Difficulty: 1/5
Back to 1000q: car detailing index
Introduction
Glass headlight lenses are no longer used in non-sealed beam headlights on most US cars. All plastic headlight lenses will pit and oxidize with age and wear. Polishing will restore their clarity and make the car look much better. It's not just a cosmetic issue, it's also a safety issue for you and oncoming cars. Cloudy or hazy headlights diffuse the light and create glare for oncoming cars by scattering the light. HID lights will have unacceptable dazzle if the lenses are cloudy.
Here is an example of before and after polishing. You can see speckled
pits in the plastic which catch the light in the before picture. In the
after picture, the city light (the
small parking light) and its reflection are sharp and there's a lot less scattered
light and glare from the foggy lens. Less glare from
clear lenses means
more light onto the road. The picture angle is slightly different but the
results aren't a camera trick - it's clear that the amount of glare and lens
fogginess is a lot less.
Headlight lenses may also have a hardened or UV layer. If you have to sand the lens to this layer to get to clear plastic, they will fog up more frequently. Once you polish the headlights, I suggest buying thin vinyl headlight protecting film with UV resistance so that you don't have to polish them again for a long time. Professional installation of the film is suggested, especially if they're curved. The other option is to do a final polish once a season to keep them clear.
There are headlight polishing kits available at auto parts stores but I suggest using the ones that use power tools. Power tools are much faster and produce much better results than hand polishing. I strongly suggest a mother's powerball mini and plastic headlight polish. Even if you do buy the polishing kits I still prefer the powerball mini over their foam polishers. Its rotation and contact surface is more consistent, easily controlled, and will give better results because of the many fingers and attaches to any power drill. The full sized powerball or porter cable polisher pads are too large and the powerball for paint is too soft.
It's a good value if you find
it on sale or have a complex curved headlight. The foam pad follows sharp curves better
than a flat electric sander. Here is what's included in the 3M headlight polishing kit: headlight
polish, polishing pad, disc attachment for the power drill, 3000 foam pad, 800 sanding
disks, and 500 sanding disks.
I found better and faster results using a power sander and a mothers powerball mini. The main problem is that the 3M kit's 500 sandpaper is pretty rough and the 800 seems soft. There's twice as many 500 sanding disks than you would ever need and too few higher grit. After the 800 they go up to 3000 pad and a polishing pad that is too soft. I found it left swirls because the change in grit is too great. If you buy the 3M kit avoid using the 500 grit paper and start with the 800. I also still recommend a powerball mini if you buy the kit because it works better. The 3M pad rotates as a flat pad perpendicular to the drill's axis. The outside diameter of the pad moves much faster than the inside diameter of the pad which is barely moving at all. The powerball mini rotates parallel to the drill's axis and gives more consistent force. The powerball also has many foam fingers that polish each stroke vs. the 3M foam pad which uses a flat surface.
Pictured is my DIY kit - plastX plastic polish, a powerball mini, and a
wet/dry electric sander.
Parts and tools
3M headlight restoration system or meguiar's headlight restoration system if you want to buy a kit
OR
800 grit wet/dry sandpaper for the first stage and 1500 for the second stage
small handheld sander approved for wet/dry use (optional) - don't get the sander wet unless
you know it's approved for wet/dry use or else it could result in serious
injury, death, and/or property damage from among other possible causes, electrical
shock.
mothers powerball mini
plastic polish - meguiar's
plastx polish or Novus2 works well
(if not included in the above kits)
microfiber cloth
painter's tape - not masking tape or duct tape - any tape that is removes
easily and cleanly and isn't too
sticky
Below
are more pictures and details on how to polish foggy lenses. The 3M headlight polish system works well
on highly curved lenses but after using it I still prefer a flat sander and powerball
mini. The 3M kit with a powerball mini works best for curved lenses.
Procedure
First, is the inside of the lens clean? Some projector headlights tend
to get dusty on the insides. Use a grabber tool like craftsman 41322 and wrap the end in
tape to prevent scratches. Then use the grabber to hold a clean
microfiber cloth. You can also use a lint free cleaning cloth. Make
sure the metal grabber fingers are covered and wrap the grabber in tape if you
are concerned about scratches. Put a small amount of no
residue window cleaner on it. Remove the light bulbs and stick the grabber
tool through the bulb holes to wipe the lens clean from the inside. You
shouldn't be able to see through projector headlight lens but you should be able
to tell if it's dusty or clean. Don't use water or alcohol to fill the
inside of the housing to clean it because some headlights have a moisture
absorbing tablet. If it gets totally soaked it can break up and cause lots
of dust particles inside to float around.
Then wash the exterior of the lens.
If the headlights are in good condition without fogging, just use a powerball mini and some plastic polish. Move the polisher up-down, left-right, crosshatched and in a diagonal pattern to cover the entire lens. That should be enough to polish the lens. If you have the 3M kit, just use the 3000 gray pad (softer than sandpaper) and follow up with polish. If there are visible pits or fogging you'll have to sand them down as described below.
Start by taping off the paint around the headlights with painter's tape.
The headlights below needed stronger sandpaper in the first stage to remove the surface defects and the yellowed oxidized layer of plastic. Don't spend too much time with 500 grit since it's pretty rough. If you are putting together your own kit I would start with 800 sandpaper. You can see the final result with these lights at the bottom of the page.
If you're using a flat electric sander, move it back and forth, up and down, and
diagonally. Wet/dry sandpaper is supposed to be wet and form a slurry as
you sand. This prevents the sandpaper from getting loaded. If you are using the 3M pad, hold it at a slight angle to the surface instead of
perfectly flat to the surface. This puts the sanding surface over one edge
and gives better contact control over the
pad. This is because as the circular pad rotates, the
center moves slower than the outer diameter. Don't pause in any spot too
long or else it will burn the lens. If the pad is getting loaded then
brush it clean.
This headlight isn't as foggy and only needs 800 grit to smooth it
out. Use the minimum grit required to smooth out your lens. Any
stronger will result in swirl lines and scratches later on.
If you see wavy lines after sanding, the surface of the lens isn't completely
flat. The wavy lines are from the high spots getting sanded down and the
low spots not. Go back and sand them down. The headlights should appear cloudy but uniform.
Rinse off the slurry and determine if you need to sand some more.
Use a higher grit sandpaper at each step. The 3M kit tells you to use 800 grit, then the 3000 foam pad. If you are using your own materials I would suggest using 800, then 1500.
Examine the lens - there should be no wavy lines. If there are, go back and sand some more. Once it's smooth and uniform, polish the lenses.
The powerball mini
is just the right size and shape for the headlights and I prefer it over the pad
provided in the 3M kit. Push the polish into
the powerball and spread it around to avoid flinging and wasted polish.
Move it up/down, rotate the powerball rotation axis and move it around
left/right, rotate it again, and move it around again.
The final result is clear headlights! To prevent the lenses from getting pitted again, use UV resistant plastic film to protect from future damage or specially designed headlight protectors. These are difficult to apply without bubbles or defects so professional installation is recommended. If you buy a new car, get headlight protectors so it will never need polishing in the future. At some point the headlight protectors will wear down but you can just peel off the old layer, wipe away any adhesive, and apply another protector.
If you insist on installing the film yourself, here are instructions and tips for installing most vinyl lens covers. Use a spritzer of water with a tiny drop of soap in it. Mist the surface to help the film adhesive glide on. Start at the top and use a squeegee to press the film flat as you press it on to squeeze the water out. Lubricate the outside of the film as you squeegee. The film can be pulled up and reapplied as long as it's wet. You can use a hair dryer to shrink any wrinkles and tighten the film around curves but too much will burn or wrinkle the film.
Below is a video demo. It take practices to get good at it and the more
curved the lens, the harder installation will be. The film should last at
least a few years before it needs removal and replacement.
The powerball mini can also be used on the turn signals or side markers and
rear taillights. Since the taillights are not bombarded with road
debris, you'll only need to polish. After polishing,
the colors will appear much more vibrant and "pop" more due to
smoother plastic.
Here is another example of headlight polishing. The originals were seen
at top. Here is after a rough sanding with 800
grit.
Light sanding with 1500 grit.
Final results after polishing.
Did this work for you? What brand of headlight polishing kit works best? Share your experience by posting in the Volkwagen diesel forums here: myturbodiesel.com forums If you need to find more google the site: