How to heat heat-shrink tubing
The heat-shrink tubing uses the principle of shrink wrapping. It is about marking or protecting a more or less large object. Once the shrink tubing is in place, it is heated with a heat gun that makes it wrap tightly and be set in place.
What are the uses of heat shrink tubing?
The heat-shrink tubing is a tube made of a flexible plastic with special properties: when heated, it shrinks, reducing the diameter of the sheath and tightening the contents of the tube.
Depending on how you use it, the shrinkage factor is between 2 and 6 times the original size. It is also necessary to take into account the reduction in the length of the tube after being heated; you can expect a 5-7% difference.
The heat-shrink tubing protects its contents from abrasion, water, chemicals, etc. It also allows you to mark objects or distinguish wires from each other, which is why it is very popular with electricians.
Here are some of the uses of heat-shrink tubing:
- assembly of two large ducts (cylindrical bars);
- sheaths for electrical wires;
- marking on a cylindrical object for easy identification (with a coloured tube) ;
- protective coating for a rod or other cylindrical object, etc.
How to heat and shape heat-shrink tubing
Choice of heat gun
The choice of your heat gun is crucial to the success of your operation. You don’t need the same heat for a tube that protects wires in an electrical circuit and a large tube that encloses cables, for example for shrink wrapping a construction site.
Check the heat you need according to your sheathing. The maximum temperature they can withstand is indicated on their instructions. Choose a heat gun that has an adjustment, with a wide temperature range, if you have different kinds of sheaths to handle.
If you don’t heat the heat-sleeve sufficiently, it won’t shrink as much as it should. If you heat it at too high a temperature, you will weaken it. It can burn and get holes in it. You will not achieve the desired insulation, and you risk damaging its contents.
Start from one side or from the middle
You must choose a starting point to heat your sheath and then follow the tube, but always towards one end, in order to provide an outlet for the air. If your sheath is short, you can start at one end and then work your way to the other end. If it is long, you can start in the middle, or at some other point that is not an end.
However, you must never close the sheath before it is retracted. For example, if you started at one end, you have no choice but to continue to the other end. If you started in the middle, you should not stop and start again from one end.
This is because if you create a closed portion, air can no longer escape as you progress. You risk ending up with air bubbles or the sheath will compensate by twisting and/or creating beads.
Then let it cool down
You must heat your tube evenly and only move forward when it is retracted, always taking care not to create air bubbles. Let everything cool down and you’re done.