Over time, plastic headlights begin to fade and fog up. As your headlights get foggy, the amount of light getting through the lens decreases significantly, making driving at night dangerous. This is due to oxidation on the lens. The fogged up effect on your headlight is probably on the outside and most likely due to oxidation or UV degradation. In effect, you have a bad translucent layer on your lenses, covering the perfectly clear plastic still underneath.

Plastic lens cleaning kits are by far the best and most-recommended way to go but, since some of you like to go it alone, this guide lets you assemble your own headlight restoration kit for diy cleaning.

Tools and Supplies:

Rags
Sand Paper in 800, 1000, and 2000 grit.
Rubbing Compound (3M is a popular choice)
Masking tape
Drill
Compound Pad for the Drill
Spray Bottle with Water
Rubbing Alcohol
Small Measuring Cup (you won’t want to use it for food later, so get a cheap one)
Minwax’s Helmsman Spar Urethane : Clear Gloss. (this specific one has been tested with good results. Another brand or type might not work as good, or cause damage)
Mineral Spirits
An afternoon or evening per headlight that needs to be restored


Preparation:

If you buy a restoration kit, you have everything you need in one convenient package. If you’re going to restore a foggy headlight on your own, there are some preparations you need to make – especially if you don’t want to fix a yellowed headlight while wrecking a fender, grill or chrome trim.

A key part of the restoration process is wet-sanding, and you want to keep the sandpaper on the plastic headlight lens but off your paint and chrome. The easiest way to do this is with masking tape.

Carefully apply the masking all the way around the headlight lens you’re going to restore, without actually getting tape on the plastic itself. Press it down firmly to help keep water from getting underneath and loosening the tape. Then continue to add more tape so that you have a wide border around the headlight. It’s also a good idea to make the tape two or three layers thick near the headlight, in case the sandpaper comes in contact with it more than once.

Usually the tape will hold for the whole job, but throughout the restoring process, take a close look at the tape to make sure it’s not working loose or wearing through.

Finally, make sure all your supplies are nearby and within reach. With or without a kit, the restoration of a cloudy headlight can take some time – depending on the severity – so maybe get a radio playing or your MP3 earbuds in.



Wet Sanding:

Assuming you bought full sheets of sandpaper for your headlight restoring, cut it into fourths.

Starting with the 800 grit sandpaper, spray it with water or dip it into a small pail of water. Spray the entire fogged up headlight with water.

Slowly begin sanding the yellowed parts in one direction (it doesn’t matter which) and be generous with the water. The water makes the sandpaper last longer, and flushes away debris as you work. Sanding in one direction makes it easier to see if you’ve missed anything.

Keep sanding until the headlight’s plastic lens looks uniformly sanded and you’re confident you’ve removed all the oxidation or yellowing.

DO NOT use any kind of sanding block or sanding disk. The sanding block doesn’t spread the force as evenly as your hand, which can lead to flat spots and gouges. A sanding disk on a drill will also give an uneven sanding on the headlight lens and, if it spins too fast, it can melt small areas.

Once you’re done with the 800 grit sandpaper, switch to the 1000 grit. Once again, keep the headlight lubricated with water throughout the process and sand the lens in one direction – but, this time, sand perpendicular to the 800 grit. This will make it easier to see where you’ve sanded and how thoroughly.

When you’re finished the 1000 grit step, the yellowed headlight will start to look a little less foggy – but you still have a way to go.

You’ve been good and patient so far, and it’s important to keep that patience as you move on to the 200 grit sandpaper. This is an important step in your diy headlight restoration and the longer you spend on it, the better the results.

Switch your sanding direction once again and then stick with it. Spray water frequently and generously on the lens. It’s literally not possible to over-spray.

Like the previous steps, continue to sand the headlight until you get an even finish.

That’s it for the sanding! If you’ve developed dishpan hands from all that water, take a short break



Polishing:

So far, the do it yourself headlight restoration has been a lot of hard work – but now you get to the fun part.

NOTE: DO NOT USE TOOTHPASTE -- IT WILL GIVE YOU SHORT TERM RESULTS.

Get your drill and compound pad or, if you have one, a polisher with a wool pad. By the way, once you have a compound pad you’ll find it useful for far more things than just restoring hazy headlights, so it pays to get a good quality one.

This is also a good time to check your masking tape to make sure it isn’t coming loose or wearing through.

Shake your rubbing compound thoroughly to make sure the abrasives are distributed evenly and put a good glob of it right onto the plastic lens. Using the compound pad on the drill, without turning the drill on, spread the compound over the headlight surface. This will save you some money on compound since it won’t all shoot off the surface at once. Which reminds me… if you’re doing this in the garage or next to another car, you might want to reconsider – otherwise you’ll be cleaning compound drips and mist off everything nearby.

Now place your compound pad on the headlight and start polishing it at low speed. When the compound is evenly distributed, move to the drill to top speed.

As you’ve probably figured out, restoring the headlights and getting rid of the fogged and yellowed surface was simple – a lot of hard work, but simple – You’re removing the haze with finer and finer abrasives. This is where the kits really come in handy, as they provide the right grits and eliminate the guess works or potential mistakes.

Continue polishing and adding compound until the headlights look new and shiny.

At this point, you’re ready for the finishing touch.



Seal Coat:

A diy headlight restoration is a lot of hard work, so you want to make the results last as long as possible. Use the Minwax spar urethane to clear coat and protect the plastic lens. Here’s how…

First you need to COMPLETELY clean the headlight you just restored. Also, if you’re going to want your car washed in the next few days, do it now! Then use a clean rag and rubbing alcohol to completely remove any residue from the plastic lens.

Combine an ounce of the urethane and an ounce of mineral spirits and stir it thoroughly.

Dip the corner of a shop towel or a fine, clean rag into your urethane/mineral spirits mixture and get rid of any drips. Then start at the top of the headlight and apply the mixture, side to side, making sure you go from edge to edge. The homemade headlight clear coat will begin to set fairly quickly, so don’t rush, but don’t dawdle either.

If you do make a mistake, don’t worry, you haven’t ruined your hard-earned headlight restoration. The clear coat can be removed with mineral spirits and you can reapply it. In fact, keep an eye on your restored headlights and if it looks like the clear coat is wearing or chipped a year or two down the road, you can remove and reapply it, without having to do the rest of the restoration process.

If possible, let the clear coat dry for at least half an hour in a garage or with a something suspended over the headlight. After all the restoring, you’d hate to have a bird poop in your clear coat, or have a gust of wind drop grit in it. Don’t let anything touch the headlight until the next day, and wait at least a couple of days before washing your car – and only hand wash it for the next week or two.



Compiled from HowToRestoreHeadlights.com

 

Can you honestly say you did this to your truck and it stayed this way for any long term amount of time? Cause I went out and bought a kit and did my wifes VW Jetta and it lasted maybe 2 years and right back to the same issue.

 

Did my truck and my wife's van. Lasted about three years for my truck and two years for my wife's van (her van was a lot older and that might have had something to do with it).

I imagine actual miles driven, where it's parked, etc would also cause some variation in how long the results last.

In the meantime I've used up the spar urethane for other projects, so I'll probably just order a kit next time and toss the leftovers when done, rather than have them cluttering up my garage.

I think I'm going to try one of these reviewed kits, probably the Sylvania one. Winter's on the way here though. I have to decide whether I want to do it in a slightly heated garage, or wait for spring.

I'll post the results when done!

 

Ok I was considering just going to a LED light and replacing them. But have put that on hold for a bit to see how this goes.

 

It will last much longer if you use an automotive urethane clear coat. I did the ones on my Focus which clouded whitish. The coating on the surface was beginning to craze and peel. This is completely different from my wife's 98 Sable where it just yellows. The yellow can be polished out easy enough and I do that 3x a year when I polish her car. Polish didn't work on the Focus though so it was sanded up to 2500 and then hit with my Makita polisher. After that some PPG clear coat and good as new if not better.

 

I agree on using clear coat to protect the headlights from yellowing again. By the way, I've seen on other forums that using bug spray helps restore headlights. Anyone familiar with this?