.
4. The insulation of its coils and conductors should be perfect.
5. It is better, when practicable, to fix it on an insulating bed.
6. All conductors in the Dynamo Room should be firmly supported, well insulated, conveniently arranged for inspection, and marked or numbered.