You’ve drawn out your circuit, laid out your components, and you’re ready to piece together your latest electrical project. While everything looks great on paper, you find that the key component of your project relies on a wire that is too short for the actual build. So, what do you do?

Short of disassembling this part to solder on a longer wire, the easiest and most reliable thing to do would be to splice on an extension wire. Here are five of the best wire splicing methods to give you a reliable connection, regardless of the tools at your disposal.

1. Twist and Tape

For any project where you need a temporary fix, or a project that will be largely stationary, a simple twist of wires wrapped in electrical tape can do the trick. While this is in no way as viable as other methods on this list, it can certainly do in a pinch!

The benefits of a simple twist and tape maneuver are mainly economical – there are no tools required, outside of a roll of electrical tape. Due to the nature of the connection, this can be very easily redone or reinforced later; as a result, this is a great solution for prototyping a build before committing to a more permanent splice.

A twist on this method would be to utilize a wire nut – these are little plastic caps that act as a secure housing to host a twisted pair of wires. While they are more secure, they are also a fair bit bulkier, and can be difficult to fit into a small chassis.

2. Soldering

Hakko FX-888D Soldering Station

The natural progression from twist and tape, soldering provides you with a secure, electrically sound, and budget-friendly method of joining two wires. The tradeoff for this is twofold – the cost of admittance with the purchase of a quality soldering iron, and the learning curve associated with proper soldering practices. That said, the soldering iron is to electronics as the wing is to the airplane – you won’t get very far without it.

Related: Tips to Consider Before Buying a New Soldering Iron

There are a couple of key things to keep in mind when splicing wires via soldering: how to identify a solid solder joint, and how to go about making one.

Firstly, take a good look at the solder joint – a proper connection will be shiny and smooth, as opposed to a grotesque blob of solder on two wires. We want shiny and smooth, not lumpy and grey:

On top of that, the solder joint should be solid - give it a good tug! If it pulls apart, that could be a weak point in your project – best to find that out before putting everything else into place.

For best soldering results when splicing wires, follow these guidelines:

  1. Twist the wire securely – test with a tug.
  2. Apply flux to the twisted pair. This helps with proper heat distribution and ensures smooth flow of solder.
  3. Tin your iron with a little bit of solder, so it has a shiny coating.
  4. Heat the twisted pair from below and apply solder from above. Let the solder melt and flow down through the wires. This will help to avoid globules of solder and make connection throughout.

3. Heat Shrink Butt Connector

Heat Shrink Butt Connector on two red wires

Combining the reliability of a solder joint with the ease of use of twist and tape, the heat shrink butt connector is an easy and clean way of splicing wires together. While a soldering iron is not required, you do still need a heat source of some sort. According to the manufacturers of these connectors, a heat gun is the way to go.

To use these connectors, simply slip the tube onto one end of your splice, twist the wires together, and position the connector over the twisted pair. Once sufficient heat is applied, the solder joint will melt, combining the wires. Simultaneously, the heat shrink wrapper will contract, providing a tidy and contained solder solution.

The main downside of these connectors is cost – not only do you need a dedicated heat gun, but the connectors themselves cost far more than the equivalent solder and heat shrink that they consist of. Still, it is a quick and clean solution.

4. Crimp Butt Connector

Crimp Butt Connector on two blue wires

For something with the strength of solder but none of the heat, a crimped connection is the way to go. Requiring only a crimping tool and the proper connectors, crimping provides a super solid splice with minimal cost of entry.

In essence, crimping squishes the wires together into a connection piece; the intense pressure and friction delivered by the crimping tool provides a gas-tight connection, which helps to prevent corrosion of the wires. Crimped connections are extremely mechanically strong, and very resistant to mechanical stresses, making them an ideal splice for a project that will be on the move, or out in the weather.

The downside to such a mechanically strong connection is that they are non-reversible. Unlike a solder joint, which could be melted and redone if need be, a crimped connection is one and done.

Related: Don’t Dispose, Repurpose: Cool DIY Ideas Using Old Cables and Wires

5. Terminal Blocks

Terminal block with multiple wires connected

One of the quickest and bulkiest methods of splicing wires, the terminal block provides a flexible connection without requiring any specialized tools. If you have a screwdriver, you can utilize a terminal block.

Similar in design to the screw terminals often found on hi-fi equipment, terminal blocks form connections by physically pinning the wire ends in place. A contact between the two terminal inputs connects the wires, and a splice is made.

These units are fantastic choices for easy connections, and for connecting more than two wires together. Instead of trying to solder multiple wires together, a simple terminal block can provide a contact across dozens of wires at once.

Splices – Making the Most of the Wire You Have

Whether connecting smaller wires to bridge a gap or better integrating existing components into your projects, splicing wires is an invaluable skill to have in your tool belt. With a little bit of know-how, you can transform that tangle of scrap cabling into a treasure trove of wiring solutions.