Splicing Wires

Discussion in 'The Garage' started by trscott, Nov 4, 2007.

  1. Sock Monkey

    Sock Monkey 99% bullshitter...the other 1% is just lies

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    FWIW, I've seen another "T splice" technique out there where you strip a section of the wire that you want to splice into, then carefully separate the strands (obviously I'm talking about stranded and not solid copper here) and stick the end of the new wire into the gap you've formed. From there, you can split the end of the new wire in two, and wrap each half around the exposed original wire (or not, up to you). Apply liberal amounts of solder, then use your favorite tape/sealing method to finish the job. This is supposed to be more mechanically sound than just relying on the solder to hold the splice together.

    Hopefully this makes sense. I'll try to find the article where I saw this and post it in here so folks have the pics to go with the words.

    OK, here it is. Let's see if cut and paste works. If not, just look here.

    -NoVector

    "Tap Soldering"

    <table border="0" width="100%"> <tbody><tr> <td width="50%"> This method is used when tapping into other wires. For instance installing alarms or remote starters where the factory wiring needs to be tapped into but not lose its original strength.</td> <td width="50%"> [​IMG]</td> </tr> </tbody></table>
    "How to Solder"

    <table border="0" width="100%"> <tbody><tr> <td width="50%"> Strip back about an inch of insulation from the middle of the wire being tapped. Use some type of probe (a dental pick or a small flat head screwdriver) to separate the wire. </td> <td width="50%"> [​IMG] [​IMG]
    </td> </tr> </tbody></table>
    <table border="0" width="100%"> <tbody><tr> <td width="50%"> Strip back an inch of insulation from the tapping wire, insert in the middle of the original wire, then twist them all together.</td> <td width="50%"> [​IMG] [​IMG]
    </td> </tr> </tbody></table>

    <table border="0" width="100%"> <tbody><tr> <td width="50%"> Prime the tip of the soldering iron with a little solder.</td> <td width="50%"> [​IMG]</td> </tr> </tbody></table>
    <table border="0" width="100%"> <tbody><tr> <td width="50%"> Hold the the iron on wire until a little solder is drawn into the wire. Now apply the solder to the point where wire and iron meet letting solder be drawn into the whole connection. Again, less is more here, if you can&#8217;t see the outline of the wire when you are done, yet see a blob of solder, you used way too much.
    </td> <td width="50%"> [​IMG]</td> </tr> </tbody></table>
    <table border="0" width="100%"><tbody><tr><td width="50%"> Run your fingers over the entire length of the solder and make sure no wires are sticking out that might pierce the insulation. Now either wrap tightly with quality electrical tape or apply heat shrink. Be careful not to scorch the heat shrink or you'll end up having to tape over it anyway.
    </td> <td width="50%"> [​IMG]</td></tr></tbody></table>
    #61
  2. Hatch

    Hatch PAR OG

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    TRScott, thanks for the OP, very helpful and so far its holding well!:thumb
    #62
  3. potatoho

    potatoho Cheese and Rice!

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    :thumb

    I bought some similar ones from a local auto shop. Labeled as weatherproof butt connectors.

    After crimping, I was using a heat gun to shrink the sheath. I had them all shrunk and I was about to stop, but one was a bit stubborn. So I turned up the heat and to my amazement there began a slight oozing of glue. It became completely sealed, even some scrapes from my plier crimp oozed a little. Very strong afterwards and glued to the insulators on both ends.

    They don't tell you that you have to heat the crap out of them.
    #63
  4. PHud

    PHud dame los tacos

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    Just practiced using your technique trscott. It was top notch :thumb
    #64
  5. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    :spam ?
    #65
  6. Larry_77084

    Larry_77084 Been here awhile

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    BTW the OP is using a Western Union Splice . It was developed in the 1800s to slice Western Union Telegraph lines
    #66
  7. Twilight Error

    Twilight Error Going nowhere slowly

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    The approved NASA/ANSI method is to tin both conductors, bend each into a J and solder the wires together. Trim off excess wire lead, re-tin the conductors if any bare copper shows. Clean off the flux and inspect your work. Individual strands should be clearly visible, with smooth fillets around the joint. The benefit of the j-hook over the western union splice is speed. Strip the conductors, tin the conductors, bend the conductors, solder. For strength, I've done hundreds of pull tests, the solder joint is consistently stronger than the wire its formed with.

    This is the way I learned to splice wires, so its what I preach.

    As far as propane/butane irons go, even cheap electric irons have better temperature control than most butane irons. The huge advantage of a butane unit is portability. Putting one and a bit of solder in your OTR toolkit is a lot more practical than hoping for a 110 AC outlet on the side of the road...
    #67
  8. Jamie Z

    Jamie Z I'm serious. Supporter

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    Bumping this thread not only because it's one of the best on ADV but also because I have a(nother) question.

    What's the best way to attach connectors like the ones shown below?

    [​IMG]

    The only way I can imagine making a good mechanical connection before soldering is to crimp, but in other places I've read that crimping is counter-productive as it can weaken the wire and the connector.

    On a more advanced note, how do I attach connectors so that they are durable and look professional?

    Jamie
    #68
  9. trscott

    trscott Been here awhile

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    What I prefer to do with these is first remove the plastic shroud (if any) from around the crimp sleeve, then crimp the wire in place securely as neatly as possible, then solder it, and finally put two layers of heat shrink around it. You may want to put the heat shrink on the wire first if you think it will be hard to slide over the lug. If the wire is not clean and brite before crimping, you may want to pre-solder-tin the wire and shake off any excess solder so that it will solder easier inside the crimp.

    If you have a clean wire, or you have pre-solder-tinned it, you should be able to heat the crimp on the back side of the connector and hold the solder at the mouth of the crimp and when the crimped connector gets hot enough the solder will flow in and fill all the spaces in the crimped connector. Remember that solder will flow where the heat is, so visualize keeping the thing you are soldering between the iron and the solder so that the solder will flow through your joint trying to get to the iron. When you have enough solder to fill the connector take the iron away and let it cool for a couple minutes till it is cool to the touch. Then slide the heat shrink down and shrink it in place.

    You have to take the plastic sleeve off first because it will just melt when you try to solder, and besides, two layers of heat shrink makes a much tidier insulation anyway. Also you can stagger the two layers of heat shrink, make the inner one longer than the outer so that it provides some strain relief to the wire as it exits the joint.

    As for the concern about weakening the wire with crimping. That is not really a concern with these type.

    This is not what the crimp lug manufacturer has in mind, but just remember they're designing these for a production environment where time is money, but we're in this for love, not money.

    Cheers!

    #69
  10. johnjen

    johnjen Now, even more NOW!…

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    The 'BEST' way is to use a specialized crimping tool setup for the specific wire size and type and the connector. This sort of setup is usually only found in production line environments where the cost and need for an 'ideal' connection is necessary.

    Short of that there are hand tools that do a decent job but they aren't the ones that RadioCrap sells. And you need to use them (or have some experience with how much hand pressure is enough etc.) in order to 'feel' when the crimp is done. Some of the connectors shown in your picture are decent quality, there are lots that are cheap and the amount of crimp pressure used for these different grades varies quite a bit. Soldering after the crimp is sometimes helpful depending again on how much experience is available (a poor solder job will ruin a good crimp job) and what the needed end use circumstance is. There is a wealth of useable tips and tricks buried in this thread which will help.

    JJ
    #70
  11. trscott

    trscott Been here awhile

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    If you are ONLY going to crimp, a better quality crimping tool will certainly do the best job of CRIMPING, but crimp and solder is still better. Under the most extensive electrical, mechanical, and corrosion testing to much harsher standards than even we care about, a crimped, soldered, and double heat-shrunk connection will outperform even a machine crimp without soldering.

    Again you need to understand that the manufacturer's goal with crimping is to make a very good, relatively "foolproof," connection with the least possible labor per termination for production environments where time is money.

    I don't suffer "fools" to work on my bike (so I don't need a "foolproof" method), and my labor is for love, not money. The amount of labor I put into each connection would drive a factory crazy, but it is the only connection I will allow on my own equipment. A proper soldered, crimped, and double heat-shrunk connection will outlast the memory of my best trip.

    Of course everyone is entitled to an opinion. That's mine.

    #71
  12. johnjen

    johnjen Now, even more NOW!…

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    I can't remember where I read it but a well executed crimp can actually lower the resistance across the wire to connector connection. Mostly because inside the connector there are sharp ridges that bite thru the outside layer of the wire strands and actually make a better metal to metal bond.

    Now that isn't to say that I don't also solder after making the crimp, I certainly do. But the solder is as much for the sealing effect of the insulation to the wire, and the internal strands to the connector, as well as increasing the current capability of the overall connection. I see soldering as icing on the cake rather than expecting it to make the connection all by itself.

    JJ
    #72
  13. trscott

    trscott Been here awhile

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    You actually "hit the nail on the head" - twice.

    The low resistance of an ideal crimp is quite correct, but soldering after this crimp then fills the open spaces in and around the strands and the connector sleeve, whereever that "pressure weld" did not occur. This both seals the crimp against oxidation, and stabilizes it against any sort of vibration induced movement which might attack this connection later. Both quite important in a severe environment like a vehicle.

    Vibration and oxidation/corrosion are the enemies of electrical connections.

    Also any connection that might undergo extremes of hot/cold cycles will experience TCO (thermal coefficient of expansion/contraction) induced "movement" which can in turn allow a joint to become gasey and oxidize/corrode. Soldering after the crimp helps prevent this.

    Soldering after crimping locks the crimp in place and helps keep it gas-tight.

    Also the heat-shrinking, if done properly will provide better strain-releif to the wire as it exits the connector than the original plastic shroud on most of these terminations.

    In extreme reliability HALT/HASS testing testing (Highly Accelerated Life Testing / Highly Accelerated Stress Screening) it is common to combine vibration of many Gs at swept frequencies, with salt spray, with temperature cycling, with high-low current cycling while continuously monitoring resistance through the connection. Typically for connectors, 30 or so connections will be connected in series so that resistance changes anywhere in the chain will add up. You would be surprised how easily failures can be induced with this sort of harsh treatment. The purpose of this "accelerated" testing of course is to take the equivalent of years' of abuse and compress it into a few days of testing.

    Automotive environments are some of the harshest, where this sort of reliability is well justified.

    #73
  14. ridin gaijin

    ridin gaijin riding > posting Supporter

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    Thank you very much for an educational thread!

    I'm trying to solder some 10 gauge, braided (as best I can) according to the pictured instructions. I have a new 45 watt iron that claims 950 degrees at the tip. I wait a few minutes for it to heat up, prime it and apply to the bottom of the connection; the wire shortly becomes too hot to hold, but never draws the solder down. I've tried with a fine point and a chisel point to no effect. What am I doing wrong?

    :dunno

    Thank you & sorry if this is obvious,

    rg
    #74
  15. johnjen

    johnjen Now, even more NOW!…

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    You need more power and a larger tip. The key here is heat transfer from the source to the wire. A low powered, small tipped soldering iron just can't deliver the watts of power needed to heat up the mass of metal enough to melt the solder.

    In situations like this I like to use a solder gun in the 100+ watt range. Just be careful to not over heat the wire and cook/burn the insulation.

    JJ
    #75
  16. trscott

    trscott Been here awhile

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    The problem you are having is not having a large enough iron for the large wires you're working on.

    Copper is an extremely good conductor of both electricity and of heat. Your iron is putting 45 watts in, and the copper wire is taking a large fraction of those watts away from the joint you are trying to solder. The result is that you can never reach the melting point of the solder. If it could reach that 950 degrees, your solder would melt.

    As you have found, given enough time, you might get the joint hot enough, but you are going to have trouble with the insulation melting and things like that before you get hot enough to solder it.

    Heat is like water, it flows to the lowest level it can find. Your copper wires are sitting at room temperature, so when you connect your iron, a lot of heat is going to begin flowing down those wires trying to find the lowest level. Imagine filling a bucket with a squirt gun, but the bucket has a 1" hole in it. On the other hand if you have a 5/8" garden hose filling a bucket with a 1/4" hole in the side, you can probably overflow that bucket. Temperature is like the level in the bucket, watts is like the rate of flow of water in the hose or the squirt gun.

    One way to think about this is that your iron is less than half the power consumed by a 100 watt lightbulb. If you concentrate that much power in a small junction of small wires, you may reach that 950 degrees, but the heat being robbed by the fat wire is fighting you.

    For an unregulated plug-in-the-wall-iron, you might need 100 watts or so (although I do not routinely use unregulated irons). Maybe you can borrow a larger iron locally?

    In a pinch there are some age old solutions that might work for you. Remember that "soldering irons" were originally not electric. They were literally large irons with big wooden handles that would be placed in a blacksmith's furnace to get hot and then used until they cooled. If you can find a big chunk of steel or iron say 1/2" cross section, grind it to a chisel point on one end, and heat it in a charcoal fire, or maybe with a torch... I think you might be surprised how well that could work. Especially if you have some extra solder flux to put on the wires. I've not tried it myself, but I know it was done that way in the past. It should work.

    In any case, the idea is to have a lot more watts of heat energy readily available in the iron than the wires can absorb and dissipate. That way the watts turn into peak temperature at the joint to get your solder to melt.

    The 950 degree rating of your iron is fine, but sort of misleading. That is its peak temperature until you begin cooling it with soldering work. The Watts are the real measure of work being done.

    I hope that helps.

    Cheers!

    #76
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  17. vnp514

    vnp514 Been here awhile

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    An older thread but fantastic info-THANKS!!

    A couple of questions- Can we talk about what type of solder to use? How about the diameter of the solder? If I want to solder 14 to 16ga wire, what diameter solder would be best? Yeah, I'm a electrical idiot!!:lol3

    Thanks!!

    Pete
    #77
  18. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    I always use rosin core solder. I also use a very small diameter, I like how quickly it melts. I use it for everything from 20 ga down to 10ga. I don't really solder outside of that range.


    Had a friend tell me that he hated soldering wires, that his never worked, come to find out he was using solid solder for copper piping. :lol3
    #78
  19. Rapid_Roy

    Rapid_Roy Rachael's Dad Supporter

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    This is awesome!

    P.S Butt and most crimp connectors suck! Solder!
    :lol3
    #79
  20. t6pilot

    t6pilot Been here awhile

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    +1 on soldering connections, + 1 also double shrink wrap. Anything that vibrates benefits from this procedure. Not difficult to do. If soldering not possible posi-tap connectors are the best alternative
    #80