To solder, or not to solder, that is the question?

[Electronpusher0]

IPC 620 section 5, crimped terminations, states "Conductors should not be tinned
prior to termination, unless otherwise specified."

Peter

[Refugee]

I have had to fix crimps that were done with one of those two layer tools that do the insulation and the stripped wire both at the same time.
The fault was caused by someone showing an apprentice how to fit the crimps without realizing that he was left handed.
They all went on with the tool held the wrong way around so that the insulation holder punctured the insulation and the stripped wire just touched the inside of the bit that should have held it firmly.
Just allow for lefthandedness when training apprentice wire-men.

[MotorBikeLes]

Mains plugs, I double the flexible conductor back, "end bit upwards", then tighten the screw.
Motorbike wiring. NEVER use the red/blue/yellow crimps, but bare crimps with optional insulating shrouds. First I crimp (with a cheap, simple tool) but I do have the "expensive" one. I then tin the very end of the wire. Good hot iron to prevent any wicking back of solder to cause embrittlement. Plenty of vibration on my 650 V twin, but no failed joints over the last 20+ years. ALL my Italian bikes were rewired by me over that period. I reduce all interconnects to a minimum.
Les.

[David Simpson]

Black & Decker & many other manufacturers often fit wee plated bootlace crimps to one or both ends of their mains flex.
Whipping & tinning the ends of multi-strand cable & flex was encouraged in the RAF in the early days. Particularly copper/cotton phono flex. Whipping into loops & then tinning was another procedure, as opposed to Ross-Courtney terminations which were also used.
Much later, when I worked for Scottish Hydro-Electric, all linesman & jointer's landrovers carried gas powered crucibles for hot-dipping cables up to 250mm plus. Although this practice was later replaced by CCL hydraulic crimps.
Electronics/Radio -wise, for all multi-strand wire & flex I would recommend tinning as it prevents the spreading &/or splitting of the individual strands when being tightened by the securing grub-screw which might be a bit smaller than the flex's diameter.
Only practice will reduce problems with capillary action of solder creeping back up from the tinned end, which would also reveal itself by excessive shrinkage of the PVC insulation. Timing & excessive heat prevention practices have been discussed in many threads in the past.
"Tin once & tighten twice" is a practice I taught to RAF apprentices many years ago. Akin to the "measure twice/cut once" practice taught to joiners etc.
Folk in the trade my also remember that many radio equipment manufacturers also fitted Hellerman or similar sleeving at the termination ends of flex & cabling, even in 3 pin mains plugs etc. Particularly AVO, Marconi, HP, Tektronix, & so on. And certainly all military plugs/terminations/connectors/etc.

Regards, David

[Keith956]

I had a job as a wireman in a wiring shop as a Saturday job in the early 70's. I remember wiring hundreds of contactor panels for APV - wires from the loom had to be tinned then looped under the contactor terminals (each of which had a plate under the screw, to clamp the wire). If they weren't tinned they were rejected...

[Herald1360]

Someone preferred form over function, there!

[G4_Pete]

in the early days of servicing desktop computers I learnt the hard way that plug tops with loosened soldered ends were invariably the cause of random crashes.

Where practical I use bootlace crimps made even more important by the low quality of some plug connector screws pinching off strands as they tighten.

Pete

Where practical I use bootlace crimps

I like bootlace ferrules, just "won" a bag of a thousand from the WEEE bin at work, should last a bit. You don't need the real crimp tool for individualy installed wire, the tool is handy when pre-terminating (stops the ferrule dropping off, I bet one of those will be WEEE soon, can't wait).

[The Philpott]

Our house has much of the original 1965 wiring, Plastic insulated (presumably PVC) and it is tinned. The lighting circuit has single conductors however the ring main has several strands (7?). I have not encountered any problems with loosening up to this point, however there's no way i can tell exactly what the tin may have been alloyed with.
Anywhere I have disturbed the conductors there is, of course, no corrosion!
Dave

[Jon_G4MDC]

Home Office inspector rejected my very well soldered earth tags.
I thought that a Hellerman sleeve over the joint was the icing on the cake.

He didn't. He said it prevents inspecting the joint for deterioration.

+1 to him.

[trickie_dickie]

And what about "Wire Wrapping" ? Does anyone do that anymore ?

[kalee20]

Originally Posted by The Philpott

Our house has much of the original 1965 wiring, Plastic insulated (presumably PVC) and it is tinned. The lighting circuit has single conductors however the ring main has several strands (7?). I have not encountered any problems with loosening up to this point, however there's no way i can tell exactly what the tin may have been alloyed with.
Any where i have disturbed the conductors there is, of course, no corrosion!
Dave

I think this a bit of confusion: Philpott is referring to multistrand, tin-plated conductors (tin-plated before stranding and twisting) whereas the thread is about 'tinning' with solder AFTER the cable lay is formed, so that the strands are 'glued' together with solder.

The former is quite OK in a crimped or screw-clamped joint, as millions in satisfactory use will bear witness to. But the latter - nope.

[David Simpson]

Richard - wire wrapping, yep I still do. Particularly old fashioned copper/cotton headphone wiring. I also do insulation binding, and looming & lacing, just to keep my hand in on occasions. I've also got some packets of Ross- Courtney terminations somewhere. But hey, I also use H/S sleeving, and modern silicone rubber Hellerman type wee sleeves.

Regards, David

[emeritus]

I believe that tinning of conductors used to be necessary with rubber-insulated wires as bare copper would have been attacked by the sulphur compounds in the rubber used. It was found to be unnecessary with PVC.