There are many ways to install heat shrink tubing, but the most common way is to use a hot air gun. The instructions below will explain how to do this. Before installation, it is extremely important to ensure that you have chosen the correct size of the product. When selecting the correct size tubing, you must consider the 80/20 rule – the chosen size should allow a minimum shrinkage of 20% and a maximum of 80%.
Apply the heat shrink over the substrate and heat evenly around the tube, working either from the middle out or from one end to the other. Gradually heat the product ensuring that no air is trapped under the tubing until full recovery is achieved.
Heat shrink tubing will also shrink in length (longitudinally) so as the tubing shrinks in diameter it is likely it will also shrink in length.
Typically the longitudinal shrinkage is no more than 10%, although different products will have different tolerances. You must always take longitudinal shrinkage into consideration, especially when cutting the tube to length.
It is possible to minimise the longitudinal shrink by recovering the product at either end first and then working towards the centre. However, when doing this, care needs to be taken to avoid trapping air in the sleeve as this may restrict the product from recovering fully.
Alternately, if your application calls for the tubing to be more critically applied at a certain point (at one end for example), start the shrinking process in the critical area and work away, towards the other end.
If the substrate onto which you are applying the heat shrink tubing is made of metal or any other heat conductive material, take the time and care to ensure that that the object is pre-heated to avoid cold spots. These cold spots can counteract the heating process and cause the tubing to recover irregularly.
It may also be worth noting
When preparing the heat shrink tubing for installation, it is essential that care is taken to ensure that any ends are cut and trimmed smoothly. Jagged or poorly cut edges can cause the tubing to split during installation.
Each product has a recommended optimum shrink temperatures that should be considered when setting the temperature of the heat gun.
During the shrinking process, you should always ensure that the workplace is well ventilated.