How to polish the headlights of your car: home and professional methods

Do you need to polish your car's headlights? Often, when we talk about our car's headlights, the safety aspect is rarely considered. They are responsible for our illumination, and by illumination we mean seeing and being seen. Their deterioration compromises our car's safety , and we're going to learn how to polish your car's headlights in 5 easy steps.

But first, we need to analyze why our headlights can deteriorate over time , what the reasons are, and what the solutions are. We must never forget that lighting is one of the cornerstones of our vehicle's safety and that, in addition to reducing visibility, it can have negative consequences, for example, when passing the vehicle inspection (MOT/ITV ). Therefore, we'll show you what headlight polishing involves and how the process is performed.

How to polish car headlights?

Just as there are different ways to detect the problem, there are several ways to fix it. The first is the quickest and most effective, but also the most expensive: replacing the headlight. This will give you a new headlight, but it will mean paying for a new one , which isn't cheap, plus labor if you don't do it yourself. Furthermore, replacing just one headlight might not be enough, so you'll have to add the price and labor for another headlight.

The other way is to polish your car's headlights . It's a more rudimentary and less effective task, but it will get you out of a pinch and leave your headlights in good enough condition to drive safely again and pass the vehicle inspection without problems. This method is also cheaper since you can hire a specialist or even do it yourself, which is what we'll discuss next.

What to use to polish headlights

To polish our headlights, we can choose to buy a headlight restoration kit , which includes its own materials and instructions, or do it ourselves using the following materials:

• Masking tape
• grit sandpaper 400, 1.000 and 2.000
• Variable speed drill
• Lint-free cloth
• wool discs
• Liquid polish with silicones
• Water

Polish headlights in 5 steps

Step 1: Clean headlights and mask

The first step in polishing your car's headlights is to clean the surface to remove any residue . To do this, use a cloth and a bucket of soapy water. Dip the cloth into the water from time to time while wiping the headlight. It's important to make sure you remove all traces of dirt, such as bird droppings, mud, or grease.

After cleaning the headlights (finishing one headlight first, then the other), we need to mask them off to protect surrounding surfaces like the car body and bumpers from the sandpaper and polish. We'll use masking tape, carefully applying it to the areas we don't want to damage. We can also use protective paper to increase the area we're not working on.

Step 2: Sanding with different grains

This step involves removing the deteriorated material from the headlight. In other words, we'll remove the worn outer surface of the thermoplastic that contributes to the headlight's opacity. Although it might seem strange, we're going to further remove the damaged part of the plastic, and for this reason, we'll use various grits of sandpaper . The first thing to do is assess the extent of the damage to the headlight, as the coarsest grit (400 grit) might not be necessary.

But we'll start with a truly damaged headlight. We'll use a variable-speed drill and focus on a low speed (we could do it by hand, but it will be more tiring). We'll attach 400-grit sandpaper to the drill and begin sanding. There are two important things to keep in mind before we start. The first is that it's a good idea to gently wet the surface as we sand. The second is that we must avoid sudden movements , applying too much pressure, or focusing on a single spot. We could end up permanently damaging the headlight.

Therefore, our movements should be smooth and constant, sliding the sandpaper across the entire surface. Once we finish, we'll clean it again, and if everything is okay, the plastic should be white , as if it were frozen. There shouldn't be any shiny surfaces, and if there are, we'll repeat the process.

Once we've finished with the 400-grit sandpaper, which we shouldn't overuse as it's very abrasive, we need to repeat the process, first with 1.000-grit sandpaper and then with 2.000-grit . These are less abrasive and will gradually remove the scratches , leaving the glass clearer. The process is the same: gradually wet the glass, for example with a spray bottle, using gentle movements and without keeping the machine in one place, and clean it afterward.

Step 3: Polish the headlights

In this step, we need to ensure the headlight is evenly coated, with no damaged or shiny surfaces, and that we have thoroughly cleaned the surface again with water. It's also essential to dry it completely so the polish can work properly. It's important to carefully dry the surrounding areas and crevices to prevent drips from falling during the process.

We need to use the liquid polish with silicones that's on our list, a material you can find at large DIY stores. It's easy to use. Attach the wool pad to the drill and apply a small amount of polish to it. Then, add more polish to the headlight and spread it over the entire surface.

It's time to polish with the drill, again at low or medium speed, and without focusing on the same spot. We'll polish the entire surface little by little without applying too much pressure, and we'll see how our headlight begins to regain the transparency we so desired. If we don't achieve the desired result, it's worth repeating the process.

Step 4: Cleaning

Once we've finished and are satisfied with the result, it's time to clean our work and examine it closely. With a completely clean headlight, we can then see if we've done the job correctly by checking if the surface is now transparent and smooth to the touch. If not, we can repeat the polishing process.

To clean the lighthouse we will have to repeat step number 1, passing a cloth wet with soap to remove all the remains that may have accumulated throughout the work. It is also convenient to dry the headlight to visualize a more realistic result: with water the plastic will always be brighter.

Step 5: Varnishing or sealing

Although this last step is optional, it's worth considering. Simply polishing the headlights isn't entirely effective, as it removes the protective varnish from the plastic, and over time it will end up just as damaged. Therefore, a protective varnish or sealant is a very important option to consider if you want a long-lasting, and not just optimal, result.

These varnishing kits are usually sold by specialists. The application process is detailed in the instructions, but it essentially involves applying the varnish layer and letting it dry . This will take a little longer, as the car won't be usable and must be protected from any external elements that could damage the finish. We can consult a specialist for this step.

How long does headlight polishing last?

Talking about how long our sanitized headlights will last is very complicated. Polishing the headlights of our car is not 100% effective, and they may not look like new. But yes, in a way that makes it safe to drive with them while improving the image of our car to, for example, sell it.

The polishing process has a limited lifespan , and if the headlights have deteriorated before, they'll most likely deteriorate again. Sunlight, harsh weather, and use all contribute to the headlights losing their appearance and effectiveness. Therefore, it's never as drastic a solution as replacing the entire headlight or, if possible, just the cover. However, polishing is always the cheaper option.

Considerations when polishing headlights

There are a few things to keep in mind when polishing your headlights. The first, related to durability, is that it's not a solution to overuse . Sanding removes material, which gradually wears it down. It's recommended not to do this more than two or three times, as the plastic will eventually become very thin and brittle. This always depends on how abrasive you are and the initial condition of the headlights.

Another consideration is whether to repair both headlights . This is important because, unless one is completely new and the other is damaged, you won't improve the lighting or avoid problems with the vehicle inspection (MOT/ITV) if you only repair one of them. Never forget, both headlight assemblies work together. Maintenance is essential , and it will suffice to clean them periodically, avoid car washes with rollers, use harsh cleaners that could damage them, or, as the best prevention, keep the car in a garage to minimize exposure to the elements.

Finally, as a safety tip, if the ITV does not tell you that your headlights are damaged and, nevertheless, you deduce that their lighting or appearance is not adequate, do not hesitate to polish them. Sometimes it can be a forgotten detail but, we finish as we started, they are responsible for us being able to see and be seen.

We hope that with all the information we've given you in this article, you now have a clearer understanding of how to polish your car's headlights so they shine like new again.

Tips for polishing headlights well

• Machine polishing is the one that gives the best results. You'd be fine with a drill with an adapter.
• Liquid polishes work great. Any of the style
• kitautos o visbella will do, because the most important thing is to apply them correctly. There are several types, but we recommend those that come with various increasingly finer polishes.
• When you put the liquid on the sponge do not turn on the machine until it is not in contact with the lighthouse. Otherwise the centrifugal force will cause the polish to come out in all directions.
• If you use a drill with adapter don't over-rev. Regulates the speed between low and medium if you have the option. If it doesn't, don't hold the trigger down continuously so it doesn't reach full speed. Go giving it small touches of a couple of seconds.
• As controlling the polisher or drill is somewhat more difficult, do not fall short with the protection of the other elements of the car. If you can, double the masking tape to have more margin for error.
• If polish falls about painting of your car do not remove it with a cloth. To do it well, pour plenty of water on it and let it fall by itself. If you have a pressure water gun it will be easier for you. 

There's also the option of using a specific polish for hand application instead of a machine. While the results are quite good, it requires a lot of work to achieve a finish similar to a machine polisher. Plus, they tend to be much more expensive than the toothpaste or baking soda tricks.

Polish headlights at home, toothpaste?

The ingredients that give toothpaste its polishing properties are abrasive particles . For example: silica, titanium dioxide, or sodium bicarbonate. These compounds keep our teeth clean while also leaving the plastic of headlights looking like new . To make sure you choose the right one, forget about clear gel toothpastes. Buy a traditional, thick, opaque cream toothpaste, which is usually white.

How to use:

1. Wash the headlights with glass cleaner to remove dust and other debris.
2. Put a good squirt of toothpaste on a towel or microfiber cloth.
3. Rub it over the entire surface of the headlight in small circles. The longer the better, but 5 or 6 minutes will suffice.
4. Add more paste as the one already on the headlight dries.
5. Rinse with plenty of water and clean it again with the glass cleaner.

Another type of homemade polish: WD-40 plus baking soda

This mixture combines the cleaning properties of WD-40 or 3-in-1 oils with the abrasive effect of baking soda . It's recommended if the headlight has stubborn stains like encrusted rust. If you use this mixture, be careful not to get the oil on the trim or other plastic parts of the car. Masking tape will help prevent this.

How to use:

1. Make a frame around the headlight with masking tape or similar.
2. Mix the WD-40 and baking soda together to get a thick mixture. To get an idea of ​​how thick it has to be, they seek to achieve a creaminess similar to toothpaste.
3. Rub it over the entire surface of the headlight in small circles. The longer the better, but 5 or 6 minutes will suffice.
4. Wash with soap and water making sure you remove all the oil
5. Clean the headlight with glass cleaner

Why do our headlights deteriorate?

To understand what happens to our headlights, we first need to analyze why they deteriorate. By deterioration, we don't mean broken glass, but rather a loss of transparency , which translates into a loss of effectiveness. This may not be such a problem nowadays, but when headlight lenses became completely transparent, many ended up with a whitish or yellowish tint.

Although we still call them glass, headlights are now usually made of polycarbonate, a lighter and, in theory, more resistant material. The problem with this material is that its continuous exposure to the elements can take its toll, such as sun exposure , which eventually burns the headlight's outer surface, or the erosion that appears with use. Even using overly powerful bulbs can damage this polycarbonate, although in this case the damage will mainly occur on the inside.

What symptoms are there?

There are three ways to detect that our headlights are worn out . For the less observant, it will probably be during the vehicle inspection (MOT/ITV) when the inspector points out that our headlights have a problem. And the problem will directly impact our wallets, since faulty headlights are a violation.

Headlights are another symptom that indicates something is wrong. It's somewhat ambiguous, as those who don't drive in low light or at night won't notice the difference, but those who do will see that their headlights no longer illuminate properly because the light passing through the plastic cover is insufficient.

Finally, the simplest and quickest way to detect the symptoms is to look at your headlights and see that they no longer look like new. They've lost their transparency, and you'll probably see a whitish or yellowish layer . Furthermore, if you touch the headlights, you'll notice a rough surface that might even leave small fragments of material on your fingers.

What consequences does it have?

The consequences of damaged windows include, first and foremost, a loss of lighting efficiency. As we mentioned earlier, this can pose a problem when passing the vehicle inspection (ITV ), and it can also result in a fine if the damage is excessive.

Beyond the potential economic impact, it poses a danger to ourselves, as our inadequate lighting will not properly illuminate the road or road signs. Furthermore, regardless of the type of headlights , they are designed to allow us to see and/or be seen; therefore, other road users, whether cars, pedestrians, or cyclists, may not see us and cause an accident.

Images – Chemicalguys, abe baksh, Turtle Wax, Janmi S, Steve Snodgrass, Tim Reckmann