It is an extremely difficult job to use the headlamp "eliminate dimming" DIY to do! Professionals scraped off a car that was more than 10 years old!

Why are the headlights depressed? What's the reason?

　The car that rides all the year round is aging, especially the dimness, yellowing and cracks of the headlights (cover). [picture] how does it work? Professionals scrape off the aging headlights (13). No matter how neat the body is, it will always make people feel like the season when the headlights are dim. Why are the headlights dimmed or yellowed?

The yellow headlights that make the car look old

　The properties of the material "polycarbonate resin" have a great influence on this. Light weight, sturdy, easy to form, and not easy to fly away in case of collision, polycarbonate resin has been used in most automobile headlamp shades. However, although the ultraviolet rays contained in sunlight are very weak and absolutely strong, they also have the weakness of causing small scars. When the car is in contact with the external air, the headlights will also encounter sand, dust, flying stones and so on. Many people park in unroofed parking lots, making it almost impossible to be exposed to direct sunlight. In this way, due to ultraviolet light, the polycarbonate of the headlights will worsen, the flying debris in the road will add small scars, and dirt such as dust and dust will enter the scar and become dim. On the other hand, the thin thread is full of "cracks", that is, the so-called cracks. Having said that, it is not a crack that enters the polycarbonate body, but something that the hard coating on the surface is damaged and ruptured due to aging. Cracks can also occur in domestic cars, but imported cars, especially European ones, are also thought to be almost certain symptoms due to aging. In order to eliminate the dimming of headlights caused by aging, there are several ways to deal with it. To be sure, each headlight unit has been replaced with a new one, but recently, many cars cannot replace the headlight cover, and even if it can be replaced, it will cost tens of thousands of yen on one side. Therefore, the most popular countermeasure is to eliminate surface darkening, yellowing and cracks. Although it is said to remove, but until the scar is difficult to identify, it is to flatten the surface. And a variety of manufacturers are selling this "dull, yellowing" special detergent and coating agent. However, it is said that this removal work is actually very difficult. The author (Kim Tian Kai) has also tried several times, if it is a mild gloom, cracks and other detergents sold on the market to deal with is very difficult. Although it requires quite strong grinding, many people are not used to it and will fail if they work with DIY.