Choosing adhesive for windshield installation and repair

Many drivers have to deal with traffic accidents that make windshield bonding necessary. Due to accidents, stones and foreign objects, chips and cracks appear on the windshield of the car. Such damage is also caused by poor-quality car service, due to which it can simply come off.

• Types of car glue
• Popular brands
• Which glue to choose?
• For chips
• Cracks
• Sealants
• Instructions for replacing a car windshield
• Tools and materials
• Work algorithm
• Drying time
• Basic mistakes when gluing glass
• Useful tips

To work, you need to choose an adhesive sealant for gluing glass on a car. With this tool it is easy to achieve the desired result. In this case, you need to follow the exact algorithm of actions and know how much time it takes to adhere the materials.

This article is devoted to the rules for gluing a windshield. It will cover:

• types of glue for cars;
• what glue to choose for car glass repair;
• popular brands of adhesives;
• How long does it take for glass sealant to dry?
• instructions for replacing the windshield;
• main mistakes when gluing;
• and other recommendations for proper operation.

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.

About gluing technologies

Glass gluing is carried out using two technologies - primer and primerless. The first involves the use of a special primer - a black primer, which is applied along the edge of the glass. The activator and glue are already applied to it, after which the glass is fixed in the frame. This technology was previously used in many service centers, but today craftsmen use a more modern method - gluing car windows without a primer.

This became possible thanks to the production of glass with a protective stripe, which is applied by silk-screen printing. And the primer is replaced with a colorless activator, which can be applied to metal or remnants of old sealant. You cannot do without an activator - it is needed to improve adhesion to the primer.

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.

Crack repair

To repair a crack, the technician must determine the presence of residual stress and remove it through an artificial chip at the end or fill the tip with crack repair glue with the highest fluidity and dry it with a lamp. Then repair the chip that caused it and fill the crack along its entire length with a polymer of medium viscosity.

Cover the outside of the polymer with a special film and dry it with ultraviolet light. Clean the repair area.

High-quality glass glue is guaranteed to seal the edges of the crack and visually hide it from view.

If you do not have experience in glass repair, then you should not undertake it in order to save money. After all, if it doesn’t work out, then even a professional will not correct the consequences. The glue will harden and the new composition will no longer penetrate into all cavities. When carrying out repairs yourself, you need to understand the risks that can lead to poor-quality results and subsequent replacement of the auto glass.

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.

Betaseal

Professional gluing of car glass requires high-quality compounds. The Betaseal brand produces automotive glass adhesive that prevents windshields from falling out, ensures the correct operation of airbags, and prevents roof deformation. Thanks to the rigidity of the fastening, the windshield and the vehicle body are firmly held together. The following characteristics speak in favor of choosing compositions with a polyurethane base:

• high level of elasticity;
• good adhesion to painted surfaces;
• high polymerization rates;
• resistance to sunlight and deformation.

Thanks to good moisture resistance and viscosity, high shear modulus and low resistivity, the windshield is completely compatible with the body.

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.

FC Kit Dinitrol

Dinitrol adhesive for gluing car glass is a universal product with a polyurethane base, which, thanks to its good consistency, easily and quickly fills all gaps and hardens under the influence of external moisture. The use of this composition is advisable for direct gluing of glass during repair or production of vehicles. Good viscosity in combination with application on a well-prepared surface ensures a reliable adhesive connection. The most popular composition in the brand’s line is Dinitrol 500, which differs:

• good adhesion to paint and varnish coatings;
• lack of odor;
• good performance characteristics;
• good dimensional stability properties;
• high elasticity.

Reviews mention that Dinitrol formulations must be used with preliminary preparation of surfaces, which involves treatment with a primer and activators.

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.

LIQUI MOLY

How to glue car windows if they are broken or cracked? The LIQUI MOLY brand offers a whole line of one- and two-component compositions that quickly harden when exposed to air moisture. Adhesive-sealants of this brand are ideal for gluing any glass in a car, and the process is completed in literally 2 hours. In addition to average strength, the glue is characterized by high viscosity and excellent quality.

Using LIQUI MOLY 1400 glue, you can quickly glue the glass, and after a few hours you can use the car. It is applied to the body opening, which is first carefully leveled and cleaned.

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.

Wurth

Wurth products have proven themselves as reliable products for gluing rear-view mirrors, parts to rotating windows and gluing glass. The line includes sealants of various types, which are characterized by ease of use, quick installation due to good adhesion, and resistance of the adhesive joint to shock loads or vibrations.

Wurth car glass adhesive is tested for safety in German laboratories and approved by leading vehicle manufacturers. As with other similar products, surfaces must be cleaned and degreased before applying glue. This will increase adhesion and improve the performance properties of the composition.

The article describes the most popular types of sealants produced by leading manufacturers. All of them are equally effective and easy to use, so there will be no problems with replacing car glass.

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.