Splicing aluminum wire can be challenging without the proper tools and connectors. However, with care and caution, it is possible to make a safe and secure splice without special connectors. This guide will walk through the entire process step-by-step to properly join aluminum wires.
Why Splice Aluminum Wires?
There are a few key reasons you may need to splice aluminum wires together:
- Extending an existing aluminum wire run that is too short.
- Repairing a damaged or broken section of aluminum wire.
- Adding a new branch from an existing aluminum wire circuit.
Splicing allows you to connect additional aluminum wiring without replacing entire wire runs. Aluminum also has advantages over copper wire in some applications:
- Aluminum is lighter weight for the same ampacity.
- Often less expensive than copper wire.
- Acceptable for many residential and commercial wiring applications.
However, aluminum has some unique properties that require special treatment when splicing:
- More brittle than copper - can break instead of bending.
- Forms an oxidized coating that can interfere with connections.
- More prone to loosening and overheating at points of high resistance.
This makes using the proper technique critical for a safe and lasting aluminum wire splice.
Dangers of Improper Aluminum Wire Splices
Improperly splicing aluminum wires can lead to very dangerous electrical conditions, including:
- Loose connections that overheat, melt, and possibly start a fire. This is a common issue with aluminum wires.
- Oxidation buildup increasing resistance and heat at the faulty splice.
- Arcing, sparking, and shorts caused by a loose wire joint.
- Eventual failure of the splice, leaving the circuit without power.
Burns, shocks, fires, and equipment damage can occur from faulty aluminum wire splices. Using special connectors suited for aluminum wire provides maximum safety. But in a pinch, you can make a secure splice without these connectors by following the right steps.
Gather Necessary Materials
Splicing aluminum wire without special connectors requires commonly available materials:
- Wire strippers - must be designed to not nick or cut into the softer aluminum wire.
- Utility knife - for carefully scraping wire.
- Sandpaper - fine grit to rough up wire ends.
- Electrical tape - high quality for insulation and securing splice.
- Wire nuts - proper size for joinng wire gauge. May need wings clipped off to fit.
Avoid using materials incompatible with aluminum:
- Steel wool - particles can get lodged in softer aluminum.
- Copper connectors - can accelerate oxidation.
- Ordinary pliers - can damage/break aluminum wire.
It is also advisable to turn power completely off at the breaker before splicing aluminum wires.
Step 1 - Strip and Clean the Wires
Strip off approx 1/2" of insulation from each wire end using wire strippers specifically for aluminum. Avoid nicking or gouging the aluminum.
Next, use fine grit sandpaper to rough up the newly exposed aluminum wire. This helps remove any oxidation and provides a better bonding surface.
Carefully scrape both wires with a utility knife to expose the fresh metal underneath. Remove any oxidation present.
Step 2 - Twist and Tape Wires
Hold the two stripped aluminum wire ends together in close alignment.
Twist the bare wire ends around each other by hand or with gentle pliers. This preserves the excellent conductivity of aluminum.
Wrap electrical tape around the twisted section. Pull tightly when wrapping to ensure a snug fit. This helps reduce oxidation and improves the splice's mechanical strength.
Step 3 - Install Wire Nut
Select an appropriate wire nut for the gauge of the aluminum wires being joined. You may need to clip the wings on the nut to get it started on the thicker wire.
Twist the nut 2-3 turns onto the taped splice until tight. The tape provides friction to keep the splice from loosening later.
If desired, wrap tape over the nut and wires to add another layer of insulation and protection.
Step 4 - Carefully Check Your Work
Before re-energizing the circuit, thoroughly inspect and test your work:
- Visually verify the splice is tightly twisted with no frayed strands.
- Check tightness of the wire nut and tape.
- Gently tug wires to ensure solid, corrosion-free joint.
- Use a multimeter to test for continuity across the splice.
If there are any issues found, redo the splice and inspection.
Tips for a Durable Aluminum Wire Splice
Follow these tips to achieve maximum safety and longevity for aluminum wire splices without connectors:
- Use only approved techniques and materials designed for aluminum wire.
- Keep wire ends tightly twisted and tape wrapped.
- Apply wire nuts correctly sized for the specific gauge.
- Thoroughly clean wires to remove oxidation before splicing.
- Inspect splices periodically to catch any loose connections forming.
- Consider coating the splice in antioxidant paste or silicone sealant.
Warnings About Unsecured Aluminum Wire Splices
Avoid these hazardous pitfalls when splicing aluminum wires:
- Loose, poorly twisted wire ends.
- Reusing old, oxidized wire ends instead of exposing fresh metal.
- Using materials and tools that damage soft aluminum.
- Failing to sand and clean wires before splicing.
- Overtightening wire nuts, cracking the aluminum.
- Allowing gaps or insulation gaps in the splice area.
Any of these issues can lead to overheating, arcing, and fire.
When to Call an Electrician
In general, exercise extreme care splicing aluminum wires without special connectors designed for it. Consider calling a licensed electrician for:
- Large gauge aluminum wires. Difficult to handle without nicking.
- Connecting aluminum wire to devices or outlets. Special connectors are mandatory.
- Whole home aluminum rewiring. splicing all connections is inefficient and risky.
Professionals have the proper tools and training to work safely with aluminum wire. They can install special connectors where needed.
Conclusion
While special connectors make splicing aluminum wire foolproof, it is possible to make a safe splice without them. By properly preparing and joining the wire ends, then securing with tape and wire nuts, a durable connection can be made. However, extreme care is needed when handling soft aluminum wire to avoid any hazardous conditions. For whole home wiring, hiring an experienced electrician is strongly advised over splicing by yourself.