Heat shrink solder butt connector test.

A few people have asked if I can take a look at these quick-repair connectors for cars and other applications.
The idea is that you can basically put the stripped ends of two wires into one of these connectors and when heated it solders the wires together, while also providing a waterproof seal with heat shrink sleeve and hot melt rings.
Note that wires should be shiny copper or tinned copper for any soldered connection to work properly. If the wire is oxidised, black and tarnished then it will not always readily take solder even with flux. In that instance it may be necessary to cut back either side to see if you can find clean copper and patch a new bit of wire in.

The word of the day is "smoosh". A special word mechanics use for smooshing things together.

Here's a typical eBay search link for these things:-

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[Ryan-kkrr]

After seeing your comparison, I did my own. If you apply a small bit of flux to the wire before sliding it into the connector, it works perfectly. I did the same experiment twice. I cut open the soldered wired with lineman's pliers and then with a dremel. Both times, the solder had successfully worked its way into all the tiny fibers to make a solid connection.

[jonnylong]

"I shall find out by touching it and seeing if I get burned" these are the brave heroes that have answered life's persistent questions

[CypherAod]

I use (used to use?) these at work, but we have the "brand name" ones which we get from RS which appear to have flux on the inside of the solder band, so they provide really quite excellent solder penetration and strong joints even in fairly high current applications, highest was nearly 25A

[pasqualz]

Clive, I suggest you test these connectors by running progressively more amperage through them until they fail and then compare to a standard soldered and hear shrunk connection.

[terrybailey]

Hi Clive, nice video. Reminds me a demo from a very eminent engineer who told his students that soldering is not always the best. He demonstated that a good clean crimp joint has a lower resistance than a soldered one. He explained that in reality the purpose of the solder was just to stop it unravelling and keep osygen from getting in and oxidising the metal. He then demonstrated that was indeed the case by measuring the resistance and then connecting the two joints in series. Passing a high current through the two joints it was the uncrimped joint that melted. That demo has always stuck with me.

[ewozniak]

Clive, You didn't try the "field method" using a cigarette I can see where these connectors would be very handy using nothing but a pocket knife and a lighter.

[azroger]

The metal "solder" may be a Bismuth alloy like they use for fire sprinkler heads. They melt at temperatures well below tin/lead allow solder.

[LakeNipissing]

I have used these when I was working avionics on the military aircraft. We also had some designed to work with shielded cables with a pigtail built in to connect to the shield screen using the solder ring. One side of the sealing glue was smaller to seal onto the center conductor of the shielded cable, and one side was larger to seal and glue onto the outer jacket. The ones we used had a color added to the solder ring to know when it was heated enough to fully melt the solder.

[breilly]

We used these to terminate drain wires to cable shielding. A couple of notes on your application of these:
Strip each end 1.5 - 2 times the width of the solder band. The idea is to contain the solder to a limited area. Strip too much and you end up getting the exact flowing problem you found.
Pre-tinning the ends is preferred, or use a 'no-clean' flux (Rosin flux corrodes the solder joint over time if not completely washed off with IPA).
Never 'mesh' the wire together. Always maintain the wire twist and lay the two ends side by side. Meshing the wire adds voids where the solder does not flow and you end up with the exact flowing problem you found (second reason for the failure).
Use a bigger nozzle for your heat gun and heat the whole area up in one shot. This is just for efficiency.

They work, but they do require a specific assembly method to work properly. Good luck!

[JeepX]

I used these and Raycem splices for years on military aircraft wiring (starting way back in the 80's) and new avionics installations. If they work on fighters they will work in your car. Since there is "no flame" allowed on aircraft we used nitrogen heat guns. Inert gas with a heating element. Never had any issues. A great solution if you hate to solder and want weather tight at the same time.

[von]

you might try a mechanical load test, see how easily the joint pulls apart... and also an electrical load test, pass a current through and measure for a voltage drop at the joint.

[howlingwolven]

I used these when I was in my aircraft maintenance course, I believe. You make a conventional union splice, then slide the sleeve over... then realise you forgot to put the sleeve on in the first place.

[delcambekevin]

Have been using this for over 8 years never ever had any issues with it but I use more heat than your first try. And mine cost +/- 0, 75 €/piece.

[ivorcomment]

I've found that they create a dry joint and often come apart unless you mechanically connect the wires first. It definitely works better if both wire ends are dipped in flux paste.

[slipstream]

These things are by far the best thing amazon has ever recommended me. I had no idea such a thing existed and they are fantastic, makes joining wires not only so much easier/faster, but when dealing with wires that are more likely to get wet, they provide some peace of mind(ive never tried soaking them underwater, when dealing with wiring underwater i just make it so there's just one continuous insulated wire leading to the device to be submerged) plus I find they work best when you just hold the wire ends next to each other and pick the smallest size that can fit the wire insulation

[aitchpea]

Man, I love solder sleeves. Had to learn how to use them to mil-spec in my training days, never once used them professionally since. The rule has always been, "better to remake the whole cable than use any kind of splice" But for home jobs, use one every time because I'm not paying to replace a perfectly good length of wire.

[vaalrus]

I’ve been using these and their slightly more rugged self-sealing crimping butt connectors for 30 years, in all sorts of 12 and 24v harsh environments and loads, mostly heavy goods and industrial vehicles and trailers, and they hold up extremely well. Both in the field repairs and in the shop. They’re more expensive than using shrink tube + solder, but they are very quick and more weatherproof. Something I appreciate in the mud and the snows of a -40C Canadian winter. Particularly in something like a trailer wiring harness.

[locouk]

They need load testing, see if they heat and fail up when passing a high current.

[captainboing]

When I was an apprentice with Thorn EMI back in 1980, we used to get these in from a company called Raychem...

[gomdrd]

I use these for stereo harnesses. Work well and quick easy connections.