(Fake) Solder seal connectors - Page 1
Forum section: electronics / general

author: 5U4GB
author_rank: Super Contributor
timestamp: July 21, 2025, 08:04:12 am
content: Friend of mine was extending some existing wiring up in a crawl space - and I do mean crawl space, hands and knees - using solder seal connectors due to the near-impossible working conditions while I offered helpful advice and feedback from a comfortable position not in the crawl space, because that's what friends do. Problem was he just couldn't get the solder to melt no matter how much heat he applied.I borrowed one or two of the connectors to take away to play with, and hit them with a hot air gun while they were held inside a heat shroud to make sure they'd stay at temperature. They're supposed to melt at 140-160 degrees C, so let's try 180. Nothing. 200? Nothing. 220? 250? 280? 300? Still nothing, although I had to turn on the extractor fan due to the plastic starting to emit signs of distress. Finally I stopped at 350 with the plastic a melted mess but the "solder" still unmelted.My suspicion is that some enterprising vendor in the Middle Kingdom has figured out that what's mostly holding the wires together is the heatshrink, so the physical contact from that is enough and you can save a bit of money and manufacturing effort by replacing the solder with an alu collar. When I'm next over there I'll try and grab some of the larger connectors and dissect them to see what the "solder" really is.

author: Gyro
author_rank: Super Contributor
timestamp: July 21, 2025, 09:53:45 am
content: Those things are absolutely not suitable for extending house wiring! They use low melting point solder and, from a video that Big Clive did, have great difficulty in tinning conductors. An insufficiently tinned lap solder joint of two solid core mains conductors with an insufficient quantity of low melting point solder will pose a fire risk, not something you want in a tight crawl space. I'm sure it will be against wiring regs in your county too, it certainly is here. There are certain 'maintenance free' connector boxes available, eg. Wago in Europe, but even these wouldn't be advised in a crawl space where they are exposed to the elements. They need some slack in the cable too.The correct method is to replace the entire length of cable so that there are no inaccessible joints (they should be made at sockets etc). If in doubt, consult a qualified electrician.[Your friend should] Be safe!Edit (and these are genuine ones)...

author: Fraser
author_rank: Super Contributor
timestamp: July 21, 2025, 10:04:08 am
content: It sounds like your friend has been supplied with heat shrink butt joint CRIMP connectors instead of the solder type ? I second the comment that the solder types are unsuitable for demanding roles.Fraser

author: tooki
author_rank: Super Contributor
timestamp: July 21, 2025, 10:28:27 am
content: Quote from: Gyro on July 21, 2025, 09:53:45 amFYI, the genuine Raychem (TE) ones are actually available in several solder alloys. Depending on the model, they are available in low melting point Sn50Pb36Cd18 and Sn42Bi58, ordinary 63/37, and/or Sn96Ag4 solder (melts at 229C).

author: Gyro
author_rank: Super Contributor
timestamp: July 21, 2025, 11:31:04 am
content: One other thought. An awful lot of heat will be conducted away from the joint by any significant sized copper conductors, versus what can be delivered to the solder joint using hot air, interrupted by an insulating sleeve.

author: Analog Kid
author_rank: Super Contributor
timestamp: July 21, 2025, 09:48:58 pm
content: Quote from: Gyro on July 21, 2025, 09:53:45 amYes, absolutely.As a former handyman who did alotof residential wiring (and even some commercial, though no 3-phase), I would never, ever, want to see any cable (presumably "Romex", AKA NM (non-metallic)) with any kind of splices in it. None.I don't even care if the code allows this. It just ain't right. All connections should be made inside junction boxes or at terminal devices (light fixtures, etc.). Not hanging out in the open air.I'd be surprised that these are even allowed, if they are.

author: tooki
author_rank: Super Contributor
timestamp: July 21, 2025, 10:38:33 pm
content: Quote from: Analog Kid on July 21, 2025, 09:48:58 pmI'd be very surprised if solder sleeves were allowed by NEC for any mains application.NEC 110.14 says:QuoteSince solder sleeves do not provide any mechanical or electrical security without being soldered, I would interpret them as not being compliant.By pure coincidence, I saw a youtube video the other day that mentioned some splices that are NEC-approved for use outside of junction boxes ("listed NM cable inter-connector devices" for "buried" splices). Apparently the 2023 NEC newly allowed them to be used in new construction, too, not just for repairs. But the youtuber agrees with you: he wouldn't do it, even if it's allowed.Of course, OP is in the UK, not USA, and I have no idea what UK code does or does not allow.

author: langwadt
author_rank: Super Contributor
timestamp: July 21, 2025, 10:56:01 pm
content: Quote from: tooki on July 21, 2025, 10:38:33 pmthey could possibly maybe be if you do like a linemans splice on the wires before sliding over the connectornot that I would do it

author: thm_w
author_rank: Super Contributor
timestamp: July 21, 2025, 11:03:16 pm
content: You could hook the wires and then slide the solder sleeve over it. But doesn't matter either way as they are not certified in any way AFAIK. edit: langwadt said the same thing.Certified Wago/butt crimp/screw terminal in a junction box is allowed in Australia and just as easy to install, all for the princely sum of $2:https://dzelectrical.com.au/products/junction-box?variant=48114150179090AS/NZS 3000:2018 Wiring Rules:https://spe.net.au/wp-content/uploads/2025/03/AS30002018.pdf

author: 5U4GB
author_rank: Super Contributor
timestamp: July 22, 2025, 05:17:26 am
content: Quote from: Gyro on July 21, 2025, 09:53:45 amIt wasn't house wiring, it was PIR sensors, so 12VDC at 10mA and easily tested for both go/no go and whether they're still connected via the EOL resistors. For house wiring he would have got his son-in-law, an electrician, to do it to code.And they definitely weren't crimp connectors, it was solder seal ones but from God knows where, certainly not the good-quality milspec/aviation-use ones.

author: Analog Kid
author_rank: Super Contributor
timestamp: July 22, 2025, 05:35:51 am
content: Quote from: tooki on July 21, 2025, 10:38:33 pmNow that is a special case, splicing buried cable. On second or third thought, I guess I could see approved splices being used there, especially if the cost/labor of digging up and replacing a run of buried cable was prohibitive.They'd have to be pretty goddamn good splices, though: I guess they're probably similar to those gel-filled wire nuts which are approved for outdoor (or buried?) usage.Once buried, presumably nothing short of an earthquake would disturb such splices.

author: Gyro
author_rank: Super Contributor
timestamp: July 22, 2025, 08:41:54 am
content: Quote from: 5U4GB on July 22, 2025, 05:17:26 amProviding that information earlier would have saved some time! I don't think we were familiar with what his his son-in-law does.

author: 5U4GB
author_rank: Super Contributor
timestamp: July 22, 2025, 09:04:25 am
content: The post was about fake solder seal connectors, not what sort of wiring was in the crawl space...

author: tooki
author_rank: Super Contributor
timestamp: July 22, 2025, 06:50:10 pm
content: Quote from: Analog Kid on July 22, 2025, 05:35:51 amIn this context, “buried” means simply “sealed inside a wall of a building”, e.g. plastered over or under the drywall, without a wall box and cover. (I.E. wiring which you’d have to rip open the wall to access.) It is not referring to in-ground wiring of any kind, nor to outdoor.

author: Analog Kid
author_rank: Super Contributor
timestamp: July 22, 2025, 06:59:09 pm
content: Quote from: tooki on July 22, 2025, 06:50:10 pmAh yes, should have picked up on that. You even put "buried" in scare quotes.And of course you can't bury NM cable; for that you need UF.

author: PlainName
author_rank: Super Contributor
timestamp: July 23, 2025, 06:27:28 pm
content: I use these and do actually bury them for real, in the ground.Got a robomower and then some moles decided to move in. In the process of digging them out, poisoning them, trapping them, fumigating them, and generally ranting down the damn holes at them, the robomower perimeter wire got snipped a few times. A bit of a tug and there is just enough of an overlap to let one of these jobbies do the biz. Crimp might be better but the only crimper I had (now fixed) was the type the completely surrounded the join, so once crimped the tool is a prisoner on endless wire.So far as I can tell (and I ain't digging them up again) they've done the job and the mower mows completely oblivious to the minor war that went on.

author: Analog Kid
author_rank: Super Contributor
timestamp: July 23, 2025, 07:10:07 pm
content: Quote from: PlainName on July 23, 2025, 06:27:28 pmInteresting, thanks.But those weren't power cables, were they? Are the perimeter wires low voltage?

author: PlainName
author_rank: Super Contributor
timestamp: July 23, 2025, 08:28:43 pm
content: 24V I think.Just saying these aren't restricted to 'power cables', just like connectors have uses other than for power.

author: Analog Kid
author_rank: Super Contributor
timestamp: July 23, 2025, 10:54:01 pm
content: Quote from: PlainName on July 23, 2025, 08:28:43 pmSure, but a greater consequence in case of failure if they're for power.I still wouldn't want to use such splices for buried power cables, although I maybe could be persuaded to do so if the alternative is digging up and replacing a hundred feet of cable.

author: Haenk
author_rank: Super Contributor
timestamp: July 24, 2025, 05:13:40 am
content: Quote from: PlainName on July 23, 2025, 06:27:28 pmDepending on the moisture in the ground, you *will* be digging them up again sooner or later. The cables are made from steel and will corrode, and the heatshrink will not protect the strands enough to not let in moisture.To do this properly, there are special 3M outdoor connectors, filled with gel (vaseline?). These seem to hold up pretty well - and yes, we have shitty weather >300 days per year.

author: PlainName
author_rank: Super Contributor
timestamp: July 24, 2025, 09:15:44 am
content: Quote from: Haenk on July 24, 2025, 05:13:40 amThat's what I figured, but no harm in giving it a go just in case. So far (a year) it's worked. Mind, there might be just one corroded strand barely in touch by now...