How to Splice Copper Wire Without Solder

Splicing copper wire without solder can be a useful skill for completing electrical projects. With some basic supplies and proper technique, you can make strong and conductive splices to extend wires and connect circuits.

Gather the Necessary Supplies

To splice copper wires without solder, you will need:

Copper wires to splice. Solid or stranded wire will work. Make sure the wires are stripped on the ends being spliced.
Wire connectors. These are sometimes called wire nuts. Choose the right size connector for the gauge of the wires being used.
Wire strippers. A proper pair of strippers will cleanly remove just the insulation without nicking the copper.
Wire cutters. Any sharp diagonal cutting pliers will work.
A utility knife can also be handy for cleaning up any frayed strands or insulation.

Prepare the Wires

Before splicing, you'll want nice clean ends to work with:

Use the wire strippers to remove 3/4" to 1" of insulation from each wire end. Take care not to cut into the copper.
For solid core wire, simply strip the insulation.
For stranded wire, also twist the strands together tightly and straighten them out. This keeps them neat and together inside the connector.
Use the utility knife or cutters to neatly trim away any frayed bits or errant strands.

Join the Wires in the Connector

With prepared wires in hand, splicing is simple:

Place the matching wire ends together, lining up stripped portions. Tightly twist them so they stay in contact.
Select the right size wire connector and place it over the twisted wire tips.
Turn the connector clockwise to thread the wires into the twist-on connector.
Continue turning until the connector is fully tight and secured onto the wires.
For a better connection, you can gently tug wires to feel it is snug.

Check Your Work

Before completing the splice, double check:

Give the connector another turn or two to ensure it is fully tight and secure.
Visually inspect that no copper wire strands are poking out.
Use a multimeter to test conductivity across the splice. It should show good continuity.
Once satisfied, you can use electrical tape to insulate and protect the connector and exposed wires.

With the right materials and proper technique, splicing copper wire without solder is straightforward. Just be sure to make strong mechanical and electrical connections. Taking a bit of extra care will ensure your splices are safe and effective.