How long can you cut off the foam

Description

Polyurethane foam is classified as a sealing agent, without which it is almost impossible to do in the construction process. It is used in cases where there is a need to seal seams or joints with a depth and width of more than 3 cm.Before using this material, builders wonder how long it takes for the foam to dry completely, but it turns out that this question has been posed incorrect. First of all, it should be said that the main secret of the complete transformation of the material into strong polyurethane foam is the degree of wetting. But we will pay attention to this fact.

First you need to decide why builders prefer polyurethane foam:

  • its application is very simple;
  • pricing policy is available;
  • long service life.

In addition, this material has qualities that isolate sound and make it possible not to lose heat from the room.

Most often, foam is used in the process of installing balcony blocks, windows or doors of various types. When applied, the composition begins to expand and at the same time fills all the voids, thereby gluing the desired surfaces. It should be noted that the curing time also depends on how thick the layer was applied. If it is not more than 5 cm, then within 3 hours after leaving the cylinder, the foam will reach the required density.

Foam is also so popular for the reason that, when cured, it is not susceptible to the effects of temperature, moisture and even electricity, in addition, fungus does not appear on it. It should be noted that the foam can undergo changes from the influence of ultraviolet radiation, but this defect can be eliminated by using decorative plaster.

Characteristics of polyurethane foam. let’s figure it out in detail!

This sealant began to be used in the construction industry relatively recently, but during this short time, polyurethane foam has almost completely replaced its former competitors. It is easy to apply, is inexpensive, lasts for many decades, and has sound and heat insulating properties. Most often it is used to seal the gaps between the doorway and the door frame during its installation, as well as when installing windows.

Expanding, the sealant fills in all the voids, reliably “glues” surfaces to each other, and when solidified, the polymer fixes the door frame or window. Foam is not afraid of precipitation and cold, it does not allow electricity to pass through and is not afraid of mold and mildew. The only drawback is the fear of ultraviolet radiation, however, often the material is applied at the stage of rough work, which are then hidden under a decorative layer of plaster.

Anyone who comes across this material quite often begins to pay attention to parameters such as:

Material features

To judge the speed of drying of the sealant, you need to understand its features:

  • After leaving the container, the volume immediately increases primarily. The sealant fills the entire space down to the smallest crevices.
  • When the polyurethane is already exposed to air, secondary expansion occurs. This feature can have a big disadvantage if the conditions of use are not followed. Polyurethane foam reduces the volume in case of extreme heat, dirty substrate or premature mechanical stress.
  • The top layer of household foam hardens after 20 minutes. You can cut off the excess after 4 hours. A two-component sealant cures faster. The chemical process ends in a day.
  • A feature of the mounting material is increased adhesion. Polyurethane adheres well to glass, wood, concrete, plastic, steel, stone.
  • Cured polyurethane does not react to temperature changes.
  • The assembly sealant is afraid of UV rays. Under the influence of the sun, it acquires an orange-brown color and collapses.

Polyurethane foam serves only as a sealing material. From above, the hardened polyurethane must be protected with putty, paint, primer.

How long does the polyurethane foam dry?

Drying time of the sealant depends on its composition. An important factor is the conditions under which the building material is used. Humidity and air temperature are taken into account. The composition depends on how much the polyurethane foam will dry.

Requirements

Polyurethane foam is a material for which, like any other, a number of requirements are put forward.

These requirements include:

  • good adhesion of surfaces;
  • elasticity;
  • after solidification, the material should not crumble, even when exposed to sub-zero temperatures;
  • shrinkage of a solution that has already dried should be moderate.

We draw the attention of users to the fact that the foam is very afraid of direct sunlight. For this reason, after complete hardening, the excess is cut off, and all sealed places are treated with paint or plaster. And in order not to violate the density of the material and to make the application sequence correctly, you need to know how long it takes to completely solidify.

To eliminate gaps between door frames and openings, only a third of the sealant will be required. The material will begin to solidify on the surface within half an hour after application. You may notice that a film will appear on the surface.

Final drying can be expected 8 hours after application. The fixing process occurs due to the expansion of the substance that comes out of the container and solidifies.

Conventionally, this is divided into several stages:

  • primary, which is carried out immediately at the exit from the package;
  • secondary, which is not completed until the final transformation of the foam into a solid composition.

If the material is of high quality, then at the second stage the expansion rate can reach 30%, this must be taken into account in the process of work. Most often, it takes a third of the material to fill the space, this is enough to fill all the cracks when expanding.

But you should also pay attention to the fact that the foam should shrink, you should not be afraid of this action, it will not bring problems. In high-quality materials, shrinkage can reach 5%, and this is invisible externally. If shrinkage still occurs, and this is clearly visible from the side, it means that the polyurethane was purchased of poor quality.

Specifications and properties

To understand how much polyurethane foam dries, you need to find out what qualities and features the composition has. After leaving the tube, the liquid mass increases in volume and takes on a porous structure. This process is called primary expansion. The assembly staff from the initial volume increases 20 (inexpensive). 50 (expensive) times. The material takes up empty space and its top layer sets in a few minutes.

Another property of the sealant is secondary expansion, in which the substance shrinks or further expands in volume. This quality of the composition is negative: a strong increase leads to a violation of the integrity of flexible structures, and shrinkage causes the formation of voids in the substance. Secondary expansion occurs due to improper use of the installation or non-observance of the temperature regime. The main properties of the sealant:

  • Good sound and heat insulation characteristics.
  • High-quality sealing at the joints of products.
  • Excellent adhesion to metal, wood, brick.
  • Multiple volume expansion. low consumption.
  • Filling hard-to-reach crevices and gaps.

Due to the liquid consistency of the substance in the container, it is possible to seal narrow joints, uneven gaps in depth, and deformed surfaces. The curing time of the polyurethane foam varies, depending on various factors. The top layer dries in 20 minutes, complete setting takes place in a day. Surplus material can be trimmed off after about 4 hours.

In order for the substance to retain its properties on the street longer, it is necessary to provide protection against ultraviolet radiation and moisture. prime, apply putty, cover with several layers of paint.

Spacers for polyurethane foam. how much to hold?

The foam bottle says “Fully cures in 12 hours”. “Completely hardens” is one thing, and “stops expanding” is a little different, it seems to me.

Since all further work rests on free access to the windowsill, I would like to know if it is possible to remove the spacers earlier? And then half a day down the cat’s tail.

Keep the rags for at least 12 hours. and this depends on the thickness of the foam layer. And don’t listen to KM.

There is compressed gas in the foam and until the foam is COMPLETELY hardened, it tends to expand, which it successfully does without spacers.

Of course, after an hour it happens less, but what difference does it make to you whether your hump on the windowsill grows 20mm or only 10?

And one more thing. do not pour more foam than necessary. leave room for expansion.

He has SEVEN. centimeters and probably at least 10 in depth. And how much such a seam will freeze inside?

“Freezing time. 24 hours” 🙂

Instructions are written for that in order to follow them.

Oh! You’re right. I’m sorry, I read the original message inattentively: (Yes, 7 cm is a lot, you have to wait for the complete solidification.

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Potatoes or something to fry? With an onion. Ma-a-scarlet cubes.

How much foam is needed to fill the cavities?

Cleaner for solid foam: Tytan Professional (Selena) (pack of 100 ml. 379 rubles).

In order to prevent the deformation of insufficiently strong walls during the expansion of the foamy mass, it is recommended to fill the voids and cracks with foam by no more than a third. When installing interior doors, it is advisable to use several spacers to fix the box. Then the expanding foam will not be able to deform it. However, with the correct professional dosage of foam, this is not necessary.

The volume of the finished foam depends on the capacity of the cylinder and its filling, the temperature of the air and the cylinder, the humidity of the air, the quality of the gun and the qualifications of the master. High-performance foams yield from 65 liters or more, and regular foams. 25-45 liters.

Briefly about manufacturers

How many times can you use polyurethane foam

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Household polyurethane foam with an applicator tube: Foam Premium (Penosil) summer (pack 750 ml. 262 rubles).

Polyurethane foam is an indispensable element of many construction work. It is used for installing windows and doors, filling various openings and openings, for connecting and sealing frame construction structures, fixing wall panels and roofing slates. Among the main manufacturers of these products are Henkel (Makroflex trademark), Bison International, Den Braven, Penosil, Profflex (Profflex, Storm Gun trademarks), Soudal, Selena (Tytan Professional trademark). The price of a cylinder with polyurethane foam depends on its volume, weight, brand popularity and ranges from 100 to 600 rubles. It should be noted that polyurethane foams are divided into one- and two-component. Since most of the foams on our market are one-component, let’s talk about them.

Poor sealing results in distortions, sagging, shortened window service life. Correct application of foam provides the required heat and sound insulation.

Which foam is better, household or professional

It is very easy to distinguish between household polyurethane foam and professional one. It is enough to look at the balloon. if a nozzle in the form of a thin plastic tube is attached to it, then it is intended for household needs. However, it is impossible to say unequivocally that only beginners use such foam, and professionals necessarily use a nozzle in the form of a pistol. Consider the main differences that will help you decide and choose the appropriate type.

  • The first thing that is immediately noticeable is the size of the packaging. Household foam is sold in cans with a capacity of 300 ml and above, while professional foam is sold in cans with a capacity of 750 ml and above.
  • An important indicator is the release of foam from the cylinder. In the case of a household aerosol, not the entire composition can be blown out completely. Usually some part remains inside, and from the volume declared by the manufacturer, you will get a somewhat average value. Thus, instead of the required one cylinder, two may be required, and this already affects the costs associated with the repair. In this regard, professional foam proved to be much better, which is blown out almost completely.
  • The secondary expansion coefficient for household compounds is very high. In the process of final hardening, they can increase in volume up to two times. The same coefficient for professional foam is practically zero. Good or bad depends on the nature of the work being performed. For example, if you are faced with the task of filling a large gap in the wall or eliminating the creaks of an old wooden floor by blowing foam under it, then a significant expansion rate in this case is a plus. If you install slopes, plastic windows or doors yourself, then it is better to fill the space around them with a composition with the lowest expansion coefficient. Otherwise, there is a possibility of surface deformation. Only with proper skills in working with this material can you use household foam for such precise work. Usually, specialists fill only 1/3 of the gaps with foam, knowing that once it has finally hardened, it will fill the entire space without changing the geometry of the adjacent surfaces.
  • The shrinkage rate of household foam is 5-7%. Professional. 0-3%.
  • Regarding the need to use an additional device in the form of a mounting gun, household foam, of course, wins. It is enough to screw the supplied tube onto the cylinder, shake well, and the foam is ready for use. Professional formulations work only with a pistol, the cost of which is several times higher than the cost of the foam cylinder itself. For a single use at home, such a waste is impractical. Indeed, in addition to that, it will be necessary to purchase a special solvent that will clean the pistol nose of the foam residues.
  • The possibility of reusability is undesirable for household cylinders, but possible. If it is not possible to use the entire cylinder to the end, clean the inner cavity of the tube from the remaining foam with a propellant gas and store in a cool, dark place. Professional foam can be used partially. But at the same time it is necessary to store it with a pistol on the cylinder. In this case, the foam inside does not harden and is suitable for further use. The gun nozzle must be cleaned with a special solvent.
  • And the most important difference is the nature of the work performed. Household foam is used for one-off, rough work that does not require precise dosage. Professional formulations are distinguished by the possibility of high-precision application and are used for sealing joints or thermal insulation.

Whether to wet surfaces before applying the foam?

A relative humidity of more than 50% is sufficient for the normal foam polymerization process. In such conditions, it is not necessary to moisten the surfaces. However, at low humidity (less than 50%), which is typical for the cold season and hot summer days, moistening the joints and cavities will increase adhesion and improve foam hardening. This should be done without fanaticism, so that there are no drops on the surface and no water accumulates, otherwise its excess will prevent the foam from connecting to the surface.

The construction gun must be cleaned of foam immediately after removing the empty cylinder, avoiding hardening of the mass inside the gun.

When to cut off excess foam?

The polymerization time of the polyurethane foam is influenced by the temperature of the environment, the cylinder itself and the size of the cavity. On average, professional foam in a cavity 30 mm wide hardens in 20–30 minutes, and household foam is somewhat slower. in 40–60 minutes. The expansion process ends in a day, and then you can begin to remove the solid mass.

How does household foam differ from professional?

Tytan Professional STD (Selena) summer (pack 750 ml. 315 rubles).

The household foam cylinder is equipped with a special applicator tube. Thanks to this device, no additional tools are required to exit the viscous mixture. Household foams are generally disposable products. The mass yield is difficult to dose, and it itself has a high density and a low polymerization rate. Professional foams are designed for repeated use and better sealing. In them, the supply and metering of the foam stream occurs with a plunger pistol. It is screwed onto a special ring on the cylinder. It is professional foam that should be preferred when installing doors and windows.

Expansion ratio

The main feature of the polyurethane foam is the fast setting and hardening time. An increase in volume by several tens of times contributes to the formation of a dense porous structure with impeccable strength characteristics. The expansion coefficient of the sealant is not the same for different formulations. it can be primary, secondary and double, triple. What you need to know about the expansion coefficient of the foam:

  • Quality products are initially increased 60 times or more of their volume. During secondary expansion, they shrink within 5% of the mass of the substance. Expansion time of polyurethane foam from primary to secondary is several hours.
  • Inexpensive polyurethane foam can increase 30-50 times, but secondary expansion can reach 30% of the volume or show a high level of shrinkage. more than 5%. Large shrinkage leads to rupture of the solidified mass.
  • Information on the maximum yield of the substance is indicated by the manufacturer on the bottle. This indicator is the coefficient of expansion of the foam after release of the composition from the tube. The top layer dries for 20-30 minutes, complete hardening occurs within a day. according to the instructions.

Sealant manufacturers calculate the coefficient of expansion under optimal application conditions and temperature conditions. You cannot completely rely on the figure indicated on the package, since it is not always possible to strictly follow the manufacturer’s recommendations. The change in the coefficient of expansion is influenced by low temperature, high humidity, uneven surface.

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Important: A 300 ml bottle of quality foam contains 30 liters of sealant. This amount of foam is enough to blow out a wide gap (up to 5 cm) around the perimeter of a door or window opening. From a 500 ml tube, you can get 40 liters of the substance, 750 ml. 50 liters of assembly sealant.

How much polyurethane foam dries: what factors affect the drying time

For sealing joints, joints, performing moisture and heat insulation work, in the construction industry, polyurethane foam is widely used. The material easily adheres to different surfaces, has a long service life, high strength. Polyurethane sealant is easy to apply with a construction gun. To finish the foam areas, you need to know how much polyurethane foam dries. This parameter depends on several factors. the quality of the sealant, the conditions of use, the type of material.

Factors Affecting Drying Time

The foam’s ability to grow in size is the main advantage of the assembly sealant. You can read the output of the substance (in liters) on the cylinder, but the following factors affect the expansion coefficient and foam setting time:

  • Humidity of the environment. Polymerization of the composition occurs under the influence of atmospheric moisture. If the room or outside is hot and dry, the humidity is minimal. The foam will not expand to its full extent. A layer of sealant 5 cm thick under these conditions will harden in 3 hours, complete hardening will occur in 7-12 hours. With normal humidity outside or in an apartment, the top layer of polyurethane foam will dry out after 20-30 minutes, after 4 hours it will harden, and after 12 hours it will completely polymerize.
  • Temperature conditions. Manufacturers produce frost-resistant sealants that can easily withstand low temperatures up to 50 degrees. But it is recommended to apply foam when the thermometer reading is from 5 to 25 ° C. If this requirement is not met, the sealant loses its characteristics. The higher the room temperature, the faster the liquid foam dries. It is better to apply the product at an average temperature (1015 degrees), so that a sufficient amount of atmospheric moisture participates in the polymerization process.
  • The quality of the balloon. Polyurethane assembly is packaged in sealed cylinders. They contain a propellant gas under pressure. High-quality tubes are equipped with reliable blocking valves that can return to their original position without letting air into the tube and not releasing gas. You can compare two cylinders of the same volume. the one that will be heavier is of higher quality. Content rolls slowly over the tube, but does not dangle inside.
  • Layer thickness. If a 5 cm thick polyurethane foam is applied to the surface under optimal temperature and humidity conditions, it dries for 3 hours, after which you can cut off the excess composition. Full polymerization will occur in 12 hours or more. To completely dry a thick layer of sealant, the masters recommend waiting a day, and then removing the excess mass and protecting from moisture and ultraviolet rays. High-quality polyurethane has a dense structure with evenly spaced pores.

The speed of complete drying is influenced by the characteristics of the surface. If it has significant defects, irregularities, differences in height, the funds are spent more, and a layer is obtained that is different in thickness. This can “postpone” the period of complete drying of the composition.

Specifications and properties

To understand how much polyurethane foam dries, you need to find out what qualities and features the composition has. After leaving the tube, the liquid mass increases in volume and takes on a porous structure. This process is called primary expansion. The assembly staff from the initial volume increases 20 (inexpensive). 50 (expensive) times. The material takes up empty space and its top layer sets in a few minutes.

Another property of the sealant is secondary expansion, in which the substance shrinks or further expands in volume. This quality of the composition is negative: a strong increase leads to a violation of the integrity of flexible structures, and shrinkage causes the formation of voids in the substance. Secondary expansion occurs due to improper use of the installation or non-observance of the temperature regime. The main properties of the sealant:

  • Good sound and heat insulation characteristics.
  • High-quality sealing at the joints of products.
  • Excellent adhesion to metal, wood, brick.
  • Multiple volume expansion. low consumption.
  • Filling hard-to-reach crevices and gaps.

Due to the liquid consistency of the substance in the container, it is possible to seal narrow joints, uneven gaps in depth, and deformed surfaces. The curing time of the polyurethane foam varies, depending on various factors. The top layer dries in 20 minutes, complete setting takes place in a day. Surplus material can be trimmed off after about 4 hours.

In order for the substance to retain its properties on the street longer, it is necessary to provide protection against ultraviolet radiation and moisture. prime, apply putty, cover with several layers of paint.

Main types

Polyurethane foam belongs to the category of one-component polyurethane sealants. Without such a tool, the process of installing windows and doors, hermetically filling voids and cracks in brickwork, and performing other work related to repair, installation and construction becomes more complicated. According to the drying time, polyurethane foam refers to substances with a high polymerization rate. Foam assembly fills well cracks, gaps and cavities of any size and shape. Manufacturers produce several types of foam with different properties:

  • By appointment. household and professional. The household foam is equipped with a plastic tube for easy application. To use professional foam you need a construction gun.
long, foam

  • According to the terms of use. winter and all-season. Frost-resistant products are suitable for outdoor work, winter foam retains its qualities at temperatures from 50 to 90 ° C. All-season sealant is a universal compound for all types of installation work.
  • Fire-fighting agents. differ in fire resistance classes. Used to seal the joints of heated surfaces or communications in rooms with a high level of fire hazard. stoves, fireplaces, baths, chimneys.

Foams are supplied in the form of cylinders in which the assembly substance (liquid prepolymer) is under the pressure of a propellant. When the foam is released from the tube, a reaction of the components occurs, the composition expands in volume and hermetically fills the gaps or crevices.

Note: In order not to buy a construction gun, a cylinder of household foam equipped with a tube is enough for one-time household installation work. If you need to fill a large number of overall voids, use a professional sealant with a gun.

Scope of application

Assembly sealants belong to the category of universal products, since they are used in various areas of construction. Polyurethane foams Makroflex, Proflex, Soudal, Titan are very popular, the drying time of which varies in the range of 12-24 hours. Scope of use of the formulations:

  • Filling cracks, crevices, voids in rooms.
  • Installation of street structures, installation of doors.
  • Sealing window openings outside and inside.
  • Fixation of heat and sound insulating materials.
  • Sealing of roof structures and masonry.
  • Repair work, installation of stoves, fireplaces.
The use of the assembly composition during the installation of windows has found the greatest application, since the foam dries for 8-12 hours, after which you can proceed to the finishing. putty, putty, painting. The use of sealants for gluing thermal insulation allows you to quickly install gypsum panels, foam plastic, mineral wool boards. When the mass has dried, after a few hours the heat-insulating material cannot be torn off the wall without damage, the fixation is so strong.

Consumption of sealant

Foam cylinders are available in volumes of 300, 500, 750 ml, there are other options. The composition yield is respectively equal to 30, 40, 50 liters. But you need to understand that you may not get so much foam. there are no ideal surfaces and working conditions. The consumption of the sealant is influenced by the correct application, the temperature and humidity of the environment, the experience of the repairman and other factors. Therefore, the foam yield indicated on the tube must be taken as a conditional figure, and buy a sealant with a margin.

To reduce foam consumption, the surface can be sprayed with water prior to application. This will help to achieve maximum expansion of the substance. The can with the assembly tool should be shaken upside down, and the joints and holes should be filled by 30-50%. The mass will gain volume and completely fill the rest of the space. For work, you need to use products of proven brands, carefully read the manufacturer’s instructions and the technical characteristics of the foam. Compared to other agents (cement mortar, putty, grout), the assembly sealant has a very high polymerization rate.

Description

Polyurethane foam is classified as a sealing agent, without which it is almost impossible to do in the construction process. It is used in cases where there is a need to seal seams or joints with a depth and width of more than 3 cm.Before using this material, builders wonder how long it takes for the foam to dry completely, but it turns out that this question has been posed incorrect. First of all, it should be said that the main secret of the complete transformation of the material into strong polyurethane foam is the degree of wetting. But we will pay attention to this fact.

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First you need to decide why builders prefer polyurethane foam:

  • its application is very simple;
  • pricing policy is available;
  • long service life.

In addition, this material has qualities that isolate sound and make it possible not to lose heat from the room.

Most often, foam is used in the process of installing balcony blocks, windows or doors of various types. When applied, the composition begins to expand and at the same time fills all the voids, thereby gluing the desired surfaces. It should be noted that the curing time also depends on how thick the layer was applied. If it is not more than 5 cm, then within 3 hours after leaving the cylinder, the foam will reach the required density.

Foam is also so popular for the reason that, when cured, it is not susceptible to the effects of temperature, moisture and even electricity, in addition, fungus does not appear on it. It should be noted that the foam can undergo changes from the influence of ultraviolet radiation, but this defect can be eliminated by using decorative plaster.

Material characteristics

With the help of polyurethane foam, various types of work are carried out, this does not necessarily apply to windows and doors; with the help of this sealing consistency, builders close up large gaps, eliminate voids and fasten structures. If you familiarize yourself with all the qualities of the material, you can understand that it can be compared to sealants due to its ability to seal the required surfaces.

Before disassembling the drying process in detail, you need to familiarize yourself with the main characteristics of the material.

  • Output volume. This indicator shows what changes have occurred with the material in comparison with its original state. The unit in which this volume is measured is liters. The main aspects that affect this indicator are the temperature and humidity of the treated surface.
  • Clutch. This characteristic allows you to determine how well the material will adhere to the surface. Exceptions in this case may be surfaces such as polyethylene, ice, greasy bases, Teflon and silicone.
  • Viscosity index. These data will depend on the quantity and quality of the components used to prepare the foam. In addition, the outside temperature will also affect this property. It is recommended to use the material only when the indicator is from 5 to 30 degrees.

If you apply foam outside the established boundaries, then it will lose its main qualities, and the original product will not meet all the requirements put forward.

If the consumer needs to purchase a sealing foam, then, in addition to the drying rate, you need to pay attention to several more main parameters.

  • Porosity index. The smaller it is, the better the foam quality. This parameter is determined by the number of pores in the closed state on the surface.
  • Volume. In this case, you need to pay attention to the mass of the polymer already in a solidified state.
  • The quality of the packaging, in our case, the bottle. It would seem that this is not such a serious criterion, but it is the design and integrity of the container that can affect the quality of the material inside and the final result.

How much polyurethane foam dries?

  • Description
  • Material characteristics
  • Requirements
  • Polymerization time

The drying process of the polyurethane foam depends on many influencing factors: the quality of the material, its composition, the temperature of the external environment and its humidity. All this must be taken into account before starting to seal seams or openings.

Requirements

Polyurethane foam is a material for which, like any other, a number of requirements are put forward.

These requirements include:

  • good adhesion of surfaces;
  • elasticity;
  • after solidification, the material should not crumble, even when exposed to sub-zero temperatures;
  • shrinkage of a solution that has already dried should be moderate.

How To Cut Pre-Cubed Foam Block. Customise Your Foam

We draw the attention of users to the fact that the foam is very afraid of direct sunlight. For this reason, after complete hardening, the excess is cut off, and all sealed places are treated with paint or plaster. And in order not to violate the density of the material and to make the application sequence correctly, you need to know how long it takes to completely solidify.

To eliminate gaps between door frames and openings, only a third of the sealant will be required. The material will begin to solidify on the surface within half an hour after application. You may notice that a film will appear on the surface.

Final drying can be expected 8 hours after application. The fixing process occurs due to the expansion of the substance that comes out of the container and solidifies.

Conventionally, this is divided into several stages:

  • primary, which is carried out immediately at the exit from the package;
  • secondary, which is not completed until the final transformation of the foam into a solid composition.

If the material is of high quality, then at the second stage the expansion rate can reach 30%, this must be taken into account in the process of work. Most often, it takes a third of the material to fill the space, this is enough to fill all the cracks when expanding.

But you should also pay attention to the fact that the foam should shrink, you should not be afraid of this action, it will not bring problems. In high-quality materials, shrinkage can reach 5%, and this is invisible externally. If shrinkage still occurs, and this is clearly visible from the side, it means that the polyurethane was purchased of poor quality.

Polymerization time

So, at the beginning we pointed out that water plays a rather important role in the use of polyurethane foam. This is due to the fact that it is the liquid that increases the adhesion rate, for this reason, experts recommend wetting the working surface before carrying out work. It is not necessary to pour a large volume of water onto the walls; it is enough to use a conventional spray bottle.

If we consider the process of installing door structures, then, as already mentioned, the drying process will be affected by the thickness of the layer and, of course, the temperature indicator of the environment. Under normal conditions, the excess foam can be cut off after 3 hours, and after that you can start plastering. Speaking of the final hardening, it should be noted that it will come after about 12 hours.

Many people wonder how much foam dries when installing windows or doors in an apartment, and if it has already been applied, then why does it take a long time to dry. Foam dries for a long time for various reasons. One of the main ones is to use it at the wrong temperature.

If the foam has been used in cold or too dry conditions, the curing may be delayed indefinitely. But experts warn that in this situation there is no need to rush to trim and finish, you need to wait for the full hardening.

To make the process faster, a special winter foam must be selected for work, its qualities correspond to the conditions in which it will be used.

In the event that you are unhappy with the drying time, it can be accelerated by spraying the material with liquid. You can use any method you like. If the work was carried out on windows, do not forget that direct ultraviolet light negatively affects not only the drying process, but also the material itself, therefore, if possible, the places of embedding should be hidden.

About what polyurethane foam is and about its features, see the next video.