5 best sealants for car headlights

If the optics of the car fails, this will greatly affect the safety of the ride and make travel impossible in the dark. The cause of serious problems on the road can become even a small crack on the headlight, because it entails a loss of tightness, moisture and dirt entering the part. When replacing optics, a headlight sealant is used, which provides high reliability and strength of the seams.

Content:

• Varieties of sealants
• Silicone sealants
• Polyurethane Compounds
• Anaerobic Compounds
• Heat Resistant Sealants
• Rating of the best sealants
• ABRO WS 904
• Dow corning 7091
• DoneDeal DD6870
• 3M PU 590
• Emfimastic PB
• Instructions for use
• Removing old sealant

Varieties of sealants

Special sealing compounds for headlights have a very specific purpose. They are used for minor repairs and installation of automotive optics made of transparent plastic or glass in order to obtain the most tight connection.

Waterproof sealants perform such tasks:

• prevent the penetration of water, air and dirt into the device;
• eliminate the appearance of condensation and a decrease in the quality of lighting;
• minimize the risk of damage to the diffuser and other metal elements;
• provide strong joining of parts without danger of peeling off.

In automotive stores, sealant for gluing headlight windows is a popular product, because optics often fail and are the first to spoil during accidents. Most of these products are suitable not only for materials for the manufacture of headlights: sealants perfectly stick together wood, leather, fabrics, ceramics, many are used for metal.

Sealing agents may have a different composition, but most of them are sold in finished form and are single-component.

Silicone sealants

Tools with silicone are widely used in the installation of headlights, lamps, car windows. They are created on the basis of rubber and its subspecies (siloxanes, fluorosiloxanes and others), they represent a transparent elastic mass. Also, silicone sealants contain vulcanizers, giving strength and elasticity like rubber, ensuring no damage when in contact with water.

Usually, silicone compounds close cracks up to 6 mm deep or glue various parts in order to seal joints. They help to eliminate small defects and roughnesses of the base, easily withstand heating up to +250 degrees and above (products with the addition of copper - up to +375 degrees), do not spoil from temperature changes. The big disadvantage of silicone is the poor tolerance of petrochemicals and a number of other substances that are used in a car. Therefore, silicone sealants can be used where there is no contact with such liquids.

Polyurethane Compounds

Products with polymers based on urethane groups are considered the most popular in the repair and installation of optics. Motorists prefer them for their versatility, because sealants are also great for gluing, protecting many body and working parts of a machine. Their properties are as follows:

• high adhesion with most known materials - plastic, glass, ceramics, rubber, wood, metal;
• excellent moisture resistance, air tightness;
• work in a wide temperature range, tolerance of differences from -60 to +80 degrees and more;
• long term of operation (up to 25 years);
• resistance to petrochemistry, weak acids, alkalis, other aggressive substances, as well as microbes, fungi, mold;
• even filling even small cracks, seams, the ability to stick optics of any geometry;
• lack of shrinkage after polymerization.

Polyurethane compositions after solidification have a slightly lower elasticity than silicone. Because of this hardness, they are not recommended for use on joints subject to strong vibrations, although they are good for headlights. Also, sealants are not suitable for the installation of collapsible joints: they are so durable that it will be problematic to remove them.

Sealants contain toxic solvents, therefore, when applying and drying, safety measures must be strictly observed. With prolonged exposure to temperatures above + 100 ... + 120 degrees, the sealant layer is destroyed, which must be taken into account during operation.

Anaerobic Compounds

Such products harden only when contact with oxygen ceases, while maintaining their ductility in air. They can be slowly applied to parts, pressed tightly against each other, which is convenient for the master. But in a vacuum, the process of rapid polymerization begins, as a result of which a strong seam is formed in a couple of minutes. Anaerobic sealants do not deteriorate at temperatures in the range of -80 ... + 175 degrees, they are resistant to action:

• fuel;
• oils;
• antifreeze;
• alkalis;
• weak acids.

Means create a reliable cushioning layer and help to mount optics, front and rear windows, as well as seal body joints, threaded joints, flanges. After solidification at the place of application of the composition, a solid, durable plastic is formed that lasts a long time, does not deform, does not shrink and does not expand. Convenience of use is not in doubt - this is the absence of the need for quick application, the application of physical efforts for bonding, safety for humans and the environment.

Heat Resistant Sealants

These compounds are characterized by increased strength and the absence of a reaction to high temperatures (usually up to +375 degrees). They are rarely used for repair and installation of headlights, because such connections are not subject to thermal stresses. The finished seam is not afraid of shock, shock, vibration, the action of water and aggressive substances. The disadvantages of heat-resistant sealants are the increased cost and long polymerization (8-12 hours until complete drying).

Rating of the best sealants

To work with automotive optics, you need to purchase high-quality tools in order not to know the problems with the functioning of lighting devices.

ABRO WS 904

Sealant ABRO WS 904 - one of the most popular at the request of users. It is implemented in the form of adhesive tape in rolls of different sizes, made on the basis of vulcanized polyisobutylene - a derivative of artificial rubber.

This butyl sealant for headlights is highly elastic, easy to use - you just need to cut a piece of tape of the right size, stretch and stick to the surface. A few seconds are enough to connect the ends of the tape to each other - the polymerization process is fast. At low ambient temperatures, it is recommended to additionally heat the sealant with a construction hair dryer.

The advantages of the tape ABRO WS 904 are as follows:

• low consumption - the packaging is enough to completely seal the set of headlights;
• ease of installation - the tape does not stick to your hands, is flexible, easy to cut, stretches to achieve the desired thickness without effort;
• high adhesion to most materials;
• lack of toxic secretions and unpleasant odor;
• strength, long service life after solidification, reliability and complete tightness of joints.

Dow corning 7091

It is recommended to purchase this sealant when working with dissimilar materials that have different thermal expansion coefficients. It is able to create high-quality joints at the junction of glass with metal, glass with plastic, metal with plastic, so it is perfect for installation and repair of automotive optics.

Dow Corning 7091 Silicone Sealant is a one-pack, ready-to-use product with high strength combined with elasticity. The sealant is suitable not only for working with car headlights, but also for installing LED lamps, various electronic devices and complex mechanisms. After polymerization, the formed seam will reliably seal the junction, while it does not collapse from temperature extremes and can be operated at -55 ... + 185 degrees. The sealant is easy to process, if required, is a good dielectric.

DoneDeal DD6870

The composition of DoneDeal DD6870 refers to polyurethane sealants, includes urethane groups, oil products, various polymers, adhesion promoters and other additives.

It can be used for installation and sealing:

• headlights;
• glasses;
• lanterns;
• fixtures;
• hatches;
• instead of gaskets.

The sealant dries completely in 15-30 minutes after application, is characterized by high strength joints, good adhesion to most materials, does not crack under the influence of vibration, shock. The product is characterized by moisture resistance, works without loss of properties in the temperature range from -60 to +270 degrees.

3M PU 590

Sealant 3M PU 590 is produced in the USA, has a polyurethane base, is packaged in convenient tubes of 300-600 g. It does not tolerate a strong temperature increase (can withstand up to +100 degrees), therefore it is not used on heating units of a car. The product quickly polymerizes (in 25-30 minutes), does not react to the action of acids, alkalis, solvents, is resistant to moisture and UV radiation, reliably connects even dissimilar materials. After hardening, the seam can be painted with most automotive paints.

Emfimastic PB

Glue-sealant of this brand is made in France, contains polyurethane groups and various improving additives. Efirmastika glues homogeneous and dissimilar materials as reliably as possible; it is ideally suited for installation and repair of automotive optics. The composition is odorless, hardens in half an hour, does not shrink, does not crack with time. It is not harmful to humans, has no unpleasant odor, can be used even indoors. To apply this flexible sealant, a hand or pneumatic gun is required.

Instructions for use

Before using any product, regardless of its shape and appearance, the surface must be carefully prepared. The headlight and the base are cleaned of dirt and old sealant (if any), degreased, while working carefully so as not to damage the lens. After applying the agent in a thin layer, acting according to the instructions:

• liquid formulations are dispensed using a dispenser;
• paste-like products are squeezed out by means of a glue gun;
• tapes are cut off and glued by hand.

If the sealant is not anaerobic, the parts must be well pressed together. When the room is cold, it is recommended to heat the seam and the elements to be glued with a construction hairdryer. After that, wait until complete drying (usually no more than 30 minutes).

Removing old sealant

Most often, when installing a new headlamp on the base, there are particles of the old sealing compound. Its removal can be a problem, especially if the product was made on the basis of polyurethane. Care must be taken not to scratch the base and damage important components.There are several ways to remove sealant:

• heat the dried composition with a hairdryer, carefully remove it after softening (it is important not to melt the plastic on the optics overlays);
• scrape off the sealant particles with a sharp knife, a flat-blade screwdriver;
• wipe with solvent.

For the installation of headlights, it is better to use proven, reliable sealants and strictly follow the instructions for their use - in this case, the optics will last a long time and will not cause problems on the road.