Choosing adhesive for windshield installation and repair

Main types of adhesives for auto glass, classification by composition

Car glass adhesive can have different compositions, which determine the degree of its transparency, quality of fixation, and scope of application. A popular option is polyurethane adhesive; it is often used in professional car repair shops for various purposes, including gluing visor frames. This glue requires careful preparation of the base before work and the mandatory use of a primer (primer), otherwise leaks will quickly appear along the contour of the part and areas of corrosion will appear.

In addition, to seal and insert auto glass, craftsmen use the following compounds:

1. Balsam. In appearance it is a glassy mass of yellowish color. The product is made from fir resin and is used to hold together fragments and seal holes in car windows. The glue dries quickly, has good penetrating ability, and is resistant to high temperatures. In addition to its advantages, it has a significant drawback - yellow spots may appear on the surface.
2. Balsam M. Made on the basis of the previous one, but better in terms of strength, water resistance, and durability. The glue is transparent, does not leave stains, and does not deform after drying.
3. UV glue. It is a transparent sealant for gluing car windows, flowing into even the smallest cracks, allowing you to remove chips of any size. Curing of the composition requires exposure to ultraviolet radiation.
4. Acrylic glue. Ideal for DIY glass repairs. It has excellent viscosity, does not spread, and is very easy to apply to the surface. The downside of the product is long drying (up to 3 days).
5. Silicone sealant. It can be black, white or transparent, it works like an elastic seal: it allows you to solve the problem of leakage of a self-inserted windshield. It can be produced in tubes, pistol cylinders, sprays. The latter are usually used in hard-to-reach areas, are convenient to use, but have a fairly high cost.

Some drivers try to remove a chip or other glass defect using regular superglue. But contact adhesives are not suitable for this type of work: after drying, they make the glass cloudy and stain it. If vibration occurs while driving, the crack will spread further, because superglues have low elasticity.

Useful tips for working with glue

The adhesive composition requires certain environmental conditions. To improve its performance, the following conditions must be met:

• Choose a room in which the air temperature will be at least +5°C, optimal conditions +15°C.
• It is necessary to ensure that the car remains static for at least 1 hour, even when using the highest quality and fastest-acting adhesives.
• After completing the procedure, you must refrain from slamming the car doors for a certain time, as well as the room itself where it is located, and do not create increased vibration by any means.
• After gluing it is worth lowering the side windows of the front doors for a while.
• When installing glass, wear protective equipment: glasses and gloves.
• After gluing joints, seams, cracks or other damage, you need to refrain from washing the car for two days.

Replacing the windshield yourself and gluing in a new one using sealant is much easier than replacing the rear one. Therefore, after successfully completing this procedure, you can move on to a more complex operation.

Using sealant for car glass (2 videos)

Sealant for auto glass (20 photos)

Types of adhesives by purpose

Auto glass adhesives vary depending on the application. In each specific case, you need to choose exactly the right product, because adhesives for installing glass differ in properties from compositions for sealing cracks. Two groups of such funds are described below.

For glass installation

These adhesives are used specifically for installing the windshield when it is completely replaced. Mounting compounds have successfully replaced rubber gaskets for fastening static glass. They increase the strength and tightness of the joint. After gluing the glass, the risk of it flying out in an accident is reduced, and the rigidity of the body increases.

To eliminate defects on glass

Such means are called repair or optical. After curing, their main advantage is that the optical properties of the seam are identical to those of the glass itself. Simply put, good adhesives remain crystal clear after curing.

Optical adhesives have high fluidity, which allows them to penetrate even small cracks, and they are resistant to water and ultraviolet radiation. Typically, repair adhesives are sold as part of a do-it-yourself kit, which additionally includes:

• transparent film;
• metal needle;
• dispenser;
• frame with suction cups;
• blade.

With the help of such a repair kit, you can easily repair defects and chips at home, following the instructions.

Rules for choosing adhesive for auto glass

To repair windshields, you need to use compounds that provide maximum bond strength. Experts recommend that beginners choose high-density adhesives, which, when dry, give the highest quality results. Also, the product must indicate its good penetrating ability, otherwise it will not be able to repair microcracks in the glass.

To choose the right glue, you need to pay attention to the following characteristics:

• degree of transparency;
• resistance to UV rays;
• elasticity, ability to withstand vibration;
• frost resistance and heat resistance;
• resistance to temperature changes.

You should also make sure that the glue has a normal shelf life and that it contains polymer resins. For a small, shallow scratch, you can choose a very thick glue, since sealing the defect does not require a high degree of penetration of the composition deep into the surface. For cracks of significant depth and length, products with the highest degree of adhesion are purchased. If the defect exists for a long time, the repair may not bring the desired result, since it will not be possible to completely clean the crack from dust. In such a situation, it is better to contact a professional car service center.

What to do about chips and cracks

Technology for properly replacing a car windshield

These damages are of different nature, so the methods for eliminating them vary. To repair any chips, an automotive sealing compound with a medium viscosity is suitable. This sealant will make the seam strong and will fill even deep chips. If the potholes are as large as possible, choose the thickest sealants and apply them strictly according to the instructions.

To eliminate cracks, experts recommend choosing liquid adhesive-sealants or compounds with an average viscosity so that the substance penetrates into the thinnest cracks. A thick composition will not be able to fill such damage.

During application, it is important to ensure that the composition does not get on adjacent areas of the glass. But if the sealant gets dirty, it's important to remove it as soon as possible before it hardens.

Advantages of adhesive sealant

Windshield sealants are popular among professionals and hobbyists. Here are their advantages:

1. Elasticity. Since glass undergoes heating and cooling every day, its fastening compounds contract and expand due to temperature changes. The integrity of the seam will be preserved only by an elastic means, which will not lose the reliability of fixation when the condition changes.
2. Shock absorption capabilities. The adhesive seam is quite elastic, so it helps to partially dampen vibration and shock during movement.
3. Fast drying. This property allows you to start using the car after just a couple of hours, because the adhesive seam will be completely hardened. Due to their high drying speed, sealants compare favorably with polyurethane adhesives.
4. Ease of use. Even a beginner can apply sealants. To work with them, you do not need to purchase additional equipment. Most of these adhesives do not require the prior use of a primer.

Purpose and main characteristics

Glass sealant is intended for installing triplex, repairing car headlights, and fastening fiberglass decorative elements. It is necessary wherever you need to glue a part that will be subject to vibration, temperature changes and moisture.

Characteristics/main properties of high-quality glass sealant:

• hardening period – up to 12 hours;
• initial setting time – from 15 minutes;
• possibility of application to old material;
• pasty stable consistency;
• high elasticity;
• density – from 1.02 to 1.35 g/cm3;
• film formation time – half an hour (humidity 50%, temperature 23 °C);
• volume change – <1%;
• operating temperature range – from -40 to +90 °C.

If you have a high-quality composition, even inexperienced motorists can glue a car window with sealant in a few hours.

The best adhesive mixtures for installing auto glass

In any specialized auto store you can find a whole list of adhesives that are suitable for installing and repairing glass. By article number, any of them can be found in online stores. It is important to choose only products from trusted manufacturers who have no complaints about quality. Here is a list of good adhesives:

• Terostat Henkel;
• DoneDeal;
• Loctite;
• Scotch-weld Rite;
• Permabond.

Most manufacturers produce both individual adhesives and kits for auto glass repair. Silicone-based sealants are in great demand, as are ultraviolet adhesives, which quickly harden when the seam is exposed to sunlight. To reduce drying time, professionals additionally use UV lamps with a wavelength of 250 Nm.

Rules for gluing the windshield

To carry out the entire process correctly, you need to meet a number of conditions and prepare the foundation. In the room where the work will be carried out, the temperature should be within +5...+20 degrees, the optimum is about +15 degrees. Before starting operation, you must not touch the car for at least an hour; its doors should not be opened or closed during this period. The car must be parked with the side windows of the front doors down. It is undesirable to open the door of the premises within an hour, otherwise there is a risk of deterioration in the quality of the seam. After sealing the glass, you can wash your car no earlier than 2 days later.

Immediately before starting crack treatment, you need to do the following:

• thoroughly wash and dry the glass;
• remove all contaminants from the crack using convenient devices, needles;
• remove remnants of old glue, sealant, if any;
• degrease the crack with solvent, acetone;
• apply glue according to the instructions;
• level, remove excess with a scraper;
• dry the defect area;
• perform polishing.

If you have to completely replace the glass, the order of work will be as follows:

1. Cutting the windshield (the work is carried out with an assistant). First, you need to carefully pierce the layer of old glue that is between the glass and the body, using an awl with a string threaded through it. Use pliers to pry the string from the reverse side, then pull the awl back. As a result, one side of the string will be located in the cabin, the other - outside. Attach the string to any handle so that it is easy to pull.
2. Glass cutting. Carefully, so as not to scratch the car, pull the string along the glass from the outside. An assistant must pull it out of the cabin. In the corner, bring the string up, repeat cutting along the side and then until you return to the starting point. Take out the glass and remove any remaining glue.
3. Preparing new glass. Fix special Velcro on the left side of the glass; the product will rise and fall on them. Repeat the manipulations on the right side of the windshield. Attach masking tape to the gluing area. Degrease the glass with a solvent.
4. Applying glue. To work with the composition, a pneumatic glue gun is usually used, which begins to operate when the trigger is pressed. Thanks to the gun, the adhesive layer will be even and continuous. You should carefully squeeze the glue out of the tube, moving around the perimeter. The glass should be placed on a flat surface, for example, on the hood.
5. Windshield installation. Take the product by the Velcro and place it in its proper place. Tape the top to temporarily secure it. Leave the car for 1-3 hours to achieve complete polymerization of the composition. Next, drive the car outside, leave it for another 12-20 hours, and only then start using it.

Flow calculation

Typically, installing new glass requires 300-600 ml of glue or sealant, depending on the size of the car. It is better to purchase the product with a reserve so that you do not have to repeat the work again if there is not enough glue.

Terms of use

It is important to apply any sealant at positive air temperatures; most manufacturers advise that the temperature be above +5 degrees, or better yet, above +15 degrees. After application, the car must not be moved for approximately 2-3 hours.

Before you begin, it is important to wear rubber gloves and safety glasses.

Sometimes old sealant is quite difficult to remove. First, it can be heated with a hair dryer, due to which the old product will soften and be easier to remove from the surface of the car.

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Remains of the substance can be removed with a regular knife, but it is important to cut off the sealant carefully so as not to leave scratches on the car body. To dissolve the remaining sealant, use a solvent or solarium. It is necessary to adhere to the following sequence of actions when gluing glass:

It is necessary to adhere to the following sequence of actions when gluing glass:

The old seal does not need to be completely removed, but cut with a sharp knife to a thickness of about 2 millimeters; if required by the instructions, the substance must first be heated before application; the sealing compound is applied using a pneumatic or mechanical gun in a uniform layer without breaks; After gluing the glass, it is important to secure it with ordinary masking tape; The side windows of the car are lowered to dry and ventilate the car.

It is important to remember that any sealant can only be applied to a surface that has been previously cleaned of dust, dirt, debris, grease stains and other contaminants. The surface must be degreased using a solvent.

Do not slam car doors until the composition has completely hardened. After gluing the glass, it is not recommended to drive the car for the first 48 hours.

Rating of adhesive mixtures for installing auto glass

Among the variety of compositions for repairing windshields, several of the most popular and high-quality ones stand out.

SikaTack Drive

The composition is made in the USA. It is very reliable and versatile: suitable for repairing glass of trucks and cars. The volume of the product is 310 ml, you need to work with it at a temperature of +20...+22 degrees. The glue hardens within 4 hours.

3M Windo-Weld SuperFast Urethane

This sealant is most often used for racing cars due to its high strength. It is easy to apply, begins to cure after 15 minutes, and fully crystallizes after 8 hours. After the same period of time, it is possible to start using the car.

Dow Automotive Betaseal 1527

The product requires preliminary application of a primer (included in the kit). It can harden already at +5 degrees, polymerization begins after 12 minutes. The car can be used an hour after applying the glue. The strength of the seam is quite high, but the conductivity is reduced.

Dow Corning 7091

The glue is produced in different packages: from 310 g to 250 l. It is very often used in car services due to its reliability, high quality and reasonable price. The glue does not stain or blot, dries in 3 hours, and does not require prior priming or heating. It is elastic and does not collapse from vibration.