Understanding stripping in conductor splicing: why removing insulation matters

Stripping: the quiet first step that makes a solid electrical connection

If you’ve ever stood in a workshop with a ragged bundle of wires, you know there’s a lot more to electrical work than just twisting two pieces together. One small, essential move sets everything up for a reliable connection: stripping. In the context of conductor splicing, stripping means removing the insulation from the conductors so the metal is exposed and ready to join. Yes, removing insulation—that plain, practical act—matters more than it sounds.

What stripping really means in conductor splicing

Here’s the thing: wires come with a protective coating, insulation, that keeps electricity from wandering where it shouldn’t go. When you splice conductors, you need bare metal to touch metal so electrons can move cleanly from one conductor to another. Stripping is simply the careful act of peeling away the insulation to reveal a clean, shiny conductor surface.

This step is foundational for a couple of reasons:

• It creates a reliable electrical path. If the copper or aluminum is not exposed correctly, you get high resistance, heat, and a weak joint.

• It helps prevent corrosion at the connection. Bare metal is more stable when it’s properly joined than its insulated counterpart that can trap moisture and contaminants.

• It’s a practical, repeatable skill. Once you know how to strip right, you can apply the same technique to different wire sizes and connector types.

Think of stripping as the bridge between “wire” and “connection.” Without a good strip, the best connector in the world can’t do its job.

Tools and how to use them (without turning it into a suspense scene)

To strip correctly, you’ll want the right tools and a steady hand. Here are the basics you’ll encounter in most NCCER Electrical Level 2 contexts, along with plain-language tips:

• Wire strippers: These are your go-to. They’re designed to cut through insulation without nicking the conductor itself. Pick the gauge you’re working with and clamp the right notch. The trick is to apply just enough pressure to remove the insulation without cutting into the metal.

• Pliers or motorized cutters: Useful for stubborn insulation or thicker jackets, but use them with care—nicks on the conductor can lead to weak spots.

• Utility knife (caution advised): A knife can be handy for larger cables, but you must go slowly and keep the blade at the correct angle away from the conductors.

• Measuring gauge or ruler: To strip the correct amount of insulation, you’ll want to know how much the connector will reveal. Different connectors call for different exposed lengths.

Here’s a practical way to approach stripping:

• Safety first: power down the circuit, verify zero volts, and wear eye protection.

• Select the correct stripping length. For most small wires, you’ll expose a short length—long enough to fit the connector without leaving a loose tail, but not so long that copper sticks out beyond the connector.

• Position the tool properly. Align the stripping notch with the insulation you want to remove, and steady your grip so you don’t slip.

• Strip with control: don’t yank. A smooth back-and-forth motion (or a single confident pull) works better than a quick, jerky motion.

• Inspect the exposed conductor. Look for nicks, rough edges, or frayed strands. If you see damage, re-strip or cut back to fresh insulation.

Solid vs. stranded wire: does stripping change?

Yes, but in different ways. Solid conductors and stranded conductors both need stripping to expose bare metal, but the finish matters for the joint’s reliability.

• Solid wire: You want a clean, straight expose. It’s easier to twist or clamp into a connector without fraying. Keep the exposed length modest.

• Stranded wire: The strands can splay or fray if you’re not careful. A light twist of the exposed strands helps keep them together, and some connections require you to tin the ends briefly (apply a thin layer of solder) to prevent fraying before you attach.

Color codes and jackets can throw a quick curveball if you’re not paying attention. The insulation color often tells you what you’re dealing with, especially in larger cables or multi-conductor runs. But the stripping action itself is color-agnostic: it’s about exposing clean metal, not leaving insulation in the wrong place.

Why stripping matters for a reliable connection

I’m fond of the analogy that a good connection is like a good handshake—firm, clean, and confident. If you strip too much, you risk leaving copper exposed to air and moisture, inviting corrosion or shorting. If you don’t strip enough, you end up with a poor contact, which can heat up and fail over time. Either way, you’ve got a weak link in your electrical chain.

A proper strip also helps ensure connectors seat properly. Some connectors are designed to bite into bare metal with teeth or clamps. If insulation is left under the clamp, you won’t get the full bite, and the joint can loosen. Over-strip, and you may expose more metal than the connector can accommodate, which creates another set of problems.

Safety and best practices you’ll appreciate

• De-energize before you strip. It’s the simplest way to avoid a shock or arc flash. Verify with a tester and follow lockout/tagout procedures where required.

• Use the right tool for the job. The labeled gauge on your stripper isn’t decorative—using the wrong notch can nick the conductor or leave insulation behind.

• Don’t rush. A steady, deliberate approach beats a frantic, sloppy one every time.

• Inspect after stripping. Look for burrs, cuts, or strands that have been damaged. If anything looks off, re-strip.

• Keep it clean. Dust and oils can interfere with a good connection, so wipe the conductor ends lightly if needed before you join them.

Connecting the strip to the bigger picture

Stripping is one moment in a sequence that includes selecting the right connector, aligning parts, and choosing an appropriate method (twisting, crimping, soldering, or using a mechanical lug). Each step matters, but stripping is the gatekeeper step: if you don’t do it right, the rest won’t fix a bad surface.

In the real world, you’ll find many connector families and joining methods:

• Crimp terminals that bite into bare metal for a tight, moisture-resistant hold.

• Soldered joints for a low-resistance, continuous path, often used in more controlled or high-reliability scenarios.

• Mechanical lugs and push-in connectors that rely on a clean strip to seat properly.

A quick note on reliability and longevity: a well-executed strip reduces resistance at the joint, which translates into less heat, less drift, and fewer maintenance headaches down the line. It’s one of those little choices that compounds into real-world stability.

Common slips to avoid (learn from the near-misses)

• Stripping too long or too short. The exposed length should match the connector’s requirements, not your guess.

• Nicking or cutting into the copper. That creates weak spots that can fail under load or vibration.

• Damaging the insulation deeper in the jacket. You want a clean strip at the very end, not a jagged line along the conductor.

• Skipping a clean surface check. Some folks skip the final glance over the exposed wire and regret it when a joint fails after a few cycles of current.

Let me explain with a quick mental picture: imagine you’re peeling an orange, but you peel five layers of rind and only leave a tiny glimpse of fruit. That tiny glimpse is your exposed conductor. If you peel too much, you expose more of the rind than you should, and the fruit dries out or bruises. Stripping is about finding that sweet spot where the metal is ready to connect, and nothing else gets in the way.

A few practical pointers you’ll actually use

• Practice with different wire sizes. Get a feel for how long a given wire needs to be stripped for a range of connectors. Your intuition will build with experience.

• Work in a clean space. A clutter-free bench makes it easier to align and inspect the exposed metal.

• Use a bright light to check the strip. A quick side-angle look helps you spot nicks you might miss straight on.

• If you’re unsure, re-strip. It’s better to start fresh than to chase a problem after you’ve locked the joint in place.

Wrapping up: the quiet craft behind every solid connection

Stripping may be a small detail, but it’s a big deal in the world of electrical work. When you remove insulation with care, you set the stage for a clean, durable connection that stands up to heat, vibration, and time. It’s one of those practical skills that separates the confident hand from the uncertain one. And once you’ve mastered it, you’ll apply the same careful touch to many other tasks in electrical installations.

If you’ve got your own strip-and-connect story or a favorite tip for keeping those exposed conductors pristine, I’d love to hear it. In the meantime, next time you’re preparing to join two wires, remember the simple rule: strip to expose clean copper, and let the rest of the connection do its job. That’s the core of a reliable electrical system—start with the strip, and the rest follows.

A quick recap for a clear takeaway

• Stripping = removing insulation to expose bare conductors.

• It’s essential for a solid, low-resistance connection.

• Use the right tools, strip the correct length, and inspect the exposed metal.

• Follow safety steps and avoid common stripping mistakes.

• Stripping is the gateway to strong, durable electrical joints.

NCCER Electrical Level 2 isn’t just a checklist; it’s a practical set of skills you’ll carry into every project. Stripping is one of those foundational moves, and getting it right makes all the difference when the lights go on and the current starts to flow.