Introduction: How to Fix Cloudy Headlights

This instructable will walk you through refinishing your plastic headlight covers without learning how to buff plastics. Here we will use only sand paper and clear paint and achieve a renewed look to the plastic lenses on your car.

You will need:

1. a can of gloss clear paint

2. 400 grit sandpaper

3. 1200 grit sandpaper (800-2000 grit is ok)

4. painters tape or masking tape

5. about 20 minutes.

Step 1: Cloudy Headlight Fix

The reason your headlight lenses are cloudy is the surface of the plastic is crazed, damaged by weather, and has tiny road dings.

We will smooth the surface and provide something for the paint to hold onto.

Tape off the area immediately around your headlight lenses. This protects the painted and surrounding surfaces from sanding and later from overspray.

Step 2: Sanding With 400 Grit

Using lots of water and the 400 grit sandpaper, lightly sand the clear plastic lenses. I usually spend only about 2 minutes sanding each side with this grit. You should see white plastic "dust" coming off in the water. This takes the surface down to a relatively smooth face with 400 grit scratches in it. Do this as much as you feel necessary depending on the starting point of your lenses.

Step 3: Sanding With 1200 Grit

Using more water and the 1200 grit sandpaper, sand the clear plastic lenses again. This should take another 2-3 minutes per side. The point here is to take those 400 grit scratches down to even smaller 1200 grit scratches.

Step 4: Dry the Lenses

Wipe the lenses dry. If you have compressed air or a leaf blower/shop vac, blow the area dry to make sure to get all the water out from the underneath the headlights. As they dry you will see they are even more cloudy than before you started. That is ok because now we have tiny little scratches that are consistent and easily filled by the paint.

Step 5: Painting the Lenses

With everything taped off, go ahead and apply light coats of clear spray paint.

Paint runs are your enemy here, so concentrate on smooth consistent strokes with a slight overlap, leaving just enough paint in each coat to make a wet look (where the small droplets of paint flow together to become one thin film).

Use two coats applied within about 10 minutes of each other. The lenses should appear clear and shiny.

Let the paint dry and remove the tape and you are done.

Comments

author
PennyL19 (author)2016-05-05

Skip all the work and just use pledge on them when needed, it works just fine.

author
bryanep (author)2016-03-01

Thank you so much! I did what you said and it worked great! No more dull yellow lenses. I went and bought UV clear coat that bonds with plastic from the auto parts store $7.99 and 220, 600, 2000 grit sand paper from hardware store $13. I did 2 cars and it took me a lot longer than 20 min. The only thing I would add to this is if your lenses are severely damaged use your phone to zoom in and see if you sanded away all the micro cracks. This will give you a better end result.

author
32Tudor (author)bryanep2016-03-01

Sounds like you have perfected this and I like the selection of a UV clear. Thanks for the excellent improvements.

author
pfriedl (author)2016-02-26

Did you know that you can get your lenses clean with a can of Deep Woods Off? It absolutely works. Spray it on an old sock, wipe in one direction and BOOM clear lenses.

author
miked2001 (author)2016-02-26

I wish I saw this 6 months ago. I bought a kit that worked awesome. It used a power drill and mad short work of it. Came out awesome.

author
fahking (author)2016-02-25

toothpaste and a cloth works also

author
cue.cello (author)2016-02-12

i would try giving them a good waxing first. I have used a real good marine wax on my lights and was amazed at how clear they were. the wax I used will bring back dead paint . if the wax isn't marine grade it won't last a month. now I try to remember to just wax them a couple times a year. if you have to sand them water water water and more water I'm out of wax and I'm not driving to the marina till spring sorry can't remember the name

author
cbjack (author)2016-02-10

I used this technique on my 2005 Nissan Altima and it worked well, but the clear coat just wasn't clear enough, will try another type of spray clear coat this spring.

author
cbjack (author)cbjack2016-02-12

Thanks for replying to my comment!

author
32Tudor (author)cbjack2016-02-10

In the right light take a look at the surface and if you see scratches, then you probably needed to sand it more with the 1200/super fine paper. Make sure the clear is high gloss clear. I noticed scratches in the one pictured, so it could have been more clear, but the improvement was more than enough for the time I put in.

author
Mihsin (author)2016-02-07

Years ago, there used to be the round glass vacuum-sealed headlight units. They were reasonably inexpensive and somewhat resistable to even desert climates. The double-headlight looks were not so ugly. Legislaturs should step in for the return of the inexspensive and durable headlights rather than for whether lights should be turned on or off poor issue of when cars are driven on tarmac.

author
madmadmal (author)Mihsin2016-02-11

Someone can correct me if I am wrong but no one made the old sealed-beam lights illegal and nothing prevents a manufacturer from using them. I am not for any legislation beyond that needed for safety. To force manufactures to return to old style lights has costs too. For example, many cars would not have the low drag coefficients (thus reduced mileage) they currently exhibit. Weight would certainly increase and many car models would be required to make a complete front end redesign.

My own opinion is that we are less than 10 years from the whole industry switching to LEDs which could result in monolithic headlights disappearing. LEDs are improving at Moore's Law rate. Once LEDs can achieve illumination on parity with today's HIDs without requiring extensive heat sinking the industry will change rapidly.

author
Atomsk102 (author)Mihsin2016-02-08

Those old "sealed beam" headlights had one major disadvantage. They were DIM. You could not build the kind of bulb, in a sealed beam that would give off as much light as a modern halogen bulb. Now, it is possible to make a glass housing, and put a halogen bulb inside it, but that would cost more, and have more shape and size restrictions than the plastic lensed housings we love to hate.

Why is that important?

For the same reason cars don't have proper bumpers anymore. Because someone in Detroit (or thereabouts, I don't think anyone lives IN Detroit anymore) decided that every part of every car needs to look like it's been half melted. No straight lines, no flat surfaces, no constant-radius curves, just lumps and bumps all over the place.

author
imboox2 (author)Atomsk1022016-02-08

?? I could buy bright sealed halogens decades ago, my 81 Prelude came with them. I went different on my older car, out in my shed I still have a set of 4 round Cibie headlights I had in a 70 Belair. I bought the lights about 1982. Leaded glass, precision cut with replaceable halogen bulbs. I bought them at an import car shop. In the outside dims I used 60/90 watt halogen bulbs, 10 watts above good stock lights on dim at the time. In the inside brights I used 100 watt halogen bulbs. I rewired the lights so my switch and floor dimmer switch only handled the current of a couple relays. The lights were ultimately run directly off the internal regulated alternator through the contacts of two relays (redundent). That gave me max voltage, 13.6 V under load. On dim the two 60 watts were activated, when on bright the outer lights switched to the 90 watt filaments and the two inner lights fired up the 100 watt bulbs. On bright the the outside lights had a very wide beam (the 90 watt filament position caused a much wider beam) and the inner brights were basically a tighter straight beam and I could see forever.

author
Atomsk102 (author)imboox22016-02-09

Yes, and all of those lamps were the same shape. That meant that all cars had to have a relatively flat front, to mount the headlights on. Also, those precision glass reflectors were expensive and time-consuming to make. Most people don't want that kind of quality and are not willing to wait for it, if they "cheap" and "now". The metal reflectors, and molded plastic lenses of modern "aero" headlights (an ironic term, since all airplanes of which I'm aware still use sealed beams for their landing lights) can be made quickly and cheaply, while the kind of units you refer to cannot.

author
RobertH25 (author)Mihsin2016-02-08

I agree but IMO, we should have the option of sealed beam or the so-called modern headlamps. It would not be all THAT much trouble to design the headlight doors to accept either format.

author
smoke king (author)2016-02-11

Flitz polish works better than anything I've ever used.

author
toyowner (author)2016-02-09

I won't endorse this method

The sanding is alright but an aerosol clear is 80% solvent and the amount you actually apply to the surface is minimal. Check with a reputable body shop to see if the could apply a production clear over your prepared lights. There is a built in UV protection plus a thicker build of a catylized clear coat that will be more durable. I am a collision tech in the business and we have sanded and coated lights for customers for a few years now. Our paint rep has informed us that the company is working on a " special" clear but won't tell us NOT to do what we're doing. We have tracked some of the customers for whom we've do this and overall people are pleased

author
32Tudor (author)toyowner2016-02-09

I agree your suggestion is better, but this site is about DIY repairs, so taking the problem to a body shop kind of defeats the purpose and costs more than a few bucks for sand paper and a rattle can of clear. If done properly a rattle can can easily fill 1200 grit scratches.

author
toyowner (author)32Tudor2016-02-09

I agree this is DIY, but it's a weak band-aid at best.
This is almost as bad as using a bug repellent which actually damages the plastic. Aerosol products are 80% solvents and are really not an all weather product.
Performing the prep work yourself and having it professionally coated is cost efficient and and far better result

author
32Tudor (author)toyowner2016-02-10

I use catalyzed automotive clear coat on some things and agree it is a better longer lasting solution. Most people don't want to pay for that, so this is a cheap alternative and the results speak for themselves. Not bad for 20 minutes of work and about $3. If it lasts for a year or two it will be well worth it. I don't like the solvents or buffing because it is more error prone. You may get better results with buffing and you have no film to worry about, but we are talking about random skill and patience levels here, so simple is better.

author
lambert4040 (author)2016-02-09

Can you please specify the type of gloss clear paint to use for head light restoration and the minutes it will dry? cos i want to do this as my part time job. Am a student. Thank you for your helpe.

author
bennyj121 (author)lambert40402016-02-10

There is a product kit on the diy market that comes with various sand paper and also a can of "uv block clear" as well as an aerosol polish. I picked mine up for around $20 online but haven't used it yet. The trick is definitely the clear coat. You can sand and polish your lenses all day and they'll be hazy again in a few months without some protective barrier.

author
32Tudor (author)lambert40402016-02-10

I use whatever I have on hand, but if you are charging people for this, you should do a little research on the most UV resistant brand. The drying time should probably be some of your criteria as you want it to dry quickly to reduce the chances of getting bugs or wind blown contaminants in your work.

author
Arny6833 (author)2016-02-09

This Doesn't work ? If you get a headlight from a wrecking yard. With 25 coats of yellowed clear coat on it ?

author
32Tudor (author)Arny68332016-02-09

Yeah, I don't recommend that.

author
lambert4040 (author)2016-02-09

How long can the headlight last?

author
32Tudor (author)lambert40402016-02-09

That will vary depending on the UV durability of the clear coat you use, but it should be between 1-5 years (depending on sun exposure).

author
lambert4040 (author)2016-02-09

How long can the headlight last?

author
scam (author)2016-02-02

Excellent... I wonder if this method would help restore some old scratched DVDs as well?

author
spark master (author)scam2016-02-08

there are good number of how to 's on cd/dvd fixes even instructable I believe

author
AnžeB (author)scam2016-02-03

I've tryed to "toothpaste" unworking CDs for my PS1 and it worked like a charm! It's woth trying it :)

author
GarryB10 (author)AnžeB2016-02-07

The toothpaste has the same refractive index as the polycarbonate so the laser beams through. Don't remove ALL the paste and when it reads, rip a new copy with www.exactaudiocopy.com, best in the world. . .

author
Jakes workshop (author)scam2016-02-03

no, that is not going to work with CD,

author
32Tudor (author)scam2016-02-02

Maybe try toothpaste like RickHarris has suggested on a DVD? That is buffing plastic and if done by hand it should be easy to control how much material you actually remove. I avoid buffing plastics with a machine because it is hard to control the heat and you can gawl the plastic, making it much worse that original. By hand you should be safe.

author
32Tudor (author)scam2016-02-02

I would not use 400 grit on a dvd. You might try 1200 or some very fine grit, then carefully buff that to a smooth surface, but no guarantees there. Same concept?

author
rreed2000 (author)2016-02-07

I don't under why they continue to use plastic for headlight lenses. This is an area of the car that is constantly exposed to grit from the road. Every car's headlights get frosted and scratched with age. Why not just use a durable, hard glass in that application and solve the problem once and for all.

author
JetMechanic (author)rreed20002016-02-07

Polycarbonate offers better impact resistance in not all but most, situations. And it allows automakers more flexibility in body design.

author
spark master (author)JetMechanic2016-02-08

and they get to sell new ones, if the things were glass they may or may not last as long, but unless you were in a sand storm they would not craze so badly that they get frosted in 5 years.

author
VendicarD (author)JetMechanic2016-02-07

What flexability?

All modern cars look pretty much identical to me.

One box on 4 wheels. One blos ix blue,another box is red or white.

author
JetMechanic (author)VendicarD2016-02-07

Borosilicates possess the necessary impact resistance, but once formed into anything other than flat sheets, lose much of their advantageous physical properties. And the exponentially higher cost for a product with only minor improvement over PC would simply be passed on to consumers. What do you propose as an alternative?

author

All headlights used to be glass. They got foggy too. It was easier to polish them with abrasives, and the work lasted longer, but the only way to have truly fog free transparent stuff on the front of a car is to not drive it. Windshields used to get foggy too, but that was long ago before modern safety glass.

Styling is the big reason for polycarbonate/acrylic headlight lenses. Even very strong glass like borosilicate and kodial treated silicate glass has a very limited shaping options that can stand up to the abuse a car headlight takes. Once you start compound curves or acutely angled edges glass of all sorts starts losing its strength. Glass wants to be flat and going too much against the wants of any given material is simply poor engineering.

As far as long lasting solutions to clearing poly headlights there aren't any and there will never be (not driving the car aside). Poly breaks down under UV light and once the process starts it can't be stopped long term. It's just the nature of the material. The material in headlight lenses is pretty impressive as far as using polycarbonate outside. Lesser variants get foggy, brittle and turn yellow (look at the gas pump volume display next time you're getting gas).

Choose the solution you find easiest and simply repeat when the lenses get foggy again. Don't go overboard fighting chemistry the sun.



author

"Glass wants to be flat and going too much against the wants of any given material is simply poor engineering."

What about, for example, wine glasses? Do they want to be flat?

Plastic is more fuel efficient and cheaper and faster to make. Glass has to anneal before it is useful. That takes time, factory area, and more equipment.

author

Wine glasses do indeed want to be flat.

As I noted above, glass can be shaped, but it loses strength the further away from flat it gets. Not flat glass can take shapes that exhibit phenomenally strong attributes for a given characteristic, but only at the expense of other attributes.

Using your wine glass as an example: A wine glass can support enormous amounts of weight if the weight is evenly applied squarely across the rim of the glass when it's standing normally. The same glass can support far less weight it's turned upside down. At the same time the wineglass cannot withstand striking or side loading.

Annealed glass is not suitable for any automotive application. Annealed glass is great for making wine glasses and some optics because it has less distortion than heat strengthened or tempered glass, but annealed glass is not very strong.

author

Glass wants to be a sphere. That is why it forms a sphere if melted in zero g.

author
VendicarD (author)rreed20002016-02-07

They don't use glass because the automotive corporations - like all corporations exist to such as much money out of your pocket as possible.

author
mad hatter503 (author)rreed20002016-02-07

Headlight design was deregulated years ago, allowing them to be styled to the body, rather than just the rectangular or round lights of the past. Glass would be a better choice, but more expensive and heavier than polycarbonate. PC is strong, but reactive to ultraviolet. 16oz = 1 lb... Lighter cars get better fuel economy!

author

Polycarbonate often provides an 80% weight savings over glass with the larger headlight covers currently being styled into automotive designs. A person tends to forget that even a 25% average weight savings in each of the components of an automobile can result in a 1000 lb total savings. That's real, palpable improvement.

author

My thoughts exactly....go back to glass.

author
DavidS589 (author)rreed20002016-02-07

$$ + lbs (same reason you no longer have aspare tire)

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