Can polyurethane foam be used several times?

Photo: ShutterStock/Fotodom.ru

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

Polyurethane foam is an indispensable element of many construction works. It is used when 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, popularity of the brand and ranges from 100 to 600 rubles. It is worth noting that polyurethane foams are divided into one- and two-component ones. Since most of the foams presented on our market are single-component, let’s talk about them.

The consequence of poor sealing is distortions, sagging, and reduced service life of windows. Correct use of foam provides the necessary heat and sound insulation. Photo: ShutterStock/Fotodom.ru

Polyurethane foam in questions and answers: how to choose, store and use it correctly

Polyurethane foam, despite its name, is not intended for installation. Its task is to fill and seal gaps and joints for the purpose of thermal and sound insulation. We answer questions regarding the selection and application of this material.

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

The consequence of poor sealing is distortions, sagging, and reduced service life of windows. Correct use of foam provides the necessary heat and sound insulation. Photo: ShutterStock/Fotodom.ru

Adhesive foam

GoldGun 65 (Penosil) (875 ml pack - 345 RUR). Photo: Penosil

The scope of application of polyurethane foam is expanding. Many manufacturers, including TECHNONICOL Corporation, Henkel, Selena companies, offer adhesive foams for fixing thermal insulation boards made of polystyrene foam, extruded and pressed polystyrene foam, when installing external and internal thermal insulation systems on surfaces made of concrete, brick, plastered, etc. In addition , adhesive foams are used in the construction of walls and partitions from aerated concrete, ceramic and other blocks. Unlike conventional foams, adhesive foams have higher adhesion and a low degree of expansion.

Professional mounting foams: all-season Construction 70 (Penosil), application temperature from –10 to 30˚С (pack of 870 ml - 336 rubles). Photo: Penosil

Summer Soudafoam Professional 60 (Soudal) (750 ml pack - 390 RUR). Photo: Soudal

Summer Tytan Professional Gun (Selena) (750 ml pack - 343 RUR). Photo: Selena

What is polyurethane foam?

Maxi (Profflex) all-season (750 ml pack - 218 RUR). Photo: Profflex

One-component polyurethane foam is a polyurethane sealant in an aerosol package. The basis of the foam is a prepolymer (prepolymer) synthesized from a polyol and isocyanate. As a result of the polymerization reaction, partly occurring inside the cylinder, and mainly in the air, after release outside, these substances form polyurethane. Coming out of the container, the prepolymer sharply increases in volume (20–40 times) and turns into foam. Expanding, it penetrates into hard-to-reach cavities and fills voids. Then the cellular mass gradually polymerizes (hardens), absorbing moisture from the air or from a previously wetted surface. After a day, it becomes a chemically stable substance - polyurethane. It is non-toxic, does not deteriorate for a long time, and is resistant to moisture. This rather rigid, finely porous material consists of closed cells and serves as a good insulator.

Pistol repair

First of all, you should remember that the gun must be washed regularly. If the tool is used regularly (professional installation of windows, doors), it is worth installing cleaning after using 3-4 foam cylinders. In this case, you should first run the flush through the entire device of the gun (by pressing the trigger), after which the tool should be put aside for 1-2 hours so that the acetone dissolves all the foam inside. Then press the trigger again and rinse the instrument for 5-10 seconds.

The main malfunctions of the spray foam gun:

When connecting the cylinder, no characteristic sound is heard and no foam flows. The reason lies in the sticking of the ball inlet valve. Most often, this problem occurs when the cylinder is disconnected from the gun, so the device should be stored with foam.

To fix this, you will have to unscrew the cylinder adapter and release the valve ball; in this case, liquid flushing (foam solvent) may be necessary. It must be poured over the valve and wait a while. When removing the ball, be careful not to damage its surface or lose the valve spring.

After cleaning the unit, the functionality of the tool is usually restored.

Another common problem is spontaneous leakage of foam from the gun nozzle. Most often, the problem lies in a clogged nozzle or needle of the control mechanism.

To fix the problem, you will have to disassemble the gun almost completely. Unscrew the regulator, disconnect the gun barrel, unscrew the nozzle (in some non-separable models, the operations may be different, but the meaning remains the same - disassemble the foam supply unit).

Particular care should be taken when handling the needle and the nozzle itself; any damage to these parts will require their replacement. Afterwards, all parts need to be washed; the barrel can even be soaked in it. At the end of processing, all parts should be wiped with a soft cloth.

Once the gun is assembled, the involuntary flow of foam usually stops. Otherwise, you will most likely have to change the parts themselves or the seals.

Sometimes you have to deal with such a problem as the inability to unscrew an empty cylinder (most often after a long break in use). The solution may be to unscrew the cylinder along with the adapter, this allows you to relieve excess pressure. After this, the cylinder is twisted, but the adapter will have to be held with a key. In the most severe cases, they even resort to cutting the cylinder with a grinder (maximum care should be taken) and unscrewing its head after first soaking it in a solvent.

In order to prevent this situation, any remaining foam should be removed from the adapter when replacing the cylinder.

When using a spray foam gun, the main thing to remember is that any tool loves to be treated carefully and with care, do not forget about this.

How is household foam different from professional foam?

Tytan Professional STD (Selena) summer (750 ml pack - 315 RUR). Photo: Selena

The container with household foam is equipped with a special applicator tube. Thanks to this device, no additional tools are required to release the viscous mixture. Household foams are generally single-use products. The yield of the mass is difficult to dose, and it itself is characterized by high density and low polymerization rate. Professional foams are designed for repeated use and better sealing. In them, the supply and dosing of the foam jet occurs using a plunger gun. It is screwed onto a special ring on the cylinder. It is professional foam that should be given preference when installing doors and windows.

Specifications

Pena is a lady with excellent technical characteristics, for which she has gained an army of fans. So, the characteristics of polyurethane foam are as follows:

shrinkage – 5%;
porosity – 88%;
output volume – 300 ml can – 20 l of foam, 500 ml – 40 l, 750 ml – 50 l, 1000 ml – 80 l;
polymerization speed - 20 minutes - gain of useful volume, 4 hours - hardening, 24 hours - complete hardening;
adhesion – excellent adhesion to wood, concrete, glass, metal, PVC, stone, poor adhesion to silicone and polyethylene;
heat resistance - -45/+90°С;
strength – 3–5 N/cm2.

Always buy extra foam. Manufacturers often deceive consumers. So, for example, they write “50 liters” on the cylinder, but in reality it is much less, well, somewhere around 25–30 liters. I think everyone understands why cunning manufacturers do this - a common marketing ploy. Therefore, play it safe.

At what temperature can foam be used?

Soft foam cleaners: PU Foam Cleaner Click (Soudal) (500 ml pack - 257 RUR). Photo: Soudal

Depending on the operating temperature range, polyurethane foams are divided into summer, winter, and all-season. For the former, the range of permissible temperatures is in the positive zone: from 5 to 30 ˚C. Winter and all-season foams are used in a wider range: from –10 °C (some from –25 °C) to 30 °C. In this case, it is worth considering the manufacturer’s advice on the temperature of the cylinder. In the cold season, with low air humidity, the course of chemical reactions slows down, the viscosity of the mixture increases, and the pressure in the cells of the foam mass decreases. For normal operation of winter foam, many manufacturers advise warming the balloon to room temperature (23 °C), keeping it in a living room for about a day or immersing it in warm water (about 30 °C). However, there are products for which the use of a cold cylinder is acceptable.

Winter foams contain components that help better absorb moisture from the environment and maintain the desired consistency at low temperatures. Winter foams can be used in cold and warm seasons without compromising their performance properties. Photo: ShutterStock/Fotodom.ru

Incorrect position of the cylinder when spraying

It would seem logical to spray the material while holding the container with the nozzle up, but as practice shows, it is better to turn it upside down. Then the light propellant gas contained inside will rise and press on the foam, providing maximum yield.

But what if you need to fill a seam in a hard-to-reach place, for example, under the ceiling? To do this, you can make a simple device by putting a flexible tube on the nose of the cylinder and attaching a stick holder to its free end.

Why do you need to shake a can of polyurethane foam before work?

ECO Tytan Professional (Selena) (500 ml pack - 235 RUR). Photo: Selena

A container of polyurethane foam contains several components of different densities. If stored immobile for a long time, they can become distributed in layers. Therefore, before starting the process, the container should be shaken vigorously for half a minute to mix the components. Also, shake it periodically during use and especially after smoking breaks. Insufficient shaking can lead to the formation of a coarse foam structure and reduced volume. During operation, the cylinder is held upside down. In this position, the propellant gas drops below the polymer mass and ensures maximum use of the contents.

The surfaces on which polyurethane foam is applied must be thoroughly dust-free and free of dirt, oils, grease and ice. Photo: ShutterStock/Fotodom.ru

How much foam is needed to fill cavities?

Cleaner for hard foam: Tytan Professional (Selena) (100 ml pack - 379 RUR). Photo: Selena

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

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

Taking a break from work and reusing the gun

It often happens that not all the contents of the container are produced in one day. In this case, you should not rush to remove the cylinder and wash the instrument. The hermetic design of the tool will not allow the mixture to harden for a month. But every four days you will need to bleed it out a little to prevent clots from forming in the trunk.

Before reusing the tool, the nozzle must be cleaned of dried residues and the contents of the container must be thoroughly shaken. Having cleaned the adjusting screw, make a test release with the trigger until a normal flow of foam appears, after which they begin to work.

Should surfaces be dampened before applying foam?

Relative air humidity of more than 50% is sufficient for the normal process of foam polymerization. In such conditions there is no need to moisten the surfaces. However, with low humidity (less than 50%), which is typical during the cold season and hot summer days, moistening the seams and cavities will increase adhesion and improve the curing of the foam. 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 cleared of foam immediately after removing the empty cylinder, preventing the mass from hardening inside the gun. Photo: ShutterStock/Fotodom.ru

Improper storage of a foam container

During breaks in work, you must not remove the gun from the container, because of this the foam in the valve will dry out and the container will become unsuitable for work. You can clean the valve with acetone or carburetor fluid if not much time has passed since the last use.

For proper storage, place the container in an upright position and screw the valve on the gun.

Most household cylinders cannot be stored after use - all work must be completed at once.

How to use polyurethane foam?

Polyurethane foam is an excellent sealant and insulation material. It is used both for the installation of such large-scale structures as doors and windows, and for repairing minor defects. This material is used to patch various cracks and crevices, restore tightness at joints, and even make other building materials. Foamed polyurethane is quite easy to use, but you need to follow certain rules for working with it and be quite careful so that the seam is smooth and lasts a long time.

How long does it take to dry?

Polyurethane foam has numerous positive properties: excellent adhesion, low shrinkage, ease of use, low thermal conductivity, and others. Individual properties are important when choosing products, as they determine the areas of application. And some parameters will be useful to the contractor already during the work. One of these parameters is the duration of drying and curing, knowledge of which allows you to have information about when it is possible to continue working with assembly joints.

Peculiarities

Cured polyurethane foam is an elastic, solid material of a yellowish-white color. This very light substance has excellent heat and sound insulation properties. It very quickly loses its properties under the influence of ultraviolet radiation, so it is used mainly indoors.

This type of foam has a number of advantages that make it stand out from other materials:

increased moisture resistance, high levels of sound and heat insulation;
low current conductivity, which allows it to be used when installing electrical networks;
many types of foam are resistant to fire, which allows expanding the scope of its application;
after leaving the cylinder, such foam expands in volume and fills even those microcracks into which it is impossible to insert the gun tube;
polyurethane can be used to glue surfaces made of different materials, for example, wood or brick;
The foam is absolutely non-toxic and resistant to chemical attack.

Almost all of the above properties must be indicated by the manufacturer in the appropriate certificates, which can be requested from the seller.

The packaging itself must contain the following information:

foam expansion volume. It can range from 10 to 300%, but most often the actual foam is still slightly less, since this percentage is indicated for ideal conditions;
its viscosity;
the volume of the container itself.

Most often, all these characteristics depend on the type and purpose of the foam, so you need to know which polyurethane it is and what it should be used for.

Device design

Let's take a brief look at how this tool works and what it consists of. It is worth noting that its configuration is very simple. Despite the huge number of models on the modern market, they are all very similar to each other.

Let's look at the main elements of the device:

A tube. This part has two tips, which are also called nozzles. The tube and nozzles have different diameters, due to which the foam is supplied under high pressure.
Trunk. You can’t do without it when working with deep holes. Its length can be 20 centimeters. There are two types of element design - collapsible and solid. The first option is much more convenient to clean after use.
Adapter (aka gearbox). The part connects the container with consumables to the mounting gun.

During use, it is this element that bears the heaviest load.

Adjustment bolt. Judging by the name, it’s easy to guess that the required foam flow rate and volume are selected using a screw. A very useful part when performing large repair work.
Fasteners This part is responsible for placing and securing the can inside the gun. Outwardly it resembles an ordinary nut.
Adjustment lever. This mechanism is designed to control the speed of output of the consumable resource, which depends on the force of pressing.
Handle. The central element of the support, acting as a clamp for the remaining elements. For its manufacture, metal or heavy-duty plastic is used. In order to increase the convenience of users, special grooves are applied to it for the fingers.

Using the instructions for the device, even a beginner can work with the tool.

Release form

All types of polyurethane insulation differ according to several criteria.

Depending on the method of application and form of release, they can be of two types.

Professional foam is produced in special cylinders, which are inserted into a plastic gun with metal clamps. This gun allows you to use polyurethane economically and in equal portions. The main thing is to thoroughly rinse the device after use so that any remaining substances in it do not harden.
Instead of a gun, household foam packages are equipped with a small tube that is placed on the lever. It is not suitable for large repairs, but it will cope perfectly with minor defects.

Depending on what time of year and at what temperature the polyurethane will expand and harden, the following types of polyurethane foam are distinguished:

summer – used at temperatures from +5 to +35 degrees;
winter – used at temperatures from -18 to +35 degrees;
universal - costs much more, but can be used all year round.

It is worth noting that the temperature ranges are indicated not for air, but for the surface on which the composition will be applied. The lower its temperature, the less expansion of the finished layer will be.

In addition, foam can vary in type depending on the flammability class:

B3 – flammable substance;
B2 – self-extinguishing substance;
B1 – fire-resistant compounds.

Finally, polyurethane foams vary in composition. They can be one- or two-component. However, the latter type of foam is so difficult to handle that it is practically not used for private construction and when renovating premises with your own hands. Two-component foam hardens in a quarter of an hour and there is practically no time left to eliminate defects, so only experienced professional builders use it.

Classification

In order not to feel like a “blonde” while “shopping”, you should study the varieties of the substance.

Release:

professional (for a pistol);

household (with a tube nozzle).

B1 – off;
B2 – lights up, but goes out;
B3 – lit.

winter – used at outside temperatures of -20/+35°C;
summer – used at +5–35°С;
winter-spring-summer-autumn – used at -10/+35°C.

reusable – reusable;
disposable – used once (the remainder is thrown away).

So, we’ve sorted out the types of the main character of the article.

Which one is better? Well, to each his own. For example, for large volumes, specialists use professional two-component polyurethane foam, which is distinguished by its all-season, non-flammable and reusable properties. For those interested, here is an article about sprayed thermal insulation. But we, as non-professionals, can use a household option with flammability class B1, intended for one-time use.

Scope of application

Most often, polyurethane foam is used in the process of installing windows and doors, laying electrical wiring and pipelines. Due to the high thermal insulation in this way, it is possible to foam seams and grooves in cooling and heating systems, cracks in the roof and when insulating the surface of walls, floors or ceilings. It perfectly fastens wall panels and foam boards, providing excellent waterproofing. It is applied to the outside of steel or cast iron bathtubs to reduce heat transfer from the metal when the bathtub is filled with hot water. Using polyurethane, you can insulate the space behind the sheathing of PVC panels. In almost half of the repair processes it remains an indispensable material.

Application area

The sealant has eclipsed many of its predecessors - plaster, mineral wool tapes, cement, bitumen, etc., which is no wonder.

It is used for:

installation of door and window blocks;
fastening insulation, waterproofing, sound insulation;
filling cracks and crevices formed during repairs;
filling voids that appeared during construction;
performing facing works;
filling holes, cracks, cracks in interior items.

The substance has a wide range of applications. Because of this, it will definitely not be forgotten, somewhere on a dusty shelf in the garage or closet.

Recommendations for use

In order to avoid any problems during both minor and major repairs of your own house or apartment, you need to be able to use both professional and household foam. To work correctly with the first one, you must correctly install and use a special construction gun.

Gun installation includes the following steps:

To begin, the foam balloon is heated in warm water to room temperature, after which it is shaken vigorously for 30 seconds. This will give the polyurethane a homogeneous state, which will allow it to come out of the cylinder smoothly and in full;
The protective cap is removed from the upper tank of the gun, it is turned with the handle down and the cylinder is screwed into it. The container is screwed in with force until a hissing sound appears, which means that the mixture has begun to flow into the tool;
if the gun has been previously used and has not been thoroughly washed, then the hissing will not be heard and you will have to purchase a new tool;
The system of connected elements is shaken vigorously several more times, the adjustment screw is turned a quarter turn and, holding the trigger, they begin to apply.

Working with such equipment does not require specific skills, but it will require considerable dexterity if this is the first time.

Applying foam from a gun is performed as follows:

first you need to clean the working surface from dust and dirt, then lightly wet it with a regular spray, since the foam interacts better with a wet surface;
the tool nozzle is directed to the surface;
foam is supplied in the required quantity by smoothly pressing the trigger;
to pour the composition into a vertical recess, it must be applied from bottom to top;
wide spaces are filled with zigzag movements of no more than a third of the volume, since the foam expands greatly in air;
It is better to replenish the area afterwards than to cut off excess hardened substance.

Polyurethane foam sealant: a little practice

So, we have learned a lot about polyurethane foam sealant. It's time to figure out how to use it without a gun.

Step-by-step instruction

I’ll be honest: it’s difficult to work with foam without a gun, but it’s possible, since the household version has a special tube. So, let's start operation "X".

The process consists of the following steps:

gloves are put on (the best option);
the surface for work is prepared: it is cleaned of dirt and dust;
if necessary (if the gaps are too wide or deep) they are sealed with pieces of foam plastic or its analogues;
shake the container (1 minute) so that the foam has a uniform consistency and intensive release from the container;
Using an ordinary household sprayer, lightly moisten the foaming area with water - (liquid should not flow or drip);
remove the cap from the cylinder;
put a special tube, which comes with the kit, onto the protrusion valve;
the edge of the tube is brought to the area that needs to be filled with foam, and the valve is pressed (the seam being processed is half filled);
important point: the working position of the cylinder is bottom up;
after 30 minutes, the treated area is checked, if there are any “jambs” left, foam is added;
after a day (but it can be done much earlier), the frozen excess polyurethane foam is cut off with a sharp stationery knife;
finishing work must be carried out, since the foam is “afraid” of ultraviolet radiation (sunlight) - this is plaster, painting or other cladding.

Difficult? Difficult? No. There is absolutely nothing to be afraid of, but there is no need to relax either...

Working with polyurethane foam without a gun: how to use

Polyurethane foam is an excellent method of sealing. It is used for large-scale repair work or when it is necessary to patch a small defect in the house. It is easier to work with it using a special gun, although you can do without it, saving on the purchase. But first you need to learn how to properly use sealant and understand how to use polyurethane foam without a gun.

Polyurethane foam is a difficult material. A frequent question from people who want to carry out construction work on their own is whether it is possible to use polyurethane foam if there is no gun. To do this, you need to know its properties and basic rules of use .

Polyurethane foam sealant: a little theory

How to work with sealant without a foam gun? Very simple. But first, let's talk a little about the main character of this article - foam. For what? And then, to understand the principle of operation of polyurethane foam. I think no one wants to ruin the substance and the home. It is so? Great. Then let's get started.

Story

The sealant was born thanks to the German chemist-technologist Otto Bayer. He invented the substance back in 1937. Or rather, he discovered polyurethane. And in 1970, specialists from an English company invented polyurethane foam sealant.

It has been tested and improved over the years. In 1980 it was used by construction workers in Sweden. The invention was to the liking of many maestros of architectural art, since it had a number of positive properties.

Polyurethane foam with a tube

First you need to determine what type will be used for repairs. In construction stores you can see two types of foam:

How to choose the right composition? To treat a large area, the volume of the cylinder should be taken into account. The quality of household products can be worse compared to professional brands. Because of this, major repairs require professional foam repairs.

Here are the basic settings for how to use polyurethane foam with a tube:

You must first shake the container for 30 seconds , ensuring that the material inside it is mixed until homogeneous and thereby increasing the intensity of the output.
The cap is removed and a PVC tube is attached to the valve. It is included in the kit if it is a household type sealant. For a professional cylinder, the tube will need to be purchased separately.
The free end is brought to the place where the sealant needs to be applied. The gap is filled by 30–50%. The composition after application increases in volume as it dries. Partial filling reduces consumption. If applied correctly, the gap will eventually fill 100%.
If the foam dries and it becomes clear that there is not enough of it, you can apply another layer. But it is better to carry out sealing without a gun the first time, because the composition comes out in excess and is less amenable to precise dosing.
The material flows first into the tube, and then to the desired place after pressing the cylinder valve.

If the gun is not at hand, this does not mean that the work will have to be postponed. You can use foam without a gun in the following ways:

Premium material requires a tube, but at high pressure a lot of excess material can come out, increasing flow and thereby costs. To avoid this effect, you can take two tubes with different lumen diameters . First, place a tube of larger diameter on the cylinder, then securely fix a tube of smaller diameter in it. This reduces pressure and helps save material.
Household polyurethane foam without a gun is already equipped with a special plastic tube.

Disadvantages of applying construction foam without a gun

If the work is done with just a tube, many people have doubts about the need to purchase a professional construction tool. But this seems to be a problem only at first glance. Professionals still advise not to abandon the use of special devices.

Fast action regardless of the amount of work. For example, to process a two-meter seam, 10-30 seconds will be enough. In turn, the work of applying polyurethane foam without a gun takes at least 15 minutes.
Accuracy. The gun has a very narrow nozzle and supports adjustable settings. Therefore, you can fill even the smallest gaps, which is simply necessary in some situations. The foamed surface is then difficult to distinguish from other areas. This rule applies equally to walls and floors.
Foam consumption is very small, since the materials are supplied in doses. In the case of a tube or cylinder, you cannot do without overspending.

Polyurethane foam with a tube is great if you only have to do one-time work on a small area. Otherwise, it is better to replace it with another device. It is also necessary to take into account that installing a tube on a cylinder is not always possible.

As an option, you can use special mini-cylinders with a volume of 250-500 ml. The main thing is to purchase them in sufficient quantities in advance. It is not recommended to use the remainder of the material; in this case, the professional foam remaining inside the small-volume cylinder is disposed of along with it.

As for the pistol itself, it also has its drawbacks. For example, after use, the tool requires cleaning (see in more detail “How to clean a foam gun?”). They produce special care compositions that act in just a few seconds. Usually the manufacturer additionally writes in the instructions about how to handle the device. Tubes often remain an independent invention.

Acetone at home easily replaces special liquids, and anyone can keep it at home. When working, the composition must be poured into the nozzle of the tool, and then completely clean it using a wire or cleaning rod. All actions must be performed as carefully as possible, otherwise delicate structural elements may be damaged.

Rules for working with polyurethane foam

Working with foam is quite simple. The main thing is to follow the detailed instructions:

Wear gloves on your hands to prevent the sealant from getting on your skin, as it is difficult to remove.
The place where the sealant will be placed is first carefully cleared of debris and dust . When the gap is large in depth and width, it is first filled with small pieces of foam.
Shake the container as recommended in the instructions, usually 30–60 seconds. Thanks to this, the composition becomes homogeneous and comes out better, which simplifies the work several times.
The planes inside the recess are wetted, but moderately; water should not flow along the walls.
The cap is removed from the cylinder , which limits its operation unnecessarily. A tube is put on the ledge, replacing the gun.
The free edge of the plastic tube is brought to the hole at a distance of 5 cm, now you should press the valve. The hole is filled halfway or a little less, since the volume increases as it dries.
After 30 minutes, you should carefully inspect the foaming area. If pits or empty cavities are visible, solution should be added.

Before foaming the gap, you need to make sure that the ambient temperature complies with the recommendations in the instructions for the sealant. It is necessary to carry out work when the ambient air temperature is within 5–20 degrees Celsius .

When applying, you need to constantly adjust the pressure so that it is uniform and the contents come out of the container in equal parts. If it gets on any surface, the composition is poorly cleaned, and there is a risk of damage to the coating. When applied to the desired areas, it must be given time to harden, only then cut off the excess. The composition contains toxic components, so the work area must be thoroughly ventilated .

Complete hardening of the composition occurs after 8 hours. There is no need to worry if swelling has formed at the treatment site - they can be easily cut off with a stationery knife.

How to remove foam from floors or walls where it shouldn’t be? After hardening, this can be done using acetone. As a precaution, you should protect your eyes by wearing clear glasses. To protect your hands, gloves are suitable, because the composition has excellent adhesion to the skin of the hands . Removing it will be painful and traumatic.

Application of polyurethane foam

Let's look at the most frequently asked questions about polyurethane foam.

What is polyurethane foam and what types of it exist?

This material is supplied in cylinders, the inside of which is filled with a special composition consisting of two components:

polyol;
isocyanate

The composition may also include various substances that promote good foaming, expansion and hardening of the material. Depending on the application and properties, a distinction is made between conventional and professional polyurethane foam.

The contents of the cylinder, in contact with air, begin to expand and harden after some time. The result is a semi-solid material with a porous structure.

Depending on the temperature, polyurethane foam is distinguished:

for summer use;
for use at low temperatures;
for year-round use.

The foam composition can be:

one-component;
two-component.

To use professional foam, a special gun is used. A container of household foam is equipped with a simple plastic tube. Depending on fire resistance, foam is divided into three classes (B1, B2 and B3).

Foam meeting class B1 is considered fire resistant. Class B2 foam does not support combustion and promotes flame extinction. B3 is considered a common foam, most commonly used for household purposes.

For what purposes is polyurethane foam used?

Polyurethane foam is mainly used to seal seams and joints. It fills well the voids between window frames and the main wall of the house, as well as between the door frame and slopes.

Hardened foam has good sound and heat insulation properties. Therefore, it can fill any cracks and holes. It is also widely used during plumbing and roofing work.

How to properly handle polyurethane foam?

1. Prepare the surface

First you need to inspect the surface being treated. If there is dirt, dust or grease stains, they should be removed. When working in positive air temperatures, the surface must be moistened with water.

2. Preparing the cylinder for use

First you need to read the manufacturer's recommendations. It is important that the temperature of the cylinder corresponds to the values indicated on its surface. In most cases it should be in the range of 20-24 degrees.

3. Application

Work should be carried out in special clothing. Hands and eyes must be protected. The foam should not get on the skin. The container must be shaken for 15 seconds, holding it upside down. You need to keep it in the same position while working.

When filling vertical joints, you need to move from bottom to top. Since the foam expands greatly, in its original form it should occupy no more than one-third of the seam space.

When working with wooden structures, polyurethane foam should not be used to fill joints more than 3 cm wide. In other cases, the width should not exceed 5 cm.

Wide gaps are filled with vertical layers. In this case, each previous layer must have time to take on its final volume. Be sure to wet it.

If the gun is not used for 5-10 minutes, then before continuing work it should be cleaned with a special compound. Foam that has hardened at the tip can be removed with a knife.

4. After applying foam

Protruding areas of hardened foam are cut off with a construction knife. To prevent deterioration of its properties due to exposure to sunlight, it is covered with plaster, paint or a special sealant.

5. Limitations

Before foaming, doors or windows must be securely secured mechanically. If this is not done, the foam, during its expansion, can cause deformation of structures.

After filling the seams and joints with polyurethane foam, you need to wait for it to completely harden and only then continue work. A started balloon should be used up within 7 days.

It is important to consider that polyurethane foam does not adhere well to materials such as silicone, Teflon or polyethylene.

To clean the surface from fresh foam, use a special cleaner. For working with hardened foam, a hardened foam remover or a construction knife with replaceable blades is best suited.

During work, you need to ensure that the room is well ventilated. The manufacturer recommends producing a container of polyurethane foam at one time.

At what temperatures can work be performed using polyurethane foam?

All necessary information about temperatures is contained on the surface of the cylinder. As a rule, the manufacturer recommends working with polyurethane foam at temperatures from +5 to + 30 degrees. For all-season work, you need to purchase foam that states that it can be used at temperatures from -20 degrees to + 30 degrees.

It is important to pay attention not only to the air temperature in the room, but also to the temperature of the cylinder. If this rule is not followed, the foam may not be fully produced, remaining on the inner walls.

Therefore, before use, you need to keep the container with polyurethane foam in the room where it will be used for 24 hours. Before starting work, the contents of the container should be shaken well. This is necessary so that all components are thoroughly mixed.

If you do not follow these recommendations, the contents of the cylinder will be too viscous. It is more difficult to work with such polyurethane foam, and its performance characteristics may deteriorate.

To store foam, it is recommended to use heated warehouses with temperatures from +5 to +30 degrees. If you order delivery of polyurethane foam to a site in winter, it is better that it be of high quality and cope well with negative temperatures.

Why shake the canister before use and in what position should it be held?

Some people claim that the balloon can be held in any position. This is a mistaken opinion, since in this case the content will not be fully developed. Also, the foam should be shaken thoroughly before use. Thanks to this, all components will be mixed and the foam will be of the highest quality.

The vapors inside the cylinder rush upward. During shaking, they are mixed again with the main composition of the polyurethane foam. This procedure must be performed each time immediately before work.

Some manufacturers produce foam that does not require any specific position of the container. In this case, its temperature should not be lower than +15 degrees. An example of such a material is TYTAN LEXY foam.

For its production, a special technology is used, thanks to which maximum performance of the cylinder is achieved. Its properties correspond to professional polyurethane foam. Moreover, it can be used both at negative and positive temperatures, without fear that it will cause deformation of any structures.

Is it permissible to reuse the cylinder?

It is advisable to use the bottle at a time. This is due to the fact that the polyurethane foam, reacting with air and the moisture contained in it, begins to harden. For this reason, the plastic tube through which the foam flows becomes easily clogged. The recommended period of time between working with the cylinder is no more than 30 minutes.

Some cylinders have special valves, thanks to which foam can be produced gradually, over long periods of time.

To work with professional polyurethane foam, a special device called a gun is required. It is recommended not to remove the gun until the foam has completely developed, as this will allow you to continue working after some time. In this case, you need to block the mechanism with a dosing screw.

If the gun is in good working order and you store the cylinder in this way, observing the temperature regime, you can reuse it.

What to do if the polyurethane foam does not come out of the container?

The reasons for this can be very different, but the main one is the hardening of the foam inside the valve. This happens due to improper storage of the cylinder after the first use. Or it was left in a horizontal position for a long time, as a result of which moisture was able to get inside, combining with the contents and causing hardening in the exhaust valve area.

To solve this problem, you can try gently tapping the valve. However, this method does not help in all cases.

Another reason why the foam does not come out of the container is also due to moisture getting inside. Because of this, hardening forms at the bottom of the rod and is shaped like a ring. By deflecting the rod, you can try to solve the problem. If this does not give a positive result, then you can try to return such a cylinder to the store, explaining that it is defective.

Also, the lack of foam supply may be caused by poor valve tightness, which causes a gas leak.

Unfortunately, there is no 100% guarantee against such cases, since valves are the weak point in such cylinders. They may be damaged during transportation due to mechanical stress or temperature changes. When heated, the valve elements become elastic and easily allow gas to pass through, without which the polyurethane foam will not be able to escape.

Is it necessary to wet the surface on which the polyurethane foam will be applied?

The answer to this question is yes. Water promotes good adhesion of foam to various types of surfaces, which include wood, brick or concrete. You can moisten it with a regular paint brush. It is especially important to do this when applying polyurethane foam to porous surfaces.

By using water, hardening will occur faster. The drier the air in the room, the more it is necessary to moisten the seams, which will foam. Once the foam has been applied, it does not need to be moistened.

When wetting the surface, you need to make sure that the moisture is completely absorbed. In other words, there should not be too much or too little water. If it is deficient, the foam may not harden sufficiently and continue to increase in volume. Moreover, the process of its expansion can continue after a long time (more than a month).

To check whether the surface has been sufficiently moistened, you can cut the already hardened foam. If at the cut site it has an uneven shade closer to brown, then this is a sure sign that the surface needed to be moistened more.

How to install windows and doors correctly? Do I need to use stops and fasteners?

Some finishers, when installing doors, fix them only with polyurethane foam, without using mechanical fasteners. You can't do that. Foam is not intended for this purpose. Therefore, the window or door should first be fixed using fasteners and only then foamed. The entire load should be placed on the mechanical fasteners, and not on the hardened foam.

Despite its name, foam is not the main installation material. It is only used during installation work to seal, fill and insulate joints.

It is also recommended to use stops when installing doors and window structures, since incorrect dosage of polyurethane foam can lead to deformation of the frame.

How to properly remove fresh or hardened polyurethane foam?

The newly applied foam can be removed using a cleaner or, in extreme cases, acetone. You need to be careful when doing this, as acetone can damage plastic or synthetic materials. It is better to remove hardened foam with a special hardened foam remover or a sharp knife with replaceable blades.

Why does foam flow off a vertical surface?

Often, when working with polyurethane foam, you may encounter the phenomenon of dripping from the surface. Main reasons:

poor adhesion of the treated surface;
low quality polyurethane foam;
temperature that does not meet the manufacturer’s recommendations;
large width of the area filled with foam.

The lower the temperature, the worse the foam adheres to the surface. It takes longer to harden and expands less well. Before starting work, it is better to heat the cylinder. This must be done naturally, keeping it at room temperature for about a day.

Foam can also drain due to improper application. Vertical seams should be filled from bottom to top, and not vice versa. If the gaps are too large (more than 5 cm), it is better not to use foam.

How long does it take polyurethane foam to harden?

The speed of hardening of polyurethane foam is influenced by the following factors:

seam width;
degree of surface moisture;
air humidity and temperature;
cylinder temperature;
quality and characteristics of the polyurethane foam used.

Foam requires moisture to harden. Therefore, the drier the air in the room, the longer the hardening process will take. When working outdoors, you need to consider the air temperature. When it decreases, the humidity level will also decrease, which will affect the hardening time of the foam.

Practice shows that under normal conditions, with a joint width of about 30 mm, hardening will occur after 25 minutes (professional foam) or after 55 minutes (household foam). But in order for the process of increase in volume to completely stop, you need to wait 24 hours.

Does foam need to be protected from UV rays?

Yes, polyurethane foam should be inaccessible to sunlight, as it has a destructive effect on it and reduces its service life. Over time, it changes color and begins to crumble. For this reason, the hardened foam must be plastered, covered with sealant or covered with casing so that it is not exposed to ultraviolet rays.

How long can one bottle last?

There is no exact answer to this question, since the resulting volume of polyurethane foam depends on many factors, which include air humidity, ambient and cylinder temperature, as well as the width of the seam. In addition, the amount of foam obtained is influenced by the skill of the installer and the quality of the gun he uses.

Under standard conditions, ordinary polyurethane foam approximately doubles in volume. From one cylinder you can get up to 45 liters of foam. To get this result, its temperature must be from 22 degrees to 25 degrees.

Some manufacturers make cylinders that can produce more than 65 liters of foam under optimal temperature and humidity conditions.

Is there a difference between one-component and two-component formulations?

The vast majority of polyurethane foams sold in hardware stores are one-component formulations. The substance inside the container needs to be shaken vigorously and it will be ready for use.

Two-component polyurethane foam is more difficult to use. Before starting work, you need to mix the two components. This is done using a special lever and shaking.

One-component polyurethane foam has the highest performance, while two-component foam has the highest performance. The expansion of already applied foam is also less for such compositions.

For this reason, two-component polyurethane foam is well suited for installing window sills and slopes. In this case, the cylinder must be used up within a few minutes, since due to the formation of high pressure after activation, an explosion may occur.

Should I use a nail gun? How to keep it in working order?

Typically, polyurethane foam is sold with a special adapter, which is a plastic tube. It is through this that the foam from the cylinder flows out through the valve. As a rule, such tubes are used once.

To reuse them, it is necessary to clean them with acetone or a special cleaning fluid. This must be done before the foam hardens inside the tube.

To avoid the above problems, it is better to use a mounting gun and professional foam. The quality of work will increase significantly and you will be able to use one cylinder several times.

It is very important to purchase a high-quality mounting gun, since if there is no good tightness, it will not be possible to completely use up the contents of the cylinder.

After disconnecting the gun from the used cylinder, you must immediately clean it. The foam inside must not be allowed to harden, as such a gun will become unsuitable for further use.

Cleaning is carried out using a bottle of cleaning liquid specially designed for this purpose. Other types of solvents not only may not help, but can also be harmful. It is strictly forbidden to attempt to clean the mounting gun with water.

After connecting the gun to the cleaning bottle, you need to lightly press the trigger so that the liquid gets inside. Then you need to wait a couple of minutes and pull the trigger again so that the pressure of the solvent removes the remaining foam. It usually takes several presses for the cleaner released outside to become transparent. If the mounting foam has frozen inside the gun, you can try to disassemble it and clean it with improvised means that do not have abrasive properties. When installing the needle back into the gun, you need to lubricate it with grease.

Does expiration date affect foam quality?

The longer the container is stored, the more viscous its contents become. Over the course of several months, this process proceeds relatively evenly and accelerates sharply by the end of the shelf life.

For this reason, when purchasing polyurethane foam, you need to look at its production date.

Is it possible to use summer foam in winter?

Some inexperienced installers do not quite understand the difference between summer and winter polyurethane foam and make mistakes in its use. At negative temperatures, chemical reactions proceed more slowly. Therefore, the foam becomes more viscous.

Another reason for the deterioration of foam properties is associated with low humidity. At low temperatures the air is drier. The presence of moisture is the main condition for the hardening of polyurethane foam. Therefore, for its use at sub-zero temperatures, the manufacturer modifies it using special components.

In other words, summer foam should not be used in winter, since its composition is not intended for use in conditions of low temperatures and low humidity.

Typically, the manufacturer on the winter polyurethane foam cylinder indicates that the ambient air temperature should be no lower than -10 degrees and no higher than +30 degrees, and the temperature of the cylinder itself should be in the range from +15 to +30 degrees.

In addition, there is premium polyurethane foam. It can be used in more severe weather conditions, for example, at temperatures of -20 degrees. The temperature of the cylinder can be only +5 degrees. It is not necessary to keep such polyurethane foam in a warm room for about a day. It can be used immediately after delivery. Such features of premium polyurethane foam allow you to complete the work faster, since you do not need to waste time heating it.

Is it permissible to use polyurethane foam for fixing thermal insulation materials?

The main purpose of polyurethane foam is to seal joints, as well as their sound and thermal insulation. Foam expands excellently and fills space, but it cannot be used for gluing insulating boards.

However, a type of polyurethane foam has appeared on the market, which in its intended purpose serves as an aerosol adhesive. It can be used to glue materials such as brick, insulation boards or sheets of drywall. This foam has good adhesion to many types of surfaces. However, it does not expand that much.

If you need a glue like this, check out products called TYTAN PROFESSIONAL STYRO 753 GUN or TYTAN 60 SECONDS. They are cylinders with a volume of 750 ml, inside of which there is a one-component glue. The range of its application is quite wide. It can be used to seal joints, like regular polyurethane foam. This material is also suitable for gluing thermal insulation boards to various types of surfaces.

Bottom line

For the most effective use of polyurethane foam, you need to ensure that the temperature of the air and the cylinder corresponds to the values specified by the manufacturer. Any deviation from the instructions may cause poor hardening of the foam and incomplete consumption of the cylinder.

Reusing the cylinder

If you need to reuse the cylinder without a gun, for example, within a month, then you need to bend the tube, securing the bend with tape. Then press the valve to maintain pressure in the tube . So a container with polyurethane foam can be used for 2 months without any problems.

If the cylinder is needed again only after 5-6 months, there is another storage method. You can use acetone. The tube is carefully removed from the cylinder and washed with acetone. They are also dripped into the valve hole. Repeat the manipulations two or better three times. So the cylinder will last up to six months.

To work with a professional-type cylinder without a gun, you will first need to select a suitable plastic tube and figure out how to press the valve.

For this purpose, a DIY tube made of 3 parts is suitable:

the first is flexible;
the second is hard;
the third is flexible.

The first part presses on the valve, the second helps prevent splashing, and the third directs the foam stream to the desired location.

Prices for polyurethane foam with a tube

Important Tips

To carry out home and household repair work, one can of polyurethane foam is enough. If all the work has been completed, the cylinder is usually thrown away as unnecessary, because after opening the substance has a limited shelf life.

Manufacturers of household polyurethane foam note that their products are designed for single use. Therefore, if, several months after the first use, the sealant in the cylinder has frozen, you need to understand that this is a completely natural process.

You can give the following advice to those people who are working with polyurethane foam for the first time:

Before starting work, it is recommended to first prepare a spray bottle with water and a knife to remove excess sealant (this is done after the applied composition has hardened).
It is also recommended to stock up on a regular sponge and acetone (or a similar solvent) in advance. They will be needed if you need to wipe off sealant that accidentally gets on other surfaces (for example, on the floor or on clothing).
You should not try to remove excess polyurethane foam immediately after application - this should be done approximately 8-10 hours after treatment. During this period, the sealant will harden, so it can be easily cut with a sharp knife or hacksaw.
If wallpapering has not been done in the room, then it is strongly recommended to carry out work on applying polyurethane foam (regardless of the volume of material sprayed), systematically ventilating the room.
If during the application process the sealant begins to gradually darken, this will indicate that the substance is exposed to ultraviolet radiation (direct sunlight). This kind of thing should be excluded when carrying out work.
It is strictly forbidden to treat surfaces with polyurethane foam if they are located in close proximity to open fire or hot objects. Regardless of the type, the sealant almost always contains flammable substances in its composition, which, in an uncured state, are quite capable of flaring up if suddenly exposed to an open flame.
Before starting work, it is necessary to clean the surface to be treated as thoroughly as possible. If it is dirty and greasy, then the polyurethane foam will not meet the characteristics specified on the packaging during operation.

Is it possible to use a can of polyurethane foam several times?

You can find information on the Internet that professional polyurethane foam can be used repeatedly, while household models are only suitable for one-time use.

This is a common misconception, because if you use household foam, then after using it you can clean the nozzle, remove the tube and block the exit hole for the substance. To be able to use the sealant again, it is recommended to do everything in the following sequence:

It is necessary to release a little of the polyurethane foam from the can, and, allowing it to come out, bend the tube and tighten it with metal wire. At the end of the tube, the sealant will begin to harden, but the presence of a bend will not allow the entire volume of the substance that remains in the cylinder to harden.
When subsequently applying polyurethane foam, you simply need to cut off part of the tube with the frozen substance and continue to treat the gaps and seams with sealant.

It should be taken into account that a container with sealant can be stored in this way for 2-3 weeks and no more. After several months of storage, the substance will almost completely harden and harden inside the package, so it will not be possible to use it again.

Is it possible to use expired polyurethane foam?

Regardless of the type of sealant chosen, the shelf life of the substance usually does not exceed 1-1.5 years from the date of production. At the same time, if during its use a delay of several days or weeks was discovered, then you should not curtail the work - most likely, the polyurethane foam has not lost its basic operating and performance characteristics.

If the expiration date is significantly exceeded, it is strongly recommended not to use the sealant even for minor household repairs (especially for installing windows or doors). This is due to the fact that after the expiration date, the sealant begins to rapidly lose its basic properties, so when you open the package, anything can happen.

Terms of use of polyurethane foam after application

Leading sealant manufacturers claim that high-quality polyurethane foam, which has been applied to the surface in accordance with all the rules, is protected from ultraviolet exposure and moisture, and is capable of performing all its functions for 10-20 years.

If the applied substance is exposed to negative operating conditions: outdoors, in direct sunlight, rain, snow, etc., then the service life of the sealant is reduced to 2-3 years (even in cases where moisture-resistant compounds were applied).

Making a gun with your own hands

You can make a gun for polyurethane foam from a pneumatic spray gun and a broken gun . They are combined and a well-functioning device is obtained. Here's a little instruction on how to make a foam gun:

The essence of connecting these structures is to replace the paint tank of the pneumatic spray gun. Instead, a bottle of sealant is screwed on. To do this, first attach the connector for the cylinder, removed from the broken foam gun.
But the threads of the connections do not match, so to fix and secure the connection you should use epoxy glue , having first cleaned both threads.
To ensure that the glue fills the threads and does not fall into the required holes, they are first plugged with hot glue. When the necessary holes are plugged, you can design further.
Epoxy glue is diluted according to the instructions: 10 parts of resin per part of the hardener. A regular 10 ml syringe is filled with 10 ml of heated resin, and then 1 ml of hardener. Mix everything thoroughly, heating as needed. First, the resulting glue is applied to the threads of the connector so that there are no empty spaces left.
The body of the spray gun is securely installed, and the connector is glued . All is ready.
The final step in how to make a foam gun is to heat the joint to a temperature so that the hot-melt adhesive that plugs the holes melts and flows out.

Pistol design features

Before we learn how to properly use mounting foam installed on a gun, let's first learn the design of the device itself.

Regardless of the manufacturer, the general arrangement remains the same and quite simple:

If household foam is supplied simply through a plastic tube, then in a gun the supply process occurs through a metal tube with a special tip - a nozzle. The size of the tip hole is five times smaller than the cross-section of the supply tube, which allows you to create a high working pressure of the mixture;
the cylinder is connected through an adapter - an adapter attached to the body;
the adjusting screw is designed to dose the mixture output;
the handle of the tool can be plastic or aluminum. It is secured to the barrel with a nut. The collapsible design allows you to easily clean the gun from frozen residues;
The last important part installed at the pistol grip is the trigger. It is designed to supply the mixture from a cylinder.

Having studied the structure of the gun itself, you can try to install the cylinder and do a test foaming of any recess.