If you offer headlight restoration services to your customers, you’ve undoubtedly noticed that not all headlights are the same. Some, such as the Nissan Quest van, have a very hard factory UV barrier coating that makes them difficult to sand and finish while others, such as the Dodge Caravan, are more straight forward and easier to complete. A variation in the headlight manufacturing process is likely the cause of this noticeable difference.
Made of polycarbonate plastic, which will yellow and cloud after exposure to ultraviolet radiation and other environmental conditions, headlights must be coated to maintain their clarity for any significant amount of time.
According to a major vehicle manufacturer, there are multiple processes and technologies for coating headlights that produce a variety of results. In fact, the hardness can vary among different vehicle model lines and years for the same car company. Unfortunately, these processes cannot be duplicated in the field. What this means to you is that the relative difficulty of stripping a headlight can be different for each vehicle you work on.
At times this difference can be very significant. In fact, one technician commented that he used “ten 320 and 600 grit discs on one light” while working on a Lamborghini Gallardo. The Chevy Malibu is also becoming notorious for having an extremely hard-to-strip coating.
To help deal with coatings that are difficult to remove,
technicians have started a topic on the Headlight Restoration Forum, called the “Harder than Normal List“. The ever growing list now includes the make and model of various vehicles that require extra attention during the refinishing process.
The good news is that the remedy for this dilemma is very straight forward. If you notice that, while sanding with the 320-grit discs, you are spending an excessive amount of time without seeing the expected results, simply switch to a 180-grit sanding disc.
This coarser grit will allow you to more easily strip the headlight. Spray the lens with water, wipe clean, and inspect it carefully to make sure you’ve removed all of original coating before moving back to the 320-grit. From this point, proceed as you normally would to finish the job.
Don’t forget to tell other technicians about your experience on the Headlight Restoration Forum!