Ronman writes:
My issue is those front plastic headlight covers that go yellow. Is there an easy way DIY to polish them back to near-original state. I didn’t mention my car for the reason that I see them on a lot of different makes and models, and what annoys me even more than the inherent safety issue, is that how much would it cost manufacturers to use a good grade plastic that won’t go yellow after three years?
Shouldn’t there be a law enforcing lights that will stay clear, or are they going to start making earth saving bio-degradable seat belts that become outdated after about three years?
Sajeev replies:
Yellowing is a problem, but these designs are “light years” (sorry) ahead of glass assemblies from the 1990s or the Stone Age sealed beam units. They weigh less, project a better beam, are less likely to crack and allow designers to make some cool shapes. Or really generic, googly eyed shapes. Whatever: yellowing over time and usage is the only downside, but that’s a function of the plastic.
Regarding the law: everyone needs to understand that plastic headlights are like a painted surface, and must be maintained as such. And much like restoring a faded paint job, this is an easy fix. Parts stores sell polish that’s marketed for headlights or plastic windows on Jeeps: follow the instructions and use a spare cloth. The best way is to apply/buff with a power buffer, just remove the light or mask the body to ensure you don’t burn off your car’s paintwork.
If the polish doesn’t work, you have a thicker layer of bad plastic. That’s when sand paper and a little water is needed. Which sounds scarier than it is, especially if you have a hand held orbital power sander. Here’s a link to an amazing step-by-step article. If this sounds excessive, price a new set of lights from the dealer and you might change your tune.
When you’re done, enjoy the best of both worlds if you “clear bra” the lights or wax them regularly: that’s an easy way to make sure you’ll never have this problem again.
Bonus! A Piston Slap Nugget of Wisdom:
You’d be amazed at how quickly Halogen headlight bulbs need replacement. I’ve seen three year old cars with 40k miles need new bulbs, simply because the used filaments put out less than half their original output. And if you bought ricer-blue bulbs with a “hotter” Kelvin temperature rating (to offset the goofy blue glass), do yourself a favor and throw them in the trash: stick with clear bulbs and ratings close to OEM specifications. The blue bulbs usually take a dump much faster (sometimes less than a year) than clear ones, but you’ll never know until you switch them out.
[Send your technical queries to sajeev.mehta@thetruthaboutcars.com]
My old (1993) Legacy wagon has yellowing headlight covers. You get clear covers and a fresh, minty after-taste by polishing them, by hand, with toothpaste. The toothpaste should contain silica in order to work, so some niche brands won’t. After this, a coat of paste wax will do no harm and might keep the covers from yellowing or getting powdery-looking for a bit longer.
I disagree with you on the plastic being better than glass. The reason they use the plastic is because it is cheaper. I bought glass euro market lights for my Volkswagen because it didn’t seem like anything could help the plastic lights. I tried all the polishes and sand paper, but just couldn’t get the light output. The euro lights were way better.
With all that being said, the polishes can help if you catch it soon enough, and it is a more affordable solution.
My girlfriend’s Intrepid has one headlight that requires semi-regular polishing. The other one was replaced when the previous owner apparently had an accident (so I inferred form Carfax). I’d rather go outside with some rubbing compound and a rag now and then, than pay the ungodly price for a new assembly ($150 and up last I looked).
Beyond that, new bulbs for the lights, regardless of housing condition, make a world of difference. If your bulbs are a few years old, change them. The cheap ones are ok, believe it or not.
Euro lights are better because the law there defines a better beam and beam cut-off pattern… which, for some reason has never been adopted by DOT.
3M’s plastic cleaner #39017 = win
Yellowing is a problem that is hard to correct perfectly. However, there are some aftermarket replacements that are reasonably cheap. If the car is older, that may be a viable option to parts from the stealership.
Regarding lights that are too dim, sometimes that is because there is excessive voltage drop in the wiring harness and light switch. On some cars, there will be a 2 volt drop, which considering nominal system voltage is 12, it is significant enough to cause a decrease in light output. An easy way around this is a relay kit that wires into the headlight circuit. When you turn on the headlights, you actually close a relay which is wired directly to the battery. SUVLights.com makes these kits for many cars. Usually the results are better than these “upgrade” bulbs that burn out in under a year…
He who recommends just replacing the lens has never stood at a dealership parts counter and asked what a pair cost.
Many products are now available to clear fogged, yellowed headlamp lens. All use a “polishing” compound to grind off the top layer of plastic. With some it’s one or more liquids, others start with one or two grits of sandpaper followed by a liquid polishing compound. You finish with a plastic sealer. Taps Plastics has a sealer that is getting good press.
I’ve read that in 1996 the lens manufacturer’s got their act together and the problem from that point on has been largely solved.
Two weeks ago I used “5 Minute Headlamp Lens Restorer” (widely available) and after 10 minutes on each lens the improvement was dramatic.
He who does not put two layers of heavy tape on the paint just to the edge of the lens will be standing at the dealership parts counter ordering a can of touchup paint.
McGuire’s (sp?) also makes a product called Plastix. It is supposed to help with yellowing and keeping clear lenses….clear.
I used to use old school sealed beams until the missus demanded brighter lights. They still can be purchased for less than 10$. I splurged and for about 80$, got a pair of Hella H4s for her 528e. Twice as bright. I’ve heard that the lenses in late model Audis go for 1400$. My cars dont cost that much.
I tried the sand paper and water thing on my headlamp (only the driver’s side was yellowing for whatever reason) and it ruined the lens. It’s not unsafe but it now looks like crap. I guess that’s what I get, since the yellowing was only in a small area on the headlamp and wasn’t that severe (so I guess I should have just gone for some polish). Ugh…I still need to get a new lens, until then, I cringe whenever I see the front of my car.
I’ll vouch for the sanding method in extreme cases… they don’t look “like new” (at least on some of the newer styles without refractors in the lens – I imagine on those old Lincolns in the link it DOES look like new since you can see blemishes in the plastic as well due to the refractors) but it looks a hell of a lot better. I used 3 grits of sand paper, metal polish and a can of clear coat.
Also Robert.Walter is right… My old GMC Sonoma uses the “Stone Age” sealed beam bulbs and I swapped out for the Hella H4’s that Andy D referred too. The difference was amazing. Before I had 2 bright spots in front of my truck; after swapping I had a very clean trapezoid shape and I could draw a chalk line on the pavement where the light projection cutoff.
SV:
Since you already started wet sanding, take a very fine grit sandpaper (1200-1500) and wet sand just a little more. It’ll look cloudy when it dries. Then take a polish of some sort and polish the lens. Repeat as necessary. The link included in the article suggested capping off with wax and waxing often. However, I used a metal polish that was chemical based not wax based and once I finished sanding and applied the last coat of polish I wiped off the excess, let it dry, and used a spray can of automotive clear coat to seal it in. I never had to touch them again. As I stated above, since it was see through plastic they never looked “brand new” again but they were much better than the pitted yellow plastic that was there when I started. You’d only be out the $10 of material if you tried it and you’re already unhappy with the way they look (which I’m guessing is due to wet sanding with no follow up polishing).
One minor quibble with your advice Sajeev. Color temperature has nothing to do with actual (physical) temperature. Rather it has to do with the temperature needed to heat an “ideal black body radiator” to match the chromatic output of the light source. In reality, we perceive “hot” as red and “cool” as blue which is inverse of the color temperature kelvin scale, that is the higher the kelvin rating the bluer the output.
The reason the blue tinted bulbs burn out earlier is due to temperature, but not because the color temperature. Rather, the coatings used to create the bluer light on most of these bulbs trap heat generated by the filament and cause premature failure. The bulbs are still rated for the same amount of energy consumption as a regular bulb, so the amount of heat generated in the same.
I have had good luck with Novus plastic polish. It’s a 2 or 3 step process, depending on how bad the plastic is. I was able to get good results using #2 (moderate abrasive) followed by #1 (a conditioner).
This is s big problem in sunny Palm Springs. If at all possible, avoid parking your car in the sun facing south or west. Parking in shade as often as feasible will make those lenses last a lot longer.
Speaking of fake HID bulbs, I once bought a pair of Sylvania Silver Star bulbs for my 98 Camry. They were definitely whiter, but the difference in intensity was probably less than 10%, not worth the money. And they’re not even close in output to the HID lamps in my newer cars.
Not only that, but they lasted just over 14 months, and quit within a week of each other.
Ironically, I put my halogens back in, and they still haven’t quit.
The three grades of Novus plastic polishing compounds are also available at TAP Plastics.
I prefer the liquid to the sandpaper as it conforms better to the shape of the lens.
Anyone remember CIBIE headlights? I had a set in the RX2 Rotary and Opel Manta. Absolutely loved the beam pattern. On high you could burn the hair off the back of the head of the occupants in the car in front of you.
Blue Coral also makes a light cover polishing / anti-fogging kit that first polishes the plastic, then applies a sealer/de-fogging compound.
BTW, the only place to use this is on the clear covers over the light.
Also, never use ammonia products to clean the plastic covers or lenses. Ammonia attacks the plastic and will cause it to yellow and/or fog.
eamiller;
Please go back and rewrite for dummies. Make it so message in an ad in autoweek would make sense.
Black body radiation loses most everyone.
And please explain why halogen bulbs do not seem available at native 6500K color. Or say where to buy that, especially in G4.
Everybody else, lets cheer the first gen Neon as first out the gate for dimming yellowy clouded lenses. .
I miss the days of standardized glass headlamp assemblies. These highly styled plastic pieces of junk are a massive step backwards.
Give me a classic set of 7″ Cibie Z-beams any day, thank you.
While you are at it, take those darn HID lights off the road. Even on low beam they are blinding to oncoming traffic.
Carperson–Funny–I had the set of Carillo’s with Carillo foglamp replacements in my ’72 Opel Manta Rallye. Torches by comparison to the yellow incandescent headlights of the day.
Our dealership carries the B/G line of chemicals, and B/G has now introduced a process to fix the headlight yellowing issue. They guarantee it for 2 years. So far, no takers.
I just do a wax and buff, and I’m good to go.
1. Crest works great for this!
2. They use plastic instead of glass because…it’s LIGHTER (weighs less too)!
3. Don’t you all know that yellow headlight lenses is one of the surest signs that you should trade in that heap of scrap and buy a new American car. It’s the patriotic thing to do.
Oh! Wait! That may be replacing scrap with crap (though not in all instances).
Thanks Sajeev,
not sure what i might do. i bought a bunch of dry and wet sanding paper but not sure if i should start the project before i find some plastic sealers. i have a good idea that if i apply a final step of 3000 grit wet sanding, it should solve the problem of a milky finish, but if i don’t seal it at the end, the problem will re-occure within a few month.
the car is a 2000 neon, but the funny thing is that a friend has a 2001 neon, and his headlights look like new still. both cars receive very similar care and live in the same weather. me thinking will borrow his car for a day and replace the headlights and let him deal with it.
but that’s just the devil on my shoulder talking….
would 50$ to a professional be too much to pay to have it done?
My old Mercury Topaz had this problem. I would just use straight up Silver polish on those buggers every few months. Made them shiny and clear. But If you want to buy the good stuff, go right ahead. I just used what I had in my garage. Probably anything that has the corrosive label will work :)
Oh, and wear gloves :P
For visibility, I’m pretty sure glass is always better than plastic. I would suggest yet another reason auto manufacturers went to plastic. Insurance crash ratings. Much less likely to break.
Still, if I had my choice, I would always choose glass.
Not that I’m lazy, exactly, but I did notice that our local Wallyworld store is offering lense polishing as a service – I think for about $10 -$15 per lense….. I might do my own taping to protect the paint, but I suspect that it’d be worth it to have a guy who already has an orbital buffer, and who has already practiced on other people’s cars do the work…
YMMV
Joe ShpoilShport, you’re right on about plastic being used because of the breakage issue seen with glass. Back in the early 1980s – when the U.S. first allowed the use of headlights with separate bulbs and lenses – all lenses were glass, and I recall my Toyota dealer trying to scare me into buying an overpriced set of acrylic lens covers (remember those?), “because if a stone hits one of those babies, you’re looking at a couple of hundred bucks.”
The manufacurers probably switched to plastic for all of the above reasons: To reduce customer complaints over breakage, save weight, save cost…and with some newer designs (Nissan’s Maxima, Altima and Z-car come to mind) it allows the headlight to take on much more complex curves, over a much greater surface area. In which case, plastic is an obvious choice from a durability/weight/cost standpoint.
Funny thing is, I’ve yet to have this problem with any of my vehicles…
The French drove around with yellow headlights for years.
I just replace them after a few years. The thing I don’t understand is why any of the “best and brightest” would spend all day blogging about cars and the drive down to a dealers parts counter for anything. I buy 85% of my replacment parts online. Generic headlight assemblies (Deco comes to mind) that I have bought have all been very high quality, make the most important part of the car look great, and are usually quite affordable. I mean take care of what you have, wax it, etc. But when plastic is shot, it’s shot, especially here in Florida. The other 14% of car parts i need II buy at a local parts store and about 1% at the dealer for obscure stuff needed right away.
Yellowing lenses are my pet peeve. I’ve never understood why this isn’t a safety factor (night time visibility) and repair/replace required of manufacturers.
Great suggestions.
I second the Plast-X suggestion. I’ve used it successfully for over a decade. A soft cloth and a spot the size of a lady bug does a square inch. It takes a bit of elbow grease to do a pair of large lenses. I heard about from motorcyclists who use it to keep their wind screens clear.
Last weekend, I used the Permatex headlight kit on my 2003 Jetta. After almost 6 years, the lights weren’t yellow, but they were horribly cloudy and scratched up where it looked like I had flashlights taped to the hood at night. The kit took about an hour and did a decent job. I’d like to buy some of the E-code lights for it, but a $20 headlight restore kit was much cheaper than about $350 for a set of European Hella lights!
MBella : I disagree with you on the plastic being better than glass. The reason they use the plastic is because it is cheaper.
Not exactly. They also use them because they can be vacuum formed into any shape, lower a car’s weight (so we can have more safely gizmos) and because they are cheaper. Two experiences with glass lights: 1990 Maxima and 1990 LS400. Both got chipped, then cracked. One didn’t pass state inspection (not sure why) and the replacements were NOT cheap. And both owners were not happy, and there’s little doubt my mind that plastic headlights fare better in road rash because they have more flex.
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eamiller : The reason the blue tinted bulbs burn out earlier is due to temperature, but not because the color temperature.
Because these bulbs usually have the same wattage as stock I thought color temperature and heat went hand in hand. My mistake.
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jet_silver: You get clear covers and a fresh, minty after-taste by polishing them, by hand, with toothpaste.
Good advice, but I haven’t found a paste that’s aggressive enough to match the plastic polishes on the market. But it is certainly worth a shot.
Ronman : i have a good idea that if i apply a final step of 3000 grit wet sanding, it should solve the problem of a milky finish, but if i don’t seal it at the end, the problem will re-occur within a few month.
would 50$ to a professional be too much to pay to have it done?
You don’t need 3000 grit, that’s why you have the plastic polish. And the problem should not come back very soon because wetsanding removes all of the “bad” plastic, kinda like removing the root of weeds instead of cutting them off with a weed-wacker.
And to those who followed this process but used silver polish and clearcoated the lense after, that sounds pretty damn smart.
$50 for wetsanding/polishing sounds pretty fair, but not for just the usual plastic polish treatment most corner shops offer.
I used to replace all my sealed beams with H series lights. I had a great set of Cibie Z-Beams on a VW which, before lights changed, would result in a ‘cop conversation” once a year. It was still worth it.
When the lights changed to the aero lights, the only bulb approved was a dual filament with no reflector…it was the worst of the sealed beam plus poor reflectors…the only worse lights were the old two square sealed beams, which were marginally better than driving by your internal dome light. I had a set of these in a GTi, and the dual filament bulbs were just crap. Luckily, the high beams mounted in the grille were metal, and accepted 100 watt H1 bulbs with a relay. So the low beams were garbage, but the high beams were great. I tried all the “higher wattage” dual filament bulbs, with relays and proper wiring, but you could not overcome the inherently poor design.
The newer bulbs, the finally approved H4 and the single filament replaceable bulbs are as good as the old H series (ok, the cutoff for the H is more severe…argue amongst yourselves).
I finally stopped having to do this when my current cars both got Xenons……and I think the real benefit is that the makers spent some money on lenses and reflectors.
@dubtee1480:
I actually did use polish after sanding (with 3 grits); maybe I just didn’t polish enough. I will try your suggestion though, thanks!
Wet sanding followed by polishing with a buffing wheel (attached to my drill) and buffing compound worked well on my girlfriend’s old car. I didn’t bother with any other coatings to protect them from the sun. The car rarely sees sunlight anymore, as it now lives in a garage and isn’t used much during the day.
On a side note, prescription “glasses” with plastic lenses also yellow/discolor, often in as little as a year there is a noticeable tint change (place them on a white sheet of bond paper and see for yourself). This is because all uncoated plastics (not just the cheap stuff) are highly susceptible to UV degradation.
The old glass optometrics never suffered from this problem.
“5 Minute Headlamp Lens Restorer” I mentioned above was supposedly invented to polish prescription lens, although the packaging says it is not intended for that use.
You get 6 pre-dusted circular sponge discs to stick on the supplied drill adapter.
Wet sand with 2000 or 1500 grit sand paper.
Then… please, take the headlamp to some paint shop and have them apply you some clear coat.
Otherwise, they will go yellow again. Because if you don’t block the UV rays from the sun (which are the ones that turn the plastic into yellow) you didn’t do much.