How To Extend or lengthen Electrical Wire (AVOID Doing This!)

Since we’re always bound to the length of the electrical wire we have, extending the wire can solve a lot of problems sometimes. 

This is usually done by a process known as “splicing”, which connects or bound two similar types of electrical wires together so that the electrical current passes through them.


If you want to know how to extend electrical wire assembly, this guide is for you. So without further ado, let’s dive right in!

How to lengthen or extend electrical wires

Step 1: Prepare Your Tools and Disconnect Your Electrical Wire

Splicing a wire is a relatively simple task, but it requires some tools in order to get the job done. Ideally, these items should be on you before you start for convenience and to save yourself the hassle of looking for missing items mid-project.

For starters, you need to have a cable ripper and a wire crimper/stripper on you. This tool has holes that are designed to remove the insulation of wires and expose the metal part for junctions. You also need pliers for twisting the wires easily.

Depending on the extension method you’re going to follow, you’ll need some extra tools, such as shrink tubes, a soldering iron, wire caps, butt splices, electrical tape, a heat gun, etc.

In addition to your tools, you’ll also need a wire of similar thickness and a suitable length for connection.

After bringing all the necessary items for the project, make sure that you disconnect the wires you’re going to extend from any electric source and wear any safety equipment that you might need. 

If you can’t unplug the wire, you’ll need to disconnect it by shutting off the electric circuit of the wire from the breaker box.

Step 2: Strip the Sheathing and Insulation from the Wires

In order to work on the wires, you’ll need to expose them by removing the sheathing and insulation, which can be easily done by a wire stripper.

Simply hold the wire you want to extend and choose a hole that is slightly smaller than the thickness of your wire.

Clamp your wire stripper on the wire with that hole and press down hard to cut through the insulation, push the insulation out to expose the wire, then repeat the same thing on the extension one.

Make sure that you only expose about 3/4 to 1 inch of wire on each side and avoid exposing more than you need.

Step 3: Pick a Suitable Splicing Method

With the two wires exposed, you’re now ready to connect them together by joining the metals of both wires to each other. This can be done through several methods, so here’s how to do each one of them properly:

1. By Soldering the Connection

Soldering the connection is known as the “Lineman Method”. To use this method, start by bending the metal part of the wire at a 90 degree angle on each wire to create a hook on both wires, then latch the hooks to each other. 

After that, twist the wires with your hand or with pliers so that they’re coiled tightly around each other.

Once the connection is made, use the soldering gun along with a lead or silver rod in order to melt it over the wires. The soldering rod may drip over, do the soldering on a safe surface.

2. Using a Wire Cap

The wire cap is the easiest method of connection of the three, but it may not look the cleanest when you’re finished, as there will be a permanent bend in the wire where the extension is made.

For this method, you’ll need to hold the two exposed wires next to each other so that the exposed parts are parallel and touching each other. You don’t need to twist or coil the wires together here, as the wire cap will do that for you.

Simply place the wire cap over the two connected wires and start twisting the wire cap in a clockwise direction for a few seconds or until they stay in place when they’re pulled lightly.

3. Using a Butt Splice

Lastly, if you don’t have a soldering iron or you don’t want to use one, you can use a butt splice instead, which is ideal for relatively thick wires too.

To use this method, simply introduce one of the wires to one side of the tubing until the wire part reaches the center, then use a wire crimper to hold it in place. 

After that, repeat the same step with the other wire, then finish with final crimping where the two wires are pressed together and connected through the middle conjunction.

Step 4: Cover the Connection

Now that you’ve successfully connected the two wires together, all that’s left is to encase the connection again to insulate it. 

This is not only necessary for protecting the connection and insulating it to avoid shocks or electrocution, but it’s also a good thing for the aesthetics and cleanliness of the finish.

The enclosing method will depend on the splicing method you’ve used. For example, if you used the butt splice or the soldering method, you’ll have a shrink tube already covering the wire. To use this shrink tube, you’ll do the following:

  1. Slide the tube until it covers the who connection completely
  2. Use the heat gun to heat up the tube and rotate the wire so that it shrinks evenly.

On the other hand, if you’ve used a wire cap or you’ve forgotten to leave a shrink tube before connecting, you can simply wrap your connection with electrical tape, but make sure that you leave nothing exposed.

Wrap Up

There you have it! A complete guide that walks you through everything you need to know to splice and extend electrical wires in a variety of methods.

You can use this knowledge to connect an 8 gauge wire.

Although extending an electrical wire is a relatively easy job, it’s still a project that requires some dealing with electricity and several tools, so it’s always necessary that you follow all safety guidelines to protect yourself from shocks or damaging your electrical appliances.

You can use electrical tape to extend wires as well. This is a temporary solution but can work in some cases. It is often not up to code though.