Repairing cracks and chips on the windshield - the best means and methods

Small cracks in the windshield may not interfere much with your visibility. But over time, due to temperature changes, increased vibration, and high humidity, small spider webs of chips turn into a significant problem. Therefore, there is no point in delaying the elimination of minor defects. Windshield adhesive for repairing cracks can help make minor repairs easier.

Why repair chips and cracks?

Repairing a car that has a crack in the windshield is a mandatory step for safe driving and no problems from the traffic police. In addition to the unpresentable appearance, driving a car with a broken glass can also lead to other troubles:

1. The presence of a large crack or with a certain location poses a risk to the life of the driver and passengers. If the chip is deep, a pebble can fly through it at full speed, which will result in injury to a person. In addition, poor visibility on the road can even cause a serious accident.
2. If there are large cracks, the car will not be able to pass inspection. Since the defect can cause injury, it is impossible to obtain an inspection mark until it is corrected. According to GOST R 51709 - 2001, cars with any cracks in the wiper area and on the driver’s side are not allowed to be used. Driving such a vehicle is fraught with a fine.
3. Any crack can become longer, wider, and deeper over time. This will lead to the need for a complete replacement of the glass or its expensive repair at a car repair shop. Also, a car with damaged glass immediately loses its market value, and it will be much more difficult to sell it.

Driving a car with a crack in the glass may result in a fine.

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.

Types of damage

The cause of cracks can be either a stone hit or a minor accident. All defects can be divided into five types according to their shape and features:

1. Ray-shaped. Formed by a strong blow. They are usually long and extend to the edge of the windshield. Removal is possible if the size of the crack does not exceed 10–12 cm.
2. Rounded. The cause of the appearance is a sharp blow from a hard object. Such defects must be removed as quickly as possible with preliminary drilling, otherwise they will spread over large areas of glass.
3. Branching. Formed when hit by a heavy object or due to temperature changes. They are a whole scattering of branching rays, which is why they are difficult to repair.
4. Double sided. They look like a beam that appears from the interior part of the triplex. Most often, the car owner has to replace the glass, since such defects are almost impossible to repair.
5. Mixed (combined). Includes elements of different types of cracks. Their sealing is not always possible.

Branching crack on the windshield
How to stop the spread of a crack directly depends on its type. Usually, simple defects, chips and small dents are successfully repaired at home.

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.

DIY kits

Automotive stores offer a large number of adhesives and ready-made kits for windshield restoration.

GlassProfi

The set includes a blade, an adhesive disk, polymer glue, a fixing suction cup, and a syringe. Using a disk and a suction cup, the syringe is securely attached to the crack area, after which the glue is squeezed out of it. After 3–4 hours, the defect will become invisible and the composition will completely harden. Using this product, cracks up to 3 cm in length can be easily removed.

Contents of GlassProfi windshield repair kit

Windshield Repair Kit

This set includes the same accessories as the previous one, but is additionally equipped with a protective film. It helps eliminate defects on regular and tinted glass. When introduced, the adhesive composition completely displaces air from the crack, so the hole will be reliably sealed. This kit is recommended for emergency repairs, as the glue hardens within 20 minutes.

Windshield Repair Kit

Done Deal DD6584

The polymer composition included in this repair kit is characterized by very high strength, almost several times higher than that of cheap analogues. The product contains acrylic acid, so you need to work with it in the air and only with gloves. Glass restoration should be carried out in the shade in summer, and in winter - after preheating the damaged area.

Windshield Repair Kit Done Deal DD6584

Permatex

The product included in the kit is recommended for removing deep chips and can also be used for quick repairs in road conditions. This glue is not suitable for filling long cracks. The composition can damage the paint on the car body, so the hood must be carefully closed before repairs.

Transparent adhesive sealant for glass Permatex

WIEDERKRAFT WDK 65182

The kit includes a set of repair plates, a scraper for cleaning the crack and removing excess glue, an injector, suction cups and glue. It is better to work with glue indoors - this way it will harden an order of magnitude faster. In the summer, after applying the composition, you can expose the car to the sun's rays to speed up polymerization.

WIEDERKRAFT WDK 65182 chip repair kit

Basic mistakes when gluing glass

Inexperienced craftsmen make many mistakes when gluing. Of these, the most frequently accepted are:

• Incorrect adhesive mixture. For gluing, only adhesive sealant for gluing glass is suitable. It is designed specifically for these purposes, which means that only it will securely and permanently secure the glass.
• Not cleaning the recesses thoroughly enough. The metal of the body to which the windshield will be attached must be well cleaned, otherwise there is a risk of poor adhesion.
• Putting the car into operation too quickly. Manufacturers indicate on the instructions for adhesives how long they need to harden. This period is minimal, which means it is better not to touch the car even a little longer than the specified time.
• Refusal of primers. Often glues are already included with primers. Their function is to limit direct contact between glue and metal. However, there are compositions without them. Read the instructions carefully: if the manufacturer indicates the importance of this product, it must be purchased separately.

To clearly understand the principles of sizing, we recommend watching the video:

Repairing a crack in a windshield with your own hands

Before work, you need to prepare all the necessary tools and consumables and thoroughly clean the glass. Restoration is carried out only at temperatures above +10 degrees, but without using heating devices near the car, otherwise there is a risk of glass cracking. In a cold room, condensation can penetrate into the crack, which will reduce the quality of the finished seam.

Preparatory stage

First, you need to remove all dirt and dust from the crack and surrounding areas. Glass can be washed, dried and degreased, but blowing it with a pump gives an even better effect. This will allow you to remove even the smallest dust particles, which in the future will reduce the adhesion of the glue to the glass. The edges of the crack should be carefully sanded and wiped with a degreaser (acetone, alcohol).

Washing a defect on the windshield

Required materials and tools

If you purchased a ready-made glass repair kit for the job, it already contains all the necessary accessories, except for electrical tools. When completing the kit yourself, the following are usually used:

1. Polymer glue. It is absolutely transparent and looks like liquid glass. Under the influence of sunlight, the composition hardens and reliably holds the edges of the chip together. When buying glue, you need to pay attention to the polymerization time and buy the one that is suitable for a particular situation.
2. Ultraviolet lamp. Typically used if glass repairs are carried out in winter, although it will make the work easier in any case.
3. Drill with a drill for glass. The device must have a speed control function.
4. Scraper (scriber). Needed to remove dirt and debris from the crack.
5. Sharp knife. Useful for removing glue residue or dirt from hard-to-reach areas.
6. Individual protection means. For safe work, you should use gloves and a respirator.
7. Injector-syringe made of metal, plastic with a suction cup and stand. Necessary for high-quality filling of the defect with glue.
8. Magnifying glass and flashlight. They are useful for a detailed examination of the boundaries of a crack and assessing the result of its elimination.

Tools and materials for auto glass repair

Crack sealing process

First, the scale of the restoration is assessed: the crack is examined and its boundaries are determined. Next, the growth of the defect is stopped and the stress in it is reduced: a hole is drilled at a distance of 1–2 mm from the end. You need to drill glass with a drill at minimum speed and very carefully so as not to break it.

Further work is carried out as follows:

1. Fill the syringe with glue.
2. Using a suction cup and stand, attach the syringe to the point where the crack begins.
3. Carefully apply the adhesive composition directly into the defect, strictly controlling the supplied volume.
4. If you have a pump, blow it through the crack (with minimal pressure) so that the composition is evenly distributed even into the smallest cracks.
5. Remove the stand and wash it of glue.
6. Use a sharp tool to remove excess product from the surface of the glass.
7. Dry the polymer composition with an ultraviolet lamp according to the instructions (the operating time of the lamp is always indicated on the glue packaging).
8. If there is no lamp available, expose the car to direct sunlight, but the drying time will increase by about 3 times.

After polymerization of the glue is completed, polishing begins, using a special attachment on a drill or doing it manually. As a result, the surface will become perfectly smooth and will get rid of irregularities and bulges.

How to glue car glass

For such a procedure, preparatory work must be carried out.
The temperature level in the room where the procedure will be performed should be from 5 to 20 degrees Celsius, preferably 15 degrees. Before work begins, the car must not be touched for about an hour, and the doors must not be touched either.

The windows on the front side doors must be lowered. It is better not to open the room itself for an hour, so as not to worsen the effect of the glue while it dries. The car can be washed only after two days.

Before starting to repair defects, you need to do the following:

1. Wash and dry the glass well;
2. Using special devices, remove all dust from the gluing area;
3. If there is an old product, it must be completely removed;
4. Remove fat from the crack using a solvent;
5. Apply sealant according to the instructions;
6. Level the applied layer, remove excess product;
7. Dry;
8. Polish.

When completely replacing a car windshield, you must do the following:

1. Remove the old windshield. An assistant will be needed for this work. First, pierce the old glue. To do this you need an awl with a string. Using pliers, pry the string from the other side, and pull the awl back. After this, it turns out that one side of the string is on the inside, and the second will be on the inside. Next, the string is attached to something to make it easier to drag.
2. The frontal bump is cut. Take and pull the string from the outside along the front. And the assistant pulls the string inside. In the corners, this part is brought to the top and carried along the sides, thus returning to the starting point. Next, the glass is carefully pulled out and the remaining glue is removed. Everything must be done slowly so as not to damage the machine.
3. Prepare new material. Special Velcro is attached to the left side, with them the frontal bumper can be moved. Do the same on the other side. Apply masking tape along the edge of the material. And wipe the windshield itself with solvent, removing grease.
4. Apply sealant. For ease of use, a special gun is often used; the glue begins to squeeze out when you press the button. This way the glue strip is uniform and without breaks. Thus, the glue must be applied along the entire perimeter of the windshield. The glass should lie down during this procedure.
5. The windshield installation itself. The windshield is taken by the Velcro and placed in the opening in the car. It is attached with tape on top to temporarily secure it. Next, the car is left for three hours so that the glue has time to set. Next, the car is driven outside, where it sits for about another twenty hours, after which the car can be used again.

In what cases can repairs be done?

Is it possible to drive with a large crack if it is located outside the driver’s field of view of the road? Most likely, such a car will not pass inspection, and without repair, the glass will become unusable in a short time. A complete windshield replacement will have to be done if:

• a significant piece has fallen out of the glass, or it has completely cracked, fallen apart,
• the defects are significant in size - from 20 cm,
• there is a whole network of cracks that extends from the main chip,
• damage passes through the edge of the glass, which compromises its strength,
• there are chips in the heating zone - in winter they will burst again anyway,
• the damaged area is a third or more of the total glass area.

If the damage is serious, the windshield needs to be replaced.

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.

Do-it-yourself repair or at a car service - what to choose?

It is not possible to repair windshield cracks on your own in all cases. Here is an approximate list of situations when you can try to deal with the problem yourself:

• have glass processing skills and the necessary tools, as well as suitable working conditions,
• a small or medium scratch, crack, or chip has appeared that has not spread to large areas of the glass,
• It is possible to purchase a high-quality adhesive composition or a ready-made repair kit.

If you do glass restoration at a service center, professionals will work on it, so the result will usually be better. All work will be completed in a minimum period of time, because the craftsmen have powerful modern tools and lamps.

However, the cost of repairs can range from 1000–1500 rubles per 1 centimeter of crack, which will ultimately result in a decent amount. Therefore, it is easier to eliminate small defects with your own hands, at least in order to save money.

Windshield restoration in a car service center

Self-repair of the windshield allows you to reliably repair the defect and make it 75–90% invisible. Good adhesives are now sold in any store, so it’s worth acquiring repair skills and not having problems in the future.

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.

Material options

All adhesives for car windshields are divided into two types:

1. Adhesive for direct installation of the windshield, which provides the necessary elasticity of the glass to absorb and absorb the deformation load transmitted by the car body.
2. Adhesive for repairing windshield cracks, which can be used to seal the effects of stones.

These two adhesives have completely different characteristics and are designed for different tasks. The glue used to seal cracks and chips is durable after complete hardening. It does not have the plasticity characteristic of polyurethane glue, which is usually used to glue a new car windshield. After sealing the crack, the cured glue becomes quite brittle and acquires the transparency of glass.

The basis for the adhesive is polymer resins, which provide the necessary characteristics for sealing and repairing glass. The composition dries under the influence of ultraviolet rays, which provide it with the necessary strength. The frozen fill element can be polished, which will provide it with the characteristic transparency of glass.

Recommendations

The room or garage where the gluing will be done must have a stable temperature. It is desirable that it is not lower than plus 5 and not higher than plus 15 degrees. During polymerization of the sealant, any dynamic loads on the machine and its individual parts are eliminated. You cannot open or close the doors, trunk, or hood. Personal safety and hygiene rules when working with glue must be observed. Upon completion of the operation, avoid contact with liquids, including body washing, for 2 days.