Black Dual Wall Heat Shrink Tubing with Adhesive Glue Lined — 0.8mm to 30mm

Measure the outer diameter of the wire or connector you need to cover, then select a size that is typically 1.2–1.5× that measurement before shrinking. For example, a 4mm wire bundle generally works well with the 6mm or 7mm tube. The 3:1 shrink ratio means the tubing will shrink down to roughly one-third of its expanded diameter, so there is more flexibility in sizing compared to standard 2:1 tubing.

This dual wall tubing has a 3:1 shrink ratio, meaning it shrinks to approximately one-third of its original expanded diameter when heat is applied. This is more aggressive than standard 2:1 heat shrink, making it suitable for covering connectors, terminals, and irregular shapes that a tighter-starting tube could not slide over.

Yes. The inner adhesive layer melts and flows during shrinking to create a moisture-resistant seal around the wire or connector. It is generally suitable for outdoor, marine, and automotive environments where protection against moisture, humidity, and mild chemical exposure is needed. For fully submerged or high-pressure water exposure, contact us to confirm suitability for your specific application.

Typically, a heat gun set to around 120–150°C (248–302°F) is sufficient to activate the shrink and melt the inner adhesive. Move the heat gun slowly and evenly along the tube to avoid hot spots. Avoid open flames, which can cause uneven shrinking, charring, or damage to the adhesive layer.

This tubing is not thread-specific — it is designed to fit over wires, cables, connectors, and terminals of the corresponding outer diameter. It is compatible with standard automotive (SAE), marine (ABYC), and general electrical wiring harnesses across a wide range of connector types, including butt connectors, ring terminals, and solder sleeves.

Yes. The adhesive-lined construction makes it a popular choice for automotive wiring harness repairs, marine cable protection against saltwater, and trailer wiring — anywhere a durable, waterproof seal is needed over a splice or connector. The flexible polyolefin outer wall also resists cracking in cold temperatures, which is important for engine bay and outdoor wiring applications.

For small repairs or prototyping, 1m (≈3.3 ft) or 3m (≈9.8 ft) rolls are typically sufficient. For wiring harness builds, automotive projects, or bulk electrical work, 10m (≈32.8 ft), 20m (≈65.6 ft), or 30m (≈98.4 ft) rolls offer better value per meter. Consider buying one size up in length if you anticipate multiple cuts or want a backup supply on hand.

Single wall heat shrink provides insulation and basic mechanical protection but does not seal against moisture. Dual wall tubing adds an inner adhesive layer that bonds to the wire or connector surface during shrinking, creating a waterproof, strain-relieved joint. This makes dual wall tubing the preferred choice for outdoor, marine, and automotive applications where moisture ingress is a concern.