How to clean dirty and hazy headlights

Words: Isaac Bober via https://practicalmotoring.com.au/

Photos: Isaac Bober and Carlos Caetano.

DIRTY OR DISCOLOURED headlights can ruin the look of your car, as well as make driving at night or in reduced visibility conditions dangerous.

As well as suffering the effects of age and general wear and tear, headlight covers can become dirty through general driving and via mud or bugs splattering onto them. Keeping your car headlights clean and clear is the way to go.

Unless your headlight covers have yellowed right through, keeping them clean and clear is pretty simple. And by following a few of our simple DIY hacks, you'll be able to keep your headlight covers bright and shiny without breaking the bank.

So, why do you need to clean your headlights?

This is just common sense. A dirty or cloudy headlight will reduce and diffuse the amount of light that shines out, no matter how good your headlights are. This means you won't be able to see as far down the road at night. If you spend a lot of time driving on country roads, you'll know how important good headlights are.

Headlights not working at their best will also make it harder for you to be seen on the road.

Cleaning mud, dirt and bugs from your headlights

Cleaning the headlights is as easy as wetting them down with a hose and then sponging them clean with a good quality car wash. You might need to do this a couple of times, especially if you've got bugs splattered on the headlights, or if they're heavily caked with mud.

You want to avoid scratching the headlights - something that's very easy to do if they're covered in mud. So, try and hose off as much mud as you can and then lightly sponge them down going in one direction only. This will minimise the risk of swirling the mud and grit around on the lens cover and creating circular scratches.

Cleaning your headlights with toothpaste

Yes, that's right, toothpaste. Toothpaste is a very fine cutting compound (it cleans plaque off your teeth, remember) and most aviation maintenance crews use toothpaste to clean/restore the cockpit windscreens on passenger aircraft.

When using toothpaste, choose one that contains baking soda, or simply add a little baking soda to a glob of toothpaste in a container and mix it through. Then, with a spray bottle, mist some water onto the headlight lens. Using either a toothbrush (preferably one you won't be using again that night!) or a new/clean microfibre cloth, apply the paste to the headlight in circular motions. You don't need to push too hard; let the toothpaste mix do the work. If the headlights aren't yellowed right through, you should be able to see and feel the transformation. Once the headlights are clear, simply wash off the excess toothpaste mixture and then wipe dry.

Now, because headlights are covered in a UV protectant film to keep them from yellowing, your toothpaste restoration mix will have totally removed that film. Unless you re-apply a UV protectant, you'll need to keep cleaning your headlights with this cutting compound mixture regularly or else they'll yellow again quite quickly. UV protectant is available from auto shops like Repco, Supercheap Auto, Autobarn, etc.

Using a commercial headlight restoration kit

If you think it's a little too DIY to use toothpaste to clean your headlights, then the good news is that most auto stores sell headlight restoration kits, starting from less than $35.

My old man has used toothpaste to clean the headlights on his old Range Rover (he's also used it to polish steel), as well as store-bought kits. The kit he used was the Meguiar’s Perfect Clarity Headlight Restoration Kit, which retails for around $70.

Using the Meguiar’s kit is pretty simple and it's the same process as most other commercially available restoration kits. You apply a small amount of the cutting compound (sometimes it's called a cleaning compound) to the provided pad and wipe it across the headlight, so the headlight looks like it's covered in wax. Then, get a damp new/clean microfibre cloth and wipe it across the headlight until it’s clean.

Use another, dry/clean microfibre cloth and wipe the headlight until it's dry.

After that, you'll need to apply two coats of the Meguiar’s Perfect Clarity Headlight Coating. This is the UV protectant and it takes about five minutes to dry. Apply a second coat once the first coat is dry. Meguiar’s backs this UV protectant for up to a year.

Some commercial kits contain graded wet and dry sandpaper, but using sandpaper on your headlights should only be done if you're handy and confident. If your headlights are at the stage where you need to use sandpaper on them, then it might be worth talking with your local mechanic who will be able to provide the service.

Using sandpaper to clean your headlights

Using sandpaper will undoubtedly give a much better finish, but it's more involved than using either toothpaste or a basic commercial restoration kit. That said, using a commercial kit that contains sandpaper, like the Invision Headlight Restoration Kit, is better than wandering the aisles of your local Bunnings and grabbing sandpaper off the shelf.

Now, if you can remove the headlight cover then do so, as this will reduce the risk of damaging the paintwork surrounding your headlight. If you don't remove the headlight, then simply apply some painter’s masking tape to the metalwork around the headlight, and make sure you use the right type of masking tape... the cheaper ones can often be more trouble than they're worth.

We'll assume you've already washed and dried the headlight. Starting out with, say, 400-grit sandpaper, wet it and the headlight and then sand gently in a circular motion, making sure you keep the paper and the headlight wet. A spray bottle will come in handy here. Before moving to the next grade of paper, sand across the headlight horizontally.

Once you've done that, move on to a finer grit sandpaper, like 600, and then keeping the paper and the headlight wet, continue sanding. Then, move onto something like a 2000-grit sandpaper and continue sanding, all the while keeping the paper and the headlight wet.

After working through the paper grades, you should end up with a crystal clear headlight. To finish the job, you'll need to apply a UV protectant to keep your handiwork from yellowing too quickly. You could also use an automotive wax applied to the manufacturer’s specifications, but this is likely to be very sacrificial and will require monthly maintenance, or even more frequently during wetter months.