Electrical tape unravels and gets sticky over time under the hood. Heat shrink tubing provides a permanent, clean seal. You slide the tube over the wire splice before connecting them, then heat it with a heat gun. The tubing shrinks up to 50 percent to grip the wire tightly. Marine-grade tubing includes a heat-activated glue inside that melts and seals out water, dirt, and salt. Use it on all exterior or engine bay wiring to prevent corrosion.
Mechanic Glossary
Heat Shrink Tubing
A flexible plastic tube that shrinks in diameter when heated, used to insulate, seal, and protect electrical wire connections.
Frequently Asked Questions
A dedicated heat gun is best because it heats evenly. Lighters can work in a pinch, but the open flame can easily char or melt the plastic.
Choose a tube with an inside diameter that is slightly larger than the wire joint, but shrinks small enough to grip the thinnest wire in the splice.
A 2:1 ratio means the tube shrinks to half its original size. A 3:1 ratio shrinks to one-third, which is better for wrapping over bulky solder joints.