How To Solder Wires

Join wires and soldering tips for beginners

By
Lee Wallender
Lee Wallender
Lee Wallender
Lee has over two decades of hands-on experience remodeling, fixing, and improving homes, and has been providing home improvement advice for years.
Learn more about The Spruce's Editorial Process
Updated on 08/23/24
Reviewed by
Larry Campbell
Larry Campbell
Reviewed by Larry Campbell
Larry Campbell is an electrical contractor with 36 years of experience in residential and light commercial electrical wiring. He worked as an electronic technician and later as an engineer for the IBM Corp. He is also a member of The Spruce Home Improvement Review Board.
Learn more about The Spruce's Review Board
Closeup of soldering wires
Credit:

The Spruce / Kevin Norris
In This Article
Project Overview
  • Working Time: 10 - 20 mins
  • Skill Level: Beginner
  • Estimated Cost: $25 to $50
  • Yield: Solder two wires together

Soldering wires is a helpful skill for DIY repairs of dishwashers and refrigerators or for fixing circuit boards and switches. With patience and a little practice, most beginners can learn how to solder wires for home repairs or projects. A soldering station that includes an iron, stand, tip cleaner, and sometimes basic starter materials, costs $50 to $75.

Safety Considerations

Work in a well-ventilated area. Leaded solder is 60-percent tin and 40-percent lead. This type of solder is safe if handled properly. For the utmost safety, choose lead-free solder.

Soldering irons become extremely hot. Work on a non-flammable surface. Wash your hands after working with the solder and wear eye protection.

What You'll Need

Equipment / Tools

  • Soldering iron
  • Soldering iron tips
  • Soldering iron stand
  • Sponge and water
  • Heat gun
  • Wire stripper
  • Eye protection

Materials

  • 60/40 rosin core solder
  • Rosin flux paste
  • Heat shrink tubing

Instructions

Tools needed to solder wires
Credit:

The Spruce / Kevin Norris

How To Solder Wires

This simple soldering project demonstrates how to solder the exposed ends of two plastic-coated stranded copper wires.

  1. Strip the Wires

    Strip away 1/2-inch of the plastic coating from the wires with the wire stripper. Removing too little plastic coating will hinder soldering, while stripping away too much coating will require you to use more heat-shrink tubing. Use the correct gauge on the wire stripper to prevent accidentally cutting strands of wire.

    Stripping the wires before soldering them
    Credit:

    The Spruce / Kevin Norris

  2. Add the Heat Shrink Tubing

    Find the smallest diameter tubing that will fit over the plastic-coated wire. The tubing should be long enough to cover the splice, plus another 1/2-inch on each end. Slip the heat shrink tubing onto the wire and then slide it another foot down the wire to get it out of the way for now.

    Adding the heat shrink tubing
    Credit:

    The Spruce / Kevin Norris

  3. Join the Wires

    Spread the strands of wire. Push the wires toward each other, interlocking the strands. Loosely twist the meshed wires. If you twist the wires too tightly, the solder will not be able to penetrate.

    Joining the wires together
    Credit:

    The Spruce / Kevin Norris

  4. Position the Wires

    Elevate the wires over the work surface. Alligator clips or metal spring clamps can be used to elevate the wires, if necessary.

    Positioning the wires before soldering
    Credit:

    The Spruce / Kevin Norris

  5. Add the Rosin Flux

    Rub a small amount of the rosin flux paste on the joined wires so that all of the copper is covered. Using flux will help draw the solder into the meshed wire strands for a cleaner, stronger bond and it helps to reduce oxidation.

    Adding the rosin flux to the wires
    Credit:

    The Spruce / Kevin Norris

  6. Turn on the Soldering Iron

    Plug in and turn on the soldering iron. Unroll about 6 inches of solder so that the end is exposed and ready to use.

    Tip

    As the soldering iron heats, rub the tip across a wet sponge to remove any previous oxidation. This is only for previously used irons, not new irons.

    Unrolling solder before beginning the soldering process
    Credit:

    The Spruce / Kevin Norris

  7. Solder the Wires

    Touch the heated tip of the soldering gun to the wire joint. Hold the tip for a few seconds to heat the wire. Touch the exposed end of solder lightly to the wire joint. The heat will instantly melt the solder and draw it into the meshed strands.

    Soldering the wires together
    Credit:

    The Spruce / Kevin Norris

  8. Shrink the Tubing

    After the solder has fully cooled, slip the heat shrink tubing over the joint. Make sure that it is evenly positioned. Run the heat gun over the tubing until it constricts completely.

    Shrinking the tubing with a dryer
    Credit:

    The Spruce / Kevin Norris

Tips for Soldering Wires

  • Rosin core solder is safest to use when soldering electrical wires; acid core is for plumbing connections, like copper pipe.
  • Solder a wire to a circuit board by putting the tip of the gun between the wire and the board and letting the solder flow rather than trying to manipulate the solder.
  • Don't try to paint the solder onto the wire or board with the soldering tip; solder can't be spread around or moved.
  • Avoid letting too much solder puddle on the circuit board or you'll risk solder touching neighboring circuits.
  • Use a clamp or vise to hold a circuit completely steady when soldering.
FAQ
  • How long do soldered wires last?

    Soldered wires can be a permanent fix as long as they are not damaged or strained. The solder bond will last for decades or more.

  • Do electricians use solder?

    Electricians do not solder standard house wiring connections. The only time solder would be used around the home is if the project involves a home theater, stereo, router, or HVAC circuitry—usually by a technician. Household electrical connections for lights and outlets are made with wire nuts and enclosed in junction boxes.

  • What are the most common soldering mistakes?

    Low temperature is usually an issue, which could cause solder to not stick. The solder may be brittle or not bind correctly if it is insufficiently melted. If the solder is overheated, the joint could be burnt. Another common problem is insufficiently wetting the sponge and the pin which can cause tools to gunk up and inhibit a clean flow of solder.

  • What is the most important rule to remember when soldering?

    An important rule with soldering is to keep the work material and tools clean. Grease and dirt may prevent the solder from sticking to the wires.

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