How do sealing compounds for autonomous heating circuits work? What are they? What is the best radiator sealant to use and is it possible to replace it with something? In this article we will try to answer the above questions.
What it is
Liquid sealant for heating radiators - common name for water-soluble compositions capable of forming strong clots upon contact with air and resistant to temperatures typical for autonomous heating circuits.
It’s interesting: the principle of their action is very similar to the work of one of the types of blood cells - platelets.
If the seal is broken, the particles of the aqueous emulsion of the sealant begin to gradually form a blood clot, which ultimately stops the leak.
Along with liquid sealing compounds threaded connections In heating systems, more conventional viscous sealants are used:
- polyurethane - with excellent adhesion to metals, elastic and moderately resistant to high temperatures;
- silicone - the most durable, able to withstand heat up to 1000 degrees or more. Among other things, silicone-based sealants are used for boiler heat exchanger cracks.
Please note: when sealing, it is advisable to use silicone sealants with a neutral base, without acetic acid.
Otherwise, the acidic environment will dramatically accelerate the corrosion of steel.
Areas and order of application
Viscous sealants
Everything is simple here: they can only be used for sealing threaded connections. Applying sealant, for example, to a radiator gasket when connecting sections is also practiced (mainly by beginners), but does not give any noticeable effect.
How to properly use silicone sealant with your own hands:
- Apply a little compound to the surface of the external thread.
- We wind a strand of plumbing flax around it along the turns.
- Apply another thin layer of sealant on top of the tightly laid flax.
When assembling the connection polymer composition evenly impregnates flax and subsequently reliably protects it from rotting and fading at high temperatures.
Liquid sealants
They are used to eliminate those leaks that are difficult to eliminate with more traditional means:
- For leaks along the longitudinal seams of electric-welded pipes or conventional welding seams.
- In case of leaks at the connection of a metal-polymer pipe with a fitting embedded in a wall or floor.
- In case of the already mentioned boiler heat exchanger leaks.
- For intersectional radiator leaks various types in conditions of difficult dismantling of heating devices.
A high-quality polymerizing sealant for radiators (for example, German BCG) is more than expensive: the price of a liter package is 9-10 thousand rubles.
- The leak is relatively small. No sealant will fill a fistula the size of a ten-kopeck coin.
- It is impossible or very difficult to localize and eliminate using more conventional means. For example, if there is an intersectional radiator leak, it will be much cheaper to simply replace it with a new one.
How to use radiator sealant if all of the above is relevant to you? First, determine what kind of composition you need. The same BCG offers the buyer the following varieties:
The photo shows the most popular BCG24.
It’s curious: the composition of all BCG sealants is described by the manufacturer in very general terms - as a mixture of silicates, cellulose and special additives, the full list of which is not disclosed.
Then the approximate amount of coolant is estimated.
In a balanced system, it is approximately equal to 13 liters per kilowatt of boiler power; the volume can be determined more accurately by draining water or antifreeze into any measuring cup.
- All filters are removed or cut off by taps. All throttling and shut-off valves opens completely.
- A pressure testing pump is connected to the heating circuit. To connect, you can use any control valve or unscrewed Mayevsky tap on one of the first radiators along the coolant flow.
The heating system starts and warms up to 60C at a pressure of at least 1 kgf/cm2. Everything is ready to use our composition.
How to pour sealant into the radiator after these procedures?
Here are the instructions:
- Through any vent we pour 8-10 liters of hot coolant into two different buckets.
- After stirring the sealant, add it to one of the buckets. Mix the solution again.
- We pump it into the heating system. Then we pump the coolant there from the second bucket. This is necessary to flush the pump of sealant.
- We bleed the air. If it remains in the circuit, it can provoke the formation of clots in places where they are not needed.
- Having raised the pressure to 1.5 kgf/cm2, we leave the system in circulation at a coolant temperature of about 60C. To eliminate the leak, the sealant must be in the system for at least a week.
Useful little things
How to flush the radiator after sealant to avoid clogging of the throttling valves? Regular hot water. However, it is quite possible to do without flushing: it is enough to open the throttles a few times and set them back to working position.
Can anything replace liquid sealant? Helps in open gravity systems old-fashioned method: a couple of packs are poured into the expansion tank mustard powder. The leaks stop within a few hours.
Conclusion
We hope that our guide to handling liquid sealants will help the reader in deciding everyday problems. The video in this article, as usual, will offer additional information to his attention. Good luck!
Sealant for home heating systems, necessary thing to eliminate small cracks and eliminate leaks. You can buy it at any hardware store, and the variety of types will allow you to choose the composition that suits you. Let's figure out how they differ and how to apply them.
The sealant is a self-consolidating solution that can be used to eliminate liquid leaks in pipes and joints. Different kinds can be used both outside and inside water systems. After application, upon contact with air, the sealant quickly hardens, which allows you to resume operation of the system almost immediately. In what cases is it rational to use sealant inside the water supply:
- there is no way to eliminate the leak using a clamp or soldering;
- the location of the leak is not visible;
- pipes are in an inaccessible place;
- if there is a heated floor.
In all such situations, the use of sealant allows you to eliminate the problem without compromising the integrity of the walls and floors.
Sealant for heating systems is used both during pipeline installation and during repair or dismantling, for example, when batteries are disassembled into separate sections. Taking into account the conditions in which the sealing composition will work, the following requirements are put forward for it:
- heat resistance;
- resistance to deformation;
- moisture resistance;
- resistance to temperature changes.
Based on where the sealant will be used, choose its type.
Types of sealants for heating systems
Various manufacturers offer big choice sealants that differ in their chemical composition and purpose. They are conventionally divided into the following groups:
- silicone;
- polyurethane;
- liquid polymer.
Each of them has its own purpose and properties.
Silicone sealants
Silicone is the most popular. With its help you can seal any joints and eliminate leaks. Withstands temperature changes ranging from 30 to 60 degrees. The composition has all the necessary qualities to perform high-quality work:
- strength;
- penetrates into the most inaccessible places;
- elastic.
When purchasing, pay attention to the composition of the silicone sealant. The acid contained in some types can cause metal corrosion.
Polyurethane
They belong to the group of oligomers. In addition to polyurethane compounds, there are also polysulfide compounds. Both types are widely used in construction. To seal heating systems, carefully study the composition, since not all materials are suitable for these purposes.
A distinctive feature of polyurethane sealants is durability, resistance to aggressive environments and mechanical stress. In addition, material consumption is very economical.
Polyurethane sealants come in one- and two-component types. The former are cheaper, but take longer to harden. They have good elasticity, adhesion to metal, resistance to high temperatures and corrosion. However, despite the many positive qualities, polyurethane sealants are not as in demand for household purposes as silicone ones due to their high price.
Liquid-type sealants are used where there is no easy access to the leak or it is simply not visible. Operating principle of polymer liquid material is based on the fact that it is poured into the system along with the coolant. In the section of the pipeline where there is a leak, the composition, interacting with air, begins to polymerize. Thus, thickening, it seals the cracks.
The following types of liquid sealants are distinguished:
- for systems installed in water;
- for heating systems running on antifreeze;
- for troubleshooting metal surfaces;
- for plastic pipes.
This variety allows you to choose a sealant to suit your individual needs, so carefully read the instructions before purchasing.
How to choose a sealant to eliminate leaks in the heating system
Heating systems differ from other communications in changing operating temperature and possible deformations. To eliminate leaks in CO, certain compounds are needed that can withstand such operating conditions. The most popular types of silicone paste sealants are:
- drying - after complete drying, the material shrinks, therefore, if the drying technology is not followed, cracks and smudges may appear;
- non-drying - used to eliminate small leaks and seal threaded connections. Their disadvantage is that with excess pressure, the sealant can be squeezed out of the joints.
Silicone and thiokol sealants are suitable for sealing threaded joints because they do not deform or clog threads after curing.
Suitable for household radiators acrylic compositions. They are resistant to temperature changes, mechanical stress and aggressive environments. Once in a crack or joint where there is no air, the sealant quickly thickens, forming a plastic mass. This makes the installation process easier, but dismantling in the future will be difficult.
In addition to the sealants described above, there are special compounds, operating at ultra-high temperatures. For example, in fireplaces, chimneys or stoves.
The manufacturer must indicate for what specific case a particular type of sealing material is used.
Technology and methods of using sealant for heating systems
Using sealant for internal or external works requires preliminary preparation. The composition corresponding to the type of system is selected. The consumption of liquid sealant for the home heating system is calculated based on the volume of water. For every 60-80 liters, 1 liter of sealant is required.
It is also necessary to prepare the system itself. All air is removed from it, filters are dismantled, and all taps are opened. A pump is installed on the first radiator, with the help of which the remaining air is eliminated and the pipe is heated to 50-60 degrees.
External treatment
Measures to seal joints and threaded connections are carried out in a certain order.
- There is a damaged area.
- All liquid is drained from the system.
- The damaged area is cleaned of dust, old sealant (if present at the joint), and degreased.
- The sealant is applied according to the instructions.
Only after the insulating composition has completely hardened is the coolant again poured into the system.
Internal processing
For interior work liquid sealant is used for the heating system. After preparation with air bleeding and removal of filters, all radiators are drained hot water in the amount required by the recipe. To do this, you need to stock up on a container of the appropriate size.
Liquid sealant for eliminating leaks in the heating system is diluted with water. In this case, a couple of liters of coolant are left in pure form for subsequent rinsing. The Mayevsky tap is removed from the radiator, and a pump is connected instead. With its help, the system is filled with liquid with sealant diluted in it. The pressure increases to 1.5 atmospheres. In this position, the system should work for approximately 6-8 hours until the entire composition hardens.
Afterwards, the coolant is drained again, but first you need to make sure that all problems have been fixed. Water without sealant is poured into the heating system, drained and filled again. Thus, the radiator is flushed from residual material.
After 3-4 days, the presence of cracks and leaks is checked again. If necessary, the sealing process is repeated.
It should be remembered that this option for eliminating holes in the heating system of a private house only works if the water leak does not exceed 30 liters per day. If this indicator increases, it is necessary major renovation with a complete replacement of the pipeline section. If you are not a master, then for these purposes it is better to contact a specialist, otherwise the problem may only get worse.
Working with sealant will not cause difficulties if you carry out all manipulations in accordance with the instructions.
Content
Important condition efficient and safe operation of heating units - no cracks in the masonry of stoves and fireplaces, tightness metal chimneys heating boilers. Heat-resistant sealant helps increase the reliability of structures if used during installation, and also serves as a repair compound, allowing you to seal cracks and gaps at joints.
A variety of high temperature and fireproof sealants
Why is tightness needed?
Brick stoves and fireplaces are prone to cracking due to uneven heating of the masonry, especially if it is not protected by a layer of plaster or tiles. If the cracks in the body of the heating unit turn out to be through, this entails unpleasant consequences:
- fuel is consumed faster because it burns under conditions of additional oxygen;
- soot may enter the room and settle on the walls and ceiling;
- Combustion products enter the room first carbon dioxide, which can cause poisoning.
Cracks in brick chimney, cracks in the metal pipe for removing combustion products reduce draft, and the heating unit cannot operate in optimal mode. This leads to the fact that the fuel burns at more low temperatures, forming a lot of ash, on inside more soot settles in the chimney.
A large amount of soot and leaks in the chimney - dangerous combination. The intake of air causes the soot to ignite, and it burns at temperatures above 1500°C, causing the chimney to heat up. An insufficiently thick layer of thermal insulation around the pipe will not save wooden structures from charring, there is a serious risk of fire.
For gas boilers, a leak in the chimney results in gusts of wind extinguishing the burner. To avoid the need to regularly check the operation of the boiler, the gaps in the chimney duct are sealed with a special sealant.
Modern materials for sealing heating units
Sealant for fireplaces and stoves - polymer material, similar in structure to paste. It can be one-component or two-component. One-component adhesive sealant is usually packaged in tubes for mounting gun, this is the most convenient option for work. The two-component material is used only by professionals, since errors are not allowed when mixing the composition - you need skill to properly prepare the working material.
High Temperature Oven Sealant For installation and repair of stoves, fireplaces and heating boilers, special high-temperature compositions, according to the scope of application and material of manufacture, they are divided into two types:
- Heat-resistant sealants. Designed for areas where heating does not exceed 350°C. Suitable for sealing cracks and seams in the external masonry of stoves and fireplaces (but not in places of contact with casting!), for sealing brick chimneys and sandwich pipes. For a single metal chimney pipe, a heat-resistant compound can only be used if it is a pyrolysis or condensing boiler- in this case, the temperature of the removed gases does not exceed 150°C.
- Heat-resistant and fire-resistant sealants. The high-temperature sealant is designed for use inside the combustion chamber, in places where the masonry comes into contact with the casting. It is used for sealing any chimneys, including the junction with the outlet pipe of the stove. Fire-resistant sealant is a type of heat-resistant sealant that can withstand direct contact with flames. Not all heat-resistant compounds are fire-resistant (fireproof); when purchasing, pay attention to the labels on the packaging.
It is necessary to select installation and repair compounds for boilers and furnaces taking into account the temperature conditions of the area where they will be used. Based on their composition, sealants are divided into silicone and silicate.
Heat-resistant compounds
Thermal sealant is a silicone-based material. Due to the introduction of iron oxide into the composition, the material has a reddish-brown tint. Manufacturers offer sealing silicone compounds with different temperature thresholds; specific data are indicated on the packaging.
Note! High-temperature silicone sealant, which is produced in ordinary tubes and is actively used by motorists, cannot be used for repairing stoves and chimneys. This material is acid based and is not compatible with cement mortar and metals prone to corrosion. The acid released during hardening reacts with the materials to form salts or oxides. The formed brittle layer is destroyed and the seam loses its tightness.
Neutral heat-resistant silicone sealant is compatible with all materials; when dry, it releases alcohols and water.
High temperature silicone sealant Its advantages include:
- resistance to UV radiation - the material is suitable for sealing cracks on the outer part of the chimney, joints of roof penetrations;
- hydrophobicity - due to water resistance, it is used to seal the junction of penetrations to the roof waterproofing;
- high adhesion to materials of different structures, including brick, cement, metal;
- maintaining elasticity after drying - the tightness of the connection will not be compromised by slight vibrations.
Attention! High-temperature silicone is universal in use - it is successfully used to seal threaded connections when installing heating circuits.
Working with heat-resistant composition
Heat-resistant sealant for stoves and fireplaces is applied to a clean, degreased surface. If the material was moistened during cleaning, you should wait for it to dry completely. Metal surface It is recommended to sand it so that the applied composition holds more firmly.
Preparing the oven before applying sealant Silicone paste requires access to air for polymerization. Therefore, the thickness of the seam should not exceed the values specified by the manufacturer.
The curing speed is a parameter designed for the use of a silicone composition at a temperature of about 23 degrees and a humidity of about 50%. IN real conditions The polymerization rate may be higher or lower than specified. At low temperatures, the paste hardens more slowly.
Due to the elasticity of the material, it cannot be painted - dried paint falls off. Silicone pastes for stoves and chimneys are red or Brown color. Transparent materials Cannot be used on silicone base!
Heat-resistant compounds
Heat-resistant sealant is a silicate-based sealing paste. In normal operating mode, such material can withstand heating up to 1300 degrees, and with short-term exposure - up to 1600 degrees. Fireproof sealant is a type of heat-resistant sealant that is not afraid of contact with fire.
Heat-resistant sealant for stoves and fireplaces Silicate pastes are intended for installation of fireclay masonry in furnace fireboxes, for treating casting installation sites, for repairing heating boilers (eliminating leaks). The same composition is suitable for installation of metal single-walled chimneys and sandwiches - they are used to glue the joints of modules and seal fistulas.
Working with heat-resistant composition
The heat-resistant composition has high adhesion to brick and cement. It adheres well to metal if the surface is pre-treated with an abrasive material and degreased. Before applying the silicate composition, brick or other porous material is dusted, degreased and always moistened with water - this is the main difference between the technology and the use of silicone heat-resistant material.
Repair and installation work using silicate paste is allowed only at positive temperatures (from +5 to +40 degrees). But at temperatures below +20 degrees the composition dries out longer than the deadline specified by the manufacturer. Excess composition is immediately removed with a damp cloth so that you do not have to scrape the dried paste from the surface of the masonry. The thickness of the seam must correspond to the parameters specified in the instructions for use, otherwise the material will not gain the necessary strength and will crack.
Filling the seam between bricks with heat-resistant sealant Heat-resistant sealant for furnace masonry is inelastic, so it cannot be used in places where the connection is subject to deformation and vibration loads. Under such influence, the dried composition will crumble. At the same time, the inelasticity of the material allows it to be painted in any chosen color. The paste itself can be gray or black. When working with it you need to use protective gloves, since if it comes into contact with the skin, the sealant can cause a chemical burn.
The silicate composition makes it possible to install a collapsible chimney - metal pipes“sit” on the oven sealant, while only the joint itself is processed. If you need to disassemble the structure, just loosen the connection - the dried paste will crumble.
Note! When using oven sealant, it is important to follow the manufacturer's directions. Some silicate compositions require drying for several hours, changing the intensity of fuel combustion. The drying mode is described in detail on the packaging.
Silicate paste is used to fill the joints of masonry stoves and fireplaces. In order not to spoil the appearance of the stove without cladding, carefully cover the bricks with masking tape before opening the seams. The expenditure of effort and time will pay off aesthetically appearance masonry
Popular brands
The market offers sealing materials for stoves, fireplaces and chimneys. They are selected according to their composition and temperature conditions operation. It is recommended to use products from reputable manufacturers.
Soudal
Soudal (Saudal) is a Belgian company that specializes in the production of sealing compounds. Soudal sealant for stoves and fireplaces is the Soudal series.
Sealant for Soudal ovens Calofer, heat-resistant compounds in black. Materials based on sodium silicate do not emit toxic substances when heated and can be painted. Suitable for sealing cast iron elements of boiler units. One of the advantages of Belgian products is their resistance to cracking and crumbling.
Penosil
An Estonian company produces silicate paste for Penosil +1500 ovens. The material has high heat resistance and is black in color. Foam is cheaper than the products of the famous Belgian manufacturer, but is not inferior in quality. This makes Estonian sealant widely in demand among professionals and home craftsmen. The company's product line also includes the silicone sealing compound Penosil Hight Temp, suitable for use for moving joints due to its elasticity.
Oven sealant Penosil Premium Tytan
Under this brand, sealing compounds are produced by Selena Group, a group of Polish manufacturers of professional materials for construction and finishing. The sealing paste contains fiberglass, which provides the sealed seams with increased gas tightness. The material is designed to be heated to high temperatures (1250 degrees), which makes it suitable for sealing seams and cracks in fireplace and stove masonry, and for installing chimneys. Products of the Tytan brand, as well as sealants with similar properties, which are produced under the Baumaster brand, belong to the average price category. In terms of price and quality ratio it is best option for a wide range of consumers.
Silicate sealant for fireplaces Tytan Macroflex
A well-known Estonian manufacturer of sealing materials supplies the market with fire-resistant silicate composition Makroflex HA147. It can withstand short-term heating up to high temperature+1500 degrees and exposure to open flame. The advantages of the paste of inorganic materials include adhesion to most materials used in construction and the absence of shrinkage upon drying and under the influence of temperature fluctuations.
Fireproof silicate sealant Makroflex Krass
The Russian manufacturer offers the refractory composition “Krass fireplaces and stoves”. Using this material, fireclay masonry and fireproof masonry can be installed in the furnace firebox. The composition can withstand sudden increases in temperature, is not afraid of open fire, and is suitable for repairs brick kilns and fireplaces, as well as heating boilers. This is a non-shrinking material made on the basis liquid glass. Thanks to its paste-like consistency, it is easy to apply.
High-temperature silicate sealant Krass Therefore
Sealing heating units requires the use of highly specialized materials, each of which has its own subtleties of application. It is important to carefully compare characteristics when choosing formulations, even those related to the same application. They may differ in requirements for drying conditions during installation and operational parameters.
Liquid sealant in a heating system is a self-sealing solution that blocks water leakage at joints and joints of parts. Varieties of solution are used both outside and inside water systems to eliminate leaks. The sealant thickens when it comes into contact with air, which enters the system in places where there are leaks.
Reasons for using liquid sealant inside a pipeline:
- The location of the leak cannot be detected;
- There is no way to eliminate the leak by soldering or using a clamp;
- For hidden installation of heating pipes;
- If there is a heated floor.
Advice! In cases where specific place leaks cannot be detected, before using liquid sealant you should make sure that the expansion tank is working correctly. A malfunction of the membrane of the latter causes a decrease in pressure in the heating system.
Liquid sealants can be classified according to their composition:
- Acrylic. Unresistant to temperature changes;
- Polyurethane. They are plastic, have good adhesion to metals, are not afraid of rust and temperature changes;
- Silicone. They do not lose elasticity and water resistance in heat and cold, are durable and versatile.
Fact! Silicone sealant, which includes acetic acid, not suitable for working with metal parts. The acid will cause a rapid corrosion process.
Sealing of threaded connections
H2_2Anaerobic sealants
A separate group is represented by anaerobic sealant. Resistance to temperature fluctuations, mechanical stress, and good leak neutralization made it possible to use an anaerobic solution even in rocket science. In heating systems, the main advantage is the substance’s resistance to compounds containing acid and alkali. Due to this property, the anaerobic sealant in the system does not interfere with cleaning chemical compounds and the use of various coolants.
In the liquid state, an anaerobic solution exists only in the presence of air. Finding itself in a closed space between the parts, it easily fills everything remaining free space and hardens quickly. The latter quality gives reliable threaded fixation and eliminates the need for great physical effort when screwing parts.
Important! The rigid adhesion created by the anaerobic solution is a serious obstacle when dismantling heating structures. Disassembling the clamps will require good warming up, as well as the use of additional tools.
Preparatory activities before filling the sealant
Before purchasing, you need to decide on the choice of sealant. The type of solution depends on the type of heating boiler and the type of coolant. Not all boilers are suitable for the same liquid sealant. Errors in choosing a sealant and improper use lead to clogging of pipe connections.
Concentration of binder in water heating system important for stopping leaks. It depends on the volume of coolant and the amount of water loss per day; up to 80 liters of total water, 1 liter of sealant is used. The volume calculation is derived from the product of the footage of all heating pipes and their diameter. The sum of the volumes of all boilers and batteries is added to the result. These values are indicated in technical specifications, you can clarify them by reading the device passport.
Advice! There is a simpler, but more time-consuming way to find out the amount of water in the system - pour the drained liquid into containers with a known volume (tanks, buckets).
Setting up the system for pouring
Air is completely removed from the pipelines. Its presence will cause a reaction and the formation of unwanted sealant clumps outside the leak areas.
All heating system valves are opened to allow free circulation and penetration of sealant into all work areas. At the first radiator along the coolant path, the Mayevsky valve is removed and a pump is installed in its place. The running system warms up to 60 degrees for about an hour. The pressure should reach 1 bar.
Before starting work, all filters must be neutralized. They are dismantled or covered. Contact with the sealing solution will clog and damage the filter.
Sealant pouring process
A bucket of hot coolant is poured into a pre-prepared container. Another half bucket is taken separately for subsequent washing of the container, in order to get all the components into the heating system. The sealing compound is shaken and added to the bucket of drained liquid. The solution should not be in contact with open air, therefore it is immediately pumped into the system. The procedure for removing air from the pipes is repeated.
To distribute the sealing composition throughout the heating fluid, temperatures up to 60 °C and pressure up to 1.5 bar are maintained for several hours. The seal is created by polymerizing the sealant. This process takes 3–4 days of continuous operation of the heating system. On the fifth day, the pressure and leaks are checked.