How To Fix A Cracked Headlight

This is our guide on how to fix a cracked headlight. 

Car headlights are made of durable polycarbonate that resists cracking and shattering. However, over time, it can develop small cracks in the surface that let in moisture, dirt and other contaminants that could damage the headlight bulb. 

If your headlight has suffered a ton of damage, such as in an accident or head-on collision, you will have to pay professionals a hefty sum to get the headlight repaired or replaced. 

The good news is, depending on how extensive the damage is, you might be able to fix a cracked headlight yourself, with only a few tools necessary. 

We’ve been working on and testing headlights for over a decade. So if you need help fixing a cracked headlight, you came to the right place. 

Keep reading for more information on how to fix a cracked headlight. 

Can You Fix A Cracked Headlight?

The answer to this question really depends on how extensive the damage to your headlight is. For example, if there is a small crack or a deep scratch in the headlight lens, you might be able to fix it at home, or pay someone to do it for you. 

However, if there is a large, gaping hole in the headlight lens, fixing it may not be possible. Additionally, your headlight lens is not a jigsaw puzzle, so if it’s in a million pieces, it can’t be put back together and you’ll have to replace it altogether. 

What You’ll Need To Fix A Cracked Headlight 

So here are all the supplies you’ll need to fix a cracked headlight. 

Headlight Cleaning Solution

This can be the solution you would normally use to clean a headlight. We recommend using a solution of distilled water and some automotive shampoo. 

Microfiber Towels

Microfiber towels will be used for drying and buffing the headlight without leaving behind any tiny particles of fabric and the like. 

Sand Paper

You will need different grits of sandpaper to fix a cracked headlight. We recommend starting with 1000 grit, and then working your way up to 2000, then 2500, and finally 3000 grit sandpaper. 

Headlight Polish 

This will be used to restore the headlight to its original shine after you’re done fixing the crack. 

Clear Silicone Sealant 

We will use clear silicone sealant to fill in the crack. If you want, you can also use a high quality super glue, like Loctite Epoxy or something similar. 

Masking Tape 

Ideally, we recommend taking the whole headlight assembly off the car so that it is a bit easier to work with and fix. However, if that’s not possible, we urge you to apply masking tape around the edge of the headlight so you can avoid damaging the rest of the bodywork.

How To Fix A Cracked Headlight

Now that you’ve got all of your supplies, let’s get cracki…sorry, poor choice of words. 

Step 1: Remove The Headlight or Apply Masking Tape

The first step is to remove the headlight assembly from the car so that it is easier to work on. 

If you don’t want to remove the headlight assembly completely, you can tape off the edges to avoid damaging the bodywork with the sandpaper or cleaning products we’ll be using. 

However, if there are cracks very close to the edges of the headlight, removing the headlight assembly might be necessary. 

Step 2: Clean The Headlight Lens

Next, thoroughly clean the entire headlight lens. We recommend using a solution of distilled water and your choice of soap or automotive shampoo. 

It is necessary to clean the headlight lens so that there is no dirt or other contaminants on the surface that could cause problems with the repair process. 

Step 3: Start The Wet Sanding 

Once the headlight lens has been cleaned thoroughly, it is time to start the sanding process. Sanding the surface of the headlight lens will even out small cracks, though this might not work for larger cracks.

We recommend starting with 1000 grit sandpaper and working your way up to 1500, 2000, and 2500, and then 3000 grit sandpaper. 

To start the sanding process, spray a healthy amount of the cleaning solution on the headlight lens. Also wet the sandpaper itself with cleaning solution. 

Now, start sanding the headlight lens using even horizontal motions. Don’t apply too much pressure or spend too long in any one spot. 

When you switch to the 1500 grit sandpaper, use vertical motions instead of horizontal. When you move up to 2000 grit sandpaper, go back to horizontal motions again, and so on. 

Step 5: Use A Cutting Compound To Clear The Haze Left From Sanding

Next, apply a cutting compound onto the headlight lens and buff it out to remove the haze left from sanding. 

Step 6: Fill In The Crack With Sealant 

If you’re finished with the wet sanding and the crack is still quite visible, it’s because it’s too large and deep. 

The only way to fix larger cracks like this is to fill them in with sealant. Start out by using just a little bit of the sealant and adding more if needed. 

Be sure to keep wiping away any excess sealant, otherwise it could ruin the look of your headlight lens. Use a paper towel to wipe away the sealant, making sure you don’t let any of it get on the headlight lens or the car’s bodywork. 

Leave the sealant to dry and harden for at least 8 hours. 

Alternatively, you can also use a premium super glue such as Loctite Epoxy instead of sealant. 

Step 7: Polish The Headlight Lens

And finally, once the sealant has hardened properly, polish the entire headlight lens to restore its shine. 

How Your Headlight Might Have Gotten Cracked

You might be thinking how your headlight lens got cracked in the first place. There are any number of reasons for this, depending on how severe the cracks actually are. 

If the cracks are very small hairline cracks, they could even have been caused by extreme heat. 

Larger cracks in the headlight lens could be the result of rocks or stones kicked up from the road hitting the headlight lens. 

And if there are very large cracks or holes in the headlight lens, they could be due to a collision with another vehicle, high velocity road debris, or other such causes. 

How To Prevent Your Headlights From Getting Cracked

So what can you do to prevent your headlight from cracking? Here’s what we recommend. 

Use A Polycarbonate Headlight Protector

This is an extra layer of polycarbonate that goes over the headlight lens and acts as a barrier that prevents anything from hitting or cracking the headlight. This method is pretty effective against even larger rocks, stones, and the like. 

Apply A Protective Headlight Sheet Over The Lens

Alternatively, you could apply a protective headlight sheet over the headlight lens. This is a sheet of plastic that sticks to the headlight and prevents small rocks and debris from cracking the headlight or getting it dirty. 

However, because this is only a thin layer of plastic, it’s not very effective against larger rocks, stones, or harder impacts. 

Conclusion

It is very easy for your headlight to get cracked over time. It could be something as small as a stone or a rock that does it, or it could be due to a serious head-on collision with another vehicle. 

But whatever the case, it is possible to fix a cracked headlight. Depending on how serious the damage is, you might have to get it done by a professional. If the crack is a bit smaller, you might even be able to do it yourself at home, with just a few simple tools and supplies.


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Author

Richard Nickleson is the author and owner behind Headlight Reviews. He first started the site as a hobby to share his insights on car parts and specifically headlight bulbs, but it soon ballooned and now he writes on all topics surrounding headlights bulbs. If you've got a bulb question, contact Richard here.