Polishing Plastic Headlight Lenses

One of the casualties of the 1970's safety blitzkrieg forced upon American-sold cars was glass headlamp covers. Used to be that durable, sleek glass could mirror the hood profile and streamline the front end (think early Jaguar XK-E). Seems that the glass was a bit of a hazard to pedestrians and in frontal collisions. Apparently one or two Nader ideas made sense, even if the Corvair never recovered. That aside, though, we're now stuck with durable, cheap and relatively easily scratched and faded plastic in front of our headlights.


Besides the potential for reduced luminosity when those plastic lenses becomes fogged and pitted, there's the fact that they plain look bad when they've aged poorly. Those headlight lenses have to shine with the same gleam of the windshield or the plastic will draw eyes right to their shabby, second-rate impression of "clear" and degrade the forward presentation your auto-ego depends on. Fortunately, there are a few methods to bring the clarity back to all but the most toasted clear plastic lenses and, combined with choice regenerative chemicals, you might just be back to shiny and like-new.

Buff With Your Elbow
Our first approach was a combination of old-fashioned elbow grease and a mild plastic polish designed particularly for clear plastics like the lenses we're working on now. After some enthusiastic rubbing (more strokes, not more pressure), the bulk of the minor pocks and ticks in the plastic had decreased, if not disappeared, and the haze had gone. This initial approach was essentially three separate efforts, going over each lens three times. We used a non-abrasive microfiber towel, though 100-percent cotton also works nicely, making sure to avoid getting this polish on already waxed painted surfaces or rubber parts.

Theory Here?Please Absorb
Arguments persist as to the best motion to employ when hand-buffing paint or plastic, with two camps essentially divided between the rotary "wax on, wax off" method, and the straight-line method with limited rotation. While you've all seen the typical "I just learned to do this" swirly marks on the sides of some unfortunate car (result of the wax-on method), it's likely due to misuse of the process. Poorly selected towels (woven with abrasive materials), too much rubbing pressure, not enough wax or polish on the applicator (which must be lightly dampened), improper polish selection, or working on a dirty car are all good examples resulting in bad work.


The lateral stroke pattern is supposed to alleviate the pitfalls of rotary waxing, but can cause straight scratches instead due to the same reasons that will flaw the rotary process. Also, straight-line rubbing might fail to improve linear scratches if you're not rubbing against their grain. Personal experience lends credibility to the need to select the best towels and applicators, use plenty of medium (whatever chemical you're working with) and employ both straight-line rubbing (when approaching scratches from an oblique angle) in combination with delicate wax-on action.