In this video, I show how to restore your headlights on the cheap. No matter how bad your headlights are, you can polish them to like new condition for under $30 and in under 30 minutes. If you've paid upwards of $100 for a professional to do the job, only to have the headlights fade again, I'll explain why and show you how to prevent it. And if you've paid $20 for one of those kits that didn't work, this will tell you what went wrong. (Hint: it wasn't you.)
(I'm also going to gush a little about my car, which I've neglected lately.) Click next to read the steps, or click the video above to watch.
Step 1: Materials You Need
At a bare minimum, you'll need the following:
- A Handheld Buffer - These are $18 at Harbor freight normally. However, they occasionally go on sale for $12.85. Alternately, you can keep an eye out for one of Harbor Freight's 40% off coupons, and it'll be (guess, just guess...) $12.85.
- Masking Tape - A roll can be had at your local dollar store for... $1.
- Ultra-Fine Grit Sandpaper - You actually can get away without this, but it takes a lot longer to get the job done. A pack of 800 to 1200 grit costs $2 at an automotive parts store.
- Polishing Compound - The best polishing compound I've found is the glass cook top cleaner. They sell this everywhere, but the cheapest price tends to usually be a big box store, where it's $7.
- Lens Sealant - This is the secret to keeping your headlight clear and bright looking. It's $8.
- A Microfiber Polishing Cloth - These show up at dollar stores all the time for $1.
- Paper Towels - $0.50
- A firm sponge - $0.50
- An old all-cotton t-shirt - $0.00
- And old spray bottle - $0.00
Step 2: Mask Off the Headlight
You need to carefully tape off the area around the headlight with about a 3" border of tape. This will make cleanup easier, but more importantly, it will protect the surrounding painted surfaces from the polishing compound.
Next, we wet-sand. Make a soap solution in your spray bottle consisting of just the tiniest drop of dish soap. This solution will help the water wash away the particles of plastic you're sanding off. Spritz the surface of the lens and get it good and wet with your soap solution. Wrap your sponge with your sandpaper, and start sanding. Technique is important here - don't apply a lot of pressure. You should just feel the sand paper dragging. The reason we use the sponge is to try to even out the pressure from your finger tips. You also want to use a tight circular pattern of sanding, and don't focus on one area too long. Work over the entire lens until it is evenly frosted, and any yellowed areas are gone. Then wipe the lens down with a paper towel.
Step 3: Buff It Out
Put the terry cloth buffing pad on your buffer. Spritz the top of the pad with your soap-water solution so that it's damp, then squeeze out some of the polishing compound onto the buffer. It doesn't take a lot - maybe 2 tablespoons worth.
The reason we spritzed the pad is so that it doesn't try to suck all the water out of your polishing compound. Dry polishing compound isn't as effective.
Now blot the pad over the headlight to get polishing compound all over it, and when you've done that, fire it up.
Work the buffer around in even circles. Keep the pad flat against the surface of the lens for the most part, but you can roll it on to the edge of the pad to get into tight areas. Just make sure you lighten up on the pressure when you do.
This step only takes a few minutes. You won't see much actual improvement in the lens as you do this, because the buffing compound leaves a light haze. After a few minutes, if you're sure you've gone over every part of the lens, and it looks relatively even, then stop buffing, and wipe the lens clean with a paper towel. This is when the magic happens, and your lens starts to look like new. Give them a complete wipe down, and look for any spots that seem to still be a little hazy. If you find them, you can go back to wet sanding and polishing with a focus on just those areas.
Step 4: Seal It Up
Here is where most DIY kits and more than a few professional detailers fail: you have to seal the headlamp after you polish it.
First, a little background - the plastic that headlamps are made out of (typically poly carbonate) is amazing stuff, but it is quickly degraded by ultra-violet radiation. Yes, basically, it gets a sunburn. To prevent that, headlamp makers typically coat it with a protective UV resistant film. That film doesn't last forever, and eventually wears off with exposure to chemicals and the environment. When that happens, the poly-carbonate starts to deteriorate. If all you do is polish the headlight to remove the deteriorated layer, the next layer will be chalked up in a few months To stop this process, you need to seal the headlamp with a sealing solution.
I'm not going to mince words here. There is only one sealant I trust, and no they didn't pay me to endorse them. It's Blue Magic Headlight Lens Sealer, and it's under $8 on Amazon. All it is is a substance called polydimethylsiloxane (PMDS) dissolve in a light petroleum distillate in a 20% solution. The PMDS bonds to polycarbonate, fills in any microscopic divots, repels water and absorbs UV light. The petroleum distallate evaporates very slowly, giving the PMDS time to do its job. If you find another sealer that is 20/80 PMDS and distillate, you can use that instead.
Before you apply the sealer, use a micro-fiber polishing cloth to buff the dickens out of the lens. We don't want any residue of grit or polishing compound on the lens when we apply the sealer, or it will get sealed in. Cut a generous square section of t-shirt material and fold it up into an applicator pad. Apply a generous amount of the sealer to the pad, and wipe onto the lens. You'll leave a thin film on there when you're done that will naturally evaporate very slowly over the course of several hours, leaving a thin layer of the sealer.
The sealer will protect the headlights for several weeks before it wears off itself. It doesn't hurt to try several applications of sealer, but it's also just as easy to re-apply it once a month. Prior to the first photo in this series, I hadn't applied the sealer in over a year, so it didn't got too extremely chalked up. Since this video was made, I have applied sealer exactly once, and it's still as clear as this video.
And now you're done. Oh, and you can remove the tape now.