The correct way of soldering two pieces of wire together.

Discussion in 'Old's Cool' started by LasseNC, Feb 12, 2011.

  1. LasseNC

    LasseNC XSessive!

    Joined:
    Jan 27, 2008
    Oddometer:
    1,082
    Location:
    Denmark, Danimarka, Danmark, Dänemark
    I was wondering, as I am quite new to soldering when working on electrics instead of cramping.

    I have two ends of old wire that has been split by PO for some reason, I don't want to tape it up. So I want to solder them and use some heatshrink on it afterwards.

    Is it just laying the besides beside eachother? Or do they need to be fixed in some way for it to be stronger?
    #1
  2. sieg

    sieg Wearing out tires......2 at a time, day after day.

    Joined:
    Jul 9, 2008
    Oddometer:
    3,015
    Location:
    Southern Illinois USA
    Tin (melt solder onto them) the ends, lay them together heat till the solder melts. With solder less is more.
    #2
  3. eric123

    eric123 Gott Mit Uns

    Joined:
    Mar 26, 2009
    Oddometer:
    1,505
    Location:
    Idaho
  4. DaveBall

    DaveBall Long timer

    Joined:
    Sep 30, 2009
    Oddometer:
    1,163
    Location:
    Vancouver Island
    Strongest method is called a "linesman's splice". Good explanaition here with pictures. http://boost-instruments.com/splicing/splicing.html It does not show the soldering, as it isn't always done, but I always solder any joint. Just remember to put the heat shrink tubing on one of the wires before attaching them together. Don't ask me how I know. :evil
    #4
  5. JUNAC

    JUNAC Straight Shooter

    Joined:
    Jun 30, 2009
    Oddometer:
    673
    Location:
    Tecumseh, Ontario
    Congratulations,

    Soldering is always better than using solderless crimp connectors especially when exposed to the elements. Clean the ends of the stripped wire with some sandpaper or steel wool. The heat shrink should be cut so that it is about a 1/2" longer than the area to be soldered. Place the heat shrink over the wire and keep it away from the area to be soldered. Twist the wires together. Use solder with a flux core. After making the repair let it cool slightly. Slide the heat shrink over the bare wire, heat with lighter or hair dryer. Done. Simple.
    #5
  6. LasseNC

    LasseNC XSessive!

    Joined:
    Jan 27, 2008
    Oddometer:
    1,082
    Location:
    Denmark, Danimarka, Danmark, Dänemark
    Daveball, that linesman splicing is exactly how I thought I'd do it! Esquependo! (Spelling)

    I will have a look at it tomorrow. Now I am just unsure if I have the correct size heatshrink, but it was on offer. 4.8/2.4 mm.
    #6
  7. bk brkr baker

    bk brkr baker Long timer

    Joined:
    Jul 19, 2006
    Oddometer:
    6,059
    Location:
    The Bluegrass
    Yep ,I go with the twist and flux metod. Watch how long you keep the heat on the wires . You want a shiny connection but the longer you keep the heat on ,the farther up the wire the solder will travel making the wire stiff.
    Don't forget to slide your heat-shrink on first and keep far enough away from the joint so it's not shrinking too soon.
    #7
  8. Martian

    Martian Long timer

    Joined:
    Sep 20, 2007
    Oddometer:
    1,104
    Location:
    Elmdale, Kansas, USA
    And keep the tip of your gun CLEAN! A dirty tip doesn't tranfer heat very well and you'll end up melting the insulation before you melt the solder. To clean the tip, heat it, stick into the can of flux, and then wipe it with a damp rag.

    Old, corroded wire is hard to solder. Clean the strands as best you can.
    #8
  9. wirewrkr

    wirewrkr the thread-killer

    Joined:
    May 23, 2008
    Oddometer:
    4,295
    Location:
    HIGH desert
    this is the way I've been doing it for 30 years. Good solder (rosin core) is KEY and also a good iron.
    step 1

    Attached Files:

    #9
  10. wirewrkr

    wirewrkr the thread-killer

    Joined:
    May 23, 2008
    Oddometer:
    4,295
    Location:
    HIGH desert
    Step 2

    Attached Files:

    #10
  11. Jasper ST4

    Jasper ST4 Guest

    Good tips. I was an electrician in the Coast Guard so wires often corroded on board ships. Don't just clean the outside of the copper in stranded wire, use a wire brush and clean them well. I also put some flux on the wires when they are hot, seems to help the solder to flow.
    #11
  12. Anorak

    Anorak Woolf Barnato

    Joined:
    Jul 23, 2004
    Oddometer:
    35,071
    Location:
    OAK
    In the context of motorcycles, a good solder joint is seems to work fine. In aircraft crimped connections are the rule but done with special crimpers and connectors. Solder can fracture over time in an environment of vibration.
    #12
  13. Martian

    Martian Long timer

    Joined:
    Sep 20, 2007
    Oddometer:
    1,104
    Location:
    Elmdale, Kansas, USA
    You can get butt splices that are encased in shrink tubing so they are watertight. As was mentioned, vibration is death to a solder joint. The biggest advantage to a solder joint is it's size. The only time we could solder wires together when I worked on aircraft avionics was if space was a consideration, and the crimp splices couldn't be staggered.

    When I worked on yacht systems, we used the sealing crimp splices on systems that were likely to be submerged......bilge pumps, etc. They work really well.
    #13
  14. Ben Carufel

    Ben Carufel Boxer Addict

    Joined:
    Dec 2, 2010
    Oddometer:
    772
    Location:
    San Diego
    #14
  15. old2wheeler

    old2wheeler Former nÔÔb

    Joined:
    Feb 16, 2008
    Oddometer:
    720
    Location:
    La Veta, CO except for the wind, it'd be heaven
    Just a tip not mentioned yet; when soldering, you apply the heat to the wires. When they heat up you touch the solder (resin core for electronics, acid for plumbing) to the wires and they draw the solder into the spaces all around the strands.
    #15
  16. wirewrkr

    wirewrkr the thread-killer

    Joined:
    May 23, 2008
    Oddometer:
    4,295
    Location:
    HIGH desert
    big #1
    #16
  17. DaveBall

    DaveBall Long timer

    Joined:
    Sep 30, 2009
    Oddometer:
    1,163
    Location:
    Vancouver Island
    I almost always use a soldering iron, not a gun. If space permits, I will heat the wire joint from the bottom and touch the solder to the top of the wire. This allows the solder to flow down, towards the iron, thru the strands of wire, ensuring a good connection.

    Crimp connectors are fine, but I have seen so many that were not done properly. I only use them as an emergency connection. I prefer soldering if at all possible.
    #17
  18. LasseNC

    LasseNC XSessive!

    Joined:
    Jan 27, 2008
    Oddometer:
    1,082
    Location:
    Denmark, Danimarka, Danmark, Dänemark
    I will give it a go today. Regarding guns/irons, have you seen those small pencil-sized butane burners for soldering? Seems quite smart and not expensive, several tips available etc.
    #18
  19. PeterW

    PeterW Long timer

    Joined:
    Nov 11, 2005
    Oddometer:
    2,820
    Location:
    Gold Coast
    GOOD temperature controlled soldering irons are well under $100 now (Ebay). If you are going to solder, get a good iron - worlds of difference.

    The big problem is that the solder makes the joint more brittle than copper wire.

    The heat shrink is important, not just to stop corrosion, but it also moves the stress points to (hopefully) beyond the soldered section.

    As others have said, ideally you heat both sections of wire, touch the solder to it - and it's done - minimal solder flow beyond the joint. That's why the twisted solder joint is the best here.

    One trick that is worth knowing "above and beyond" - use a hot melt glue gun and run hot melt glue onto the soldered section before you push the heat shrink back over. When you hit it with a heat gun, it'll flow and REALLY seal the joint.

    Telco's use large versions of this for their large cable joints.

    FWIW:
    The small gas pencil irons are crap compared to a real soldering iron, solder only works well if the metal ratio is correct, get it too hot and you loose zinc - which makes it brittle. The gas irons will almost always be too hot.

    Pete
    #19
  20. Zagando

    Zagando BMW uber alles!

    Joined:
    Sep 4, 2007
    Oddometer:
    1,090
    Location:
    EL18 Rockport, TX
    Thank you for this brilliant tip---I've been soldering for decades and never, ever once thought of doing this before!
    #20