Dual Wall Heat Shrink Tubing is widely used for insulating, sealing, and protecting wires, cables, and connectors in automotive, electrical, telecom, and industrial applications. It features an outer polyolefin layer and an inner adhesive lining that melts during the shrinking process to create a strong, moisture-resistant seal. However, many users notice adhesive flowing or "leaking" from the ends of the tubing after installation. In most cases, this is completely normal.

When heat is applied, the inner adhesive softens and flows to fill gaps between the tubing and the cable or connector. This ensures a tight seal against moisture, dust, and contaminants. A small amount of adhesive squeezing out from the ends indicates that the tubing has properly sealed the joint.

However, excessive adhesive leakage may occur due to incorrect installation. Applying too much heat, using the wrong heat source, or heating the tubing for an extended period can cause the adhesive to become overly fluid and escape in larger quantities. Similarly, selecting an oversized tubing size may require more shrinking, resulting in additional adhesive flow.

To achieve the best results, always choose the correct tubing size, use a controlled heat gun instead of an open flame whenever possible, and apply heat evenly from the centre towards both ends. This allows the tubing to shrink uniformly while distributing the adhesive effectively.

It is important to understand that slight adhesive extrusion is not a product defect—it is often a sign that the adhesive has successfully filled the voids and created a reliable environmental seal. Proper installation ensures excellent insulation, strain relief, corrosion protection, and long-term durability.

By following the recommended application process and selecting the correct heat shrink tubing, users can achieve consistent, professional-quality cable protection with dependable sealing performance.