Weathered headlights? How to make them look new again

Make the plastic headlight lens look new again. If you run xenon, it matters that your headlights look spotless. Weathered headlights are not just ugly, they also cause stray light, which dazzles other road users. That can have nasty consequences, and we would rather you avoided them.

In the videos below we show how to make your headlights look new again in a fairly simple way, without having to invest in expensive new headlights.

Polishing weathered headlights with toothpaste

This video shows how to polish the headlight easily with toothpaste: watch the video on YouTube.

Restoring headlights the professional way

You can also do it the professional way, as in this video: watch the video on YouTube.

Why headlights weather

Most modern cars no longer have glass headlights, but plastic ones, usually polycarbonate. It is lighter and less likely to break than glass. To protect the plastic, it leaves the factory with a thin, hard coating. Over time that coating wears away because of:

• UV radiation from the sun
• stone chips and sand
• road salt and grime in winter
• hard brushes in the car wash and aggressive cleaning products

Once the coating is gone, the plastic itself starts to suffer. The lens turns dull, yellow or gets a kind of matte haze. Your bulb's light then gets scattered: less light reaches the road and more ends up in the eyes of oncoming drivers. The brighter your bulbs, such as xenon or LED, the bigger that effect.

Step by step: sanding and polishing headlights

If the weathering is more than a light haze, polishing alone often will not get you far enough. In that case, tackle it in steps:

1. Clean the headlight with water and a mild cleaning product and let it dry.
2. Tape off the surroundings with masking tape, so you do not damage the paint around the headlight.
3. Wet sand with waterproof sandpaper. Start coarse enough to remove the weathered layer, then work through ever finer grits. Keep the surface wet the whole time.
4. Polish the sanded surface with a plastic polish, by hand or with a polishing machine on low speed, until it is clear again.
5. Clean and degrease the headlight.
6. Protect the plastic with a UV-resistant headlight coating or sealant. Skip this step and the plastic is left unprotected and will usually turn dull again fast.

Take your time and work evenly. Sanding or polishing one spot for too long or too hard can make the plastic hot or warp it.

Toothpaste or professional: which should you pick?

Toothpaste contains fine abrasive particles, so it works as a mild polish. For a light haze that can already make a visible difference, and you usually have it in the bathroom cabinet. For heavily yellowed or rough headlights, toothpaste is too gentle: then you need sandpaper, polish and a protective coating.

A few rules of thumb:

• Light haze: try polishing with toothpaste or a polish first.
• Clearly yellow or rough: sand, polish and protect.
• Moisture, yellowing or damage on the inside: polishing from the outside will not help. Think about replacing the headlight.

After polishing: check the bulbs and the beam

Clear headlights are the foundation, but the light still comes from the bulb. So after the restoration, also check:

• whether both bulbs burn equally bright and in the same colour;
• whether the beam is aimed correctly: the cut-off line of the low beam should sit at the same height on the left and the right;
• whether the dust covers on the back are closed properly, so no moisture gets into the headlight.

If a bulb needs replacing, have a look at the xenon bulbs or the LED low beam and high beam. Also read how to recognise a good xenon bulb. After fitting new bulbs, have the beam aimed and check that your car still meets the APK requirements (the Dutch roadworthiness inspection); if in doubt, ask the RDW or your inspector.

How to keep your headlights clear for longer

Once you have restored your headlights, you want that result to last as long as possible. A few habits help:

• Wash the headlights with a soft sponge or microfibre cloth and plenty of water, so sand and grime do not scrape across the plastic.
• Avoid aggressive cleaning products and solvents on the headlights.
• Park in the shade or in a garage when you can, so the headlights catch less UV radiation.
• Check the protective coating now and then and reapply it as soon as water no longer beads nicely off the headlight.