Heat shrink solder sleeve butt connectors, great for skinny boat wires

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

15 Responses

  1. Joseph Pica says:

    Ben, how about using euro block style connectors with ferrules crimped on to the wires. https://www.practical-sailor.com/issues/37_50/features/Out-Out-Brief-Wiring-Terminals_11614-1.html by yoiur neighbor RC Collins As much as you change out devices these may be proctical.
    Practical Sailor evaluated these no lead solder butt connectors and found them to not be secure or as effective.

    • Ben Ellison Ben Ellison says:

      Thanks, Joseph; that’s a very useful article.

      But note that in the ferrule kit Rod recommends “The terminals are color-coded: red, 22-16 gauge; blue 16-14 gauge; yellow, 12-10 gauge.” They are not designed for extra thin wire gauges, I’m not sure ferrules small enough exist, and I think most of us would also need a small delicate crimping tool as well.

      • Joseph Pica says:

        Ben, the kit I have does up to 28 ga. and includes the crimper.

        • Ben Ellison Ben Ellison says:

          Thanks, Joseph; I may have to add that or similar to my collection. I do like ferrules for screw type terminations, but think solder sleaves have their place too.

          • Hi Guys – just back from the Bahamas and late to the discussion. I, too bought a kit of ferrules (Chinese, of course) with a crimper and they are the bomb for the euro-style connection blocks (that are very popular with sailing instruments, it seems). I also used them on the #6 connections to my Victron MPPT controller, so they’re not just for big stuff.
            If I was connecting wire-to-wire and didn’t want to put in a connection block, I would use the IDC (AKA “Scotchlok”) connectors, the silicone grease-filled ones. No heat source needed!

  2. This is a really neat way to deal with small wire connections. I have used the 3M scotchloks, Dolphin connectors, and the terribly unreliable high heat butt connectors with shrink tubing. Out of all of those the 3M ones are the most reliable and easiest to use, but these seem like they could be easier for my fat clumsy fingers and not be as bulky as the 3M’s.

  3. Mike Coleman says:

    I wouldn’t use the solder shrink type. You can get really tiny ferrules for using in connector blocks. When they are that small, you can crimp with the flat bit of combination pliers. In UK we have Wago 221 connectors which are reliable on small wires. They come in 2, 3 and 5-way common, ideal for an easy NMEA split. Best used in a small box so you can tie down the separate cables coming in.

    • Ben Ellison Ben Ellison says:

      Why not solder sleeves? I think there are cases where the connections you’re talking about can be done more compactly, more waterproof, stronger and faster with these connectors (assuming you get ones that work right). What am I missing?

  4. William says:

    Don’t get stuck on the fact that the butt connectors have two ends. Strip the wires, twist them together, and then crimp in one end of the connection. When heat shrinking, when it’s still soft, pinch the heatshrink down around the wires. Put dielectric grease in other end, shrink and pinch. Use something to protect your fingers, that heat shrink adhesive is like molten lava.

    • Ben Ellison Ben Ellison says:

      Thanks, William, that sounds like an excellent way to make an oversize crimp connector work with thin wires, and the technique probably also works well when connecting two wires with substantially different gauges. I’d say it’s obvious except I’ve never seen it done and never thought of it myself. Too much linear thinking!

      • KenN says:

        I like nylon cap splices, if one has the room. Twist wires together, cover with appropriate size of cap splice, crimp… done. You can squirt glue or sealant into the open end to waterproof them.

  5. Ben Ellison Ben Ellison says:

    For more detail on how precisely engineered TE Connectivity’s solder sleeves are, check out the “B-155 SolderSleeve One-Step Wire & Cable Term Install” PDF you can download here:


    They also illustrate some unusual uses, like using solder sleeves to connect wires to long pins that come on some parts like some temperature sensors I’d like to add to my Victron Venus system 😉

  6. Jeff says:

    Monster Bolts has a great suggestion of waterproof crimp and seal, and also crimp and solder connectors.

  7. Patrick J Hughes says:

    There is really nothing wrong with this technique, even per ABYC, it could be improved slightly by the manner in which the two wires are twisted together prior to applying the solder connecter. ABYC says that solder will not be the “sole means” . The “Western Union splice” is a mechanical splice that was developed to take a considerable mechanical strain. Using that technique and then improving it with the solder for connectivity and shrink seal for moisture protection should exceed ABYC.

    On a tangent ABYC and NMEA are great organizations for manufacturers in insuring standardization and minimum quality, However they are not friendly towards owners. Both organizations push that you should always get a “certified” technician to do the work. Their standards are not openly published and are prohibitively expensive for the average owner to obtain. In my opinion this ends up counter productive to safe maintenance and modification after manufacture.

  8. Patrick J Hughes says:

    Ben, a second thought that does not need posting…
    The 16 awg minimum ABYC recommendation is for single conductors. Once bundled into a “cable assembly” there is no minimum I am aware of. The mechanical strength gained by the outer jacket and very often a nylon center cord prevents the smaller conductors from being stretched to their breaking point. So some method of splicing these small conductors is important. And most of these are signal circuits today not power carrying. An overall adhesive shrink tube restoring the “outer sheath” would restore the mechanical strength of the “cable assembly”.
    As I stated ABYC sets minimum and best practices for the recreational boating industry. Yet they still approve the ridiculously outdated 30 amp twist lock shore connector a demonstrated electrical fire source. Time and technology moves on.
    I started in the 1980s as a USCG Machinery Technician. I have completely re-wired numerous military and Auxiliary civilian boats. We always soldered every crimped eye terminal to ensure electrical connectivity and prevent moisture corrosion, adhesive heat shrink wasn’t even invented yet.
    I’m sure we’ve both seen dozens of boats that were hacked by mostly well meaning but ignorant owners. It’s mostly a matter of education. Access to proper techniques is difficult even today as so many of these “standards” are kept restricted. The link provide to ANCOR only publishes “excerpts” of E11 because they are not allowed to reprint the entire section.
    Just my 2 cents…

Join the conversation

Your email address will not be published. Required fields are marked *