Maintaining headlight plastic

This topic comes up from time to time, and since it was coming up on 7 years since our 2007's headlights were fully redone, I thought I would take some pictures.

Supplies:

Nu Finish
Turtle Wax Polishing Compound (or equivalent)
Bucket of clean water
Small cup to ladle out water
Clean sponge
Dawn dishwashing liquid
Paper towels (Blue shop towels would be best, here just regular white kitchen ones. Microfiber towels would be good too.)
A clean piece of fabric (Here, an old cotton sock)
Nitrile gloves (suggested)

Method:
1. Wet sponge, pour a little Dawn on the headlight, scrub with sponge. Rinse thoroughly by ladling clean water onto headlight, work top to bottom. (Image 20260107_2.png is after this step)
2. Fold a paper towel, pour a little clean water onto it to make it damp, scoop up a volume of Turtle Wax polish a little bigger than a U.S. Nickel. Rub it all over the headlight.
3. Take a clean paper towel and polish the headlight until the white polish is gone, or at least reduced to a thin haze. The towel will pick up an orange/brown color from previously applied Nu Finish. Possibly some pigment from the plastic if that is in bad shape.
4. Take a second clean paper towel and polish the headlight more, until it feels very smooth. It may pick up a little more pigment. (Image 20260107_3.png is after this step).
5. Repeat steps 2,3,4 using 1/3 as much polish. (Image 20270107_4.png is after this step.)
6. Fold a paper towel, pour a little clean water onto it to make it damp, pour about a U.S. Nickel sized amount of Nu Finish (thoroughly shaken first) onto the towel. Use a circular motion to spread it all over the headlight. Let it dry completely.
7. Take a clean paper towel and polish off the Nu Finish haze.
8. Repeat step 7. (Image 20270107_5.png is after this step.)
9. Repeat steps 6,7,8. (Image 20270107_6.png is after this step.)

Images 20270107_1.png and 20270107_8.png are the driver's side headlight after all work was completed, from different angles.

Image 20270107_7.png shows the two products used and the orange/brown pigment picked up at the polishing stage.

The headlight was in pretty good shape but the surface damage in front of the main bulb had accumulated to the point where it looked fuzzy when viewed from directly in front and in line with the bulb. When viewed from other angles, off axis, the bulb was still quite sharp. I have no pictures to prove it, but the "fuzzy bulb from the front" issue must have been scattering light to the sides which should have gone straight forward. After this work the bulb was sharp when viewed from directly in front.

Total time to do both headlights, including taking the pictures was 45 minutes. It could be done in 20 if the headlights were processed in parallel, whereas here the driver's side was done, then the passenger's side.
It really shouldn't be done in direct sunlight, which part of this was, but it was not very hot today, and the plastic was cool to the touch, and it turned out OK.

Rationale for this method. The polish removes surface dirt and probably a tiny amount of plastic, but it is far gentler than any sandpaper method. To protect the surface I have had the best luck with Nu Finish. It isn't permanent and it must be washed off and reapplied occasionally. (Like once a year or every six months.) The polish step is only when needed when after the Nu Finish is removed and reapplied the bulb is not sharp when viewed from the front. I have tried wax and a silicone treatment, and they both had the problem that they either attracted dirt or it got stuck in them easily. The Nu Finish stays clean longer.

It is hard to tell from these pictures, but there is still damage to the headlight surface, comprised of tiny pits and scratches. But the polish reduces those slightly, while cleaning the dirt out of them, and the Nu Finish fills them in with a substance with a similar refractive index. So the headlight is still serviceable, despite that damage.

 

As far as I know. The CarFax when we bought it in 2019 didn't list headlight replacement. Also no collisions, which is a common reason for replacing headlights. Of course a CarFax not listing a collision does not mean one never happened, just that nobody reported it. There isn't a hint of a collision on this car though, straight panels, no odd paint or welds, and so forth.