Repair Damaged Power Tool Cord




Introduction: Repair Damaged Power Tool Cord

In a moment of carelessness and daydreaming, I made a major shop safety mistake and ran over the power cord of the power planer while using it. I quickly unplugged the cord from the wall, before setting out to unravel the mess I had created.

After removing the now damaged power cord and cleaning the planer, it was time to repair the cord and get back to work. The following Instructable was how I fixed the power cord.

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Step 1: Tools and Materials

The process of butt splicing wiring, is fairly straightforward. I chose a butt splice over using wire nuts, to keep the power cord streamlined and looking clean. I also wanted to make sure that I had the most flexibility and movement for wrapping up the power cord for future use and storage.

The potential for the butt splice to fail (over wire nuts or other splicing) is when the wires separate from the connector. This is generally caused by not getting a proper crimp from the connector on to the wire and the wire can pull out of the connector. I had to re-do the whole process twice, before getting a good solid splice and connection.


Insulated Butt Splice Connector

- I opted for the heat sealable over the standard connector for the hopes of an extra strong connection.

Electrical Tape

- I used the Cloth Friction tape, because it is what I had on hand, but I also like the double sided stickiness factor, which helps hold the heat shrink in place. Standard vinyl electrical tape will work as well.

Heat Shrink Tube

- I used a 1/2" diameter heat shrink tube with a 2:1 shrink rate, meaning it will shrink to 1/4" final diameter. Make sure to measure the cord diameter and take into account the width of the two splice connectors next to each other.


Electric Crimping/Stripping Tool


Box Cutter

Hair dryer or heat gun

Step 2: Clean and Prep Damaged Wires

Using the wire cutter and box cutter to get your wires clean and even. Don't be afraid to cut the wires completely fresh and expose new wire.

Remove the outer insulation by carefully using the wire stripper tool or box cutter. Be careful not to cut too deep and cut into the inner wires insulation.

Trim the copper wire using scissors or wire cutter so that they are even. It is important the they are at equal lengths so that the splice connectors are in line with each other.

The copper wire should only be long enough to go about halfway through the splice connect. Make sure the copper wire isn't too long so that there is exposed copper at the ends of the splice connector, i.e. insulation of the copper wire should be inside the shrinkable ends of the splice connector tube.

Step 3: Step 3: Attach Splice Connectors

Insert the trimmed copper wire into one end of the splice connector. Using the Upper portion of the crimping tool, crimp the connector in two places to secure the wire.

Add the connectors to any additional exposed wires.

Once both connectors are on, you can get an approximate idea for the amount of heat shrink tube you will need. Trim the heat shrink tube so that it covers both connectors, the exposed inner wires and has adequate (1/4"-1/2") coverage on both sides of the power cord.

After trimming the heat shrink slide it on one side of the power cord so that it can be moved into place later.

Now repeat the crimping process to connect the still free section of the power cord. Make sure to connect the same colored wires - in this case, white to white and black to black.

This would be a good time to test your work and make sure that the connectors are working properly. Carefully plug in the power cord and turn the tool on. Be careful to not apply much strain to the connectors, so they don't come apart.

Step 4: Heat Shrink!

If the connection works and the tool turned on in the previous step, you can now seal the connection with the shrink and tape.

First, slide the larger heat shrink out of the way and apply heat to the splice connector heat shrinkable tube ends. Make sure to use a heat gun, hair dryer or other indirect source of heat and not an open flame. An open flame can cause further damage to the cord and wire. You can skip this step if you didn't use heat shrinkable connectors.

Once the tube ends have shrunk enough (they may not shrink all the way tight, depending on the guage of wire), wrap the ends of each tube on to the exposed inner wire insulation with the tape. This is simply a precautionary step to add insulation and insure no future issues in the event the wire comes loose from the connector.

I also did an additional tape wrap around the base of the inner wires and on to the main cord. This provides extra insulation and strength to the wires.

Once all joints/seams have been taped, it's time to slide the large diameter tubing over the connectors and tape and apply heat.

Step 5: Finishing

Make sure to apply even heat from all sides so the tube shrinks evenly and secures the repair.

The heat shrink tube gets a bit "tacky" and can be formed to follow the shape of the inner connectors.

Once the tube has been tightened to your liking, you're all done and the power cord is repaired.

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    3 Discussions


    3 years ago

    Thank you, I felt like such an idiot running over my cable. Thought I was out 100 bucks. I fixed it and saved my tool!


    5 years ago on Introduction

    After all that effort, the repair would still fail a health & safety Portable Appliance test! Better to simply replace the whole cable with a new one (probably just as easy too). Well thought out instructable though and very informative on the use of heat shrink tubing.