Can you use electrical tape to splice wires together?

Splice wires and extend speaker connections with electrical crimps

By Stanley Goodner Stanley Goodner Writer Excelsior College Stanley Goodner is a former Lifewire writer who writes about audio equipment, music management, computer hardware, and other consumer technologies. lifewire’s editorial guidelines Updated on July 28, 2021

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Using twist connectors (wire nuts)

Wire nuts, also called wire twist connectors, are typically used for wiring installation in homes & buildings. They’re another option although I don’t recommend them as they’re a bit less reliable than crimp connectors or solder.

Wire nuts work by using a threaded metal insert to screw down onto the wire, holding it together as it goes.

They’re pretty fast, but unfortunately, on occasion, I’ve seen them come loose from wire so I don’t advise using them. Instead, I’d highly recommend crimp connectors.

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Which speaker wire is positive? Which is negative?

The most common kinds of positive wire markings are shown here as examples. 99% of the time, figuring out which wire is positive is really easy once you know what to look for.

The good news is that once you know what to look for, 99% of the time it’s very easy to tell which speaker wire is positive and which is negative.

How do I check if a speaker wire is positive or negative?

Here’s a list of the most common ways to tell which is the positive wire:

  1. A printed line or series of dashes/lines is on the positive wire
  2. One wire’s insulation is red or a different color than the negative wire (most often red is used)
  3. One wire has a copper color and one has a silver finish
  4. The positive wire may have small positive (“+”) symbols and/or wire gauge info printed on it
  5. An imprint or molded stripe is made in the positive wire’s insulation

Of the 5 kinds, imprints can occasionally be a little bit harder to notice so sometimes you need to look very closely under good lighting. Also, positive wires that use a “+” print can be a little hard to read sometimes, too.

Which is positive: copper or silver?

These are less common, but of speaker & power wires that have a copper and a silver color, you can pick one of the two to be positive. However, as a rule the copper wire is treated as the positive.

The “silver” wire isn’t really silver – it’s copper wire that’s been lightly coated (“tinned”) in most cases.

Once you know which is the positive wire then the other is the negative wire.

Music uses alternating current (AC) signals and doesn’t flow in only one direction. We use one wire as the positive one when connecting speakers to be consistent when connecting them so as to wire them all the same way for the best results.

Use an approved connector to secure your electrical splice

Twist-on Electrical Connectors – "wire nuts" & MAAR Connectors

Splices in an building’s electrical circuit must be connected using an approved wiring connector, such as a twist-on connector ("Wire Nut" is a trademarked name for a brand of twist-on connectors.)

Twist-on connectors come in different color-coded sizes, and you must choose the proper twist-on connector, depending on the thickness (gauge) of the wire and the number of wires you’re combining in your splice.

The connector is placed over the end of your twisted splice, pressed onto the wires, and turned clockwise until it is tight. Be careful when pushing an electrical splice back into the junction box – don’t loosen the connector you’ve installed or your connection will be poor and possibly unsafe.

Using the wrong type of electrical splice connector, or one for which studies have shown poor performance, can lead to a melted or failed electrical connection, possibly risking shock or fire.

Our photo at above left shows an expert using a Scotchlok 3M electrical connector to cap a splice which was also coated with an antioxidant. We discuss this connector (now obsolete for aluminum wire repair) in more detail

at HOW to REDUCE the RISK of ALUMINUM WIRING

Apply Heat to Shrink Connectors

Amazon

After attaching the crimp connectors to the positive and negative wire ends, gently apply a heat source to shrink the connectors. A hot air gun or a blow dryer set to high heat is best (held a few inches away), but you can use a lighter if you’re extremely careful and hold the lighter at least an inch away.

Hold the wires with your offhand (a few inches below the crimp connections) as you apply the heat. Slowly rotate the so that you get around all sides. The crimp casings will shrink snug against the speaker wire, creating a protective and waterproof seal. Some electrical crimp connectors are designed with a bit of solder on the inside, which melts from the heat and fuses the wires for a stronger connection.

Continue stripping speaker wires and attaching/shrinking crimp connectors until all lengths have been spliced and extended.

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Final Thoughts

Knowing how to splice wires can save you time and money on numerous electrical and lighting projects around the house. If, however, you’re apprehensive about working with electricity or lack basic electrical knowledge, do not hesitate to hire a licensed electrician for your project.

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While hiring an electrician can easily set you back at least $50 per hour, it’s a small price to pay to protect your family and your property from the severe consequences of poorly performed electrical work.

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What Does it Mean To Splice a Wire?

If you are splicing wires together, you combine two separate lengths of wire so that they can carry a current for you. There are many ways you can splice wires together. In some cases, you may simply use a few wire caps. In other cases, you may try to solder them together. You might use a wire cap or nut if you are working with smaller wires; however, you may decide to use a butt splice if you are working with larger wires. What are the pros and cons of each method? There are several steps to follow.

Method 1: The Strip and Splice

The first option is to strip the wires and then splice them. Wires come with insulation around them. Before you splice them together, you may decide to strip the insulation. To complete this method, the steps you need to follow include:

  • First, unplug the device that contains the wires you are going to be splicing. If the wire is attached to the wall and cannot be unplugged, always turn off the circuit. That way, you do not get shocked.
  • Then, you need to remove approximately one inch of insulation from each wire you will be splicing. For this, you will need a wire stripper that is approximately one to two sizes smaller than your wire. Clamp the wire in the hole and pull the stripper towards the other end of the wire. This should remove the insulation.
  • After this, you need to slide a small piece of shrink tube onto one of the wires. Approximately three inches of shrink tubing should be enough. A shrink tube is made from plastic. That usually shrinks after it is heated. Then, slide the tubing on the wire before you splice them together.

This is one of the easiest ways you can splice wires together.

Some of the main benefits of this method include:

  • This is one of the least expensive methods available
  • It does not take very long to splice wires together
  • The shrink tubing should be durable enough to stand up the routine wear and tear

On the other hand, this method does require some physical dexterity. If you are not proficient with wire strippers, you may have issues. In addition, this method is probably not going to work well if you are working with larger wires.

Method 2: Try Using a Wire Cap

Various small wires joined with a wire nut connect
Various small wires joined with a wire nut connector

Another option is to try using a wire cap. A wire cap is something that will pinch two wires together for you. In order to use a wire cap, the steps you need to follow include:

  • First, you need to pull out the wire strippers again. Strip back the insulation if you have not done so already. You should have approximately one inch of exposed wire on each cord.
  • Next, hold two ends of the wire together so that they are touching one another. Do not coil the wires together. Otherwise, they are not going to fit in the wire cap. It is the job of the wire caps to twist the wires together. You do not have to twist them together yourself.
  • Next, twist the wire cap clockwise on top of the exposed wires. To do this, set the wire cap on top of the exposed wires and start twisting. Rotate the cap clockwise for approximately five seconds. The wires should coil themselves inside of the cap. After this, tug on the wires to make sure they stay in place. If the wires come loose, you need to twist a wire tap some more.
  • If you find that the cap is still loose, you may be using a wire cap that is too big. Or, you can strip back some more insulation, so there’s more wire to coil inside of the cap.
  • Once you are done, take some electrical tape and layer it around the exposed wires. You should wrap some black electrical tape around the bottom of the wire caps to cover it completely. You need to overlap each layer of tapes of the wires are not exposed. When you are done, use a pair of scissors to cut the electrical tape.

This is another straightforward method for splicing wires together.

A few benefits of this method include:

  • You can use this method with larger wires
  • This is also a relatively inexpensive method
  • It does not take that long to use a wire cap to combine your wires

The downside is that wire caps are not always that secure. If the electrical tape comes loose over time, it could lead to exposed wires that create a safety hazard. Take a look at the wire cap from time to time and make sure the wires are still spliced appropriately.

Method 3: Use a Butt Splice

Another option that may work well for thicker wires is to use something called a butt splice. You can find a butt splice at most of your hardware stores. If you know how big your wires are, there may be someone at the store who can help you find the right butt splice. In order to complete this wire splicing method, a few steps you should follow include:

  • First, you need to strip the insulation from the wires using wire strippers. You need to remove approximately one inch of insulation from every wire you are going to be working with.
  • After this, take one of the exposed wires and insert it into the butt splice. You should push the exposed end until it is in the middle of the butt splice.
  • Next, take a wire crimper. Press it approximately one-quarter of the way into the butt splice from the end into what you just said the wire. You should match the crimper hole the exact size of the butt splice. Press the crimper handles all the way down. You are using this to hold the wire in place. There is a chance that your wire strippers may have a wire crimper as well.
  • After this, you need to do the same thing to the other side. Place the second wire in the butt splice. Make sure it touches the other wire that is already in the butt splice. Then, use the wire crimper to secure the wire in place again. There is a good chance your butt splice is transparent, allowing you to see the wires touch one another.
  • After the wires are secure, slide some shrink tubing over the entire butt splice. If you find a shrink tube falls off after you slide it in place, use the wire crimper to crimp that in place as well. Another option is to use electrical tape instead.
  • Finally, you should take a heat gun and point it toward the shrink tubing. Rotate the spliced wire in your hands. The shrink tube should effectively insulate the wires after you heat them appropriately.

This is one of the most popular methods for splicing wires together if you have thicker wires:

A few of the biggest benefits of using this method include:

  • This is the ideal method if you have thicker wires you are trying to splice together.
  • This is one of the safest options, as you are going to add multiple layers of protection between the exposed wires and the external environment.
  • This is a durable wire splicing method that should keep the wires spliced together for a long time.

Even though this method does work well for thicker wires, it does take a bit longer to accomplish. In addition, this method requires more tools, making this slightly more expensive.

How to make a Pigtail Splice in Electrical Wire Using a Twist-on Connector

Our our enlargement above and our page top photo shows a pigtail splice at the lower left of the drawing.

Strip off at about 1 an inch of insulation from the end of each wire.

When you are joining electrical wires used to carry current in a home you’ll be using a solderless twist-on connector such as we show at left. In this case the length of wire from which you need to strip insulation depends on the number of wires being joined together and the size of the twist-on connector you’re going to use.

In good practice you don’t want to strip off too much insulation – when the splice has been completed and the twist-on connector has been installed, you should not see any bare wire exposed extending beneath the bottom edge of the mechanical connector.

If you are stripping wires that are not part of the building’s electrical system, such as speaker wires, you may not be using a mechanical connector, just tape, and the length of wire that you need to strip depends on the number of wires being joined and your ability to twist them securely together.

[Click to enlarge any image]

Don’t damage the wire during stripping of insulation: Be careful that you don’t nick the metal wire when cutting the insulation in preparation to strip it off.

If you do nick the wire, as shown in my photo (above left) and in Carson Dunlop Associates’ sketch above, the risk is that the nicked end will later break off, destroying your connection, and perhaps also becoming unsafe.

OK to be honest, the nicked copper wire shown in the photo above had taken a beating during our stripping and insertion of the wire into a push-in type back-wired electrical receptacle discussed separately

at RECEPTACLE WIRE-TO-CONNECTOR CONTACT AREA SIZES

and in a companion articled

at BACK-WIRED ELECTRICAL DEVICES.

Twist the electrical wires together tightly starting at or near the first bit of exposed wire. Always twist the wires in a clockwise direction. That way when you screw on a twist-on connector (which also is tightened by turning it clockwise) you won’t be un-twisting your wires. We describe just how we twist wires together for a twisted splice just below in this article.

Trim off sharp points protruding from the end of the twist. Solder the twisted wires at the point where the twist began.

Secure the completed electrical wire splice with an approved twist-on connector as we discuss below.

Our photo above shows some pigtail splices inside of a metal junction box – in this case, because the wires are aluminum, the connectors shown are not the proper ones, and these splices are a fire hazard.

Splicing three or more wires together

The pigtail type of splice is best when joining three or more wires. The thing to guard against when more than two wires are involved in the twist is the tendency for one or more of the wires to remain fairly straight while the others are wrapped around it.

When this happens the straight conductors can be pulled free of the splice fairly readily.

The way to prevent this is to make certain the twist is started with all the wires bent at approximately a right angle. (Don’t bend current-conducting electrical wires at a sharp angle however.) Then if the bent wires are interlocked and held with pliers, the twist will continue as started.

  1. Starting a three-wire pigtail splice. To interlock all three wires bend each one at a right angle when you make the first twist. A straight wire will pull out under relatively little stress.
  2. Testing a three-wire pigtail splice. Check that all of your wires participated in the twist by pulling each individually. Make this check before applying your mechanical connector such as a twist-on or MAAR.
  3. Finish the three-wire pigtail splice by securing it with a mechanical connector as we discuss below.

Complete Guide to Home Electrical Wiring

Perfect for Homeowners, Students, Handyman, Handy Women, and Electricians Includes: Wiring GFCI Outlets Wiring Home Electric Circuits 120 Volt and 240 Volt Outlet Circuits Wiring Light Switches Wiring 3-Wire and 4-Wire Electric Range Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet How to Troubleshoot and Repair Electrical Wiring Wiring Methods for Upgrading Electrical Wiring NEC Codes for Home Electrical Wiring ….and much more.

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