Heat-resistant sealants: properties and scope

The heating system and its constituent elements are an important part of the engineering communications of the house, cottage and any other structure. These systems are responsible not only for the heat in the house, but also for safety. So, all the components of the heating system, as well as the equipment itself, must ensure the appropriate level of operational and fire safety.

The tightness of the heating system is the key to safety and efficiency

An important point of fire and operational safety is the complete tightness of all required elements of the heating system and equipment. This applies both directly to the hearth and to the chimney, especially if it is made of brick or ceramic. Today, for high-quality masonry of heating stoves and fireplaces made of brick and steel, as well as for the competent connection of the chimney, special sealants and masonry compounds are used. At the same time, sealants are also used for repair and maintenance work - when closing cracks and crevices that can form in the functional parts of heaters and chimneys due to thermal expansion and a sharp temperature drop.

Modern sealants have an optimally balanced composition, which allows you to solve a wide range of problems. All sealants produced on the world market are designed to ensure the tightness, insulation and fire safety of the heating system in conditions of high temperatures and extreme operating conditions.

High temperature sealants: purpose

In Russia, the operation of heating equipment is particularly active due to the often harsh climate and the long winter season. During the active use of the fireplace, stove and chimney, cracks and crevices may form through which smoke can enter the room. Also, cracks and cracks significantly reduce the tightness of the heating device, increase fuel consumption and generally reduce the heating performance of fireplaces and stoves.

Cracks and crevices can appear both in the chimney and on the foci themselves, as well as at the junction of functional elements. At the same time, damages directly to the chimney can not only lower the operational characteristics of the heating system, but also create fire-hazardous situations. Therefore, when identifying such defects as the heater and the smoke channel, it is urgent to repair and seal cracks, holes and cracks. It is for this kind of repair work that high-temperature sealants are used. Sealants are also used during installation work on the installation of heating and smoke exhaust equipment.

High Temperature Compounds and Sealants: Classification

Those or other characteristics of sealed pastes for fireplaces, stoves and chimneys are revealed by the composition of the base from which they are made. So, compositions based on silicone and silicate are used for stoves and fireplaces. This type of sealant is included in the first group, which is characterized by:

• heat resistance
• resistance to direct fire
• durability
• light application to the surface

The second group of sealants includes heat-resistant pastes that withstand lower temperature loads than sealants of the first group.

All types of high-temperature sealants are characterized by their own characteristics and have a specific scope. Let us examine in more detail each of the species.

Heat Resistant Silicate Blends

This type of sealant is a paste, the main component of which is sodium silicate. This composition of the paste makes it viscous and plastic, while it is characterized by a black color. After solidification, this type of sealant forms a non-elastic surface and a rather rigid seam. Due to this, silicate mixtures are used to treat stoves and fireplaces that have already shrunk.

The main technical parameters of silicate sealants:

• able to withstand long-term temperature loads up to 1300 degrees and short-term - up to 1500 degrees Celsius
• the thickness of the joints after solidification is a maximum of 15 mm
• sealant freezes from 15 minutes
• available in the form of plastic tubes
• it is recommended to apply the composition at an ambient temperature of 1 to 40 degrees Celsius

It is important to pay attention to the fact that not every heat-resistant paste is at the same time a refractory sealant. In other words, not every mixture is designed for direct contact with fire. In this regard, before buying, it is necessary to study the information given on the sealant packaging. Heat-resistant pastes are most relevant for application at the joints of those elements of the heating system that are characterized by immobility and the same rates of expansion coefficient.

Areas of application for silicate based sealants:

• to create tightness of the combustion chambers, joints of the lining and processing of those surfaces and elements that have direct contact with the flame and hot flue gases
• for sealing cracks and cracks between brick surfaces and adjacent metal or cast iron parts
• for sealing chimneys designed for the removal of high-temperature combustion products (for example, for bath stoves and boilers)
• for processing and preparing furnace casting installation areas
• to eliminate leaks in water tanks and heating boilers
• for mounting chimneys and connecting (docking) sandwich pipe modules to each other

Heat Resistant Seals - Silicone Sealants

Sealants based on silicone have iron oxide in their composition, due to which pastes are characterized by a brown-red color. The temperature that silicone mixtures can withstand is significantly lower than silicate and ranges from 170 to 300 degrees Celsius. Silicone pastes are packed in tubes. Unlike silicate, their elasticity is preserved after solidification, so that the seams are not subject to deformation. At the same time, silicone gaskets have good moisture impermeability and water resistance - these characteristics make them popular for insulation of those sections of the chimney that interact with the roof of buildings or are carried along the external walls of the building.

The main technical parameters of silicone sealants:

• workloads with temperature up to 300 degrees Celsius
• tube packing
• drying for 20 minutes
• resistance to sunshine
• suitable for processing cracks and cracks up to 6 mm in size
• it is recommended to apply on cold surfaces at a positive temperature (not higher than 40 degrees Celsius)
• cost lower than silicate analogues

It is important to understand that the differences in the technical and operational characteristics of silicate and silicone sealants are based not on a lower or higher level of quality of each mixture, but on different fields of their application and purpose. So, we list the main areas of application of silicone pastes.

Scope of application of silicone based sealants:

• treatment of brick chimney sections located on the street
• sealing chimney and roof junctions
• processing chimneys made of steel, brick, or sandwich pipe modules in cases of their connection to boiler plants, the temperature of the exhaust smoke from which is not higher than 150 degrees Celsius
• processing joints and threads during the installation of several heating circuits

Release form of heat-resistant sealants

The overwhelming majority of offers of sealants from various manufacturers are available in the form of convenient cylindrical plastic tubes. In this form, the packaging is conveniently installed in a special construction gun, which makes it easy to squeeze the paste in the required volume during application to the surface. There are also forms of release without a gun - in an ordinary soft tube. Sealants in this form of release are used to seal small areas without the use of any special devices.

One-component and two-component sealants

The form of release of sealants also varies in composition. There are one-component and two-component compositions. The first type is a ready-to-use composition that can be used immediately after purchase. It is actively used in everyday conditions and does not require any qualified knowledge and skills when used. This type of sealant has a longer drying time, which allows you to correct any errors and inaccuracies in the application. Two-component sealants are a set of paste and hardener, which must be mixed in certain proportions before use. Sealants of this type are most in demand in the industry for processing impressive areas in size and volume.

The choice of sealant - what you need to know?

The right choice of high-temperature sealant suitable for the specific goals and objectives is based on identifying its scope and technical properties. During the selection, you should be based on the following parameters:

• the maximum temperature that the surface or element to which the sealant is applied produces
• maximum temperature for which this or that sealant is calculated
• brand and manufacturer
• preferred base - silicate or silicone: the choice is based on the maximum operating temperatures of the heating equipment, chimney and its elements

Silicone Sealant Operation:

To work with silicone-based thermal grease, a rubber spatula, latex gloves and a special brush should be used, and items such as a knife and masking tape (tape) will also be needed. At the same time, the working surface on which the sealant will be applied should be previously prepared. To do this:

• clean and degrease the surface
• it is recommended to wipe the steel parts with sandpaper to increase surface adhesion
• after processing, allow the surface to dry completely

After the surface is prepared, cut off the sealant cap and insert the tube into the gun. When applying the mixture, it is desirable that its thickness be slightly less than the thickness of the crack, gap or seam. In order for the sealant to evenly dry and harden, it is important to provide oxygen access to it. The full drying time depends on the level of temperature and humidity in the room - the required temperature and humidity indicators are always indicated by the manufacturer on the package. To protect those substrates that will not be subject to sealant treatment, use masking tape.

Silicate sealant operation:

In cases of using high-temperature silicate-based sealants, preliminary preparation of the base is also required. Porous surfaces should be dusted and moistened. Carrying out work is possible only at positive air temperatures, preferably above 20 degrees Celsius. The thickness of the coating should be recommended by the manufacturer of the mixture parameters. It is important to remove excess sealant (residues) from the surface immediately - before the mixture has hardened. The amount of time required to completely dry the sealant should be calculated based on the manufacturer's instructions for use.

TOP 5 of the best high-temperature sealants

Both silicate and silicone sealants are in high demand, so their offer is great, and a wide range of such products is presented in every hardware store. Among the variety of proposals for their technical and operational characteristics, the following brands and types have especially proven themselves:

1st place - Penosil + 1500 ° C Sealant
2nd place - Makroflex TA145
3rd place - Soudal
4th place - KraftoolKraftflex FR150
5th place - Moment Herment

We will analyze in more detail each brand of sealant:

1. Penosil + 1500 ° C Sealant - Silicate high-temperature sealant made in Estonia. It has excellent technical parameters, while being sold at an affordable cost. This heat-resistant sealant belongs to the professional class and is used for sealing and sealing joints, processing cracks and cracks in fireplaces, heating furnaces and chimneys. It can be used both inside and outside buildings, suitable for various materials - metal, brick, concrete, stone and others. Withstands temperatures up to 1500 degrees Celsius, freezes for a day, has a dark gray tint, it is recommended to apply at an ambient temperature in the range from 5 to 40 degrees.

Penosil + 1500 ° C Sealant Advantages

• affordable price
• high quality
• simple application
• universal characteristics

2. Makroflex TA145 - thermally stable silicone-based sealant made in Belgium. Fields of application - any, but taking into account temperature limits - sealant can be used only where the temperature is not more than +250 degrees Celsius. This sealant is characterized by good adhesion and resistance to climatic influences. However, it is not recommended for use on steel parts subject to corrosion. Makroflex TA145 is resistant to temperature effects in the range from 60 to 250 degrees Celsius, is able to withstand temperatures of 310 degrees for a short time. This sealant dries in about two days, it must be applied at a temperature of 5 to 40 degrees. During drying, it releases harmful acids, therefore, constant ventilation of the room is required until the mixture completely dries.

3. Sealant Soudal It is made on the basis of silicate, after drying it is formed into a durable layer without cracks. Designed for exposure to temperatures up to 1500 degrees Celsius. Suitable for sealing seals and areas around chimneys, for creating tightness of fireplace inserts, for professional installation and repair of stoves and fireplaces, boilers, for eliminating cracks and crevices up to 5 mm deep. It can be used together with concrete, brick, metal.

4. Kraftool Kraftflex FR150 Sealant It is based on silicate, therefore it can withstand temperatures up to 1500 degrees Celsius. This sealant has good weather resistance and is suitable for use both inside and outside buildings. The scope of the sealant is quite extensive - can be used for parts in contact with direct fire. It has a black color, completely hardens within two days, is applied at an ambient temperature in the range from 5 to 40 degrees.

Advantages of Kraftool Kraftflex FR150 Sealant:

• universality
• suitable for extreme, difficult operating conditions
• suitable for use in low temperatures (up to -40 degrees)

5. Sealant Moment Herment made on the basis of silicone, withstands thermal effects up to about 200 - 250 degrees Celsius. It is used for sealing and sealing joints in chimneys, in furnaces, including between steel parts. It has a good level of adhesion, resistance to sunlight.It has a red, brick tint, dries - quickly, forms an excellent bond with a wide variety of materials. Excellent sealant, but has a fairly high cost.

Key Findings and Recommendations

When choosing, buying and further using sealants and sealing pastes, it is very important to follow certain rules. Compliance with the manufacturer's recommendations, as well as fire safety rules, is the best guarantee of the optimal and efficient operation of the entire heating and smoke removal system of the facility.

When choosing a sealant, the following factors should be considered:

• sealant composition suitable for specific user needs
• area and part of the heating system for which sealant is required
• surface sealant and drying technology
• maximum exposure temperature and the possibility of contact with direct fire

In the salons of the company "Domotekhnika" there is a wide range of sealants and pastes of various characteristics, manufacturers, composition and scope. The specialists of our company are ready to provide professional advice on the choice of sealant of optimal characteristics and properties suitable for the specific needs of the client.

Articles

Sealants are vulcanizable compositions based on polymers (polysulfide or liquid silicone rubbers) designed to seal joints and joints between different types of surfaces.

The following main characteristics of sealants are distinguished:

• strength,
• resistance to deformation,
• adhesion to materials
• curing shrinkage (for curable sealants),
• elasticity,
• term of operation in the room and in the environment.

High-quality sealants must preserve the physicochemical and physicomechanical properties throughout the operation, have good adhesion to the material of which the sealed structure is made, and not release toxic substances.

Sealant Classifications

When ready for use, sealants are divided into:

• single-component (suitable for direct use),
• two-component and multi-component (requiring accurate and thorough mixing of the components before use).

One-component sealing materials, in turn, are divided according to the chemical composition of the base. The table below shows the types of sealants, their composition, scope, advantages and disadvantages.

Separately, it is worth noting that silicone sealants are the most versatile of all those listed. Taking into account the fact that they necessarily contain a curing component, they are further subdivided into two more types: acidic (during the vulcanization, acetic acid with a characteristic odor is released) and neutral (amine, amide, oxime and alcohol). Sealants of both subspecies have their advantages and disadvantages. For example, acidic is cheaper than neutral, but they cannot be used to seal surfaces and materials that form soluble salts (cement-containing materials, aluminum, marble, etc.) as a result of reaction with acetic acid. In this regard, neutral sealants are preferred.

By introducing additional components and additives, silicone sealants are given properties such as water resistance (aquarium sealants), heat resistance (motor), and mold resistance (sanitary sealants with fungicidal additives).

In contrast to single-component sealants, cured by moisture and air, two-component sealants are cured using a special catalyst, which is stored separately from the base.

Guaranteed cure time is the main technical advantage of two-component formulations. In addition, they have better strength characteristics than single-component, more environmentally friendly and cheaper. The main disadvantage of two-component sealants is the possibility of errors when dosing and mixing the components, which leads to a loss of quality of the finished material in the seam. However, it is worth noting that the packaging form of a two-component sealant with simultaneous portioned measuring of the components practically eliminates dosing errors. The quality of the mixed composition can be easily achieved visually - for this purpose, the components of the sealant have different colors.

Typical sealant applications

Each type of sealant has its most typical application. So, acrylic compounds are used for sealing indoors, but are not recommended for external sealing of windows, double-glazed windows and places exposed to water, solutions and other liquids.

For gluing and sealing work in a biologically aggressive environment (toilet and bathrooms, kitchens, pools, showers, etc.), sealants with fungicidal (antifungal) additives are needed - they prevent the formation of mold on surfaces. However, such sealants cannot be used for products and materials in contact with food (other than those specifically designed for this).

For the repair and manufacture of aquariums, only those sealants are used that meet the high requirements for tensile strength (at least 25 kgf / cm2), resistance to biologically aggressive environments and safety for living organisms.

For sealing joints in engines and gearboxes, furnaces and fireplaces, sealants are used with an operating temperature of up to +300 ° С. They do not lose elasticity and do not collapse when heated, are oil resistant and do not react with metals.

To seal joints that are constantly exposed to ultrahigh temperatures (up to +1500 ° C), there are special fireproof sealants.

Sealant Recommendations

Sealants packaged in standard cartridges and folic tubes are applied using special guns or a spatula. The materials in the tubes are directly extruded onto the seam. Immediately after applying the composition, the seam can be shaped with a special spatula. The initial setting time of the sealant is from 10 to 30 minutes, complete solidification occurs within 24 hours.

To some materials, mainly plastics (polycarbonate, polyethylene, polypropylene, Teflon, PVC), the adhesion of the vast majority of sealants is insufficient. In this case, either specialized sealants for specific materials or primers are used. The latter create an intermediate layer between the surface and the sealant, providing a strong bond between dissimilar and initially incompatible substrates.

Sealant Removal

Unfrozen sealants are removed with a cloth and special napkins impregnated with solvent or water (depending on the type of sealant and the surface to be treated).

Polymerized formulations can only be removed mechanically: solid - with abrasive materials and tools, uncured - with a knife or scissors.

Sealant Storage

It must be remembered that after opening the packaging, the sealant cannot be stored for a long time, as as a result of loss of tightness it loses its properties.

Sealing materials are stored in a cool, dry place at a temperature of +5 to +30 ° C. Silicone, butyl, bituminous and polyurethane sealants withstand short-term storage at temperatures up to -18 ° C.

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Types of flame retardant sealants

Refractory sealant is a heat-resistant pasty or viscous substance based on polymers, which is used to prevent leakage of liquids through gaps, as well as for waterproofing and sealing. All sealants that can withstand temperatures from +200 degrees are considered heat-resistant, they are similar in physical properties, although they have different chemical composition and specific technical characteristics.

Sealants depending on the field of application, heat resistance index and composition are divided into the following groups:

1. Polymer intumescent. They are thermally expanding: when heated, they increase in size, as a result, the joints are more densified. Flame retardant sealant with such properties is ideal for closing holes during wiring, for sealing expansion joints.
2. Acrylic Made on the basis of acrylic, they are most often used to close the joints between ceramic tiles on the outside of stoves, fireplaces. Usually have a white color. May be subject to moderate heat, but do not tolerate contact with open flame. Nevertheless, acrylic sealants are considered fireproof: they flash, but immediately stop burning and almost do not emit smoke, they do not contribute to the spread of flame.
3. Silicone One-component transparent compositions widely used for sealing the visible part of structures. Suitable for metal, concrete, tile, plastic and many other materials. Most often, silicone-based products are used in the transit installation of equipment in fire hazardous areas, and during the installation of pipelines. They can be acidic and neutral, with the latter being an order of magnitude more expensive and more efficient.
4. Silicate. Organosilicon-based products (“liquid glass”) can withstand up to +1500 degrees, so they can even be used to seal joints that are in direct contact with fire.

Fields of application of heat-resistant sealing compounds

Heat-resistant sealant has many areas of use. Such compositions are necessary for the arrangement and repair of stoves and fireplaces. In such cases, high-temperature sealant for furnaces is used to eliminate the holes that have occurred during operation of the walls of the combustion chamber. It is recommended to use some compositions even for restoration of refractory masonry made of chamonit brick, since they are able to withstand the effects of high temperatures reaching + 1500 ° C.

The material is suitable for both metal and brick. This composition is optimal for chimney pipes, contributing to its reliable sealing. Using the composition allows you to prevent the penetration of dangerous carbon monoxide into the room. Silicate sealant for stoves and fireplaces is effective for exterior decoration. Heat-resistant adhesive sealant is necessary when fixing asbestos and graphite-asbestos cords and gaskets on metal latches, doors and other accessories. In addition, the composition can be used to seal the connection of the chimneys.

Heat-resistant silicone is available for sale. When choosing such a sealant, you need to pay attention to what temperature it can withstand. These compounds are often used to process joints when installing heating appliances. They are suitable not only for boilers, but also for the arrangement of the circuit. Similar compositions are also used when laying hot water pipes. Heat-resistant silicone can not be used if the material will subsequently come into contact with an open flame.

There is a food sealant on sale. These compounds can be used to repair kitchen utensils, including they are suitable for a kettle or pot in which defects have appeared. Nowadays, heat-resistant sealant is often used for the hob and for the oven, where additional processing of joints is required and there is a possibility of contact with products. When repairing cars, a special heat-resistant sealant for the engine is often used. It is necessary to connect the individual parts.

Considering that there are many varieties of this material on the market, each of which has its own characteristics and properties, sealants are now used in many areas. When choosing a material, it is necessary to take into account the melting temperature, fire properties and recommendations for its operation.

Heat resistant and heat resistant

All varieties of sealants are divided into heat-resistant and heat-resistant. Each option has its own characteristics. The basis for the production of heat-resistant sealants is high-temperature silicone, capable of withstanding temperatures up to + 300 ... + 350 ° C. This heat-resistant adhesive sealant is a thick paste of red color. It is resistant to environmental factors.

Due to the limited temperature threshold, this material can be used for insulation of heating pipes and water pipes, eliminating gaps located on the outside of the house. In addition, it can be used to a limited extent for processing gaps in furnaces and waterproofing joints in the bathroom to ensure their waterproofness, since such a silicone gasket is resistant to moisture and high temperatures.Transparent compositions are more often used for filling seams.

Most heat-resistant sealants are based on silicate, so they are black. Fireproof silicone sealant is also available on the market, but its performance is slightly worse.

The heat-resistant version of the material is resistant to a temperature of + 1500 ° C. They differ in that after solidification they form a solid mass of low elasticity. Most often they are used for joining threaded joints of titanium, steel and cast iron products.

Silicate refractory sealant is often used in slit processing in furnaces. It is possible to use such formulations in conditions where they will come into contact with extreme temperatures. Refractory silicone is best used for treating the exterior surfaces of fireplaces and stoves.

Acrylic

This type is a mixture of acrylate polymers and additional components. The composition of the material is highly resistant to various environmental factors, therefore, it is suitable for both internal and external works. However, at high temperatures, this sealant becomes soft and hardens in the cold.

Such sealants are often used when installing heating equipment and water circuits. The sealant is highly moisture resistant, therefore, it is often used in the arrangement of sewer systems and in the processing of joints and gaps in bathrooms. The advantages of this material include:

• high elasticity
• long-term preservation of properties,
• good grip even with flat surfaces
• high adhesion with brick, wood, concrete and plaster,
• lack of strong odor solvents,
• UV resistance
• the possibility of coloring the stiffened joints.

The disadvantage of such sealants is the long polymerization period. Complete solidification is often observed only after 15-20 days. In addition, it must be borne in mind that the composition should be applied only on dry surfaces, while it is desirable that the air humidity does not exceed 50%. This will provide better grip.

Bitumen

The basis for the manufacture of such sealants are viscous bitumen, a stable filler and special additives. Similar sealants can be used both for thermal insulation and for waterproofing. Similar compositions are also often used to eliminate deformations and splits on rubber, brick, bitumen and other surfaces.

Bituminous sealants are often used for the installation of roofing material and other insulating materials. The main advantages of this type include high curing speed and resistance to ultraviolet radiation, various weather conditions and mechanical damage. The positive properties of bitumen sealants include:

• high elasticity
• resistance to large temperature differences,
• ability to adhere to any surfaces,
• high anti-corrosion properties,
• long service life.

However, it must be borne in mind that bituminous sealants can soften on contact with mineral oils. In addition, after hardening, the surface must not be painted. Nowadays, such sealants are less and less used in the repair and installation of surfaces that will be exposed to high temperatures. Exceeding the recommended temperature for this material can provoke its softening.

Polyurethane

Polyurethane sealants are either one-component or two-component. These compounds have high performance. Polyurethane compounds are used to solve many construction problems. They are used for insulation of roof joints, chimneys, surface treatment of brick, metal, wood and plastic. The advantages of such formulations include:

• quick drying
• frost resistance
• high elasticity
• lack of solvents,
• good adhesion
• corrosion resistance.

During polymerization, such compositions do not emit harmful substances. Hardening occurs even at high humidity. However, polyurethane sealants may break under the influence of temperatures above + 120 ° C. In addition, it must be used immediately after opening the package, since it is not designed for long-term storage. When applying polyurethane compounds, personal protective equipment must be used, since caustic substances are present in them.

Silicone

High-temperature silicone is produced from a substance such as silicon organic polymer, characterized by the possibility of hardening at room temperature. Depending on the chemical composition, they are neutral and acid curing. The first option is mainly used for sealing plastic elements. Such compositions are easy to use and do not have a pungent odor. Acid curing adhesives adhere well to any surface. After solidification, they are highly resistant to high temperature and moisture.

In addition, a number of additives and additional components are introduced into the composition. By scope of application, such formulations are divided into:

It is important to choose the right sealant for its application. Silicone compounds have the following advantages:

• service life about 15-20 years,
• UV resistance
• ability to withstand large temperature differences,
• high heat resistance of special varieties,
• the ability to adhere to most types of surfaces,
• no need for primer,
• the possibility of deformation without loss of properties.

Silicone sealants have some drawbacks. Such formulations are recommended to be applied on dry surfaces. You can not apply a fresh layer on top of the old one, since adhesion in this case will be insufficient. Acid cured grades can corrode concrete and metal.

Thiocolov

Thiocol sealants are made on the basis of a thiol-containing polymer and liquid thiol. Such compositions are two-component and three-component. Mixing of the components is carried out immediately before use, since the primary hardening occurs within 1-2 hours. Final hardening occurs after about a day. Some varieties of thiocol compositions can retain their properties when exposed to temperatures up to + 800 ° C. The advantages of this material can also include:

• moisture resistance
• frost resistance
• long service life
• resistance to alkalis and acids,
• adhesion to most types of surfaces,
• high rates of permanent deformation,
• UV resistance.

The disadvantages of such compositions include quick drying, so you need to work with them quickly. It is necessary to use personal protective equipment and avoid contact of the composition with the skin, because this can cause irritation.

Well-known brands of heat-resistant sealants

There are many types of heat-resistant sealants from different manufacturers on the market. Preference should be given to the products of time-tested companies, including:

The most popular among professionals is the NA147 brand from the Estonian company Makroflex. It retains properties at temperatures up to + 1200 ° C. This composition can be used to seal elements of almost all materials. It can be used for furnishing and restoration of furnaces.

SOUDAL Sealant does not include asbestos. It is capable of withstanding temperatures up to + 1500 ° C. Well suited for arranging silicate stone fireplaces.

High heat-resistant properties have a composition from the company Krass. It can even be used to connect fireclay masonry. It is resistant even to open flames.

To seal pipe joints, it is recommended to use a product of the Polish company Tytan. The material can withstand temperatures up to + 1250 ° C. It is recommended for use to eliminate cracks and joints in fireplaces. In comparison with the products of other companies, it has a relatively low cost.

Sealants of the Estonian company Penosil Soudal are distinguished by their ability to withstand temperatures above + 1500 ° C. The composition of this material includes silicone, so it is highly elastic and can be used to process moving joints.

Composition from the brand Moment is able to withstand temperatures up to + 260 ° C. In addition, the material can retain its properties during short-term heating up to + 315 ° C. It adheres well to most types of non-porous materials. The positive characteristics of this material include resistance to ultraviolet and frost resistance.

Fireproof joint sealing requirements

Any fireproof sealant is made in accordance with existing state standards, technical specifications, norms and other documents regulating production. Each product must receive a certificate of conformity, which is assigned after passing tests for resistance to heat, fire, etc.

The list of requirements for flame retardant sealants is specified in the PPB Fire Protection Joint Venture, and their amendments are reflected in Art. 87, 88 Federal Law No. 123. The main requirement for water-tight flame retardant sealants is the ability to localize the flame, to limit the spread of fire, to maintain the integrity of the fire walls. As indicated in the normative documentation, refractory sealants are used for fire protection. Here are the main ones:

• sealing pipe joints and ceilings,
• sealing joints between structures made of wood and metal,
• cable protection when laying wiring,
• tightness tightening of fire-prevention double-glazed windows,
• installation of ventilation systems, air ducts,
• joining of floor slabs to each other,
• sealing different joints in fire compartments,
• waterproofing of rooms, roofs.

Sealant Properties

Fireproof sealants are available in cartridges, tubes, buckets and barrels. Their main difference from conventional sealing compounds is the ability to withstand the action of the flame, strong heating, while not flashing or not supporting combustion. Some sealants are not combustible at all, others are slow-burning, self-extinguishing within a short period of time.

Any sealant is quite elastic, because it has to regularly undergo expansion and contraction of the base material, which inevitably occurs during heating and cooling. Also, all sealants are waterproof, have excellent adhesion to the surface. Depending on the composition, sealing agents to varying degrees withstand contact with oils, chemicals, and petroleum products.

Criteria for choosing flame retardant sealants and the best tools

To choose the right composition, you should carefully read the instructions and look at the markings. The degree of fire resistance is always indicated on the packaging under the designation EI with numbers, where E is the time of loss of integrity, I is the period of loss of thermal insulation (in minutes). The higher these indicators, the more reliable the composition, the longer it will withstand heating or contact with fire.

When buying, it is also important to take into account the nature of the work: some sealants are suitable for the exterior, others for the interior, although there are universal compounds. There are specialized tools for sale, for example, for sealing window blocks. Neutral silicone sealants are suitable for absolutely all materials, acidic can harm natural stone, some types of metal.

The quality of the sealant is of great importance, therefore it is better to purchase only means of proven brands:

1. "Stop Fire EP-71." Neutral composition for local sealing of cavities, joints, seams, fixing of double-glazed windows, doors. It withstands up to +200 degrees for a short time, up to +270 degrees for a short time.
2. Siloterm EP-100. Operating temperature reaches +250 degrees. Great for wet rooms to seal joints.
3. "Fire GT". When heated to +200, it swells, expanding in three directions, which prevents the penetration of smoke and fire into neighboring rooms. It has high frost resistance. Refractory tape “Ogneza-LTU” is also produced under this brand.
4. "Macroflex HA147". Withstands up to +1200 degrees, does not deteriorate from short-term heating up to +1500, does not shrink, can be painted.
5. Invamat. Acrylic sealant designed to contain an open flame. It is used for work on glass, metal, wood.
6. Soudal Silicone B1 FR. Neutral silicone composition for exterior and interior use, has a low flammability class, resistant to UV radiation, water.
7. Intumex MG. Pasty gray acrylic based sealant that prevents the spread of fire. Expands under pressure, can be painted after drying.
8. VGO-100. Viscous intumescent composition, well suited for sealing cable passages, filling cavities when installing refractory glasses.

Scope of fireproof sealants

Initially, fire fighting compounds were made on the basis of clay and cement and used for various construction works. Nowadays modern refractory sealants are produced with the addition of various synthetic substances, polymers, and the scope of their use has expanded significantly. They are suitable for:

• ductwork
• fire windows, doors,
• pipeline networks
• ventilation ducts,
• vehicle engines
• heat generating units
• electric tracks
• wire entries into equipment enclosures, junction boxes.

The most heat-resistant sealants ensure the tightness of joints in aggressive conditions of long-term high-temperature exposure. They are also able to tolerate extremely high temperatures and contact with undiluted acids for a short time.

Such tools are used in the installation of stoves, fireplaces, for a number of other purposes. Sealants that do not deteriorate from the influence of fuels and lubricants are suitable for the assembly and repair of cars, diesel locomotives, and other equipment.

Advantages and disadvantages

Fireproof sealants have a number of advantages that distinguish them among materials with a similar purpose:

• resistance to high-temperature action, no burnouts (for a number of products),
• high degree of adhesion to most building, finishing materials,
• the absence of hazardous substances in the composition, the release of toxins when heated,
• dielectric properties
• lack of deformation, cracking due to elasticity,
• the ability to withstand vibration, UV radiation, radiation exposure, the influence of moisture, detergents, the life of microbes,
• long period of operation (up to 40 years),
• the availability of convenient forms and various volumes on sale.

The disadvantages include the increased cost of such products compared to conventional sealants, but this pays off with a host of advantages.

Nullifire Heat Resistant Sealants

The Nullifire brand is a leader in the manufacture of flame retardant compounds. Here are the most famous products:

• Nullifire M701. Acrylic composition for enclosed spaces, does not burn for at least 300 minutes when exposed to fire. Suitable for wood, metal, reinforced concrete. It can withstand severe deformation without cracking (up to 20%).
• Nullifire M703. The estimated sealant deformation without spoilage is 50%. It is suitable for outdoor use, does not lose properties at sub-zero temperatures, withstands heating up to +1200 degrees.
• Nullifire M705. Intumescent composition, expands at + 250 ... + 300 degrees, made on the basis of graphite.Most often used to seal cable penetrations, pipelines.

Hilti flame retardant sealants

Hilti sealants are designed for structures prone to deformation. The most popular are such tools:

• Hilti CP 601S is a neutral silicone sealant that traps smoke, gas, water, hardens after 15 minutes, is suitable for outdoor use,
• Hilti CP 606 is an acrylic composition for sealing sedentary joints, hardens in 30 minutes, can be painted, intended for interior use.

Heat-resistant sealant "Siloterm EP-71"

This sealant is prepared on the basis of durable silicone elastomer. It is used for sealing joints, joints on building structures, arranging fire protection systems, sealing cables, couplings and adapters, installing double-glazed windows.

A variety of sealant "Silotherm EP-71M" is used to create fire-resistant electrical insulation coatings, perform anti-corrosion protection. The Siloterm EP-71 kNS version has enhanced elasticity, therefore it is suitable for highly deformable joints. All means differ:

• radiation resistance
• moisture resistance
• the ability to coke under the influence of fire,
• explosion proof
• frost resistance
• ability to electrical insulation.

The use of sealants will help strengthen fire protection, reliably seal all seams and cavities. You should not save on their purchase: it is better to choose a reliable product of a well-known brand in order to take care of its safety.

Types of sealing compounds

High-temperature sealants for furnaces are divided into single-component (most convenient) and two-component. The first are preferred more often, because they can be applied immediately after purchase, without the need for mixing. A two-component sealant for furnaces consists of several elements, namely, the main substance and the catalyst. They should be mixed independently, just before work.

Depending on the basis, heat-resistant sealants for stoves and fireplaces are:

• Acrylic
• Bituminous.
• Polyurethane
• Silicone
• Thiocolov.

Insulators used at different temperatures are divided into heat-resistant (Titanium, Lacryl, Kerezit) and heat-resistant (Soma Fix, Bostik, Knaufman). The first can withstand up to 350 degrees. Heat-resistant sealant withstands extreme temperatures up to 1500 degrees. The latter can interact with fire, without compromising on quality.

Famous representatives of high-temperature insulators are characterized by wear resistance and a long service life. High-quality sealants have a slight shrinkage and do not provoke surface damage.

By the polymer composition, high-temperature sealants are acidic and neutral. The first, according to experts, are not entirely suitable for the installation of stoves and fireplaces, since acetic aldehyde adversely affects the surfaces. It can lead to corrosion.

Neutral heat-resistant sealant will be the most optimal way to interact with high temperatures. It consists of heat resistant silicone. The service life of such compositions exceeds 15 years, in addition, they can restore almost any (according to the material of manufacture) surface.

Features of heat-resistant sealants

Heat-resistant sealant is made on the basis of silicone. Some time after application and curing, silicone resembles rubber, and is a durable elastic composition. The sealant can stay in conditions where the temperature does not exceed 300-350 degrees.

According to the heat engineering parameters, it has a low temperature threshold, so the scope of its use is limited.

Heat-resistant high-temperature composition can be used for the following purposes: