Polyurethane foam: how to choose, buy and use

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Polyurethane foam has excellent insulating properties and has a fairly wide range of applications. We will help you understand its types, talk about the rules of application and tell you which mounting foam to choose. We will also talk about how to wash the polyurethane foam from the surface..

Polyurethane foam. How to buy and use

Types of polyurethane foam and main characteristics

The appearance of polyurethane foam on the building materials market at one time became a real revolution in this area. And all because it has such properties as:

  • high moisture resistance, heat and sound insulation;
  • low electrical conductivity;
  • fire resistance;
  • the ability to fill various voids with oneself, thereby ensuring high quality seams and joints;
  • environmental friendliness;
  • ease of use;
  • the ability to glue together various materials, etc..

Polyurethane foam. How to buy and use

Due to these characteristics, many builders can no longer imagine their work without this sealant. With its help, they install various structures (windows, doors), seal construction joints, cracks and cracks in the surface, provide heat and sound insulation in rooms, etc..

Household and professional

According to the method of application, household and professional foam is distinguished. Professional foam is used only in conjunction with a special gun for polyurethane foam, which helps to dose it more accurately, increase yield and extend its service life. Such foam increases predictably in volume, has a small percentage of shrinkage and is suitable for large amounts of work, such as installing windows, doors, etc..

Polyurethane foam. How to buy and use

Household foam does not require a gun, as it has a special adapter tube with a lever through which the foam is supplied. It is intended for single use only. Therefore, most often it is bought for minor work, for example, sealing cracks or cracks. Household sealant has a lower filling density of the container compared to professional sealant. The foam yield is average, and it may not come out completely. This foam approximately doubles in volume, and shrinkage is 5-7%.

Polyurethane foam. How to buy and use

Winter and summer

Polyurethane foam, which is currently on sale, can be conditionally divided into three types depending on its operating temperature:

  • summer foam is used if the temperature of the treated surface is from +5 to +35 degrees Celsius;
  • winter foam allows installation work in the cold season at temperatures from -18 to +30 degrees Celsius;
  • all-season has all the positive properties of the previous two types. It can be used at air temperatures from -100 to +350 degrees Celsius.

Polyurethane foam. How to buy and use

One-component and multi-component

One-component and multi-component foam is also found. The difference lies in the technology of its production. The first is the most common. It is a ready-made mixture of various elements that is sold in an aerosol can. A partial chemical reaction takes place already inside such a package. The second, multicomponent, goes on sale in a special container, divided into two parts inside. One of them contains the components of the substance, and the second contains various additives – foaming agents, catalysts, etc., which are mixed with each other only before use. For this, the container must be shaken well. Since the chemical reaction in the second case occurs much later, the service life of such a sealant is much longer..

Selection tips for applications and ambient temperatures

When choosing a polyurethane foam, the conditions in which it will be applied play an important role. In particular, temperature and humidity should be considered. The process of polymerization or hardening of the sealant depends on these indicators. The higher the temperature, the faster the surface hardens of the foam and, consequently, the slower the volumetric hardening. As the temperature decreases, the viscosity of the product increases, due to which the foam comes out worse, and the cylinder is not completely emptied.

Polyurethane foam. How to buy and use

Experts point out that the ideal working conditions for ordinary polyurethane foam are an ambient temperature of 18-25 degrees Celsius and a humidity of 60 to 80%. Therefore, before using the balloon, it is recommended to keep it at room temperature for 24 hours and in no case try to heat it in a water bath. This can lead to balloon rupture or material degradation. Do not forget that there is a special frost-resistant sealant that can be used in the winter season. But in any case, when working with winter polyurethane foam, the cylinder itself should not be below 0 degrees, but preferably not below 10 degrees.

The main stages of working with polyurethane foam

Polyurethane foam is a versatile material that is quite easy to work with. The process itself consists of the following stages:

  1. Before starting work, the aerosol can with polyurethane foam must be shaken well for one minute. Thus, its contents will receive a uniform consistency and will be evenly distributed..
  2. Moisten the surface to be treated with water. This will help increase the adhesion to the material..
  3. During the application of the foam, the household balloon must be kept upside down. Then the foam stream will be continuous. Vertical seams are closed from the bottom up. The first layer of foam should be no more than 3 cm, each subsequent layer is applied only after the previous one has completely solidified. Do not forget about moistening the work surface.
  4. After hardening, the foam can be processed, for example, cut off in those places where it interferes, cover the place of its application with platbands, putty or plaster the surface, cover with paint, etc..

Polyurethane foam. How to buy and use

There are certain rules for working with a sealant that will help achieve a good result:

  1. Do not touch the foam during polymerization..
  2. It is better to work with gloves, since the sealant is not easily washed off.
  3. If foam gets on other surfaces, remove it immediately with a cloth soaked in solvent.
  4. Dried foam is destroyed by sunlight, so it must be treated: plaster, paint or cover.

Polyurethane foam. How to buy and use

Rules for using the assembly gun

When working, it is very important to be able to use the assembly gun correctly. This will help you cope with the task quickly and without any problems, and will also extend the life of the device itself..

An assembly gun is a device through which foam is supplied under pressure to the surface to be treated. The first thing a master must face is setting the pistol to its working position. To do this, you need to take the can in your hands and shake it thoroughly for 30 seconds. Then remove the protective cap and, turning the neck down, screw the cylinder into the gun thread. Having checked the correctness of the installation of the gun by means of a control start of the foam to the side, you can proceed to the work itself on foaming cracks and voids.

Polyurethane foam. How to buy and use

If, during operation, the foam in the cylinder suddenly runs out and it is necessary to screw on a new cylinder, then first turn the gun upside down and unscrew the empty cylinder. Then, with the help of flushing liquid, the attachment point is cleaned and only then a new cylinder is screwed on.

If the work on sealing the seams is over, and the foam remains in the cylinder, it is imperative to tighten the adjusting screw to the very end so that the foam stops flowing into the barrel. After that, you need to clean the outlet from the residual substance with a solvent, while the gun should not be unscrewed from the cylinder. So the foam during storage is guaranteed not to dry out and it can be used another time..

Polyurethane foam. How to buy and use

In order to clean the assembly gun from foam residues, use a special flushing liquid. It is sold in the same container as the foam. It is screwed onto the barrel of the pistol and the barrel is filled by pressing the trigger. In this state, the device is left for 10-15 minutes, after which the remaining foam is released with a cleaning agent and the operation is repeated again.

How to wash polyurethane foam and remove traces of it

After the completion of the work, as a rule, you have to deal with the removal of traces from the polyurethane foam. The main condition is a fresh stain. Dried foam is much more difficult to wipe off. First, a mechanical method is used. Where possible, the foam is cut with a knife or removed with a rag or napkin, being careful not to smear the foam on the surface. Where this cannot be done, use a solvent (nailer flush, acetone, gasoline, solvent 646, etc.). First, a small amount of the substance is applied over the dried foam. When it softens, remove it with a damp cloth. If there are still traces, the procedure is repeated. Do not forget that the use of a solvent increases the risk of damage to the surface to be cleaned, so you need to be very careful. Try the solvent on the material on an inconspicuous area.

Polyurethane foam. How to buy and use

Advice! Masters advise “Dimexid”. This drug is sold in a pharmacy, is inexpensive and will help you clean the foam from the surface..

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