How to fix a crack on your windshield

Elimination of cracks and chips on the windshield – the best tools and methods

Car owners often get such a problem as a crack on the windshield. Most often the appearance of the defect is noted after hitting a pebble at high speed or due to sudden temperature changes. To fix the crack in a number of cases you can with your own hands using available means.

Why eliminate chips and cracks?

Repair the car, which has a crack on the windshield – a mandatory action for safe driving and the absence of problems from the traffic police. In addition to the unpresentable appearance, driving a car with a broken glass threatens other troubles:

  1. The presence of a crack of large size or with a certain location poses a risk to the life of the driver, passengers. If the crack is deep, a pebble can fly through it at full speed, which will result in human injury. In addition, poor visibility on the road can cause a serious accident.
  2. In the presence of large cracks the car will not be able to pass a technical inspection. Since the defect may cause injuries, it is impossible to get an inspection mark until its elimination. According to the GOST P 51709-2001, the cars with any cracks in the windshield wiper and driver’s side are not allowed to operate. Driving such machinery is fraught with a fine.
  3. Any crack over time can become longer, wider, deeper. It will lead to the necessity of full replacement of glass or its expensive repair in an auto 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 cracked windshield may get you fined

Driving a car with a cracked windshield can get you fined.

Types of damage

The cause of cracks can be as a hit by a stone, and a small accident. All defects according to their shape and features can be divided into five types:

  1. Radial. They are formed by a strong impact. Usually they are long and go 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 with a hard object. Such defects should be removed as soon as possible with preliminary drilling, otherwise they will spread to a large area of glass.
  3. Branching. Formed by impact with a heavy object or due to temperature differences. They represent a whole scattering of branching beams, that’s why they are difficult to repair.
  4. Bilateral. They look like a ray, which appears from the interior part of the triplex. More often than not, the car owner has to replace the glass, because such defects are almost impossible to fix.
  5. Mixed (combined). Includes elements of different types of cracks. Their sealing is not always possible.

Windshield Branch Crack

Branching crack on the windshield

How to stop the spread of the crack, directly depends on its type. Usually in home conditions are successfully repaired simple defects, chips and dings of small size.

What cracks can you drive with?

It is possible to drive a car with small cracks or chips on the windshield without any problems. According to GOST, they should not exceed 15.7 cm and have no inconvenient location for the driver. However, any chip from the temperature difference or strong frost, as well as shock, vibration, water intrusion will expand, so it is better to remove it immediately.

Cracked car windshield tolerances

Panel rebuild from VAZ 2110

Kits for self-repair

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

GlassProfi .

This kit includes a blade, glue disc, polymer glue, fixing suction cup, syringe. With the help of disc and suction cup syringe is firmly attached in the area of the crack, and then the glue is squeezed out of it. After 3-4 hours, the defect will be invisible, and the composition will fully harden. With the help of this tool you can easily remove cracks up to 3 cm long.

Windshield repair kit GlassProfi

Windshield repair kit GlassProfi

Windshield Repair Kit

This kit includes the same tools as the previous one, but additionally equipped with a protective film. It helps you repair defects on regular and tinted glass. The adhesive completely forces the air out of the crack when it is introduced, so the hole will be reliably sealed. This kit is recommended for emergency repairs as the adhesive hardens in as little as 20 minutes.

Windshield Repair Kit

Windshield Repair Kit

Done Deal DD6584

The polymer compound included in this repair kit has a very high strength, almost several times that of cheaper counterparts. The product contains acrylic acid, so you should work with it in the open air and only wear gloves. Glass repair should be done in the shade in summer and after preheating the damaged area in winter.

Done Deal Windshield Repair Kit DD6584

Done Deal Windshield Repair Kit DD6584


The product included in the kit is recommended for removing deep chips, and can also be used for rapid repair in road conditions. It is not suitable for filling long cracks. The composition can damage the paint on the body of the car, so the hood must be carefully covered before repairing.

Permatex clear glue sealant for windshields

Permatex transparent adhesive sealant for glass


The kit includes a set of repair plates, a scraper to clean the crack and remove excess glue, an injector, suction cups and glue. It is better to work with glue indoors, so it will harden much faster. In summertime, after applying the compound, you can put the car under the sunlight to accelerate the polymerization.

WIEDERKRAFT WDK 65182 Chip Repair Kit

WIEDERKRAFT WDK 65182 Chip Repair Kit

Filling in a crack on your windscreen with your own hands

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

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 an even better effect is achieved by blowing it out with a pump. This will remove even the smallest dust particles that will reduce the adhesion of the adhesive to the glass in the future. The edges of the crack should be carefully sanded and wiped with a degreaser (acetone, alcohol).

Windshield defect washing

Washing the defect on the windshield

Materials and tools needed

If a ready-made set for glass repair was purchased for the work, it already has all the necessary devices, except for electrical tools. When completing a set on your own, you usually use:

  1. Polymer glue. It is absolutely transparent and looks like liquid glass. Under the influence of sunlight, the composition hardens and reliably fastens the edges of the chip. When buying glue, you need to pay attention to the curing time and buy the one that is suitable in a particular situation.
  2. Lamp with an ultraviolet glow. Usually used if the glass repair is done in the winter, although it will facilitate the work in any case.
  3. Drill with a drill on the glass. The device must necessarily have the function of regulating the speed.
  4. Scraper (scraber). Needed to remove dirt and debris from the crack.
  5. A sharp knife. Useful for removing glue residue or dirt from hard-to-reach areas.
  6. Personal protective equipment. For safe work, it is worth using gloves, a respirator.
  7. Injector-syringe made of metal, plastic with a suction cup and a stand. Necessary for high-quality filling of the defect with glue.
  8. Magnifying glass and flashlight. Useful for a detailed examination of the borders of the crack and the evaluation of the result of its elimination.
Treatment of a chipped body paint to galvanizing on a car

Tools and materials for windshield repair

Tools and materials for auto glass repair

Process of patching the crack

First, assess the scale of the restoration: inspect the crack, determine its boundaries. Next, stop the growth of the defect and reduce the tension in it: drill a hole at a distance of 1-2 mm from the end. Drill the glass with a drill should be 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 a stand, fix the syringe to the place of the beginning of the crack.
  3. Carefully feed the adhesive directly into the defect, strictly controlling the volume fed.
  4. If a pump is available, blow through the crack (with minimum pressure), so that the composition is evenly distributed even in the smallest cracks.
  5. Remove the base, wash it from the adhesive.
  6. Use a sharp tool to remove excess product from the glass surface.
  7. Dry the polymer compound with ultraviolet lamp according to the instructions (lamp hours are always listed on the adhesive package).
  8. If the lamp is not available, put the car in direct sunlight, but the drying time will increase by about 3 times.

After the polymerization of the adhesive, proceed to polish, using a special attachment to the drill or doing it manually. As a result, the surface will be perfectly smooth, getting rid of irregularities, bulges.

In what case can you do with the repair?

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

  • a significant piece of glass flew out of the glass, or it is completely cracked, collapsed into pieces,
  • the size of the defects are significant – from 20 cm,
  • There is a network of cracks that comes off the main chipped pane,
  • the damage goes through the edge of the glass, which breaks its strength,
  • there are chips in the heating zone – in winter they will break again anyway,
  • the damaged area is one-third or more of the total area of the glass.

Replace your windshield if it has been damaged badly

With serious damages it is necessary to replace the windshield

Repair with your own hands or in an auto service center – what to choose?

It is not possible to fix cracks in the windshield by yourself in all cases. Here is a sample list of situations when you can try to cope with the problem yourself:

  • there are skills of glass processing and the necessary tools, as well as suitable conditions for work,
  • There is a small or medium scratch, crack, or chip that has not yet spread to a large area of the glass,
  • It is possible to purchase a quality adhesive composition or a ready-made repair kit.
Refurbishment of the rhombus jack

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

Nevertheless, the cost of repair can be from 1000-1500 rubles per centimeter crack, which in the end will cost a decent amount. Therefore, small defects are easier to eliminate with their own hands at least in order to save money.

Windshield restoration at a car repair shop

Restoration of the windshield at the car service center

Self-repair windshield restoration allows you to reliably seal the defect and make it 75-90% invisible. Good adhesives are now sold in any store, so you should acquire the skills of repair and not know the problems in the future.

Guide: Repairing a crack on the windshield with your own hands

Good afternoon everyone. This post is about the important nuances of windshield crack repair with your own hands, using a kit from aliexpress, etc. I hope this will help you to achieve the desired result.

In general, I’m not in the habit of writing something on my block – a chukcha is not a writer at all. However, today I decided to pile up a short article on how to properly fill a crack on the windshield with my own hands, using a kit from aliexpress. Here it is:

Be warned right away: if you want to achieve a perfect result, go to the service, they will do beautifully. By yourself to fix the crack without experience is difficult, and without special tools sometimes even impossible, and it will remain visible. What is written below will not guarantee you a perfect result, but it will increase your chances for success. If you are firmly decided to fix the crack by yourself and you are not afraid of screwing it up with wrong hands (and after that the service will not undertake to fix it) – read on.

So, let’s proceed. At first let’s run through the main points in order, and then condensed instructions from beginning to end.

Crack stopping. Whether and how to stop the crack, we will not consider within the framework of this post. In short, if the crack is fresh – it is desirable. If it is old and does not move – it can be neglected.

2. Preparation and cleaning of the crack Again, there is no point in stopping in detail. It is clear that you need to wash out all the dirt from the crack. But with what – this is who is rich. Water, glass cleaner, alcohol, solvent – the main thing that the crack in the end was clean from these means. You may not wash at all if the crack is fresh.

3. Preparing the workplace Many sources claim that the polymer for filling chips and cracks is light-curing. Yes, professional materials most likely are. About aliexpress – who knows. But it is not worth checking. Take the car to an underground parking lot, where there is no sunlight (even reflected) and put it under a lamp so that from the cabin was well visible cut (glare) of the crack.

Laptop Battery Charger from Laptop Adapter

4. Prepare the tools Take tissues or toilet paper to scrub your hands and glass. Purchase a small syringe to accurately dispense the polymer on the crack. This makes it easy to dispense, and the tip of the needle can be used to find the crack and cling to it for greater accuracy. In case the polymer is frozen in the syringe (for example, the light did get on it) or you can’t pour the polymer from the bottle into the syringe, put the needle directly on the polymer bottle. It fits well. Prepare the foil from the kit and cut it lengthwise to cover the long crack. If there is little or no film, take any other kind, even a cellophane bag.

5. The process of filling the crack Here it is highly desirable to have a helper. It is much more difficult without it. So, the process of filling the crack is the most critical stage. Two people work. One person from the salon presses his fingers on the crack for better flowability of the polymer, and the second one pours the crack from the top. The one who sits inside is in charge of the process. His instructions and finger movements are used to guide the pourer.

I will now explain why this is important. When pouring a crack, it is important to control the penetration of the polymer to its full depth. In addition, the polymer must spread from the drop on the surface along the crack. If you fill the crack from the top, there will be air inside, which has nowhere to go, it is sealed there, and all your repairs are wasted – like you filled the crack, but the air remained and it glitters. That’s why the process is led by a person from the salon, who sees the cut of the crack and how it is filled with polymer. He presses it with his fingers, and his assistant just follows his fingers with the needle. And there is no other way – haste will lead to failure.

If there is some tricky area – by pressing you will help the polymer pass into the crack.

A very important note: the crack must go from the beginning to the end, without gaps. As you pour, you press on the crack with your fingers to help the polymer penetrate, and it starts to cure after a short time, even without the light. If you press again, it will tear away from the glass and air bubbles will form in the crack, which there is no way to remove. So you catch a wave and go from beginning to end. It is impossible to press on the poured area again.

Correctly filled crack (with a small missed bubble) in one pass:

A crack that has been re-pressed 30 seconds after pouring:

If the crack is vertical – it is advisable to move from the bottom up (so that the flowing drop does not seal the air in the crack). But if you have an arc crack, then moving from one edge to the other you will at some point have to move from top to bottom – then clean up the polymer drips with a napkin, and carefully dispense it. The end of a crack is usually difficult, so if you have a choice, it’s better to start at the chipped end, and move toward the end of it. Also, if the end cracks when you apply pressure, you’ll just go further down the crack to fill it. If you start at the end and it cracks, you’re trapped – no matter which way you go, you have to go back, and there’s almost 100% air left if you press down on that area again or without pressing down – the polymer just won’t flow.

Fourteen rules for selecting and installing a car radio.

6. After the crack has been poured, pour a track of polymer over it and cover it with film. And the polymer on the glass must be poured enough so that under the film it spreads as a stain and the whole (!) surface of the crack was under the layer of polymer and film. The thing is that, although nowhere is it written about it, but it has been established by experience that the Chinese polymer is anaerobic, which means that in the presence of air it does not solidify in principle. In the crack – yes, but on its surface – no. So you have to fill the surface of the crack and close the film. If you see that under the film, part of the surface of the crack is not covered with polymer – remove the film, refill it, put it back, no big deal. After that, carefully move out into the sunlight (or UV lamp) and wait 15-20 minutes until the polymer hardens. Then we peel it off with the supplied blade.

Notes: The polymer needs to squeeze through the crack to spread, so there’s a chance it will go further. Be prepared for this development.

So, the main points we have in detail disassembled, now let’s formulate in a brief instruction all the same, but concisely.

Instructions: 1. We drive the car in an underground parking lot with washed and dried crack, put under the lamp so that from the cabin was visible to the crack to its full depth 2. Commander of the process sits in the cabin and begins to push through the crack with two fingers, starting with a chip (not the end). The second gently dispenses the polymer with a syringe (or needle from it on the bottle), focusing on one of the fingers of the commander, as well as his instructions 3. The commander looks at the fill and makes sure there is no air left in the crack (see first illustration) 4. The crack is poured preferably from the bottom up, in a single pass, without pressing it again after the pour 5. 5. After pouring, polymer is added to the crack surface, the entire crack surface is covered with film, and the machine is rolled out into the sun for 15 minutes. 6. We clean the residue off the glass with a blade.

I hope this helps you and that everything works out for you. I’ve written everything I know here to keep you from making mistakes. Do you know anything else? Fill in the comments, it will not be redundant. And I repeat – if you want the perfect result, go to the service.

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