Automotive Plastics: plastic headlight lense, head ligth restoration, headlamp


Question
Why do the lenses get milky/cloudy? Can it be cleaned?  Seems to be common in late 90's to early 2000's GM models.  Is it the coating or type of plastic use for these headlights?  What manufacturer made these headlights?  I have the 2001 Olds Silhouette and I've replaced the bulbs, but in the past year, the plastic lenses have gotten milky/cloudy.  Make visability POOR!

Answer
Hi Ann,lenses get dull for various reasons including: photodecomposition, micro-chipping because of gravel, sand , asphalt and other common solids hitting the outer lens surface. These, in addition to ultraviolet radiation and normal scratching from normal washing and rubbing with harsh rags or towels. On the other hand, there is also a chance for a missing  dust rubber seal around the bulbs or, the bulbs themselves being loose allowing all kind of substances  entering the lamp interior.


                                                                                                 If your problem is a combination of the two cases, proceed like this. for the outside, watch some videos in youtube under "headligth restoring". Try to understand the procedure but never buy any of the offered stuff. Some sand  grit papers,rubbing compound and soft rags will do a nice job. For the inside just wash with clean water and soap, making sure you get rid of all traces of soap. use a hair dryer and reasemble everything in a proper way. IT MAY BE POSSIBLE TO HAVE SOME WATER CONDENSATION BUT DO NOT WORRY, THIS WILL DISSAPEAR WITH USE. Plastic lenses are made of Polycarbonate a polymer manufactured by GENERAL ELECTRIC, RHOM AND HAAS, BAYER AND OTHERS. The very units made by BOSCH,VALEO,MAGNETTI MARELLY,AL,JHONSON and others. when you are done, please share  the results with us.