Why are the lenses on my headlamp cracking?
Most late model vehicles have these types of headlamp lenses. This material is used because of its temperature and high impact resistance. A variety of chemicals can cause crazing or cracking of the headlamp lens. Headlamp lenses are very sensitive.
What to do if your lens is cracking?
If you polish it, you are going to rub off the UV protective coating on the lens as well as those cracks (which might actually be the UV protective coating that is cracking). So, you will need to re-apply the UV protective coating or polish the lenses regularly to remove the UV damage.
Why are headlamp lenses made out of polycarbonate?
The bulletin is being issued to make dealers and customers aware of chemical damage that may be caused to exterior polycarbonate headlamp lenses. Most late model vehicles have these types of headlamp lenses. This material is used because of its temperature and high impact resistance.
Why are there cracks in my headlight lens?
My headlight lens don’t yellow up, and it’s a really odd scenario. The cracks aren’t small spider cracks / crazing, but are deep vertical cracks /lines that originate exactly where my HID beam goes through.
Where are the stress cracks on the lens?
The stress cracks on the lens now can almost be felt with your finger nail on the outside of the lens (it doesn’t catch, but you can feel them), but they all originate from inside of the lens.
How big is a crack in a lens?
Examination of the cross section indicated that the cracking was limited to the exterior portion of the lens. The crack network was primarily present within the hard surface coating, but also penetrated into the lens base material. The cracking ranged from 0.35 to 0.50 mm in depth. A SEM examination was performed on a typical crack surface.
If you polish it, you are going to rub off the UV protective coating on the lens as well as those cracks (which might actually be the UV protective coating that is cracking). So, you will need to re-apply the UV protective coating or polish the lenses regularly to remove the UV damage.