Post-heating is not anything new on our blog. But still, it is a step where some installers would underestimate and even skip over. Today we will show you why it is crucial and what would happen if you did not post heat your film in a rather visualized way.
In general, there are some key points to achieve a successful finish: proper cleaning, the right material for the right vehicle, no overstretch and post heat. Post heat is something that would help your job to achieve long term durability. And it can be applied to any area of the film that is stretched over 10%.
Here we will take door handle as an example. This is quite a recess area. Even though we apply the material on this area, and we form it nicely as well as evenly with our finger, the material is tempted to go back flat because of its nature – the memory effect. But on the other hand, the adhesive is trying to hold it as we want. This creates tension on the surface right now.
Let’s take a second to do a demonstration and you will surely understand why post-heating is so important. We can pick the material back up and now hang it over the window. We can still see the shape of the door handle at this moment. But if we heat it with my heat gun and trigger the memory effect now, you will see the material go back flat completely because of its nature.
This is mostly because of chemical PVC. Most materials have this. Although some new films do not have PVC, they have the same effect in this case. Post-heating is the only way where you can get rid of this tension during wrapping.
Now let’s put the material back to the door handle area and do it again. We can give it a bit of heat as we form it, to soften the material. For films that have no air regress technology, remember to be sure all the air bubbles are popped. Because you are going to heat the material to a certain temperature when post heating, and if there is any air bubble there, it will possibly damage or even split the film as the air expands. So make sure there is no air in the area you are wrapping.
Once the application is done, we can post heat it. What we will need is a heat gun as well as an infrared thermometer. You can use an IR heater instead, but DO NOT use a propane torch. As for infrared thermometer, it is just as important as squeegee which you have to have it in this process. Never guess the temperature, because post-heating is an exact science and a chemical process.
The post-heating temperature for most films is around 180 degrees Fahrenheit or 90 degree Celsius. But different types of films might vary. TeckWrap films have 100-110 degree post-heating temperature. Once you reach that certain degree, the heat would change the structure of the PVC (or any chemical that is used to make the material). As soon as the structure is changed, the memory effect is killed.
We can now pick up this film and hang it over the window again. Just like before, we can see the shape of the door handle there. And if we heat it again, the shape remains there, because the memory is dead. There is no more tension in the film there. Thus, the nature of the film will not fight against the adhesive anymore.
And if we do not post heat, the material will often go back flat within short time. When you see wraps on bumper or mirror curling, it is mostly because they were not post heated. This is why post heat almost guarantees long term durability.
It is good to do it all over the vehicle that is wrapped, either on overlaps or recess area or any area where the film is stretched over 10%. And make sure you do it thoroughly enough. Just be patient and get to the right temperature. Although it can be a slow process, it is better to have it done rather than have your client come back with the vehicle within three weeks with the film lifting.