rayray086
19-02-2010, 03:02 AM
http://rayray086.blogspot.com/2008/01/diy-headlight-refurbish.html
Before
http://i25.photobucket.com/albums/c67/rayray086/Random/passatheadlightrefinish/CIMG8267.jpg
After sanding
http://i25.photobucket.com/albums/c67/rayray086/Random/passatheadlightrefinish/CIMG8269.jpg
After polishing
http://i25.photobucket.com/albums/c67/rayray086/Random/passatheadlightrefinish/CIMG8271.jpg
Often seen on Soarers and B5 Passats, and no doubt many other cars. Mainly caused by UV rays, which oxidises the polycarbonate compound to form that dreaded yellow cloudiness.
I know the above is not the best example and I haven't had the chance to try it again, but it's best to spend more time with the harsh sandpaper and sanding the lens down until all trace of yellow is gone, and all the sand strokes can be seen to go in one direction. Then, with the next grit up, sand in the perpendicular direction until all previous scratches are gone. Repeat with each gradual increase in grit until you reach 2000 grit. I've found this to be very very similar to metal polishing - the finer you sand it down, the clearer the result.
And remember, use a plastic polish and not a glass polish on the lens, as most headlight lenses are made from some polycarbonate compound. Also, after doing all that hardwork, use a protectant. Doing this sort of work basically breaks down the factory protective coating that attempts (badly I might add) to reduce oxidation of the lens, so doing this job will only temporarily erase the yellow-ing. I don't know what's best to use as a protectant, but I assume detailing sealants like Optiseal, and maybe clear LaminX could help prolong the life of the lens. Until at least you sell the car :p
Before
http://i25.photobucket.com/albums/c67/rayray086/Random/passatheadlightrefinish/CIMG8267.jpg
After sanding
http://i25.photobucket.com/albums/c67/rayray086/Random/passatheadlightrefinish/CIMG8269.jpg
After polishing
http://i25.photobucket.com/albums/c67/rayray086/Random/passatheadlightrefinish/CIMG8271.jpg
Often seen on Soarers and B5 Passats, and no doubt many other cars. Mainly caused by UV rays, which oxidises the polycarbonate compound to form that dreaded yellow cloudiness.
I know the above is not the best example and I haven't had the chance to try it again, but it's best to spend more time with the harsh sandpaper and sanding the lens down until all trace of yellow is gone, and all the sand strokes can be seen to go in one direction. Then, with the next grit up, sand in the perpendicular direction until all previous scratches are gone. Repeat with each gradual increase in grit until you reach 2000 grit. I've found this to be very very similar to metal polishing - the finer you sand it down, the clearer the result.
And remember, use a plastic polish and not a glass polish on the lens, as most headlight lenses are made from some polycarbonate compound. Also, after doing all that hardwork, use a protectant. Doing this sort of work basically breaks down the factory protective coating that attempts (badly I might add) to reduce oxidation of the lens, so doing this job will only temporarily erase the yellow-ing. I don't know what's best to use as a protectant, but I assume detailing sealants like Optiseal, and maybe clear LaminX could help prolong the life of the lens. Until at least you sell the car :p