Work · lenses
Polishing a headlight clear is the easy half.
A headlight lens is polycarbonate with a thin factory UV hard coat sprayed over it. Sunlight breaks that coat down from the outside in. Once it has failed, the plastic underneath oxidizes and the lens goes yellow and cloudy — and polishing removes the failed coating along with the yellowing.
Polishing is the easy half
It removes the failed factory UV coat along with the yellowing. Replacing that coat is the step that decides whether this lasts years or months.
Why the cheap version fails
Sand and polish a lens and it comes up genuinely clear in twenty minutes. It looks like a transformation and it photographs beautifully. But the factory UV coating is now entirely gone, and bare polycarbonate has no UV resistance at all. In Florida sun a bare lens can start hazing again within months, and the second time it usually comes back worse and faster than the first.
That is the whole reason headlight restoration has a bad reputation. The work is not wrong; it is unfinished.
How it is done properly
- Mask the paint. Tape around every edge. Abrasive dragged from a lens onto adjacent paint is a genuine repair job, and it is the most common way this work goes wrong.
- Wet sand through the grades. Starting only as coarse as the damage requires, then stepping up through progressively finer grades and rinsing between each, until the scratch pattern from the previous grade is completely gone. Skip a grade and the deeper marks show through the finish as a permanent haze under the final polish.
- Machine polish to clarity. A cutting compound then a refining pass, checked with the lens dry, because a wet lens looks clear even when it is not.
- Clean and re-seal. A dedicated UV-resistant clear applied to the bare polycarbonate, which is the step that decides whether this lasts years or months. It has to go on a properly prepared, solvent-wiped surface and it has to cure.
What restoration cannot fix
- Internal condensation and clouding. If moisture is getting inside the housing, the haze is on the inside of the lens and no amount of external work touches it. That is a seal failure or a blocked breather, and it is a repair.
- Crazing. A fine crack network deep in the plastic rather than a surface film. It can sometimes be reduced but it goes deeper than anyone should sand.
- A damaged reflector. If the silvered surface inside has burned or peeled, the lens can be made perfectly clear and the light output will still be poor. Only a new unit fixes that.
All three get identified before any work starts, because the honest answer in those cases is that you need a headlight, not a detailer.
Lens gallery · no images on this site
Empty on purpose. A yellowed lens beside a clear one is the most reproduced before-and-after in detailing, and a generated pair here would be a fabricated result rather than an illustration.
On a live site this frame would hold the studio’s own photographs, shot dry, in the same light, with the car identified.