Headlight grunge

There some products on the market that claim to be able to remove the yellowing from headlight lenses. You apply them and lightly buff the plastic to remove it. I'm more reserved to the fact, upon noticing many vehicles from the past 15 years with this problem, that replacement may be a better viable option. You can usually get replacements for most vehicles fairly inexpensively on eBay. The sun's UV rays deteriorate the plastic and will continue to do so until better UV protection can be designed into the plastic. Probably, in the future, plastic headlight lenses may be considered "normal wear items" that may need replacement sometime in their lifespan due to UV damage, similar to the way we replace tires and spark plug.

You can certainly clean the crud that's developed in there over the years; it's similar to a bottle washing operation, so you have to remove the headlight assembly from the car to do it. As far as exterior yellowing goes, waxing the headlight lenses at least once a year along with the rest of the car will prevent most of it from ever happening.

"Rod" a écrit dans le message de news: faampi$55p$ snipped-for-privacy@registered.motzarella.org...

As for the outside at least uyou can use number 1200 black sandpaper wet. That does the trick. The headlites comes back cristal clear like new. But go slow as not to burn the plastic. Good luck. L.G.R.

Hi...

Respectfully suggest that you'll do much better finishing up with

2000 grip paper - and even then they'll be very hazy until you wax them or even better give them a coat of clear coat.

Take care.

Ken

Something we had in the past with those very functional glass sealed beam head lamps.

Not only are there plastic polishes out there that go from fine to extremely fine, there are even kits sold (usually by restoration supply places) for doing exactly what you want...

You will probably find the the grunge is actually a surface phenomenon on the *outside* of the headlight. People have a lot of success with using sandpaper of successively finer grits, starting with 800 or 1000, depending on how thick/coarse the grunge is, and working your way to

2000 or 2500, and engine with polish, like Meguiar's PlastX.

Be aware that you will be removing (sanding thru) a "protective, UV-resistant" layer of plastic on the surface, which ironically is the material that broke down under UV light and oxidation. You will need to periodically (every few weeks) polish the surface again to maintain the clarity of the renewed surface.

If you want to not have to periodically polish them, then, afer polishing, chemically remove the polish and spray with clear coat - that's essentially what they had on them from the factory.

There are some kits in WalMart - about $20 IIRC - for doing the sdame thing. They take more time and elbow grease than the package hype lead you to believe. They come with a wipe-on clear coat.

Here's a recent thread on the 300M Club forums to show you that cleaning them up is very doable using either the kits or purchasing the sandpaper and polish separately, and the results are pretty impressive:

Scroll down to look at the photos of the results obtained by several people.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Right on, Ken!

Take a look at the results some people got in this thread on the 300M Club forums (scroll down to see 'before' and 'after' photos):

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Glas can be moulded into the same shape as the plastic headlight lenses. This nonsense with the plastic lenses is a cost-saving thing.

Ted

This thing with the plastic (Lexan) headlight lenses is something Ford cooked up (1st car was an '84 Lincoln Mark VII) to enhance safety (shatterproof), reduce weight (not much), improve fuel mileage (hardly measurable) due to ?Aero? design, and allow headlight changing with zero tools. Ford lied to DOT/NHTSA about the need for maintenance to get approval for these lights, saying that fighter plane canopies were made of the same stuff, and while true, they DIDN'T tell the feds that the military changed out those canopies for new on a 12~18 month maintenance basis. The replaceable 9004 bulb that went into the headlight fixture was also the most terribly (non) designed bulb ever made, leaving the driver with a choice of a big black hole in front of the car to be able to see down the road, or lots of foreground light but very little distance lighting, depending on aim. big business for "foglight" makers. :)

Chrysler also used some plastic sealed beam headlights as OEM in the

1990s. They got cloudy too, but you just replaced them with glass units. I think Sylvania build them?

Beam pattern is not specifically related to the 9004 bulb itself but the REFLECTOR the bulb works with. It doesn't matter if the headlight is a sealed beam, composite unit, projector beam, or HID, if the beam pattern is not good (or as good as the Euro-spec lights with normal bulbs, even semi-sealed beams!), then you can't see at night . . . even with 100 watt bulbs (which have been known to melt the plastic housings they fit into).

If you look at the "crystal lens" headlights on the new GM full size pickups, the lens is "invisible" and will probably stay that way for a long time.

Personally, I'm not in favor of using sandpaper on plastic to get it cleaned up. You might use it for the first "attacks", but using a compound/foam buffer item would probably be a better deal. In the Reatta forum, somebody mentioned using a Shell AeroShield polish to remove the haze from the Reatta tail light panel. Seems several posters had used that product with good results.

I do concur that any work needs to be done on the outside of the composite housing. There might be some accumulation on the inside of the lens, but most of the issues will be on the outside where "the elements" (and bugs) have deteriorated the finish on the lens.

Just some thoughts,

C-BODY

Indeed, I have only seen it suggested for the initial cleaning up, followed by polish (to fill in the flat-looking microscopic surface finish) *or*, for maintenance free surface at least for a few years, clear coating the surface after the sanding, polishing, and chemical removal of the polish residue.

When that factory clear coat layer deteriorates like it often does, only the aggressive behavior of relatively coarse grit sandpaper (followed by successively finer grades) is going to get down to plastic that is free of crazing and haze.

For your consideration - and *your* enjoyment:

(lots of photos, so give the thread time to download) Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')