Currently, in practice, for any type of construction or repair work, polyurethane foam is widely used. This convenient material is widely used for arranging door and window openings, installing plumbing fixtures, sealing window sills and in the case of other similar manipulations.
In addition, a universal sealant is often used in the manufacture of heat-insulating panels, it is filled with various types of cavities and cracks in building structures. The main advantage of this building material is its versatility. It is easy and convenient to use.
Foam, gun and cleaner are the main attributes of working with polyurethane foamWhat is polyurethane foam
This sealing material comes in the household and professional varieties. Their performance characteristics are comparable, the main differences are in the volume of containers in which this or that type of packaging is packaged. Household foam is produced in cylinders with a capacity of up to eight hundred milliliters, equipped with a small section tube. The magnitude of the internal pressure does not reach high values, this helps to reduce the consumption of the active substance even when using a cartridge without special devices.
Professional foam is labeled accordingly A sealant for professional use is produced in cylinders with a capacity of one and a half liters and is designed to perform large-scale work on sealing doors, windows, filling large cavities, and so on. The pressure inside the container is very high, so it is difficult to apply the material correctly without special tools. The outlet of the professional closure is equipped with a mount for installing a pistol spray gun.
Preparation for material application
The processed elements must be prepared before applying the polyurethane foam. To do this, perform the following manipulations:
- The surface is thoroughly cleaned from construction dirt and degreased. If the width of the cavity exceeds eight centimeters, it is recommended to fill it with polystyrene to reduce the consumption of polyurethane foam and improve the thermal insulation properties.
- The area to be treated is moistened. To do this, it is better to use a spray, then the surface will be wetted evenly.
- The ambient temperature is monitored. The foam can be applied in a positive temperature range of five to twenty degrees Celsius. The upper limit is thirty degrees. In frost conditions, a material resistant to low temperatures is used.
Winter foam is designed to work at low temperatures When working, it is necessary to comply with safety requirements. All manipulations are performed with goggles and gloves. The respirator is used if the active ingredient contains toluene.
Working with a spray can with a straw
You can work without a gun as follows. Before starting, the can of polyurethane foam must be shaken vigorously. Then the supplied tube is screwed onto the adapter, and the container is turned upside down. This is done due to the fact that the propellant gas is much lighter than the active substance, and in this position of the balloon, all the components of the material are better mixed and leave the container.
Rules for applying foam with a straw When applying foam, it must be borne in mind that the material significantly increases in volume when solidified, and therefore, the cavity should be filled no more than a third of its depth. The resulting excess can always be cut off with a long, sharp knife.
It is necessary to moisten with water not only the surface to be treated, but also the sealant itself, so it will set faster.
The thickness of the applied material should not exceed four centimeters. Before continuing work, you must wait about thirty minutes for the previous layer to harden. Final curing will take place after eight hours. It must be admitted that it is not always convenient to use polyurethane foam without a gun. The following video will help resolve the remaining questions.
Benefits of using pistol foam
The use of pistol foam has a number of advantages over the use of household spray cans. The main one is the precisely calibrated amount of the sealing material supplied to the surface to be treated. In addition, rather long breaks from work are possible. Polyurethane foam in a pistol device does not freeze much longer than in a can with a straw.
Gun foam is easier to work with The long barrel of the gun allows for the treatment of hard-to-reach places, the delivery of foam through the nozzle is much smoother than through a plastic tube. This is very important when filling large-volume cavities layer-by-layer and, if necessary, vertical application of the sealant.
The plasticity indicators of professional foam are better than that of household foam, due to this and a more accurate dosage, the material is consumed more economically.
The productivity of labor with the pistol is greatly increased. This is especially important when performing large construction work.
How does a pistol work
The foam gun is arranged quite simply. The main components of its design are:
- Threaded or snap-on mounting on a container with polyurethane foam. It houses a valve with a pin.
- Foam outlet opening mechanism. It is made in the form of a trigger.
- A device that regulates the supply of material. It is made in the form of a screw.
- Outlet tube. Foam is fed through it.
- Pistol grip. She is obliged to fit comfortably in the hand.
The quality of the gun determines the ease of use The more metal parts there are in the gun, the more reliable it is to use. This is especially true for the details of its structure, which are subject to the greatest operational loads.
Preparing and replacing a spray can, installing a gun
Before installing the can on the gun, the material must be prepared. For this, the following procedures are performed:
- The container is heated in water to operating temperature and vigorously shaken to bring the active substance to a uniform consistency. This is done to ensure an even release of the material.
- The pistol device is positioned downward with the handle, the cylinder is screwed on top or snapped into place with the protective cap previously removed. A hissing sound indicates the beginning of the foam release process.
- With the adjustment screw, when the trigger mechanism is pressed, the foam of normal density is released. The first portions are sent to a plastic bag to release excess air from the system.
Even with a small amount of work, it is difficult to do without a foam cleaner Before replacing the cylinder, the structural parts of the pistol device must be cleaned of contamination. For this, the following manipulations are performed:
- the trigger mechanism is pressed to relieve excess pressure in the system;
- a container with a cleaning solution is installed on the pistol device;
- several times for about ten seconds, flushing is performed until a clean solution comes out;
- structural elements are lubricated.
Rules for working with pistol foam
Spray gun foam is applied to the surfaces to be treated evenly from left to right or vertically from bottom to top. The cavity is filled by half or one third of the volume in accordance with the coefficient of expansion of the material. If it is necessary to seal joints on the ceiling, the gun barrel is lengthened with a flexible tube so that the can is placed under the ceiling. The length of the applied layer should not exceed ten, and the thickness - four centimeters. The next coat is applied after the initial hardening of the previous one.
When grouting ceilings, the benefits of the gun are even more noticeable Spray foam expands as it cures and presses against adjacent surfaces, which can cause deformation. As a result, in case of the need to fill the through gaps, the polyurethane foam is poured only on one side, and on the opposite side, a different sealant is used, most often based on silicone.
In the process of performing the work, it is necessary to ensure such a situation that the end of the gun barrel is always located inside the applied layer of sealing material. The hardened foam is cleaned with a rag moistened with acetone or other solvent. A specially selected video demonstrates the described process.
Setting time and seam treatment
Complete curing of the polyurethane foam occurs eight hours after its application. All this time, it is not necessary to exert a mechanical effect on its surface, since the internal structure of the sealing material may undergo undesirable changes. After this time, excess polyurethane foam is cut off with a sharpened cutting tool or a metal hacksaw. If this is done prematurely, the quality of the seam itself may be disturbed, it may sag and fall inside. To accelerate the hardening of the sealing material, it is recommended to moisten it with a spray bottle.
Stages of processing, protection and finishing after applying the polyurethane foam Polyurethane foam has excellent heat and sound insulating performance, but the surface of the seams formed by this material does not look very nice. As a result, in most cases, they are decoratively treated with putty, cement mortar, paint or other finishing building material.
The cured sealant can withstand significant temperature fluctuations in the environment, but decomposes under the influence of ultraviolet radiation when exposed to direct sunlight. As a result, the surface of the seams formed by the polyurethane foam is painted, plastered, covered with platbands or protected from solar radiation in some other way.
The emergence of new generation windows in the modern construction industry has opened up wide possibilities for the use of a modern polyurethane-based sealant - polyurethane foam. It is designed to connect various structural elements to each other. Installation of plastic windows is no longer complete without construction foam. Previously, the installation of windows was notable for the inconvenience and increased laboriousness of sealing due to the use of tow on cement mortar, which ignored numerous small inaccessible spaces. Polyurethane foam is able to fill them, thereby providing heat, sound insulation and sealing properties during installation. Filling voids and cracks in door and window blocks, water pipes, roofing materials and other building structures, polyurethane foam creates not only tightness, sound insulation by filling the voids, but also reliable fixation of the elements.
Features of polyurethane foam
Construction foam, as a rule, is stored in aerosol cans of various capacities, as it is a mixture of a polyurethane substance and a gas under pressure in a ratio of 3/1. In this proportion, the foam easily fills any voids, cracks, potholes.
The ability of the polyurethane foam to provide the structure with thermal insulation, tightness and resistance to various kinds of influences can be increased, provided that its peculiarity is destroyed under the influence of direct sunlight.
The advantage of construction foam is its relatively low cost. It is used with almost all building materials - concrete, wood, plastic, glass, brick. The exceptions are plastic, teflon, silicone, polyethylene. If, nevertheless, foam is applied to these materials, then their surface is pre-treated with acetone. Labor and time costs when working with polyurethane foam are insignificant due to its rapid polymerization.
Note! The disadvantages of polyurethane foam include its chemical basis (ventilation of living quarters and the use of protective equipment - gloves, a respirator - when working with aerosol), instability against ultraviolet rays and natural precipitation - rain, snow. Therefore, cracks filled with polyurethane foam must be covered with paint, sealant or covered with a casing.
It is also worth noting that the cost of a pneumatic gun for a foam cylinder is much higher than the cost of the cylinder itself, but thanks to its repeated use, it will pay off in speed.
Polyurethane foam can be one- and two-component. When spraying one-component foam, a chemical reaction occurs with the formation of polyurethane foam, which, in an environment with 35% humidity, can transform into a solid consistency, the volume of which increases by 250%. The ambient temperature should vary between + 5- + 35 degrees Celsius. Ideally, the air temperature should be 20 degrees, the humidity should be 60-80%.
Note! There are types of specialized foam that are used in winter conditions (at sub-zero temperatures), but under the main condition - sufficient air humidity. Otherwise, the polyurethane foam will not harden.
Operating principle
Before you understand how to apply polyurethane foam, it is important to know the principle of its formation. In an aerosol can, polyurethane foam is contained in the form of polyurethane ingredients, which are placed in the center of the container. In the lower part there are diisocyanates, in the upper part there are gas. The main condition for using the contents of the container is mixing the components, therefore, the cartridge should be thoroughly shaken before applying the polyurethane foam. Under the influence of gas, the foam is forced out from the cylinder, increases in volume due to the interaction of polyurethane and diisocyanates, and then absorbs moisture from the environment and hardens, forming a dense plastic.
Note! For hardening (polymerization) of the foam, it takes at least 8 hours, for complete drying - 2 days. After drying, the foam gives some shrinkage from 5% and more (household sealant gives 50% shrinkage). The smallest shrinkage (5%) is allowed by foam applied with a pneumatic gun.
Surface preparation and material handling
Depending on the scope of work, preference is given either to polyurethane foam with a tube in the cylinder valve ("amateur"), or to apply it with a pneumatic gun ("professional"). In terms of chemical composition, such foams are no different from each other. For sealing small cracks, a "hobbyist" package with a tube is suitable, which in a few hours after use becomes unusable due to the foam hardened in it. A “professional” package with a special thread on the valve for connecting the gun is important in the case of a large volume of “delicate” work, where precise, economical dispensing in hard-to-reach places is required.
When applying foam, the following work procedure should be followed:
- Remove debris (chips, etc., old foam is removed mechanically) from the places where the foam is applied. Foam is used for slots 2-8 cm wide. Slots up to 2 cm are sealed with another sealant, slots wider than 8 cm are reduced.
- Moisten the surface on which the polyurethane foam will be applied with a spray gun, avoiding dripping moisture.
- The temperature of the foam cylinder should be the same as the air temperature. To do this, the balloon is lowered for several hours in a container with water of the required temperature.
- Shake the can for 1 minute to allow the foam components to react.
- Apply foam from bottom to top in smooth movements on 1/3 of the gap. In this case, the cylinder must be in the upside-down position.
- Deep gaps and large voids are filled with foam in layers or by 50%, with breaks of 10 minutes for the foam to swell. The diameter of the foam stream is 1 cm. During a break, as well as during storage, the cylinder must always be in an upright position.
- After removing the pistol from the cylinder, you need to clean them of the remaining foam using a special solution, apply technical Vaseline to treat the screw, socket and gun barrel.
After the foam has hardened, its excess is removed with a knife, the places of its application are protected from environmental influences with a layer of paint, sealant or putty, or covered with a casing.
Video
How to work with pistol foam, see below:
When it becomes necessary to fill cracks, holes, seams, various voids, during repair or construction work, polyurethane foam is primarily used. This material is widely used as insulation. Polyurethane foam can be used almost in conjunction with any material: stone, iron, wood, plastic. We will consider instructions on how to use construction foam and its properties in the article below..
Polyurethane foam properties
The main property of the substance, which ensures its widespread use, is a high degree of filling and excellent adhesion. The expansion coefficient in this case varies from 10 to 60%. Curing occurs due to the interaction of the material with moisture and air. Gas is also added to the cylinder, with the help of which pressure is created to displace the substance. The main components are methylene diphenyldiisocyanate (MDI), a polyol, a blowing agent, and a catalyst.
Varieties
The material can be divided into one-component and two-component, as well as household and professional. The quality does not differ greatly from this, but the way the foam comes out of the container is different. When using professional cylinders, an assembly gun is required: a device that controls the consumption of a substance. While household ones are equipped with PVC guide tubes, which are sprayers. In addition, the material has differences in application temperature:
The disadvantages include sensitivity to ultraviolet rays, under the influence of which it is destroyed and a long solidification time. The setting time of a substance is characterized by the duration of polymerization and depends on the volume. The hardening period is from 8 to 12 hours.
Correct use
A cylinder with household polyurethane foam is intended for single use, so you should think about its effective use, since unused material will be lost. Polyurethane foam is usually produced in cylinders, tubes, on the surface of which information is applied about the conditions of use and preparation for use.
The capacity is 600-800 milliliters. A non-professional balloon comes with a disposable PVC tube with special notches. Thanks to the notches, the length of the tube can be shortened, and in the case of hard-to-reach places, an extension adapter in the form of a flexible hose is put on it.
Before starting work, the cylinder is shaken vigorously and the cap is removed, which serves as a kind of safety lock. Then it remains only to screw the plastic tube, which is supplied with it and has an internal thread, onto the threaded part of the cylinder.
It is important to note that the straw can be used several times. It has a collapsible design and Lego is cleaned with a ramrod or a piece of thick wire from the foam frozen in it.
To improve the degree of expansion of the solution and its hardening, the required amount of moisture contained in the air may be insufficient, therefore additional wetting is applied.
How to use polyurethane foam without a gun? Consider the recommendations:
The process itself is as follows. The end of the tube is positioned approximately five centimeters from the point to be filled. I would like to draw your attention to the fact that about half of the required volume is filled due to the expansion of the substance. The material is squeezed out in wavy movements. As the substance increases in size, surpluses are formed, which are cut off with a sharp knife after hardening.
Precautions for use
Construction foam is a tricky material to use. Since it contains toxic substances, the working area must be well ventilated. It is flammable and should not be exposed to flame. When applying it, it is necessary to regulate the force of pressure, it is necessary to press evenly so that the contents come out in an equal amount.
The substance, when it gets on the surface, is very difficult to remove and can subsequently damage the coating. In case of contact with unwanted areas, it is necessary to wait for it to harden, and only then try to remove it. Residues can be removed with acetone and, on solvent-sensitive coatings, treated with special detergents.
It is extremely important to protect the organs of vision. To do this, wear transparent glasses. Gloves are used to protect hands, as the foam has excellent adhesion to the skin.
Disadvantages and advantages of household construction foam
The following can be noted:
- increased material consumption due to the impossibility of accurate metering of its output;
- difficulties in work: the balloon has to be held upside down, with a girth, which puts a load on the arms and leads to fatigue;
- the cost is usually cheaper compared to the professional one;
- satisfactory work result.
Thus, if there is no assembly gun available, then there will be nothing left but to use polyurethane foam with a straw. The video process of the work can be viewed on numerous sites on the Internet dedicated to construction.
Polyurethane foam is one of the most difficult to remove materials: once it gets on fabric, leather or other surfaces, it is quite difficult to clean them. But it's worth a try.
| Surface | Fresh foam | Cured foam |
| Hand skin | Gently removed with a sponge, residues are removed with improvised means - scrub, acetone, solvent, gasoline, saturated saline solution | It can be removed only mechanically. Usually loses its properties and falls off after 2-3 days |
| Textile | It is collected with a stick, the remains are removed with a cleaner. Important! Stains may occur when processing fabric! |
If possible, large pieces are cut off, and the remains are treated with a special solvent for cured foam, white spirit or gasoline. Remove stains that appear with stain removers |
| PVC (frames, window sills) | Carefully removed, the surface is wiped with a special cleaner for PVC | Carefully cut, the surface is wiped with a special cleaner for PVC (usually marked - for installing windows) |
| Floor covering (linoleum, laminate, parquet) | Remove foam with a spatula, collect the rest with a sponge soaked in cleaner. Stains may appear! They are removed from wooden surfaces by grinding, but varnished coatings cannot be cleaned - they will have to be replaced. | After cutting off the foam, the residues are carefully dissolved with a special cleaner or the drug "Dimexid" (sold in pharmacies). It is necessary to work with such substances with gloves - strong components can cause burns! |
As you already know, polyurethane foam is not intended for sealing holes less than 1 cm in size - it is better to fill such gaps with silicone sealants.
Alexander Birzhin, rmnt.ru
If you have started repairs in an apartment, then at certain stages you will have to think about how to use polyurethane foam, if you have not experienced this before. Despite the fact that this material cannot be called an innovation in the construction industry, not everyone knows the rules for its use, as well as its advantages and disadvantages.
Nuances when using polyurethane foam
Polyurethane foam is used not only by professional builders, but also by people renovating their homes, dacha or other premises with their own hands. It is necessary for fixing products, improving thermal and sound insulation and sealing.
Due to its wide area of use, polyurethane foam is rapidly displacing cement, putty, bitumen and tow from the construction market. This is easy to explain. If you have never used this product before during repair and construction work, it is simply because you did not know all its advantages, of which there are a lot.
So, here is a list of some of the benefits that you will experience when using polyurethane foam:
- high rates of thermal insulation;
- short drying time;
- ease of work;
- good sound insulation;
- stable sealing;
- elasticity of polyurethane;
- reliable fastening of products;
- interaction with almost all types of building materials, with the exception of silicone, teflon and polyethylene;
- an increase in volume several times;
- resistance to moisture;
- fire resistance;
- poor electrical conductivity;
- filling all gaps and cracks, even in a hard-to-reach place;
- if necessary, excess material can be cut off with a knife;
- when used as fasteners, there is no need to use additional fixing means;
- not susceptible to chemicals.
However, like any material, foam has some drawbacks:
- certain requirements for temperature and humidity during operation;
- instability to ultraviolet radiation;
- when using, protective equipment for eyes and hands is required;
- difficult dismantling.
As you can see, there are quite a few drawbacks, moreover, they can be avoided if the technology of use is observed.
Material application technology
Take protective measures by wearing gloves and goggles before starting work. Next, moisten the surface to be treated and shake the can thoroughly several times.
When using summer foam, it is necessary to ensure that the air temperature is within the range from +5 to +35 degrees.
If all the conditions are met, remove the cap from the cylinder, screw on a special tube, and then turn the cylinder itself over. If you are machining a vertical hole, start the process from the bottom, working your way up. When finished, sprinkle the surface with water, thereby speeding up the curing process.
If after work there are gaps in the surface, re-run the foam over them and leave it to dry completely (for 8 hours). After the required time, carefully cut off the excess material with a knife.
When using foam as a fixer for products, window or door openings, it is necessary to use spacers to avoid deformation.
- To work in cold weather, you need to make a choice in favor of winter or all-purpose foam.
- Foam elements left on hands or clothes are removed with solvent or acetone.
- You should not buy cheap products, since they are of low quality, and during the dismantling process, there is a high probability of damage to the surfaces.
- To protect polyurethane from ultraviolet radiation, you can paint it, plaster or putty, or use platbands.
- Work can only be done with high quality if the work area is well ventilated and ventilated.
- To make the processing of horizontal surfaces and hard-to-reach places less difficult, it is advisable to use an assembly gun.
- If the gap to be treated is more than 80 mm wide, it should be pre-filled with bricks, wood or cement mortar.
- If the gap opposite is less than 10 mm, it is better to use a putty.
With the above information, you will learn how to easily use polyurethane foam where you need it. Do not be afraid to start using a material unfamiliar to you, since there is nothing difficult in this, and having realized the advantages, you simply will not find an analogue when performing repair and construction work.
In addition, now almost all the work that used to be trusted by professionals, you can do it yourself without any special skills and knowledge. Soon you will feel all the benefits of polyurethane foam.
Video
In addition to the information presented above, there is the following video.