How to use a foam gun

When installing plastic windows, doors, as well as sealing seams and insulating buildings, polyurethane foam is used. It is divided into household and professional, and is a special liquid that solidifies upon contact with oxygen. To work with professional cylinders, a tool called a mounting gun is produced. Not many craftsmen know how to use a foam gun, so you have to understand this in detail.

Foam gun design details and operating principle

Before you master the use of a foam mounting gun, you will need to understand the internal structure and operating principle of this tool. The main design elements of the device in question are the following parts:

Handle – used to hold the device in your hand, making it easier to use
The trigger or trigger is an element that, when pressed, releases foam from the container
The barrel is an elongated cylindrical tube, inside of which there is a channel for transporting a liquid substance from the container to the nozzle
Adapter - a mechanism to which a cylinder with polyurethane foam is attached when using it
The adjustment screw is an additional element that is present on all models of mounting guns. The screw is designed to adjust the speed and volume of foamed liquid supply. When the position of the screw changes, the trigger stroke increases or decreases

The photo below shows the design of the foam gun, indicating the main components.

The tool is operated by hand, so it belongs to the category of hand-held devices. The device is called a pistol due to its external resemblance to a firearm. The adapter for connecting a cylinder with a polyurethane composition is located in the upper part of the tool body. This arrangement is not accidental, since the container must be used upside down to ensure the release of liquid. Having understood the design of the spray foam gun, it will be useful to know the principle of its operation. First, let's look at the cross-sectional design of a spray foam gun.

Next, we will learn in detail what the internal components of the instrument in question are intended for.

Nozzle or fitting - the tip of the barrel through which the polyurethane composition exits
The barrel is an oblong part through which the polyurethane mixture is transferred from the adapter to the nozzle
Needle rod - the internal channel of the barrel through which liquid foam is transported when the trigger is pressed
Adapter - a device to which a cylinder with a polyurethane composition is attached
Housing - the base of the device, made of metal or plastic
Through hole - the inner chamber in which the linings are located
Liners - connected to needle valve retaining sleeve
Adjustment screw - designed to adjust the volume and speed of foam output
A spring is a component of the adjustment mechanism, which, depending on the clamping force, ensures a high or low level of passage of polyurethane liquid
Handle - an integral part of the body designed to hold the tool in the hand
Retaining sleeve - connected to the adjusting screw spring and needle valve. Responsible for the quantitative supply of the composition to the nozzle
Trigger - connected to a needle valve that moves when the part is acted upon

Knowing the external and internal structure of the tool in question, you should find out the operating principle by which the foam mounting gun functions. When the trigger is pulled, the needle valve located inside the tool barrel is displaced. The internal cavity of the barrel has a channel, which is filled with mounting foam when the cylinder is secured to the adapter. The movement of the rod helps to open the channel to the nozzle, as a result of which the passage opens and the release of the polyurethane composition. To adjust the speed and volume of foam supply, there is an adjusting screw (on all models). Its rotation in one direction or the other helps to weaken or compress the spring acting on the fixing sleeve.

This is interesting!
Polyurethane or polyurethane foam has another name - polyurethane foam sealant. This chemical composition received the name sealant due to its properties and application features.

Installing the cylinder on the gun

To learn how to properly use a spray foam gun, you need to move on to practical work, starting with charging it:

The container is closed on top with a protective cap, which must be removed before installation. The gun is positioned with the handle down and the cylinder is screwed to the adapter in a vertical position. During connection, hold the gun firmly by the handle with one hand, and with the other hand, screw the cylinder onto the adapter with rotational movements.
After connecting, the contents of the container must be shaken well. This process brings the polyurethane foam substance to a homogeneous composition. The container mounted on the gun is held firmly with your hand and shaken sharply from top to bottom about twenty times. When shaking, the handle should only be at the top.
After shaking, the device is moved with the container up and the handle down. This is his working position. Turn the adjusting screw a quarter turn and try to pull the trigger. After filling the entire barrel with foam, the tool is ready for use.

Read also: How to check an LED with a multimeter without desoldering

During operation, it may be necessary to adjust the mixture supply. This can be done by turning the same adjusting bolt.

The working position of the gun is with the cylinder up

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 device options are made from cheap materials, while expensive ones involve the use of high-quality metal and impact-resistant plastic.
Disassembly - To ensure that the tool can be reused, the internal parts must 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.
Used to work 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.

Replacing the cylinder

When foam stops flowing from the cylinder, it is necessary to replace it with a new one. First, you should make sure that it is really empty. The remaining foam is then released into a waste bin. This is done until all the foam comes out of the container.

The new container must be shaken thoroughly. This is done within 15–20 seconds. Now you can unscrew the old cylinder, clean the place where the gun connects to the cylinder, and immediately screw on the new one. There is no need to clean the gun. It must be filled with foam immediately.

Where and for what are polyurethane foam mounting guns used?

The types of tools under consideration have found their application to perform various tasks. Most often, they are used by window and door installers, as well as builders. Moreover, their use is impossible without special cylinders with a polyurethane composition. Moreover, it should be noted that the polyurethane composition can be used both for sealing and insulation, and for gluing. Let's take a closer look at the purposes for which polyurethane foam is used with a gun:

Sealing seams and holes that occur when walls are insulated with polystyrene foam or polystyrene foam
Insulation of window and door openings, as well as elimination of drafts
Bonding door and window frames, as well as sheets of polystyrene foam and expanded polystyrene when insulating walls
Sealing joints
Soundproofing
Production of various designs, layouts, crafts, etc.
Blowing out holes when installing air conditioners
Filling cracks and other voids

The scope of use of foam squeezed out of a cylinder using a mounting gun is not limited to the above description. It is used always and wherever it is necessary to quickly and efficiently eliminate cracks or holes in the walls, from which a draft arises and mold appears. Some even use the material in question to blow out car exhaust pipes, doors, hoods and trunks, which is done in order to teach persistent violators of parking rules a lesson. However, such use of the composition is considered hooliganism, since getting rid of the sprayed and dried composition is quite problematic.

This is interesting!
When using foam, it is important to know one of its features - it is susceptible to losing its properties when exposed to ultraviolet radiation. That is why it is not recommended to apply foam where the sun will shine on it. If cracks or holes are being sealed on the outside of the wall, then after applying the composition, the areas should be covered with plaster.

How to use foam under the gun instructions

After purchasing a mounting gun and a special cylinder with polyurethane liquid, you will need to learn how to use them correctly. There is nothing complicated about how to use foam for a gun, and even a child can handle it. However, children should not be allowed to use polyurethane foam, since despite its harmlessness, the composition is a chemical substance that can cause serious injuries.

Instructions for using a foam mounting gun are as follows:

The first step is to thoroughly shake the container of polyurethane liquid. Moreover, it is recommended to hold the balloon in your hand upside down.
If work using foam is carried out outdoors at low temperatures, then the container should first be heated in a warm room. It is not recommended to store cylinders outdoors at sub-zero temperatures
After these requirements are met, the tool is charged. To do this, remove the protective cap from the cylinder, and then screw the gun on top
Rotate the gun all the way, you will hear a characteristic sound of air bleed
Read also: The structure of a chainsaw and important rules for handling gas-powered tools
After this, you need to take the tool in your hand, and the cylinder will be on top. This is the correct location of the cylinder when using the device. If work is carried out under the ceiling, then you should use a flexible connector, through which the gun remains in the same position
After the cylinder is connected to the gun, you should pull the trigger and wait for the foam to come out through the nozzle. If necessary, adjust the release rate of the polyurethane composition using the adjusting screw.
After this, we proceed to directly apply the foam to the required areas. To ensure a better connection of the foam with the surface on which it is applied, it should be moistened with water. Water helps improve adhesive properties. Few people know about this, so the composition is often applied to dusty areas, which leads to a decrease in the quality of gluing, sealing, etc.
The tip of the tool is pointed directly at the seam and the trigger is pulled. If the foam flows weakly, you should tighten the adjusting screw, opening the nozzle holes to the maximum
Filling the seams is carried out from the bottom up, while performing zigzag movements
You should not fill the seam completely, as the foam tends to expand when it dries. This is important to consider, since when drying, the pressure of the material increases, which can lead to deformation of products that are blown with foam.
If a long-lasting seam is blown with a polyurethane compound, you can find how the foam changes its consistency during the process. To ensure high-quality filling of the seam with foam, the container should be shaken periodically
After finishing the work, you need to remove the empty cylinder from the gun and wash the device. For this purpose, special cylinders with cleaning liquid are used. A cylinder with a special liquid is screwed into the adapter, after which it is necessary to spray by making 5 short presses on the trigger. In this case, the barrel of the gun is directed towards the surface where the foam was applied. Also keep in mind that the cleaning liquid even corrodes paint, so the best option is to spray it on a concrete or brick wall

The outside of the gun should also be wiped with a cloth soaked in solvent. If it is necessary to check or further clean the tool, it can be disassembled. However, practice shows that there is no need to disassemble the gun if you use cleaning material in a timely manner.

When working with a tool, it is important to use protective equipment, namely:

Gloves - not cotton
Glasses
Working clothes
Respirator

If foam gets on the skin, do not rub it. To remove foam from the covers, you will need to use a cloth soaked in solvent. Another way to remove polyurethane foam from the skin is to wait until it hardens. It is easier to clean the chemical composition after it has dried than in liquid form. Glasses are needed to protect the eyes from contact with the composition, especially when working near the ceiling. When working with polyurethane foam, a harmful odor is released that is dangerous to humans. That is why, when frequently working with polyurethane foam in unventilated areas, you should use respirators.

Having understood the question of how to use foam under the gun, you can start working with the tool. After finishing the work and washing the device, do not forget to screw the adjusting screw all the way.

This is interesting!
Not all craftsmen know one very important feature of professional pistols, which is the possibility of long-term storage with a canister installed. A mounting gun with an unfinished container of polyurethane foam can be stored for more than a month. But at the same time, it is worth considering one important feature: polymerization of the spring occurs, which subsequently interferes with the normal functioning of the tool. You can store a gun with a charged foam cylinder if it is completely sealed, and if there are places where foam leaks, this will lead to it hardening inside the tool.

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.

How to use foam without a gun - useful tips

Very often, craftsmen wonder how to use foam without a gun. There are times when, after purchasing a foam canister, a disposable pistol is lost. It can not only get lost, but also break, and going to the city and buying a cheap device is expensive and irrational. It will also not be possible to use a professional cylinder gun that is not designed for this purpose, so you need to look for a solution. There is a solution, and then we will clearly look at how to use polyurethane foam without a gun:

To use a regular foam cylinder without a gun, you will need to prepare two things - a thin tube, the diameter of which must match the cylinder fitting, and a wide washer
First you need to attach a thin tube to the fitting of the can.
Place a washer on top of the tube, which should rest against the cylinder mechanism
By pressing the washer, foam will be supplied from the cylinder through the fitting into the tube, which should only be directed to the required area

If you cannot find a plastic tube, then you should use a flexible hose or insulation from an electrical wire. The video below shows how you can easily use construction foam without a gun.

Another situation is when at the most inopportune moment there is no foam mounting gun at hand. It may get lost, broken, or not found at all. What to do in this case? The main thing is never to panic and turn to the Internet for help, because there are always smart thoughts that will help you get out of various situations. To use a professional foam canister without a gun, you must follow these steps:

Initially, you should find a trunk through which the polyurethane foam will be released. As a barrel, you can use a flexible hose, tube or insulation from a wire. If a wire is used, the cores should initially be removed from it.
Next, select a suitable size plastic dowel. The dowel will play the role of a trigger. When choosing a dowel, it is important to pay attention to its upper part, where the “skirt” should be present. This “skirt” ensures a hermetically sealed connection of the part to the foam container.
Having prepared a hose from the electrical cable, and also using a dowel, you need to connect the two elements. The end of the dowel can be cut off if it is not possible to put the insulation on it from the cable
After this, all that remains is to attach the resulting homemade structure in the form of a pistol, and resort to squeezing out the foam

Long-term or constant use of foam in this way is very inconvenient, but if you need to use the device for a short time, then every master can handle this task. Below is a video showing how to use polyurethane foam without a gun.

The life hacks described above will help you use a can of polyurethane foam when you don’t have a gun at hand. If you have not yet purchased a device for polyurethane sealant, then next we will consider the features of choosing the right tool.

Rules for caring for the device

So, the main thing that is really worth remembering when buying a foam mounting gun is that this type of equipment should be cleaned after each use, and also try not to waste time. The main cause of failure of such devices is foam hardening.

Blockages can form in the following places:

In a locking ball.
In the nose of the bottle.
In the supply valve.

Such breakdowns can be classified as mechanical, and to eliminate them immediately, you should simply clean the tool; do not throw it away immediately. But if, due to something, sticking occurred directly in the barrel of the gun, then cleaning will not help, and repair work will also not be possible. A simple way to prevent this kind of trouble is to follow the operating instructions and proper care. Repair work on the gun is usually not carried out; the most common procedure is mechanical cleaning and lubrication.

How to choose a foam gun

The tool in question has a simple design, so there are no difficulties with either selection or repair. Next, we will consider the main criteria that you should pay attention to in order to choose the appropriate mounting gun for polyurethane sealant.

Tool manufacturer - choosing tools from well-known manufacturers is a 100% guarantee that the buyer will purchase a reliable device that will last a long time if used correctly
Material of manufacture - if you come across a completely plastic pistol, then you should refuse to buy it. You should choose tools that are made of metal or metal and plastic. Moreover, the body and handle of the device are made of plastic, and the main working parts are metal.
Type (collapsible or non-collapsible) - almost all versions of mounting guns are collapsible, which allows for their cleaning, maintenance and repair if necessary. If you see a foam gun that is not collapsible, then it is better not to buy it
Leak testing is one of the most important parameters. If you buy an initially leaky tool, then in addition to the fact that polyurethane liquid will leak when working with it, you will also not be able to leave it with a charged cylinder for a long time. There are various methods for checking a gun under polyurethane foam, which we will consider in detail. When purchasing, remove the pistol from its packaging and pull the trigger. At the same time, you will hear the characteristic sound of air escaping. This is a sign that the device is sealed and worth buying. If the air does not bleed out, it means someone has already pulled the trigger before you, or the tool is not sealed. You can check this in other ways. To do this, install a flushing bottle on the device and make several presses. After this, inspect all connections. The absence of liquid drips other than the nozzle indicates the serviceability of the device. And the last way to check is after several pulls of the trigger, you need to remove the flushing bottle. The next day, pull the trigger, and if the remaining liquid comes out under pressure, then everything is in order with the tightness of the tool. If it simply leaks, then it is necessary to check the seals and, if necessary, replace them

When choosing, you should also hold the tool in your hand and make sure that it will be comfortable to use. The adjustment screw should move smoothly, and the barrel and channels should be made of stainless steel. Ultimately, you need to compare tool prices. It is not recommended to buy the cheapest one, since the manufacturer saved on parts during its manufacture, so such a device will not last long. The most expensive foam gun should be purchased if you plan to use it often; otherwise, it is not a rational waste of money.

For the manufacture of some parts of the instruments in question, non-ferrous metals such as brass, copper, etc. can be used, which affects the cost of the device. Well-known manufacturers of the instruments in question:

Matrix
Hilti
Atoll
Kraftool
Stayer

Now you know not only how to choose a professional spray foam gun, but also which brand of device is best to buy. And be sure to read reviews about certain models on our website or on various forums.

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.

Malfunctions of a foam gun and features of its repair

When working with the tool, malfunctions may occur, which will require some knowledge to resolve. Let's look at what malfunctions of a foam gun there are, how they manifest themselves, and how to eliminate them.

When you press the trigger, the polyurethane consistency does not come out - if the screw on the tool is adjusted, then the reason may be that the internal cavity of the barrel, as well as the adapter channel, is clogged. Disassemble the tool and make sure that its internal parts are not clogged. If the tool is working properly, then the cause may be in the cylinder. Foam does not come out of the gun if the work is carried out in cold weather, and the cylinder has not been previously warmed up to room temperature. Install another cylinder to make sure the device is working properly
Foam leaks when using the gun - such a malfunction indicates a violation of the tightness. In this case, you should resort to replacing the seals (if any), cleaning the parts, and also coating the threads with epoxy glue. If there is a foam leak, then you should not leave the gun with a charged cylinder for a long time.
Foam comes out through the nozzle without pulling the trigger. This malfunction indicates that the nozzle has worn out. To repair the mounting gun, the tip must be replaced. First make sure that the adjusting screw is screwed in all the way
The shut-off valve in the adapter is faulty. The adapter consists of a channel as well as a locking mechanism. When the foam container is removed, the ball-type valve closes, preventing liquid leakage from the instrument. To close the valve, a spring acts on the ball.

When a new cylinder is installed, the fitting rests against the ball, displacing it inward. In this case, the gun is filled with a polyurethane mixture coming out of the barrel. If the spring is worn out (which occurs due to the influence of foam), then when the spent cylinder is removed, the remaining foam will be released from the reducer. This type of malfunction can be solved by replacing the adapter, since manufacturers do not provide the ability to replace one spring.

When the trigger is pulled, a small amount of foam comes out - This is often caused by a malfunction of the mechanism. Often such breakdowns occur on Chinese foam guns.

To repair, unscrew the adjusting screw and look where the washer is located. Details of the repair can be seen in the video.

Disassembling the tool is not particularly difficult, but it is important to take into account that it is strictly contraindicated to use a vice, as the plastic body of the tool can be damaged. When assembling the gun, it is recommended to use epoxy glue or sealant to improve the tightness of the joints.

If you are buying a foam gun for your home, you should also purchase a cleaning liquid along with it. It should always be used after finishing applying the foam. The liquid allows you to extend the service life of the tool and eliminate the need for frequent repairs or replacement of parts. After reading this material, you will learn the design of the tool, the principle of operation, features of selection, repair and correct use of the device. Give due attention to this simple tool to make your work efficient and productive.

Peculiarities

In the process of installing door frames, as well as PVC windows (metal-plastic models), you cannot do without the use of polyurethane foam. Professionals say that applying the product manually is very difficult. Special equipment allows installation to be carried out in the shortest possible time. Specialized stores offer a wide variety of different tool models for practical and convenient use of the composition. The foam cylinders themselves also have distinctive characteristics.

Despite the rich assortment, most types of products are universal. That is, almost all manufactured cylinders are suitable for most pistols.

When working with foam, you must definitely think about personal safety . Professionals strongly recommend wearing gloves and protecting your eyes with construction glasses.

You should also carefully study the instructions for using the product, especially if you do not have proper experience in handling it.