Headlight seals, also known as headlight sealants or headlight sealers, are designed to keep moisture, dirt, and debris out of a vehicle’s headlights.
The headlights need to remain unobstructed because when they get foggy on the inside with beads of moisture, they don’t illuminate well.
There are many different headlight sealers to keep track of, each made of different materials even if they all serve the same purpose. Common headlight sealer types include acrylic sealant, butyl tape, epoxy sealant, polyurethane sealant, and silicone sealant.
One of the most common types of headlight seals is acrylic sealant. It’s known for its durability and protection against moisture. Acrylic sealant is also resistant to the elements, preventing water, snow, and flying debris from entering the headlights.
Many drivers love acrylic sealant because it comes in both clear and colored versions, allowing them to choose which one fits the aesthetics of their vehicles more.
Butyl tape, also known as butyl rubber sealant, is another type of headlight seal. Its reliability makes it quite popular. On top of that, it’s pliable and built to last, making it an excellent choice for sealing headlights.
It’s made of materials that can handle constant vibration from driving and has minimal thermal expansion.
Butyl tape is typically installed by heating it first, which melts it and makes it stick better to the vehicle.
Unlike other sealer types, epoxy sealant is made of two different components: resin and hardener. When these two components cure, they form a strong and durable seal on headlights. This sealant isn’t as flexible as the others, but its rigidity makes it good at preserving the structural integrity of the headlights.
Despite its flexibility, polyurethane sealant is known for its strength and longevity. This makes it an excellent choice for sealing headlights and other components that might need extra protection.
On top of its flexibility, it’s also resistant to the elements, making it good at keeping headlights safe from harsh weather conditions. Some polyurethane sealants also cure quickly, whereas others are safe to paint over.
Another popular sealant type is silicone sealant. This material is known for its resistance to UV light and high temperatures, which means it’s perfect for drivers in hotter, sunnier states.
On top of being resistant to sunlight, silicone sealants are waterproof and effective at keeping moisture away from the headlights.
Are you considering resealing your headlights on your own or hiring a professional to do it for you? Here’s a closer look at what the process may entail:
Once you get the headlights removed, take all the bulbs out, but don’t touch the glass on the actual headlight bulbs. The grease from your fingers will cause the headlights to fail, so handle them with gloves or tissue. If there are turn signal or marker lamp bulbs in the assembly, remove those too.
If there has been moisture in the lights for a while, you may have had some headlight bulbs shatter and there may be glass shards rattling around in there, so get all those out, along with any sloshing water. Next, use compressed air or a coat hanger with a piece of absorbent cloth taped to the end to go in through the headlight port and clean the inside of the lens as completely as you can.
You may not be able to see where the water is getting in past the original sealing joints, but if you’re handy with shop air, you can pressurize the headlight bulb through the headlight port with gentle air pressure and spray soapy water along the sealing joints to find the leak point. This is important, because this will be where you’ll focus your efforts in addition to sealing the entire joint where the lens and housing meet.
You may as well go ahead and make the headlights look new while you’re at it, eh? You might want to do this after resealing the lights, but you can do it before. Each process needs to be dry before you move on to the next one though.
Most of the time, headlight lenses are plastic welded to the housings, so this won’t apply on those. But if the headlight was sealed with soft sealant to begin with, apply heat to the headlight len perimeters to remove the sealant that protects it from moisture and debris.
This can be done by baking your headlights in the oven at 220 °F for 15 minutes or by using a blow dryer. Heating the sealant makes it easier to remove it. You can use tools such as flathead screwdrivers to help you scrape off the sealant. Do not use too much heat.
After the old sealant has been removed from your headlights, apply the replacement headlight sealer. The process of applying sealant varies depending on the type of sealer used. Pay close attention to the instructions included with the product of your choice.
After applying the replacement sealant, reinstall your headlights.
The most common signs you need to reseal your headlights include noticeable moisture buildup, in the housing, and/or crumbling seals.
Headlight seals exist to prevent the buildup of moisture inside your headlight. If it fails to do that and the headlights fog up, there’s a good chance your sealant’s damaged. If you see water or condensation inside, that’s a clear sign that it’s time to remove the old headlight seal and replace it with a new one.
Headlight seals don’t last forever. When these seals wear out or get too dry, they crumble and crack. If this ever happens, that’s a sign it’s time to reseal your vehicle’s headlights. Failing to do so invites dirt and moisture, obscuring your headlights.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.