Polyurethane foam without a gun: how to use it for home repairs?

Mounting guns have become popular in the repair and construction industry due to their versatility. A convenient and easy-to-use tool does not require special skills or experience. It is intended for installation of door and window openings, insulation and other purposes. When using the gun correctly, it is possible to apply sealant as accurately as possible and reduce its costs. This universal tool will help you quickly complete all manipulations using foams, silicone and other sealants.

Despite the ease of use of mounting guns, it is important to follow the rules and know the basic features of their structure. This will help to preserve its properties throughout its entire service life; use the gun skillfully.

Types of foam guns

Guns for working with mounting sealant are classified into two types - professional and household. Household appliances are often sold together with cylinders of polyurethane foam, and they are intended for one-time use. They are made of plastic or polyethylene, which allows foam to escape from the container. Household foam guns are used exclusively for ordinary cans that are not intended for use with professional equipment.

The advantage of household pistols is that they cost pennies. After use, they cannot be cleaned to be reused. In addition, if you start using polyurethane foam, it should be used up within 20-30 minutes. If this is not done, the gun nozzle will become clogged with the drying polyurethane compound, and it will be impossible to continue working with it.

This is interesting!
Many people do not know that if they start using household foam, they should use it entirely.
You cannot leave a started container for storage, as the foam will dry out inside. It is also impossible to store a container of foam for a long time, which will lead to the loss of its technical properties. The most common case of long-term storage of a foam container is a decrease in the volume of polyurethane liquid. Professional guns for polyurethane foam are the devices discussed in the material. The main advantage of such devices is that they are reusable. But first things first:

Material of manufacture - to create professional guns for working with polyurethane foam, metal and plastic are used. Moreover, cheap versions of devices are made from cheap materials, while expensive ones involve the use of high-quality metal and impact-resistant plastic. Disassembly ability - in order for the tool to be reused, the internal parts should be cleaned after use. For this purpose, the device is made dismountable, which allows, if necessary, to disassemble it in order to clean or replace faulty parts. To clean the foam composition inside the gun, you will need special dissolving liquids. However, such liquids are powerless if the polyurethane composition has dried out. They are used for working with special cylinders

To operate a foam spray gun, it is important to consider the selection of the appropriate cylinder. They differ from a regular cylinder for a household gun in the presence of a threaded adapter

Using this threaded adapter, the cylinder is fixed to the gun adapter, ensuring a tight connection

Knowing the differences between the types of foam guns, you should understand in which case it is recommended to choose the appropriate options.

To perform one-time work on blowing out cracks in walls or other structures, it is recommended to choose cylinders with polyurethane foam and disposable guns. After the cylinder is used up, it should be disposed of along with the plastic tool.
If it is necessary to install a window frame, carry out sealing, insulation and other types of manipulations, then you should choose cylinders with polyurethane foam for professional guns. The use of a special tool affects not only the convenience of work, but also the efficient and economical use of material

When the main differences between household (disposable) and professional devices for working with polyurethane foam are known, an appropriate decision should be made - which is better to use in a particular case.

This is interesting!
Despite the significant differences between the types of mounting guns, they are affordable for everyone. The cost of professional devices for foam ranges from 500 rubles to 3000 rubles.

Is it possible to reuse an already opened cylinder without a gun?

The possibility of reusing construction foam without guns is not excluded. To do this you need to take several steps. The tube is carefully bent, then this place is fixed with tape or tape. The valve is pressed to maintain the pressure reading.

If the substance used is stored for more than 5-6 months, acetone will be needed. After removing the tube from the cylinder, it must be thoroughly treated with the specified solvent. It wouldn't hurt to clean the valve itself. The procedure is repeated 2-3 times to achieve better results. A separate question is how to replace construction foam guns.

Types of polyurethane foam and their application

It can be found on sale in small cylinders that are filled with either propellant or pre-polymer. Due to the fairly high air humidity, the composition gradually becomes hard, and its structure becomes quite rigid.

Today, there are only two types of polyurethane foam, which can be found in any store that specializes in construction.

Foam for professional use. It is sold in fairly large cylinders that can hold more than one and a half liters. Such foam comes out of the packaging under fairly high pressure and in some cases can be sold complete with tubes (they are used for manual use). It would be unwise to take this type of foam without a gun, because due to the high pressure you will spend too much foam.
Polyurethane foam, which is used in everyday life, is sold in small cylinders, which have half the volume - 600-800 ml; a special tube is also sold complete with a cylinder of foam. It has the same technical characteristics as for professional use. It is worth noting that a cylinder of this size can also be used with a pistol. The second type of foam is usually used to fill some minor depressions or seams. Its cost is much lower than the professional one, although the volume is several times smaller.

Polyurethane foam is widely used in construction for a variety of purposes. Most often it is used to reduce noise levels. This building material is an ideal option for sound insulation. In order to achieve a positive result, it is enough to fill with foam the places where the pipes touch and all the holes that are in the walls (see the video for details).

If, for example, there are cracks in the roof, then they can be perfectly sealed by using polyurethane foam. The same can be done with window or door frames, cold rooms and voids, which are often observed directly around pipes.

What is polyurethane foam and its features video

Recently, it has even begun to be used to glue various types of elements together. It perfectly and reliably glues a variety of materials and over time they do not come off and hold quite firmly. In order to perform these types of work, you can use both professional foam and for household use. It is worth noting that before using polyurethane foam without a gun, you need to know and train, because using it with a gun is much easier than with a tube.

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.

Foam with a tube - threat of expansion

The main disadvantage of household foam with a straw is significant secondary expansion

When hardening, it can increase several times, so it is extremely important to comply with all conditions of use.

Instructions for using household foam can be seen on the back of the cylinder, but let’s look at it in more detail and step by step:

Surface cleaning and preparation. Before applying foam, you must carefully check all cracks and holes for the presence of small debris and, if necessary, degrease the surface with acetone. Surface moistening. Polyurethane foam requires contact with moist air to harden, so before using the can, the surfaces need to be moistened - a regular spray bottle is quite suitable for this purpose. Preparing a foam bottle. A little trick - before using the foam, you need to hold it for several hours in water with a temperature of about 20 ° C - after this procedure it will lie down better. Before starting work, shake the container for a minute so that all components are evenly mixed - this will ensure maximum foam yield. Attaching a tube or gun to a cylinder. The tube is simply screwed onto the valve, but with a pistol the situation is somewhat more complicated - we will consider the issue of its selection and use below. Working with foam. Using the correct technology, polyurethane foam is applied in small sections (about 10 cm) from bottom to top - this helps to avoid unnecessary spreading of the material. It is necessary to ensure that the gap is not filled by more than 50% - during hardening the volume will increase greatly, which can lead to damage to the structure being treated. It is extremely important not to touch uncured foam - any physical impact and disruption of the structure worsens hardening and negatively affects volume and density. It is necessary to ensure that the cylinder is always in the “upside down” position - this will ensure the most complete consumption of foam.

Difficult moments:

Problem when using	How to solve
Foaming hole wider than 3cm	Polyurethane foam must be applied in several stages, waiting for each layer to harden. Before reapplying the foam, be sure to moisten the hardened base.
Through slots	Under no circumstances should such holes be filled with foam on both sides - this can lead to severe deformation of the structure. Foam is used on one side only, the other side is usually filled with silicone sealant.
Installation of door and window frames	To reduce the pressure on the structure, it is recommended to use dowels and additional spacers (they are removed after hardening). Otherwise, the foam, expanding, can seriously distort the frames of doors and windows.

The container of household foam must be used completely, otherwise the composition will harden during storage and will be unsuitable for use. With professional foam such problems do not arise, but there are some nuances.

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.

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.

Before foaming the gap, you need to make sure that the ambient temperature complies with the recommendations in the instructions for the sealant.

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.

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.

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

Gun device

The design is simple and consists of the following mechanisms and parts:

body (made of metal or plastic);
trunk;
needle rod;
trigger mechanism on the handle;
nozzle (it is possible to use removable nozzles with different characteristics);
reducer with valve for installing a cylinder;
an adjusting screw that allows you to change the trajectory of the trigger mechanism, which makes it possible to control the amount of foam coming out of the device.

If you look at the cross-sectional drawing of the pistol, you will notice that the diameter of the barrel is slightly larger than the diameter of the needle rod. It is through this cavity that foam flows from the cylinder under pressure.

Mounting gun price or quality

A professional gun ensures accurate and dosed application of polyurethane foam, reusable use of the container and accuracy when working. There are many modifications of such a tool, but the design of the device and the principle of operation are approximately the same:

The tip of the gun - as a rule, its diameter is several times smaller than the diameter of the tube itself. This feature allows you to repeatedly increase the pressure when foam comes out, which, in turn, guarantees a good volume.
The barrel (tube) is the channel through which the foam comes out. It can be one-piece or collapsible (in two parts), which simplifies the maintenance of the instrument.
Adapter - an adapter for connecting to the neck of a foam bottle. In high-quality models it is coated with Teflon.
Adjustment unit - allows you to dose the foam output and its pressure.
Fastening nut - with its help the barrel is attached to the handle. This design allows the tube to be removed for cleaning or replacement.
Trigger - used to adjust the supply of polyurethane foam.
Handle - made from various types of plastic and metals. Aluminum handles are considered the most reliable and comfortable.

The operating principle of the mounting gun is based on simple mechanics: after attaching to the cylinder, the foam passes through the supply valve into the barrel, where it remains until the trigger is pressed. Pulling the trigger opens the valve on the tip, releasing the foam. The regulating mechanism allows you to control the volume of foam supplied.

Since there is nothing superfluous in the design of the pistol, choosing such a tool is quite simple. There are just a few factors to consider:

The quality of the materials from which the gun is made. It is better if it is made entirely of hard metals. There are high-quality models made of plastic, but this is very rare.
Collapsible design: monolithic guns are cheaper, but the price of a collapsible tool will pay for itself many times over when cleaning and replacing parts.
Working pressure in the gun. This characteristic cannot be checked in a store, but there is a little trick. When buying a gun, immediately purchase a can of cleaner (it contains acetone). At home, you need to screw the gun onto a bottle of cleaning liquid, press the trigger to release it inside, then remove it and leave it for a couple of days. If after this time the acetone fires when the trigger is pressed, the pressure is normal. If not, you can return the low-quality product to the store; acetone does not leave any traces on the surface of the barrel.

Rules for using professional polyurethane foam sealant

How to prepare the surface

In order to reliably seal, it is necessary to properly prepare the surface.

To do this you should:

Clean the surface from dust and dirt.
Thoroughly wet the hole or crack with water from a spray bottle.

Recommendations for correct and safe use

If polyurethane foam is used, be sure to moisten the sealing area with water.
The foam should be used at ambient temperatures from +5 to +20 degrees.
If sealing is required at subzero air temperatures, then it is necessary to use special frost-resistant polyurethane foam.
Carry out sealing work wearing rubber gloves and safety glasses.

Technique for using a can of sealant

When performing installation work on sealing, without using a gun, a PVC tube is used, which is equipped with a “household” and sometimes “professional” foam cylinder.
The tube is installed on the cylinder valve.
The end of the tube is placed in the hole, which needs to be filled with polyurethane foam mixture.
By pressing the valve, the sealant flows through the tube directly into the hole.
When hardening, polyurethane foam expands significantly and can extend beyond the crack or hole being sealed, so the cavity is not completely filled with the mixture, leaving some space for the foam to increase in volume after drying.
Frozen excess is removed with a stationery knife half an hour after sealing.

Tool maintenance after work

If sealing work is carried out from a cylinder with polyurethane foam, without a gun. Then, after a single use, even if all the material is not completely used up, the cylinder is thrown away, since due to the frozen foam inside the valve and tube, further use is not possible.

But, you can use the folk method of maintaining the functionality of the valve mechanism.

Drying of the foam inside the valve and tube will not occur if air access to this mechanism is reliably blocked.

Therefore, it is enough to insert an object slightly larger in diameter than the hole into a tube completely filled with foam.

Important! The tube must be completely filled with polyurethane foam until there is an object that prevents it from flowing out.

After the tube is sealed, the cylinder is stored in a dark, cool room.

If it becomes necessary to use polyurethane foam, re-preservation occurs by cutting off the section of the tube where there is an object that blocks the hole.

If the cylinder was contaminated during work, it should be wiped with a solvent, and care must be taken not to allow the solvent to come into contact with plastic parts.

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.

What types of material are there?

There are two classes of polyurethane foam:

domestic;
professional.

In terms of technical characteristics, both types of materials are similar, however, differences still exist. First of all, the volume of the cylinders should be noted. Thus, household foam is usually offered in small quantities (up to 800 ml). The kit includes a small piece of tube with a small cross-section. The pressure level in the container is relatively low. This allows you to reduce material consumption in cases where you plan to use a cylinder of polyurethane foam without a gun.

Professional material can be purchased in volumes starting from 1.5 liters; in addition, it is used for large-scale tasks: sealing the seams of window and door openings, sealing large cracks. The foam is contained under high pressure, so it is very difficult to apply it correctly without a gun. There is one more nuance. Thus, the outlet of a professional cylinder is equipped with a fastening element: a threaded cap (bayonet). The gun is installed at this point.

Applying foam using a gun

Adviсe

When choosing polyurethane foam, you need to remember that the container can only be used once. Therefore, before purchasing, you must carefully calculate the required volume. If you have any doubts about this, it is better to consult a specialist.

Take note of some useful tips.

Before starting work, you should prepare a spray bottle to spray water on the surface before applying foam; you will need a knife to cut off excess material.
While doing the work, you will need a sponge or soft cloth soaked in acetone or solvent.
The correct dosage of sealant will significantly reduce material consumption.

It is more convenient to remove excess sealant from the surface after four hours after application; after complete hardening, this process will become much more difficult.
Be sure to use personal protective equipment (respirator, goggles, gloves).
It is necessary to ventilate the room during work.
After completing all work, it is necessary to treat the hardened foam with a special means to protect it from sunlight. This must be done before the foam darkens.
It is strictly forbidden to use the cylinder near an open fire.

This is especially important to consider when you are processing a steel bath. Polyurethane foam contains flammable substances

Therefore, when choosing a sealant, you should pay attention to what type of material is selected (fireproof, self-extinguishing, flammable). This will help you avoid trouble

When storing polyurethane foam, it is necessary to observe the temperature regime. The optimal storage temperature varies from +5 to +35 degrees. Failure to comply with temperature standards leads to a significant loss of technical qualities of the polyurethane foam. You can find all-season foam on retail shelves. The optimal storage temperature for such foam ranges from -10 to +40 degrees.

Even if you have never used polyurethane foam, after reading all the tips and recommendations, you will be able to handle this process quite easily and simply. Using this material, you can independently insulate door and window openings, seal all unnecessary cracks, crevices and joints in wall surfaces. While working, do not forget about the safety rules.

For information on the rules for using polyurethane foam, see below.

How to use a foam gun?

Working with a polyurethane foam sealant gun takes minimal time and is not difficult. To avoid equipment failure, you must adhere to the operating rules: both the tool itself and the cylinder. Shake the container well before use: 30 seconds is enough for this operation. If you plan to work outside in cold weather, then the cylinder should be at room temperature. Otherwise, it needs to be preheated first.

How do you load a “weapon”?

Correct installation of the cylinder occurs in the following sequence:

First, place the container with foam on a flat surface and remove the cap;
attach the gun adapter: leave the cylinder in place, holding it with one hand, screw the threaded adapter of the tool onto it until it stops;
shake the container with the gun attached vigorously for about half a minute;
the gun is turned with the handle down, the adjusting screw is tightened ¼ turn;
then lightly press the trigger of the tool, ensuring that the polyurethane foam enters the needle rod.

The foam that fills the barrel allows you to begin work without hesitation.

How does the process work?

The first step is to prepare the seam - moisten it with water. After this, they move on to the main work. The operation is carried out as follows:

the nozzle is directed at the seam, then the trigger is lightly pressed;
if the sealant flows weakly, tighten the adjusting screw;
the seam is filled with zigzag movements from the bottom up, however, due to the subsequent expansion of the foam, too much polyurethane foam is not consumed;
since the material can change consistency, the container is shaken periodically;
During a break in operation, the nozzle is cleaned of foam with special wipes or a cloth soaked in a solvent.

If foam is blown into hard-to-reach places, then use an extension adapter - a thin plastic tube, which is often included in the kit. Having completed the work, the adjusting screw is tightened again. After the sealant has dried, areas where there is little of it are filled with an additional layer, acting in a similar way.

How is the cylinder replaced?

When working on a large area, one container is not enough. Then it needs to be replaced. Foam not coming out of the nozzle does not guarantee the cylinder is empty, so first it is vented:

find some unnecessary or working container (for example, a thick bag or a trash can), point the barrel into it and “shoot” until all hissing stops;
the gun is turned with the handle up, the empty container is unscrewed;
The adapter is cleaned with a special solution, then a new cylinder is screwed on.

Haste is needed not only when catching insects. Delay during refilling may well present an unpleasant surprise. This surprise is the hardening of the sealant in the barrel. To remove the obstacle, you will have to clean the gun.

How to clean a gun?

Excessive zeal, called fanaticism, is not recommended in any business. Equipment for polyurethane foam does not need it either. The instrument naturally requires cleaning, but this operation is not necessary. There is no point in disconnecting the container, disassembling and cleaning the gun every time after work. The cylinder is removed if the work is over and it is not expected in the near future - at least for a month. Such a long break requires cleaning the instrument.

The cylinder is unscrewed from the reducer and its plastic tip is removed. The foam is removed from the adapter using a knife from the outside. To speed up the work, the sealant is sprayed with cleaning liquid.
First, clean the nozzle, barrel and body outside. Then insert the bottle of liquid into the adapter, tighten it, and loosen the adjusting screw. The trigger is pressed until no more pieces of foam come out.

If these manipulations do not help, then in such a severe case the gun is disassembled and all parts are soaked in acetone. Then they are cleaned. The biggest difficulty is often caused by the adapter, in which frozen foam blocks the movement of the ball valve. Then the gearbox is unscrewed, the plastic sleeve is removed, the ball is pryed off with a pointed object, and then pulled out.

Subtleties of application

First you need to determine what type of material to use: household, professional foam. If you plan to process a large area, you need to take into account the volume of the cylinder. Household-grade products from some manufacturers are sometimes of worse quality than their professional-type counterparts. For this reason, for more serious problems, it is better to choose the latter option. Possible methods of applying foam without a gun:

Professional grade material is used, for which a tube is used. You should be prepared for the fact that under high pressure foam will come out in excess.
Use household material, attaching a tube to the valve, which is equipped with a cylinder.
Professional foam is used by attaching two tubes of different sections: first a larger one, then a tube of a smaller diameter is inserted into it and fixed well. This will reduce material consumption.

A container of polyurethane foam that does not require a gun to work with

Preparing for work

The site that will be processed must be put in order. Having figured out how to work with polyurethane foam without a gun, perform simple manipulations:

Remove any contaminants: dust, dirt. If the gap is quite large, it is pre-filled with foam, which will provide improved thermal insulation qualities in this area and will reduce foam consumption. Using a material such as foam, it is recommended to seal cracks no more than 8 cm in width.
The area is moistened with water, for which it is better to use a spray bottle, then the surface will be moistened evenly.
Monitor environmental conditions. It is better to carry out work at air temperatures from +5 to +20 degrees. The maximum upper limit is +30 degrees. But in cold conditions, a different type of polyurethane foam is used - frost-resistant.

The procedure must be carried out wearing protective equipment. Gloves and goggles are usually sufficient.

Instructions for applying foam without a gun

The principle of performing the work is similar to that when using a special tool. If polyurethane foam is used without a gun, how to properly use the tube included in the kit? Step-by-step instruction:

The container must be shaken, and to get a good result this should be done for about 30 seconds. This way ensures the homogeneity of the material and increases the intensity of its output.
The protective cap of the cylinder is removed, and a PVC tube is attached to the valve. It may be included in the kit if the foam is household, or it will have to be purchased separately, since a cylinder with professional-grade material may not be equipped with such a part.
The free end of the tube is brought to the area that is planned to be sealed. When considering how to use polyurethane foam without a gun, you should know that the gap is filled no more than 30-50%. This is due to the properties of such a material - it increases in volume as it dries. In addition, partial filling of the area reduces foam consumption. As a result, if everything was done correctly, the gap will be filled 100%. In cases where not enough material was initially laid, an additional layer can be applied as it dries. However, manual sealing (without a gun) is usually carried out the first time, since the foam comes out in excess and is dispensed worse.
The material begins to flow into the tube, and then to the desired area when the valve is pressed.

It takes an average of 8 hours for the foam to completely harden. Do not worry if, after this period of time, swelling appears on the treated area. They can be cut with a stationery or regular sharp knife.

How to care for a foam gun?

Proper handling of the tool will allow even an inexpensive gun to “handle” a large number of polyurethane foam cylinders. This simple device, if used flawlessly, will not require either complete disassembly or external intervention. To guarantee the long life of your equipment, you must adhere to certain rules.

The foam container is removed from the gun only in one case: if the container needs to be replaced. A container that is “successfully” empty at the end of the job does not require its removal.
After blowing out the sealant from the seams, only clean the shut-off valve and nozzle.
Washing the adapter when changing the container is mandatory. The foam is removed with a solvent.
If frozen sealant interferes with disassembly, you can use acetone or inexpensive solvent 646 to soften and remove it.

A gun that refuses to work due to unexplained problems is not a reason to send it to the landfill. The tool is simple, so in most cases you can find the cause of the breakdown and then fix it. The broken part is replaced with a new one, the parts are lubricated. These simple steps will extend the life of useful equipment.

Benefits of use

The mounting guns have a well-thought-out and ergonomic design. First of all, they are equipped with a comfortable handle for holding during work and are lightweight. The combination of these factors allows you to move freely and eliminates serious strain on your hands, which would make it inconvenient to carry out work. Other advantages of use include the following factors:

precision during application - the long tip of the gun allows you to penetrate deep joints and holes, ensuring high-quality application strictly in the right areas and obtaining a foam layer of uniform thickness;
dosed supply - a nozzle with a variable size allows you to distribute the material strictly in the required volume, which allows you to further eliminate the deformation of structures due to secondary expansion of the composition;
optimal speed of foam release - adjustable speed of foam release allows you to work with greater comfort, adjusting the tool to your own pace;
ease of processing difficult areas - when using cylinders with a plastic tube, a big problem is foaming areas under the ceiling or with other natural obstacles. When working with the gun, you can forget about this; it allows you to easily reach any hard-to-reach places thanks to the long nose;
high work productivity - a convenient supply adjustment system allows for faster installation, and a simple system for replacing cylinders also contributes to this.

A mounting gun is an excellent solution for those cases when you need to work quickly and at the same time efficiently. The tool is convenient and easy to use, indispensable for the home workshop or professional use.

Types and use of foam for installation work

There is an excellent opportunity to find foam for installation work in small cylinders, which are filled with either propellant or pre-polymer. Due to the sufficiently high air humidity, the composition gradually becomes solid, and its structure becomes quite solid.

;

Nowadays there are only a few types of foam for installation work, which is an excellent opportunity to find in every store that works on a building.

Foam for professional use. It is sold in fairly large cylinders that can hold more than one and a half liters. This type of foam comes out of packaging under high pressure and in some cases can be sold in a set with tubes (they are used for manual use of foam for installation work). It would be unwise to take this type of foam without a gun, because due to the high pressure you will end up wasting too much foam.
Foam for installation work, which is used in domestic conditions, is sold in small cylinders, which have half the volume - 600-800 ml. In a set with a foam bottle, a specialized tube is also sold. This kind of foam has the same characteristics in technical terms as for professional use. It must be emphasized that a cylinder of this size can also be used with a pistol. The second type of foam is mainly used to fill some small depressions or joints. The price of such foam is not significantly less than professional foam, although the volume is many times smaller.

Foam for installation work is very widely used in construction work for very different purposes. Very often it is used to reduce noise levels. This construction material is an excellent option for sound insulation. To achieve a good result, it is enough to fill with foam the places where the pipes touch and all the holes that are in the walls (see the video for details).

If, for example, there are cracks in the roof, then they can be perfectly covered with sealant by using foam for installation work. The same can be done with window or door frames, cool rooms and vacuums, which are very often found directly around pipes.

Now foam has begun to be used for installation work, even to glue various types of components together. It perfectly and firmly glues a variety of materials and after some time they do not come off and are held very firmly. To do these types of work, you can use both professional foam and for home use. It must be emphasized that you need to know and train how to use foam for installation work without a gun, because using it with a gun is much easier than with a tube.

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.

Recommendations for use

If we talk about how to properly use polyurethane foam and how to work with it, then you need to clarify whether a gun is used or not. If you plan to carry out a full renovation of your home, you will have to use both professional and household foam to foam joints, seams, gaps, and install windows and doors.

You can install the gun on professional sealant as follows:

First, the canister with the substance needs to be warmed up a little in warm water to 20-25 degrees. Then you need to shake it several times so that the substance becomes as homogeneous as possible and comes out of the can smoothly and easily.
At the top of the gun, you need to remove the protective cover, then turn it with the handle down and screw on the can of sealant. You need to screw it in until a characteristic hissing sound appears, which will indicate the beginning of the substance entering the gun.
If the gun is not new and has already been used, then it is necessary to inspect it before screwing in the can so that it is washed thoroughly. If after screwing in there is no hissing, then the gun is dirty and you need to buy a new one.
Before starting to work with polyurethane foam, according to the rules, you need to shake the gun with the cylinder again, turn the adjusting screw ¼ turn and, holding the trigger, begin processing.

To work with a gun, there is no need to have any skills and abilities in the field of construction and installation work. Work is usually performed in the following sequence:

The first step is to clean the surface where the sealant will be applied to remove dirt, and then moisten it with water from a spray bottle to ensure good adhesion.

2.Next, the gun nozzle must be directed at the surface to be treated, gently pull the trigger and apply the sealant in the required volume.

3.To fill a vertical gap, it is recommended to process it from the bottom up.

4.If the surface to be treated is wide, you need to fill it with zigzag movements, but no more than 1/3 of the volume, because the polyurethane foam will increase in size.

5.If there are any untreated areas left, they can be filled in later.

If it is necessary to perform treatment in remote areas, it is recommended to additionally purchase a special extension hose, since it is unlikely that it will be possible to foam hard-to-reach areas with foam without using it.

The can usually indicates how long it takes for the composition to harden. Despite the instructions, it is recommended to wait 10-12 hours. Once the sealant has completely cured, you can remove the excess using a knife or saw.

When using household sealant, there is no provision for a gun. It’s okay if the polyurethane foam comes without a gun, since you can use it with a straw. The tube is made of polymer materials - you just need to put it on the adapter. The work is performed in the same sequence as in the case of a gun, but when using a tube you will have to put in more effort.

You can easily use polyurethane foam without a gun if you have the appropriate tube. But in construction stores, sealant can be sold without a tube (cheap models), so you will have to purchase it separately

You should also pay special attention to this when choosing suitable polyurethane foam.

The use of a tube is relevant if a small amount of work is expected to be performed. It is recommended to use polyurethane foam with a tube if you need to fill joints, gaps, seams, or glue different materials. Household sealant is rarely used when constructing door and window structures or when treating large surfaces. For thermal insulation and sound insulation, you should also choose professional analogues.

On video: Using polyurethane foam without a gun.

Heating a cylinder on a gas stove

The container must be heated to the desired temperature at room temperature or in warm water. Do not heat foam on a gas stove or other sources of open fire. Propelled gas is flammable and easily explodes; if the cylinder ruptures, all the foam will end up on furniture and clothes.

It is not recommended to burn old cylinders in a fire. You should not smoke or use other open flame sources near them. Read more about the composition of polyurethane foam in the article “What does polyurethane foam consist of”

How to use the product?

Before using sealant, you need to correctly calculate its volume. If you need to foam the door with polyurethane foam, then the gaps between the frame and the wall 3–5 cm wide will be filled from a 300 ml cylinder. The output will be about 30 liters of expanded polyurethane. A 500 ml container will produce 35 to 40 liters of foam. This is enough for one and a half door frames. A 750 ml container is capable of dispensing from 45 to 50 liters of sealant. Enough foam to handle two doors.

Before foaming, the surface is cleaned of dust and grease and moistened generously with water. In winter, ice, snow, and frost are removed. To increase the foam yield, shake the container for 30 seconds and warm it to room temperature, but not over the fire.

To properly foam with polyurethane foam, the container is held upside down. In the reverse position, only gas will come out. When using a gun, the cylinder is screwed onto the seat. Extrusion occurs by pressing the trigger. If household foam is used, a plastic tube with handles for pressing is screwed onto the spout of the balloon.

The seams are foamed from bottom to top. They try to apply a uniform layer with a thickness of half the free space. Crevices with a depth of more than 5 cm are filled in twice, allowing time for the first layer to dry.

At the end of the work, the gun is washed with a special solvent. The cylinder is disposed of. After drying, the excess that appears is cut off with a knife.

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.

Shutdown

After all work is completed, the following steps should be performed:

Turn off the flow regulator completely.
It is not recommended to clean the gun nozzle; the fact is that hardened foam can provide additional sealing, especially if there is a suspicion of a leak in the exhaust valve.
It is strictly not recommended to remove a container in which foam remains. This will lead to the need to wash the instrument and the inability to use the substance remaining in the cylinder.
In this assembled state, a pistol with a screwed-on cylinder can be stored for several months, but this, of course, depends on the quality of the foam and the device itself. If there is any doubt about any of these parameters, it is recommended to pull the trigger of the gun every 3-4 days and refresh the foam in the barrel.

Procedure for changing a used cylinder

When performing large volumes of work, naturally, it will be necessary to replace the used empty cylinder with a new container. This action has its own order:

Even if the nozzle has stopped delivering mixture, the container may still contain some residual pressure. Before replacing the cylinder, you must bleed it by pointing the barrel into construction debris and pulling the trigger. After the hissing sound has completely stopped, the instrument is placed with the handle up and the empty container is unscrewed.
The connection point, that is, the adapter, will be covered with excess foam. They must be immediately washed off with a washing solution and a new cylinder quickly screwed on. Delaying these actions will lead to solidification of the remaining mixture in the barrel. Then for further work you will have to completely clean the entire tool.

Having made a quick change of container according to all the rules, you can begin further work with the tool.

When replacing the cylinder, you must quickly wash off any remaining foam from the adapter and do not let it harden.

The working process

Charger

Each can has a protective cap for sealed storage of consumables. Before you start using it, you need to remove it and insert the cylinder inside the device holder. Remember the basic rule - during operation it is necessary to keep the container upside down (that is, the holder must be at the bottom, like the handle, and the adapter must be at the top).

Installing the container into the gun design is not difficult. During the screwing process, it is necessary to hold the tool with one hand and install the cylinder with the other using gradual rotational movements.

To ensure that the composition becomes homogeneous, the vessel must be shaken. It is advisable to do this in the standard position (handle on top).

About 15-20 shakes are necessary.

Foam application

Before applying foam to a specific area, you need to wet it. Moisture is necessary for swelling, so that this process occurs faster and more efficiently.

The tip is directed towards the seam. Press the trigger carefully and accurately, without sudden movements or jerks. In this case, the possibility of trigger breakage will be minimal, and the quality of the foam at the exit will be higher. The hole is filled completely with material. While working, move the nozzle from side to side in a zigzag shape.

Use the adjustment screw to change the amount of foam that is supplied to the barrel. The volume depends on the size and depth of the seam.

To ensure that the composition does not lose homogeneity, do not forget to shake it from time to time.

How to replace the cylinder?

Changing a foam container is a simple process that does not require special knowledge, training, preliminary preparation or other manipulations. Sooner or later the foam runs out and you have to replace the empty container with a full cylinder. The replacement procedure is carried out as follows:

The barrel of the device must be directed into a bucket or other deep container.
To get rid of the remaining consumables, you should press the trigger and wait until the remaining foam comes out.
Next, the device is turned over so that the handle is on top, and the empty container is simply unscrewed.
Using a special liquid compound, you should thoroughly clean the mounting area and install a new vessel. The device is now recharged and can be used again.

Read also: How to measure cable insulation resistance

Completion of work

As soon as the repair work has come to an end, the adjusting screw should be tightly closed to block the access of oxygen to the foam as much as possible. If there is still foam in the container, and the next use is planned for the near future, then there is no need to remove the incomplete container. On the contrary, experts recommend leaving it inside the instrument. In this case, the foam will not dry out due to being under constant pressure.

Before finishing using the product, treat the tip of the nozzle with a special liquid. This procedure will prevent the consumable resource from drying out. Subsequent use will be much easier and more comfortable, without mandatory cleaning before use. If the old bottle is empty and there is no new one at hand, you need to remove the bottle, thoroughly clean the construction gun and leave it in storage until the next use.

Interval in work and repeated use of the tool

In many situations, it happens that the capacity of the container is not used completely at one time. In this case, there is no need to rush to remove the cylinder and start washing the gun. Due to the special tightness of its design, the mixture does not harden for a month, but it is still necessary to slightly bleed it once every 4 days to avoid the formation of clots in the barrel area.

Before re-use, it is first necessary to clean the nozzle from frozen residues of polyurethane foam and thoroughly shake the container. After cleaning the adjusting screw, you need to test pull the trigger until the mixture begins to flow at the optimal pace. After this you can start spraying.

Cleaning the tool after finishing work

If the work is completed or a long break of more than a month is expected, the instrument must be washed with a special washing solution. To do this, point the gun with the nozzle away from you and replace the container with foam with a similar one only with a washing solution.

By pressing the trigger, fill the barrel with liquid and leave the tool for 15 minutes to dissolve the remaining mixture. After the time has passed, the trigger is pressed again to drain the liquid from the remaining mixture and flush the barrel with a clean solution. Next, unscrew the container with the washing solution, bleed the residue from the barrel and put the instrument into storage until next use.