Thursday, September 3, 2009

Headlight Polishing

Back in the day, the headlight of your car was a sealed unit. A glass enclosure the size of a box of tissue, which contained the reflector, and the bulb, made up your headlight unit. Often times this sealed unit contained two bulbs, one for the low and one for the high beam. My 1996 Nissan Pickup truck still had sealed units. When your headlights burned out, you needed to replace the entire unit. However most modern cars stopped using this type of headlight set up. Instead most auto manufactures opt for a replacement bulb type of set up. My 1990 300zx was this type, so it is not just based on year. Why did this switch occur? Let's list the pros and con's of both type of headlights.

Sealed Beam Pro: Robust pre manufactured unit. Damaged headlight easily replaced.

Sealed Beam Con: Wasteful, perfectly good lenses, and reflector replaced when only the bulb is burnt out. Sometime lamp replacement requires the re aiming of the head light.

Bulb type Pro: Easier to replace burnt headlight. Though the bulb is not always cheaper than the a sealed headlight unit. More integrated headlight design. Auto designers have more freedom to design a headlight that fits the car. This has almost completely eliminated the pop up head light. Ability to use different types of bulbs.

Bulb type Con: Damaged headlight cost alot to fix. Headlight lenses often discolors with age.

This last issue is the topic of our post. When replaceable bulb type headlights first came out the lenses were made of glass. However that trend was short lived and almost all cars use plastic these days. Over the years (sometimes not even many years) the headlights become hazy or begin to turn yellow. This really effects the amount of light thrown out onto the road by your head lights.
(This is the headlight before polishing. It is not too bad however the difference was noticeable in light output.)

The solution: polish your headlight lenses. Almost all plastics can be polished. That includes eye glass lenses, and headlight lenses. Polishing is usually accomplished, by a buffer using a series of decreasing grit polishing agents. A fine wet sand followed by a fabric or foam polisher with a liquid polishing agent. The foam polisher to the right is what I used. However if you do a search on-line there are many different ways to accomplish this task.

I bought a prepackaged headlight polishing kit from HF tools.

1 comment:

  1. I was just looking at that in the flier. I actually alreard circuled it for pickup before we left for the valley. :-p