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Truck repair advice: soldering wiars

MisterT | Posted in General Discussion on October 27, 2003 01:50am

The bone head who put in my trailer/electric brake socket, used those inline crimp splice garbage things.

So yesterday I get under to try and do it right.

How do I get wires clean enough for solder to take?

My electric solder gun doesn’t seem to get the wire hot enough.

Got a Sears 80/140 watt unit  is this for hobbys? 

The Weller units were approx. the same wattages and 20$ more

Should I pry open the wallet or should I look elswhere?

NAPA? Electric supply house? Online?

help

Mr T

Do not try this at home!

I am an Experienced Professional!

Reply

Replies

  1. vasalesman | Oct 27, 2003 02:07pm | #1

    Sandpaper or emery cloth will clean them right up.  If it ain't bright, it ain't right!  Your gun should be fine.  On some guns, the first click is the higher wattage and the second is the lower.  You can use full juice on something like that.

    Al

  2. TLJ | Oct 27, 2003 02:34pm | #2

    I'm sorry if this is obvious to you. But I'll say it anyway. Did you tin the tip of the gun? Melt a bit of solder on to the tip, then apply the tip to the wires. The drop of melted solder on the tip will transfer the heat better to your wires. Then apply the solder to the hot wires. Use the flux core solder as it will bond the solder to the wires. It would be hard to clean stranded wire with emery cloth. If water has gotten into the wires and corroded them, you may have to cut back to clean wire, even if you have to splice a piece in.

  3. OneofmanyBobs | Oct 27, 2003 03:42pm | #3

    Too hot is as bad as too cold.  Put the iron to the splice briefly.  Touch the solder to it.  Don't get it any hotter than necessary to melt.  Flux?  You can't use plumbing flux.  Its acid.  You need rosin flux, preferably rosin-core solder.  You can get a little hunk for a buck at most hardware places.  While you're there, get some heat-shrink tubing.  Put a piece WAY down the wire so it doesn't get hot while you solder.  Solder, slide the tubing over, shrink carefully with a match or lighter.  A pro job.  Stay away from the gas tank.  The wire needs to be shiny bright.  If its oxidized black it won't solder.  Sandpaper or scrape with a pocket knife.

    Crimps are fine if you use the right crimper, just not regular pliers.  A proper crimp tool is not a cheap item.  Factory stuff is crimped and will last indefinitely if done right.  Bonehead jobs will last 3 minutes.

  4. fredsmart48 | Oct 27, 2003 03:43pm | #4

    First of all I like to use heat shrink over solder wires it is water proof instade of just tape .

    Solder comes in many forms the one for soldering wire is on a spool and comes either with no flux core and it also comes with a core containing a rosin core of flux.

    You want rosin core solder along with a can of rosin flux for cleaning the copper wires and the solder iron.

    There is also a acid core for pipe and copper sheets. this type will cause the wire to cored in time.

    Put a heat shrink over the wire and now strip it back exposing 3/4 inch of wire twist the wire tightly. Repeat that to the other wire that is to be solder to the first wire. Now twist both wires together tightly.

    Now put a small amount of rosin flux on the wire. It is for cleaning the wire.

    Clean the solder gun by dipping in the can of rosin flux. Now turn on the soldering gun and melt the flux on the tip of the gun and tin the tip of the gun.

    Place the tip of the gun on the wire to be solder as the flux melts on the wire and the solder flows on to the wire add some more solder to the wire. (The wire should not be touching any thing, because what ever it touches will act as heat sink and take away a lot of the heat so the solder won’t make a good connection and take a lot more heat.) (You should not move the wire until the solder has set or you will get what is called cold solder joint which will impede the flow of electricity.)

    The heat shrink tube is now pulled down over the solder joint and heated with a lighter or a small torch the tube will shrink tight around the wire and form a water tight seal to keep out water and road salt out.

    1. tenpenny | Oct 27, 2003 04:00pm | #5

      I have a question about the whole concept.  How many wires in a truck or car are soldered?  Not many.  Crimp ons are the connectors of choice in automotive applications.  Despite the good soldering advice, I wouldn't bother.  Make sure the crimp ons are done properly, and leave it at that.

      1. OneofmanyBobs | Oct 27, 2003 04:56pm | #6

        A high-quality ratchet crimping tool with the right dies is around $50 and can go up over $250.  It makes a cold-weld joint that is gas-tight and highly reliable.  You need the right die for the size barrel and wire you use.  MAny different sizes.  Squashing the connector with pliers or something that may look like a crimper makes a loose connection that corrodes and is worthless.  Crimping if fine if you're a factory or want to make the investment in tools.  A cheap soldering iron and solder can be had for $10.  Works great for about any wire size from nothing to 10 gauge.  Takes a little skill.  Wire nuts are also excellent, but need lots of sizes and are generally not suitable for wet locations, like under a truck.  Solder is the right way in this case.

    2. 4Lorn2 | Oct 28, 2003 04:50am | #14

      Look around for some "Scotchcoat" to seal those connections against water and other chemical abuse. You can find it at any good electrical supply house and some hardware and big box hardwares.

      Clean the connection and on a bit onto the un damaged insulation. I use alcohol but anything that will get it clean and remove grease and oil will work. wrap with high quality tape or heatshrink. Seal with several coats of Scotchcoat. You can use a blow drier to dry each coat. 

      1. User avater
        Luka | Oct 28, 2003 05:01am | #15

        Is that possibly what is inside those heat shrink tubes that have the extra sealant inside ?

        Can't we all just get a log ? - Paul Bunyon

        Quittin' Time

        1. User avater
          BillHartmann | Oct 28, 2003 08:14pm | #16

          I think that the stuff in the heat shrink tubing is more related to hot melt adhesive.

          Comerically there are a large number of different forumlation of hot melt sealants/adhesives.

          1. User avater
            Luka | Oct 28, 2003 10:28pm | #17

            Ah yes, that makes sense.

            Can't we all just get a log ? - Paul Bunyon

            Quittin' Time

          2. 4Lorn2 | Oct 29, 2003 01:25am | #18

            I agree. Stuff looks like a "goopy", when all else fails baffle them with technical terminology, version of hot melt glue.

          3. CstlEng | Oct 29, 2003 03:01am | #20

            A small wire brush in a high RPM roto tool does a nice job brightening stranded wire, especially when the space is tight.

          4. 4Lorn2 | Oct 30, 2003 05:19am | #21

            Good tip. I wouldn't have thought of that.

            In the past I have muddled along with a bit of emery cloth. I spread the strands and pinch them lightly between a piece folded over. Then I just pull the wire out.  A few repetitions and the strands come out mostly clean.

            Next time I try your method.

  5. jimshome | Oct 28, 2003 12:25am | #7

    The usual reason not to solder automotive wiring is that a solder joint is extremely stiff.  Not a good thing around any amount of vibration. The wire winds up fatiging and breaks right next to the solder.

    Check your automotive supply houses. there is a type of crimp connector that is designed to be used on trailers and automotive wiring that is waterproof. They are a little more expensive. but well worth it. I've used them several times with great results.

    Be certain to leave a little slack in the wiring. If it is pulled tight when you are turning a corner or hit too many bumps in the road no kind of connection will keep it from breaking.

    Jim

     This above all, to thine own self be true, and it must follow as the night the day, Thou cans't not then be false to any man      Hamlet

  6. User avater
    Luka | Oct 28, 2003 12:49am | #8

    I once wrangled with a bad connection for months.

    After so much frustration, I decided to do it bullet-proof.

    I stripped off about an inch and a quarter of insulation from both wires.

    I twisted the two together very tightly.

    I then pinched the twist at about it's middle, and folded that over.

    I then laid the fold down against the wire. In this case, I was splicing a wire that was one size larger than the original, so I laid the fold down on the thinner of the two wires.

    Soldered.

    Put on two pieces of heat shrink. Smaller one first, enough to cover the bare wire. Then a longer one, so that the smaller one was overlapped.

    Wraped all this in tape. Then put on three vinyl wire ties. One on each end, and one, as tight as I could get it, right on the knot where the fold was.

    The connection was good. I sold the truck, but I gare-own-tee that connection never came loose, corroded, etc.

    ...

    Soldering...

    Go to radio shack, or even the car parts place.

    Get one of those little torches that uses a bic lighter inside it.

    Get some solder "tape". This stuff will work with just a match.

    Get the heat shrink tubing. There is a variety available that has some kind of sealer inside. Seals better than just the standard heat shrink.

    You simply cannot beat that torch. I worked on cars to earn a living, for several years after I broke my back. While I was doing so, I always kept that torch in my electric work boxes.

    I enjoyed the electrical work. Because it wasn't as bad on the back, and because I liked the challenge.

    ...

    The above connection will work even without the solder. Yes, 4Lorn1, it does.

    ; ) 

    Twist, fold, lie the knot flat on the wire. Maybe crimp lightly with some pliers. I do sometimes. When finished, make sure that a nylon wire tie is on the knot. If you do so, it will never come loose. The wire will break somewhere else, first.

    Can't we all just get a log ? - Paul Bunyon

    Quittin' Time

    1. MisterT | Oct 28, 2003 01:21am | #9

      Thanks for all the advice boys!

      Seems I wasn't getting my wire clean enough and was using plumbers flux.

      I got it working Ok and used about a mile of electric tape.

      So if it acts up again, I'll do it righter!Mr T

      Do not try this at home!

      I am an Experienced Professional!

  7. WorkshopJon | Oct 28, 2003 02:19am | #10

    "The bone head who put in my trailer/electric brake socket, used those inline crimp splice garbage things."

    Mr T,

    There is nothing wrong with one if done correctly. Just as an aside, the FAA does not approve of soldered splices in most circumstances in aircraft. The approved method is a crimped connection.

    Jon

    1. MisterT | Oct 28, 2003 03:03am | #11

      How often do slices in airplanes get exposed to road salt and slush.

      Never me thinks Mr T

      Do not try this at home!

      I am an Experienced Professional!

      1. maneyj | Oct 28, 2003 03:52am | #12

        You got a lot of good advice on cleaning the solder joints. As far as size of the solder iron, I have used 22 watt and 37 watt Ungar solder Irons for years. Very simple, but they will solder almost any clean connection when the iron is clean, hot, and tinned.

        But, a good crimp connection is your best connection for automotive wiring. You won't get a good crimp from a pair of pliers. You need a crimping tool that matches the connector. It does not have to be an expensive tool, just a match.

      2. DavidxDoud | Oct 28, 2003 03:57am | #13

        if your having trouble with your soldering iron,  try tightening the connection at the replacible tip - - if it is not t-i-g-h-t,  the tip won't get as hot as it should...

      3. CstlEng | Oct 29, 2003 02:59am | #19

        Planes see salt and slush and water a lot more than you might think. 

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