Which glue sealant is best for car glass and bonding rules
What kind of adhesive to use for scratched car glasses is not just a matter of experienced owners. It is not uncommon that a fragment of rubble accidentally escapes from under the wheels can spoil the mood of the owner of a new car. And the formation of a crack, a picturesque mark on the windshield is guaranteed. And the replacement will cost a pretty penny. A reasonable solution is to use a polymer (glue) to mask the effects of glass impact.
Varieties
When one is convinced of the very fact of the existence of miraculous glues for glass, it remains to classify them by type. Depending on the composition, there are silicone, polyurethane, epoxy and polymer sealants. By the amount of reagents - one- and two-component. There may also be adhesives for fixing and optics, restoring the damaged area, masking the appearance of the defect on the glass.
On appointment
According to their purpose, sealing glues are divided into assembly (for installing new glass) and repair. It is advisable to avoid attempts by sellers and consultants to impose universal sealants.
The subtlety lies in the fact that the glass structure not only provides visibility, but also the overall rigidity of the car, being an important part of the frame. A badly or badly repaired glass will not be able to fulfill this function.
Mounting compound for bonding
These familiar, soft and elastic strips, which reliably fix the plane of the glass in the frame, absorb the vibrations transmitted by the suspension, belong to the past. Instead, an on-site sealant layer based on polyurethane or silicone is used.
The advantages of this solution are obvious: when painting, straightening, replacing parts (including glass), there is no need to worry about the safety of the sealing profile. It is replaced by glue, transparent or colored.
More often than others, masters use DOW, 3M, Sika, Wurth, Teroson, Eftec formulations of sealants for gluing. A few hours will pass, and the sealant will harden, fixing the plane of the car glass, providing reliable contact with the body.
Optical sealant or repair
The next group of compounds is intended for repair or optics. Dealing with them is easy: you need to get rid of chips, seal the crack on the glass - opt for an optical sealant. To form the bead of the glass gasket that holds the plane of the window, you need a different composition - an assembly. These adhesives are not interchangeable as they serve different purposes. Their setting speed is not necessarily the same.
For optical silicone, it is important that after polymerization it does not become cloudy, does not lose transparency and is not visible. Otherwise, the repair does not make sense, then it is easier to change the glass. At the service of refiners - compositions of the brands Henkel, 3M, Dow, sealants of other manufacturers.
By membership
The basis of modern miracle adhesives are polymers.Polyurethane, silicone, acrylic compounds with ultraviolet stabilization - this is an approximate list of sealants offered by car manufacturers. They also differ in the degree of adhesion, the depth of penetration into the glass and the curing time of the glue.
Balm
The main component of this glue is fir resin, sap. Suitable for gluing glasses, fixing fragments together. The putty has a slight yellowish tint.
In modern realities, it is gradually being replaced by polymeric compounds.
Balm
A variation of the previous composition, with a more pronounced yellowing of the hardened vitreous mass. Differs in increased grip, reliability. Despite the quality characteristics of putty, glue is rarely used due to its low transparency.
Balzamin-M
Modifier based on natural ingredients with improved transparency. The composition retains the advantages of the balm: elasticity of the joint, work in a wide temperature range, transparency of the glue.
UV
For stabilization, the setting of this composition, a source of ultraviolet radiation is certainly necessary. After polymerization, the putty is transparent, durable and reliable.
Acrylic based
With the discovery of acrylic resins, they quickly found use in a variety of applications, including automotive glass repair. There is nothing to complain about the characteristics of the resulting glue roll, except for the slow and "thoughtful" setting. On average, acrylic sealants cure in 2-3 days.
Silicone
Viscous composition with a characteristic smell of vinegar. Used in plumbing, construction, renovation. Also suitable for bonding glass. It sets quickly, the seam is moderately elastic, the glue does not lose its properties over time.
Polyurethane based
Rubber-like polyurethane sealants are a strong competitor to silicone. They form a liquid-resistant, durable and elastic adhesive layer. They are not afraid of heat and cold, they are comfortable to work with.
Polymer
According to their characteristics, polymer glues are close to silicones and polyurethanes, but after hardening it is difficult to remove excess composition without special solvents. Sealants are characterized by increased adhesion, are resistant to chemicals and can be stained.
What is the risk of a bad choice?
The wrong or wrong choice of sealant will lead to unpredictable results. This is a loss of transparency, unsatisfactory resistance of the joint to vibrations, possible destruction due to humidity or an aggressive environment.
Reduced glass transparency
The master, choosing the glue for sealing the crack, made a little mistake (or the customer decided to save money) using balsam instead of a transparent polyurethane compound. The result will not be long in coming: drips, visible sags and color differences between the main structure and the seam. And also wasted money, the lack of expected effect of glass repair.
Unsightly stains
One of the probable manifestations of the wrong choice of glue. Spots may appear immediately after the start of polymerization, or a little later, during the operation of the glass. It is impossible to remove them, and this is the main problem of the sealant.
Increase in crack size
In the practice of craftsmen, it also happens that broken glass continues to crumble for several reasons: it expands (the crack lengthens), new shards appear. The fact is that in a car, the windows are subject to the same dynamic loads as the rest of the frame elements. If you do not restore the integrity of the glass, do not fix it securely in the opening, irreversible processes will continue until it completely bursts or falls off.
Selection rules
In order to avoid difficulties in the future with the almost irreparable consequences of unsuccessful application of glue, it must be chosen correctly. Everything is taken into account: the working conditions of the glass, the wishes of the customer, the temperature regime, the time allotted for the repair, you need to insert or repair the damaged surface.
It would be nice to get acquainted with the reviews of the sealant for the vending machine in advance, read its characteristics and composition. The science does not stand still, every day new and improved adhesives appear, surpassing the old ones. And the lack of information will become a negative factor in the choice, it will interfere with the objective determination of the required product for a particular case.
Overview of the mixture
Below are several popular adhesive formulations that are rightly in demand by automotive repairers.These sealants are used not only in service, but also in well-known companies specializing in well-known automotive brands.
SikaTack-Drive
Medium elastic glue, not particularly fluid. The applied roller does not fall off, which is especially important when gluing. Does not require priming of surfaces to increase adhesion, hardens in 10 minutes. Refers to single-component mixtures, supplied in standard 310 milliliter tubes.
It is not necessary to heat the composition before application; in the temperature range of 20-22 degrees, it retains its plasticity. The average "ready" time of the machine after the installation of the glass is 40 minutes. For models with airbags, this parameter is increased by 10 times - up to 4 hours.
3M Windo-Weld SuperFast Urethane
A polyurethane sealant used even in race car repairs. The polymerization period of the composition is about 15 minutes, readiness for car use - up to 3 hours without the airbag system, and up to 8 - with them. The composition is one-component, does not need to create additional conditions for application (heating, deep cleaning). Bond strength increases with time, reaching a peak of 150 lbf/s2 after 8 hours of rest.
Dow Automotive Betaseal 1527
A well-known European manufacturer, one of the leaders in the production of polymers. Glue of this brand is universal, it can be used to glue glass in a car with airbags in an hour. But it does not work without a primer and prior surface preparation. The adhesive is certified to meet the requirements of most standards and will not interfere with radio and satellite communications (the sealant is non-conductive).
Dow Corning 7091
Silicone type sealant.Suitable for installing glass, repairing auto body parts, it has high adhesion. Strong, but elastic, catches quickly. The glue does not lose its properties after polymerization in the working range from minus 55 to 185 degrees. It is widely used in service departments.
VR emphimasticism
A single component, high performance guaranteed. The composition of the French manufacturer is characterized by strength, elasticity of the finished gasket, as well as a polymerization time of 30 minutes. Glue is easily applied to glass, does not require special cleaning of surfaces.
3M EU 590
Polyurethane sealant from a famous North American brand. The adhesive takes 25 minutes for older cars and up to 40 minutes for airbags. Unfortunately, it does not tolerate a temperature threshold of 100 degrees, it is prone to cracking.
ABRO WS-904
An unusual option, which differs from others in that it is not putty in a tube, but a special adhesive tape. The basis of the product is polyisobutylene. To use it, you must carefully and systematically remove the protective strips on both sides, apply and press the tape. Putty is characterized by high adhesion, easy to use when gluing glass.
DoneDeal DD6870
High temperature adhesive for universal use. Putty is found in clear and black versions. It is used in small car repairs, as well as for installing glass. It sets in 15 minutes, fully cures in a day. The seam is stable in the range of minus 45 to 105 degrees. The disadvantage is the "small" packaging - 82 grams. For serious work, a tube of glue is not enough.
LIQUIMOLY
A product of a well-known brand for motor oils, for sealing small seams and cracks. The seam "holds" the temperature up to 150 degrees. One-component, air-curing sealant.
Terostat
Monocomponent composition based on MS polymer. The putty is moderately elastic, practically does not change the volume after polymerization.
Resistant to UV rays, it is therefore recommended for the repair of the windshield, side and rear windows of a car.
Betaseal
Made of medium viscosity polyurethane, fast curing. Convenient to apply, characterized by the absence of streaks after hardening. The adhesive needs a primer.
Kit FC Dinitrol
An original solution from a major European brand, which includes a unique ready-to-use repair kit: glue, primer, cleaning cloth, gloves. The basis of the waterproofing composition is polyurethane.
Wurth
German brand of automotive products, it also includes adhesives from the group of polyurethane polymers. Refers to universal sealants, can be used for bonding glass, reducing vibration and noise in the cabin.
Calculation of consumption
The rules for calculating glue are simple. In a standard situation, a tube full of sealant (300-600 milliliters) will go to the windshield. Sometimes more, it is therefore advisable to have on hand a supply of glue of the same composition and from the same manufacturer.
Windshield bonding rules
The entire procedure is divided into several interdependent stages. The end result depends on respecting consistency and precision. So that:
- Remove the old glass. At the same time, gaskets and decorative inserts are removed. A sharp knife or a piece of thread is used and inserted into the seam.
- Then the contact areas of the new window panel are cleaned, the mating units of the body.If damage to the paint and varnish layer is found, they are restored.
- If, according to the technology, the glue is applied at a certain temperature, then this condition must be met.
- It remains to carefully distribute the glue (create a roll) on the glass or in the recess of the body, and then glue the glass to the composition.
Remove the old putty
The old seal is removed mechanically using a sharp knife. Then the surfaces are cleaned of dust, dirt, degreased, prepared for the installation of glass. It is very important that no fragments remain, otherwise a high quality adhesive joint is not guaranteed.
how dry
The setting time of the glue depends on the brand of specific composition, the version of the car (with or without cushions), the thickness of the layer, the temperature. For modern polyurethane sealants, the average cure time is 10-15 minutes and the adhesive gains strength within an hour. For comparison: acrylic mixes dry up to 3 days.
Recommendations
There must be a stable temperature in the room or garage where the bonding will be carried out. It is desirable that it should not be lower than plus 5 or higher than plus 15 degrees. During the polymerization of the putty, dynamic, any load on the machine and its individual parts is excluded. Do not open and close the doors, trunk, hood. Personal safety and hygiene rules are strictly observed when working with glue. At the end of the operation, avoid contact with liquids, including washing the body, for 2 days.