When carrying out repair and construction work, a person is faced with various types of sealants, some are designed to connect materials located in a high humid environment, while others are able to withstand high temperatures. The latter are in great demand among motorists and builders, as they are able to provide good technical characteristics and guarantee better sealing.
The editors of the YaNashla website have prepared for you a rating of the best heat-resistant sealants for 2020.
Purpose and features of each model
Each product is based on a polymer composition, without which it is impossible to guarantee good adhesion and strength. Depending on the application, various materials can be used: silicone, silicate, bitumen, etc. Most manufacturers of sealing products prefer to produce products in tubes, as this simplifies operation. A person can squeeze out the contents themselves or use a mounting gun.
Depending on the production method and composition, sealants can be of three types:
- One-component. This product is used ready-made; no pre-mixing is required. Adhesion occurs within a few hours, while the climate requirements are minimal, it is only important to maintain room temperature and normal humidity. The layer thickness should not exceed 10 mm, in some cases 2 mm is allowed, a larger value will only do harm. More detailed instructions on consumption and method of application are indicated on the product label.
- Two-component. This sealant consists of two materials - a base and a catalyst. To bond to the surface, the product is first mixed. It is important to remember that the resulting mixture cannot be stored for a long time, so it is recommended to use it immediately so that it does not dry out.
- Three-component products consist of a base, a hardener and a catalyst. As in the previous version, in order to achieve polymerization, you must first combine the components.
When purchasing sealants for high temperature applications, keep in mind that there are two broad categories:
- The first category includes products that can function properly at temperatures of 1300 degrees; they are called heat-resistant. Such components are suitable for arranging stoves, as they can withstand open flames. This sealant contains sodium silicate. Stores sell products called “fireproof” and “fire-resistant” - all of these refer to the same type, the difference lies in the maximum temperature.
- The second category is heat-resistant products. This type is the most popular and is used in various structures and structures where the temperature does not rise above 350 degrees. The substance is intended for joints, connections and filling external cracks. This option is most popular, since its scope is vast and the price is affordable.
Based on the composition of the polymer component, the products are divided into two groups:
- Acidic. The peculiarity of sealants is that during polymerization they create acetaldehyde. The resulting substance is dangerous for some surfaces, as it can destroy the outer part. Therefore, it is important to correctly select the material on which the sealant is applied. Metal and concrete structures should be immediately excluded, as the former will undergo a corrosion process, and the latter will begin to crumble. All this will disrupt the beautiful appearance and worsen the technical characteristics.
- Neutral. The product consists of heat-resistant silicone, when the polymerization process is carried out, water and ethanol are released. The main advantage of the composition is safety for materials and humans. Often found in stores and has a wide range of applications. A seam filled with a neutral substance is restored in a few hours and retains its aesthetic appearance for 15 years.
Despite all the divisions and varieties in composition, all products have some common properties:
- Strong connection of materials - polymer components that are present in the sealing liquid have good adhesion to almost any surface. The product is not limited to metal and concrete; builders use the composition for wood, glass, ceramic structures, plastic, etc. A wide range of applications is one of the main advantages of heat-resistant sealant.
- Plastic. After installation work and completion of polymerization, a person receives a material that has good ductility. Increases vibration resistance and minimizes the chance of cracking. Temperature changes and climate change are not dangerous for such substances.
- Most are highly resistant to moisture and sunlight. Sealants are used to treat external surfaces located on the street side.
Based on the area of use, the product is divided into three large categories, but in reality there may be more:
- Sealants for construction work. Used in the construction of stoves, baths, etc.
- Automotive mechanics use heat-resistant substances when repairing vehicles.
- Compositions for special purposes. Such models are designed for specific surfaces and situations.
Features of heat-resistant sealants
Heat-resistant or low-temperature sealants are produced on a silicone basis. Their scope of application is limited to the external surfaces of stoves, fireplaces and brick chimneys. For application inside, these products are not heat-resistant enough, and for steel pipes they are aggressive because they have an acidic component.
The peculiarity of their use is also in the thickness of the layer applied. For each product, the manufacturer indicates the optimal application thickness. Don't neglect these recommendations to get a reliable connection.
Note! To harden, the heat-resistant insulator uses moisture from the surrounding air. With an increased thickness of the applied product, its inner layers will not be able to harden sufficiently.
Distinctive qualities of heat-resistant sealants for chimneys:
- The silicone base contains iron oxide, which gives the product a brown color.
- When applied, there is often a vinegar smell as the acid base evaporates.
- Neutral low-temperature insulators release alcohol and water when they harden, rather than acid. Such products can be used to insulate iron elements of chimneys or roofs. An example of such an insulator is PENOSIL Premium High Temp Sealant from the international brand Wolf Group.
- Silicone chimney sealants have good adhesion to different surfaces. They adhere equally well to mortar, brick, ceramics, glass, and soft roofing materials.
- Maintaining high elasticity during hardening makes it possible to maintain the tightness of connections during thermal expansion-compression of materials, under vibration loads of open segments of the chimney.
Moisture resistance and ultraviolet resistance make these materials indispensable for sealing the external elements of the chimney and roof penetration.
Note! It is not advisable to use low-temperature sealants to seal deep chimney cracks. There, the layer thickness will exceed the recommended parameters, not allowing the inner layers to harden sufficiently.
Low-temperature insulators have proven themselves well among motorists. However, when choosing a car repair product, you should pay attention to the acidity level of the paste. Belife Silicone sealants have proven themselves to be excellent for metal elements.
We recommend that you read: How to install a ventilation duct in the kitchen with your own hands?
Advantages and disadvantages of high temperature sealants
Often such adhesives are used to connect stoves, fireplaces, chimneys and similar structures. But no less popular are substances designed to create a seal inside automotive components that are exposed to high temperatures.
Positive sides
- Heat-resistant products can withstand temperatures up to 1300 degrees. This allows them to be used in almost any area. In addition, manufacturers produce models capable of operating at 1500°, but they can withstand this temperature for several seconds or minutes, after which the composition will begin to decompose.
- By choosing the right sealant, a person can connect and seal any surface, including glass and ceramics. It is only important to look at the purpose of the product in order to avoid mistakes, since models are sold that can only function with a specific material.
- Manufacturers produce substances in various colors, which allows you to choose the model that will match a specific item or interior. Of course, there is little technical benefit from this, but maintaining an aesthetic appearance is an additional plus.
- Previously, using high-temperature sealants was dangerous, since the composition contained asbestos products, which were recognized as carcinogens. Today they are replaced by a safer substance – sodium silicate.
- Installation of heated floors, chimneys, ventilation and even doors is impossible without the use of sealing substances. Since they guarantee the user not only a strong connection and good insulation, but also protect structures from unexpected fire. This is also important to consider when purchasing adhesive.
Flaws
- Some manufacturers add iron oxide to the composition, which is good in principle, but upon contact with work surfaces, the color can acquire an unpleasant brown tint, reminiscent of rust. Of course, there is nothing negative about this phenomenon, but the external impression is spoiled. Therefore, such compositions are recommended for use for interior decoration, where aesthetics do not play an important role.
- Due to the fact that most sealants contain silicone, it will not be possible to apply paint to such a surface, since it simply will not adhere to the working part. If in some cases there is nothing wrong with this, then when repairing cars, a mechanic faces certain difficulties.
- The drying speed of some models reaches 2-3 mm per day, which is a very long time, considering that more layers are applied. Therefore, the operating time increases significantly. When a person needs to seal thick seams, there is a possibility that the composition will not set, since high-quality polymerization requires constant access to oxygen.
- When repairing cars, it is important to consider that the room temperature must exceed 0 degrees, since at negative values polymerization is disrupted, which will lead to negative consequences.
Rules for using thermosealants
During active use of fireplaces and stoves, brickwork may crack. The risk of cracks appears increases if the brickwork is not lined with tiles, protected by a layer of plaster and not covered with heat-resistant paint.
Repair work cannot be postponed - using such a fireplace or stove becomes unsafe.
Depressurization of the walls of the combustion chamber, chimney or other elements of the furnace negatively affects the operational characteristics of the device and entails a number of dangerous consequences
Possible problems caused by the appearance of through gaps:
- fuel consumption increases due to the fact that additional air leaks into the combustion chamber;
- soot appears outward from the cracks - a corresponding coating appears on the ceiling and walls; in such situations, even cleaning the chimney does not solve the problem;
- combustion products hazardous to health enter the room - there is a risk of poisoning;
- periodic extinguishing of the pilot flame - probably due to depressurization of the chimney;
- fuel burns at low temperatures, which causes more soot to settle on the walls of chimney pipes.
Depressurization of the heating system and an abundance of soot is a fire hazardous combination. Incoming oxygen provokes fire inside the chimney.
If the exhaust duct is poorly insulated, the likelihood of a fire increases significantly.
Most manufacturers sell insulating compounds for furnaces in tubes. Before use, the cylindrical container is placed in a construction gun.
This option is most convenient when filling masonry joints and formed cracks. Sealants are easily squeezed out of the packaging due to their homogeneity and semi-liquid consistency
There are products in soft small tubes. It is advisable to use them for processing small areas. No additional equipment is needed to apply the composition.
High-temperature sealants are produced in the form of one- or two-component compositions. The first category is most actively used in everyday life.
Two-component compositions are supplied in a set - hardener and paste. Substances are mixed before use in strictly designated proportions
This option is more often used in industrial settings, when it is necessary to process large areas. Two-component mixtures have not taken root in everyday life due to the technological complexity of use.
The tactics for using silicone and silicate mixtures are similar. However, there are also features that should be kept in mind when sealing furnace equipment.
In addition to the construction tools for work, you need to prepare: a rubber spatula, latex gloves, and a brush.
The surface to be treated needs preparation:
- clean and degrease the base;
- It is advisable to treat metal elements with sandpaper to improve adhesion;
- wait for the surface to dry completely if water was used during cleaning.
It is desirable that the thickness of the extruded sealant be slightly less than the width of the seam or crack being processed
For uniform hardening, the silicone composition must be provided with air access. Therefore, the thickness of the sealant recommended by the manufacturer cannot be exceeded.
The time for complete polymerization depends on the conditions. The packaging indicates the rate of hardening at optimal parameters: humidity - 50%, temperature - 23°C. In practice, the values vary significantly. The lower the room temperature, the longer it will take for the sealant to “set.”
Adhesive tape is necessary to protect the outer coating - the sealant dries quickly, and then removing it from the base will be problematic
The surfaces are prepared in the same way as before applying the silicone composition: cleaned, degreased, and the metal is “sanded” with an abrasive.
Technological nuances of using silicate sealant:
- the porous base must be dusted and slightly moistened;
- work is carried out only at above-zero temperatures, optimally above 20°C;
- when applying the mixture, adhere to the insulation thickness recommended by the manufacturer;
- excess sealant must be removed immediately, without waiting for the mixture to dry;
- The masking tape is removed after applying the composition.
Some oven sealants require many hours of drying at different temperatures. This information must be clarified in the product instructions.
Rating of quality acrylic models
RAMSAUER 420 KACHELOFEN
Heat-resistant mass designed to create a high-quality connection with stove tiles and any absorbent base. The product is based on acrylic. The product is completely ready for use after purchase, which increases the efficiency of the device.
Any crack on the tile will no longer be visible, and the surface will also gain additional protection from water penetration. After 24 hours, as soon as polymerization occurs, paint can be applied on top. The manufacturer offers 18 colors, so finding the right one is easy.
Sold at a price of 722 rubles per 310 ml.
RAMSAUER 420 KACHELOFEN
Advantages:
- Good connection;
- Withstands high temperatures;
- 18 colors;
- Compatible with water-based paints and varnishes;
- Film formation time is 10 minutes.
Flaws:
- Price.
MasterTeks ProfiMaster
One-component sealant based on acrylic polymer. Suitable for providing reliable sealing in bathrooms, kitchens, basements and similar places. Withstands temperatures up to 80 degrees. Before use, it is important to pre-treat the working surface and clean it of various contaminants, such as grease.
The average price is 239 rubles for 290 ml.
MasterTeks ProfiMaster
Advantages:
- Good efficiency;
- Suitable for bathroom use;
- The hardened composition can be painted in any color.
Flaws:
- Not detected.
Soudal colorless 280 ml
The model is designed for construction work of medium complexity. The product guarantees a high-quality seam with maximum resistance up to 120°, which is a good result. Easily bonds to surfaces including ceramic, glass, metal, wood and PVC. The only drawback is that it cannot be painted after drying. Can be used for external and internal operations.
The average price is 307 rubles.
Soudal colorless 280 ml
Advantages:
- Wide scope of application;
- Good adhesion;
- Convenient application;
- Optimal price;
- Withstands temperatures up to 120 degrees.
Flaws:
- Not detected.
Top 3 bitumen-based products
MasterTeks Profi Master
If a person is looking for a good option for a roof, then this is a suitable solution that will glue and seal the top coverings. Can be used to organize high-speed repairs. Any crack in the roofing felt will be effectively sealed with bitumen resins that will not allow moisture to pass through. The only caveat is that it cannot be used in conjunction with galvanized iron. After drying, it is not painted, this is important to consider when purchasing.
Sold at a price of 240 rubles per 260 ml.
MasterTeks Profi Master
Advantages:
- Durability;
- Compacts the material well;
- Suitable for wood;
- Withstands temperatures up to 90 degrees.
Flaws:
- Not found.
Tytan Professional
A more expensive option that will create a high-quality seal for any roof. The product is based on modified bitumen, which increases the technical characteristics and capabilities of the product. Used as a main product in the renovation and protection of seams. Can be used on surfaces where drainage is provided or ventilation ducts are present. Adhesion to various materials, including metal, differs.
Sold at a price of 530 rubles per 310 ml.
Tytan Professional
Advantages:
- Connects steel and wood structures;
- Suitable for use under drainage elements;
- Thermal resistance of the seam is 90 degrees;
- High-quality composition.
Flaws:
- Not found.
Quelyd black 310 ml
A good model that can create a reliable seam with various materials. Can be used in ventilation systems, when organizing a chimney, as well as in roof windows. The product is based on standard bitumen, so the maximum heat resistance of the seam can reach 80 degrees and no more. It is produced using German technology, so its aesthetic appearance is maintained for a long period, which also has a positive effect on operation.
Average price – 270 rubles.
Quelyd black 310 ml
Advantages:
- Reliability;
- High service life;
- Produced using German technologies.
Flaws:
- Low heat resistance.
Silicone compounds
Once applied and cured, high-temperature silicone forms a hard but elastic layer of material vaguely reminiscent of rubber. The color of the composition is most often red, this is due to the presence of iron oxide in it. The maximum temperature threshold is on average 250 ºС, some manufacturers declare it at the level of 280-300 ºС.
You will say that this is the red substance you applied to car engine parts during repairs, but what does this have to do with ovens? In fact, high-temperature silicone sealant for internal combustion engines and furnace applications differ from each other in chemical composition. The familiar red substance used to seal engine parts contains acid. In the open air it begins to evaporate, giving off a strong vinegar smell.
Silicone sealants designed for use with ovens are neutral and practically odorless; due to their elasticity, they are resistant to temperature changes and environmental conditions. The maximum layer thickness depends on the manufacturer and is indicated in the instructions on the packaging. However, due to the low temperature threshold by thermal engineering standards, the scope of application of heat-resistant sealants is limited to the following types of work:
- sealing cracks in brick chimneys on a site located on the street;
- sealing the junction of roofing materials to the chimney pipe to prevent water from flowing in;
- installation or sealing of chimneys made of any materials, including sandwich, working in conjunction with highly efficient boilers (efficiency above 90%). The temperature of the gases in this case does not exceed 150 ºС, this is the normal mode for silicone compounds;
- any work related to filling cracks (not through ones!) on the outside of brick kilns.
High-quality polyurethane-based sealants
Bostik PU 2637 light gray 600 ml
A one-component product designed for sealing various seams. The main advantage of this product is that it can be painted after drying. Used for external and internal work. Maximum seam stability is 70 degrees. Manufacturer – Sweden. When performing repair work, it is important to understand that the maximum seam depth is 4 mm.
Sold at a price of 465 rubles.
Bostik PU 2637 light gray 600 ml
Advantages:
- Efficiency;
- Suitable for working with various materials;
- Durability;
- Price.
Flaws:
- Not found.
Tiamat PU WindShield
A reliable sealant that is suitable for many tasks. A high-quality composition can ensure adhesion to steel, copper, aluminum, ceramics and carbon. In addition, it is used for gluing glass. The maximum operating temperature is 90 degrees, which is an excellent result. Hardening speed – 3.5 mm per day.
Sold at a price: from 600 rubles per 600 ml.
Tiamat PU WindShield
Advantages:
- Excellent adhesion to metal surfaces;
- Heat resistance;
- Good hardening speed;
- Efficiency.
Flaws:
- Not found.
WS PU gray 600 ml
An elastic sealant designed to create a tight seal between ventilation ducts and metal structures. The main element in the composition is polyurethane, which can be painted upon completion of work. Suitable for ensuring high-quality connections and filling cracks with a width of at least 6 mm. Convenient packaging will make it easier to store the product.
The average cost is 406 rubles.
WS PU gray 600 ml
Advantages:
- Designed for filling seams larger than 6 mm;
- Convenient packaging;
- Ready to use;
- Suitable for various materials;
- Elongation at break about 750%
- Heat resistance – 80 degrees.
Flaws:
- Not found.
Top best silicone-based products
GERMENT High temperature
An excellent one-component sealant designed for sealing structures that are constantly exposed to high temperatures. Suitable for use in heating systems, and will also become an indispensable assistant in the repair of cars and internal combustion engines. The product features high-quality adhesion to enamel, metal, wood and glass. Color – red-brown.
Sold at a price of 406 rubles.
GERMENT High temperature
Advantages:
- Price;
- Good adhesion;
- Efficiency;
- Chemical resistance.
Flaws:
- Not found.
OTTOSEAL S17 C65
A good product that can withstand temperatures up to 285 degrees. Does not cause corrosion when used on metal surfaces and guarantees reliable adhesion. Suitable for use in households and car services.
Sold at a price of 1,400 rubles.
OTTOSEAL S17 C65
Advantages:
- Best quality;
- Convenient packaging;
- Efficiency.
Flaws:
- High price.
Kudo KSK-152
A cheap option that is suitable for use in various systems. Of course, compared to the previous model, this product will have significant shortcomings, for example, a short service life. However, efficiency is not lacking, since the sealant is highly resistant to temperatures, where the maximum value is 300 degrees.
Sold at a price of 380 rubles.
Kudo KSK-152
Advantages:
- Low cost;
- Withstands high temperatures;
- Low consumption;
- Wide range of applications.
Flaws:
- Short service life.
Makroflex TA145
One of the best options that can handle any surface. Heat resistance reaches 260 degrees, but can also withstand temperatures up to 315o. Guarantees the user high-quality adhesion to most building materials, which allows increasing the scope of application. The only drawback is that during vulcanization a pungent odor is released, so it is recommended to carry out work with construction masks.
The average cost is 390 rubles.
Makroflex TA145
Advantages:
- Resistance to atmospheric changes;
- Suitable for metal structures;
- Good grip on the surface.
Flaws:
- Strong smell.
Types of sealants for furnace work
A through crack that appears in the furnace body or the wall of the smoke duct leads to depressurization of the combustion chamber or flue. As a result, smoke begins to enter the room, the chimney draft decreases, and the overall efficiency of the stove deteriorates. Of course, the cracks can be covered with clay mortar the old fashioned way, but this will not help for long. It is more convenient and reliable to use high-temperature furnace sealants for this purpose.
Although there are dozens of types of similar compositions offered on the modern market, only 2 of them are suitable for use in furnaces:
- silicone-based (heat-resistant compounds);
- on a silicate basis (heat-resistant compounds).
As you might guess, in both cases modern polymers come to the aid of stove makers. The product is a ready-made paste with various characteristics and colors, sold in tubes. In addition, there are heat-resistant sealants consisting of two components. But working with them is more troublesome; dosage and mixing must be carried out accurately before use, this will affect the quality of the seal and the service life of the seam.
