Ensure your shrink wrap is the correct gauge for your wiring. The sheath or jacket of the wire lists the gauge as well as the packaging for the shrink wrap. If you know the diameter and need help finding the gauge, check out the Wire Gauge Size Calculator (See Resources 1).
Turn off the power running through the electrical wire. If it is in an appliance, unplug it. If it is in a wall, make sure you have turned off the circuit that runs through that wiring before attempting any repairs. If the wire is nicked or frayed, cut it cleanly through at the repair area.
Heat the soldering iron. Be careful not to leave it near anything, or in an area where it might fall over.
Mark the wire a half inch past the area you need to remove with the permanent marker. Lightly nick the sheath or score it by rotating the razor blade all the way around the wire. Do not cut any of the actual wire inside the jacket. Flex the wire at the repair area until the sheath comes apart. Remove it from the broken wire. Repeat this process on the other side of the repair area.
Cut two inches of the heat shrink and slide it over one side of the repair area, past the unsheathed area. Put on safety goggles.
Dip both sides of the unsheathed wire in the wire flux. Use as little as possible to get a fine coat and make sure you do not get any on the sheath.
Moisten the sponge and melt a thin layer of solder a quarter inch from the end of the soldering iron. Rotate the end of the soldering iron on the sponge and gently push both sides of the repair area together, until they mesh. Smooth the halves down so there are no strings hanging off.
Touch the soldering iron to one side of the meshed wire, until it just begins to smoke. On the other side, hold a small strand of solder, which melts to coat the wire and leaves a shiny silver coating around the wire. If it looks dull or gray rather than shiny, repeat this step.
Clean the bonded area with the small paintbrush and isopropyl alcohol. Slide the shrink wrap over the soldered repair and heat it with a blow dryer until it is sealed at both ends. Keep your safety goggles on and stand back several feet with a fire extinguisher ready, just in case. Test the wire.
Things You Will Need
- Heat Shrink
- Diagonal wire cutters
- Safety goggles
- Soldering iron
- Permanent marker
- Razor blade
- 8-inch rosin core solder
- Wire flux
- Small paintbrush
- Isopropyl alcohol
- Fire extinguisher
- Wires for home appliances are more prone to nicks, frays and breaks than those in a car. To avoid electrical wiring problems in your home, do not place furniture on top of wiring, do not staple wiring to anything, and keep wiring out of areas where people walk. You can find more tips in Popular Mechanics Home Safety Handbook (See Resources 2).
- Once you have finished the repair, have an inspector ensure it is up to code.