1.Measure the diameter of the wire, and then choose a piece of heat shrink that will be large enough to slide onto the wire before heating but will still provide a snug fit once heated. The shrunken diameter should be slightly smaller than the wire's diameter to ensure a tight fit.Heat shrink tubing has a shrink ratio that dictates how much the tubing will shrink once heated, so it's important to choose the right ratio for the job. For example, a length of 2:1 ratio tubing with a diameter of 2 mm will shrink to a diameter of 1 mm.
2. Measure a length of heat shrink tubing that is slightly longer than the damaged section of wire.Most heat shrink tubing will also shrink longitudinally (around 5-15%), so be sure to give yourself enough tubing to cover the exposed area after heating.
3. Use a pair of scissors to cut the tubing to the appropriate length.
4. Slide the tubing onto the wire so that it covers the damaged/exposed section.
5.Use a heat gun to shrink the tubing.Keep the heat gun moving back and forth along the length of tubing, as staying in one place can damage the wire even further.Continue heating the tubing until it is tightly secured to the wire.