Fail-Safe Waterproof Splice Kits | Merrill Manufacturing

Fail-Safe
Waterproof Splices. Zero
Call Backs.

Choose Your Splice Kit

Built for buried, wet, out-of-sight connections—where failures cause big problems.

Merrill splice kits with metal connectors and clear heat-shrink tubing
{"statementLink":"","footerHtml":"","hideMobile":false,"hideTrigger":false,"disableBgProcess":false,"language":"en","position":"left","leadColor":"#146ff8","triggerColor":"#146ff8","triggerRadius":"50%","triggerPositionX":"right","triggerPositionY":"bottom","triggerIcon":"people","triggerSize":"medium","triggerOffsetX":20,"triggerOffsetY":20,"mobile":{"triggerSize":"small","triggerPositionX":"right","triggerPositionY":"bottom","triggerOffsetX":10,"triggerOffsetY":10,"triggerRadius":"50%"}}
true
Why Merrill Quality Splice Kits Matter

Why Wire
Splices Fail

1. No Adhesive Seal

Cheaper kits may slide off plice if hits coupling and start out let moisture in.

2. Overheating the Sleeve

Direct flame can burn the material and damage protection.

3. Uneven Shrinkage

Heating from one end can leave gaps and air pockets.

4. Low-Quality Kits

Poor materials cause loose connections, failures, and callbacks.

Why Merrill Quality
Splice Kits Matter

1. Adhesive + Sealant

Locks out moisture and creates a secure watertight seal that will not move and keeps electrical connection.

2. Controlled Heat

Even heating starting from the middle positions protects the sleeve and keeps the seal intact.

3. Even Shrinkage

Shrinks smoothly for a tight, reliable waterproof seal.

4. Built for Harsh Conditions

Better materials perform in buried and wet applications. Will not cause loose connections.

3:1 Heat Shrink Ratio | Merrill Manufacturing

3:1 Heat Shrink Ratio

Available in black and clear tubing for secure, sealed splice connections.

Black Heat Shrink Tubing

Black heat shrink tubing showing the size before shrinking and after shrinking

Clear Heat Shrink Tubing

Clear heat shrink tubing showing the size before shrinking and after shrinking
Splice Kit Decision Guide | Merrill Manufacturing

Splice Kit

Decision Guide

All kits include: Heat Shrink Tubes  •  Stainless Crimp Connectors  •  Adhesive and Sealant-Lined Tubing

Choose Clear Tubing

Clear heat shrink tubing and metal crimp connectors

See Your Connection

Transparent tubing allows easy visual inspection.

Waterproof Seal

Adhesive lined for a secure, watertight bond.

Reliable Performance

Built for marine, UV, chemical, and extreme-temperature exposure.

Choose Black Tubing

Black heat shrink tubing and metal crimp connectors

Maximum Protection

Black tubing provides excellent UV resistance and durability.

Waterproof Seal

Adhesive + sealant lined for a secure, watertight bond.

Heavy Duty

Thick-wall construction provides added strength and abrasion resistance.

Shop Splice Kits | Merrill Manufacturing
3 Steps to a Perfect Seal | Merrill Manufacturing

3 Steps to a Perfect Seal

1

Slide sleeve on wire before crimping.

Heat shrink sleeve positioned over the wire before crimping
2

Crimp the wire connection securely.

Metal connector securely crimped onto the wire
3

Apply controlled heat from the middle outward until fully sealed.

Heat shrink tubing sealed over the crimped wire connection

Tight. Sealed. Moisture Protected.

Heat shrink tubes and metal crimp connectors
Trusted Splice Kit Reviews | Merrill Manufacturing
Customer Reviews

Trusted Splice Kit Reviews

See what customers are saying about Merrill waterproof wire-splice kits.

DesertDweller

Amazon Review
★★★★★

Quality Well Pump Wiring Kit

With the right crimping tool and a heat gun or torch, this kit is what you need to make waterproof wire connections.

The butt connectors are sized for well-pump wiring and create a lasting waterproof connection with #8, #10, #12 and #14 AWG wire.

The pre-cut shrink tubes provide plenty of coverage, and the adhesive can be seen sealing each end as they shrink.

Customer highlight
Waterproof connection for multiple wire sizes

Engineer, Deep Thinker

Amazon Review
★★★★★

Heavy-Duty Shrink Tube and Robust Crimp Connectors

This is definitely the most heavy-duty shrink tube I have used. It is very thick, and the crimp connectors are very robust.

I can definitely see why it is rated for underground and marine applications. Very nice kit.

Customer highlight
Heavy-duty construction for demanding applications

Sotto Voce

Amazon Review
★★★★★

Handy Package

Turnkey parts in a box. Quality components.

As advertised and pictured.

Customer highlight
Convenient kit with quality components

DesertDweller

Amazon Review
★★★★★

Good Kit for Well Pump Wiring

With the right crimping tool and heat gun or torch, this kit has everything needed to make waterproof wire connections.

The connectors and heat-shrink tubing are ideal for well-pump wiring using #8, #10, #12 and #14 AWG wire.

The pre-cut tubes are long enough to provide lasting protection, potentially for the service life of the well pump.

Customer highlight
Complete kit for long-lasting well-pump connections
Splice Kit FAQs | Merrill Manufacturing
Common Questions

Common Questions

What type of splice kit do I need?

Choose a waterproof splice kit that matches your wire size and application. For underground repairs and direct-bury installations, Merrill offers heat-shrink splice kits in several common wire sizes.

Will this splice kit actually hold up?

A dependable splice kit should be watertight, easy to install, and built for long-term performance. Merrill’s adhesive-lined heat-shrink design helps create a durable, sealed connection.

Is this splice kit code compliant?

Code requirements depend on the wire type, application, and installation location. Always use a listed splice kit that matches your system and local electrical requirements. Merrill offers splice kits for submersible-pump and pump-motor applications in multiple wire sizes.

What is the best splice kit for underground wire?

Look for an underground splice kit designed for direct-bury use and protection against moisture. Merrill’s black and clear heat-shrink splice kits are built for underground and submersible applications.

How do I make an electrical splice watertight?

Use a waterproof splice kit with adhesive-lined heat-shrink tubing and correctly sized crimp connectors. Merrill’s inner adhesive and sealant help create a secure, long-lasting watertight seal.

How do I know which splice kit to buy?

Match the splice kit to your wire size, installation location, and application. Determine whether the connection will be underground, submerged, direct buried, or exposed to moisture before selecting your kit.

Waterproof Splice Kits

Why Your Electrical Wire Splice Actually Matters

Shop Merrill Splice Kits →

That small connection can determine whether the entire system works or fails. When properly installed and sealed, it can be buried once and trusted for years—without callbacks, downtime, or unnecessary safety concerns.