In case they don't issue a recallfiestafrank wrote:As a former senior headlamp engineer and head of R&D with 15+ years in the industry, I want to warn you about what is happening here. Headlamps lenses have been made from PC (polycarbonate) for the last many years after previously being made from glass. PC can be formed into more complex shapes than glass and is less prone to shattering when hit with road debris plus is less expensive to boot. The problem is that it yellows when exposed to UV light (i.e. sunlight). So headlamp manufacturers "hard coat" the exterior with various products available from companies like DOW, GE and Red Spot to protect against the yellowing. A yellow headlamp lens is a catastrophic failure caused by the breakdown of this hardcoat. If you sand your lens to remove the upper layer of the lens then yes you can remove the yellowing. But, since you have also removed the remaining hard coat it will just yellow the next time much faster. Also, any sanding on the lens is likely to distrot the photometric beam pattern of the headlamps. Although I would be surprised if it made much of a difference after doing it once, repeated or heavy sanding can result in an unsafe condition. I would report any yellow headlamp lenses to NHTSA on their web site and if enought people complain Mazda will be directed to issue a recall and replace the lamps, they are a major safety device you know.
- is there anything you can recommend to us that we could spray on the headlamps again like a clearcoat to protect from further yellowing??
