Anaerobic sealants are a type of acrylic adhesives. They are suitable for fixing and strengthening threaded connections and demonstrate high technical and operational characteristics. Let's take a closer look at this type of compositions.
What it is?
Anaerobic sealant is a polymer gel used to seal the thread and also provide corrosion protection. It provides absolute sealing of threaded connections, therefore it is used primarily in the military and aerospace sectors. If we talk about domestic use, then this is plumbing work - water, gas and heat supply networks.
The polymer has a liquid consistency, thanks to which it manages to fill all the recesses and spaces of the working base. In conditions of contact with metal surfaces in the absence of air, the gel solidifies, providing a reliable seal. Anaerobic glue is a type of sealant, the main difference of which is the provision of super-strong fixation.
Such a composition has increased strength and is suitable for joints that cannot be further disassembled.
In contact with air, the polymer does not freeze, so excess composition can be easily removed from the surface of parts. From the inside of the pipeline, they will simply be washed off with water. And inside the parts, in the place of the thread, the gel polymerizes, reliably seizing the elements and ensuring their tightness.
The principle of operation is based on a polymerization reaction and can only take place in an anaerobic (airless) space. This process involves several stages. First of all, free radicals are formed between the parts to be bonded. Further, the ions of the metal surfaces start the polymerization process, as a result of which the sealant begins to solidify.
The gel is resistant to vibration and high pressure, high and low temperatures and their abrupt change, aggressive substances.
It can even be used in drinking water taps.
The properties and consistency of the gel are determined by its composition. The basis is acrylic oligomers and monomers. Plasticizers and stabilizers, as well as an initiating system, are responsible for the appearance of certain qualities of the product.
The viscosity and shade of the gel depend on the concentration of the thickeners and pigments included in the composition.
Advantages and disadvantages
Anaerobic sealants have replaced obsolete gaskets and seals. They are not only easier to use, they also provide better fixation of the elements. Thanks to the use of polymer gel, you can refuse to use special keys and carry out work, even without professional skills.
Plumbing anaerobic sealant also has the following benefits:
- wide scope, the ability to perform a huge range of works;
- mechanical stability;
- easy-to-use consistency, which also provides better penetration and distribution of the composition;
- the ability to select the composition of the required viscosity for certain types of work;
- resistance of glue to temperature extremes, wide range of operation (-60 … + 300 ° С);
- vibration resistance of the composition;
- high strength indicators - up to 39 MPa of gas pressure and 58 MPa - of liquid;
- resistance of the gel to the influence of aggressive substances;
- ease of use;
- fast solidification (depending on the type - from 5 to 6 minutes);
- economy of consumption;
- environmental friendliness of the gel;
Of the "minuses", one can single out too strong fixation of elements. Separating them requires preheating the sealed surfaces and tools. Excessive force can break the part. The sealant dries quickly enough, but only on condition that the process takes place at a temperature of at least + 15 ° C.
If the temperature is below the specified, polymerization slows down, additional heating of parts may be required.
Anaerobic sealants are divided into one- and two-component. The former are used in everyday life, the latter are used for the needs of industry and are characterized by higher technical properties.
Depending on the characteristics of strength indicators, the scope of use of sealants is determined.
In this regard, the following varieties are distinguished
- Low strength formulations. Suitable for fixing threaded joints, including those experiencing increased loads.
- Medium strength gels. Scope of application - strengthening joints, performing service work. The latter, as a rule, involve periodic disassembly of the connections and their subsequent reassembly.
- High strength adhesives. Provide strong fixation, after which it is impossible to dismantle the threaded elements.
Depending on the ability to withstand high and low temperatures and the influence of aggressive environments, the compositions can be conditionally divided into the following groups:
- sealants for sealing elements and units of the heating system, the maximum operating temperature is + 120 ° C;
- gels that can withstand the effects of a wide range of aggressive substances with a temperature range of use in the range of -60 … + 140 ° С;
- universal fast-curing compounds, characterized by equally high adhesion to all types of surfaces.
Depending on the consistency, sealants are strong and medium flowing, flowing, difficult to flow and pasty. Finally, the differences relate to the colors of the sealant.
They can be white, red, green, blue and some other shades.
Today, there are many anaerobic sealants of various brands on the construction market.
When choosing a specific composition, you should be guided by the following criteria:
- conformity of the sealant to the material from which the thread is made and its features;
- envisaged temperature conditions for the operation of the composition;
- requirements for the type of strength of joints.
Among the most famous, which have earned positive customer reviews, the following manufacturers should be highlighted.
Loctite. The manufacturer's assortment includes several forms of anaerobic sealants - liquid gels, sealing threads of a similar effect, formulations developed specifically for gas pipes, etc. The products are distinguished by their reliability and durability. The cost depends on the type of gel. For example, for a tube of 50 ml of Loctite 577 universal glue, characterized by a high solidification rate, you will have to pay 1,700-1750 rubles. For an analogue of low viscosity Loctite 542 - 50-100 rubles more
- "Anaterm". The products of this brand are also famous for their high quality, but they are domestic, and therefore have a slightly lower cost. The manufacturer offers several modifications of the composition that are suitable for fastening parts at the time of assembly and for a more durable connection, for eliminating pores and small cracks in a threaded connection. Separately, a line for steam pipelines and means for repairing units and mechanisms should be highlighted. The average price ranges from 2,400 to 2,500 rubles per tube of 200 g.
- "Santechmaster". A worthy representative of Russian-made anaerobic sealants, used for adhesion and strengthening of threaded and flange connections, provides anti-corrosion protection.The glue does not have an unpleasant odor, is easy to apply, tolerates “surges” of pressure and temperature, is resistant to the effects of chemical elements (including gasoline, antifreeze, alcohol), and is suitable for use in extreme conditions. The only inconvenience is the need to apply the composition with your hands. At the same time, prolonged contact of the agent with the skin cannot be called useful. Available in 15 ml tubes. According to the manufacturer, this volume is sufficient to process 30 ½”fittings. The average price is 150 rubles per tube.
- Siseal. Medium strength sealant suitable for use in heating, gas and water systems. Cannot be used in systems characterized by increased oxidation. The color is white, the form of release is tubes of 100 g, the price of one is on average 900-1000 rubles.
- Permatex. Under this brand, gels of increased strength are produced that can withstand extreme vibrations and temperatures and are used for industrial purposes. Suitable for sealing flanges in pumping systems, gearboxes, cylindrical blocks.
- Tangit. The tool is a universal paste for household use. Available in tubes with a brush, volume - 50 mg. The average price per unit of goods is about 550-600 rubles.
- Dirko. High strength sealant, thanks to which it has found application in industrial purposes, as well as in auto repair. One of the advantages of the composition is the ability to apply the gel to moving parts without interrupting the work process. Suitable for use in extreme conditions, it is available in several modifications. For domestic use, you can choose a heat-resistant universal sealant, all other varieties are more suitable for industrial purposes.
- "Catch No. 3". It is an anaerobic adhesive for household use. Due to the uniqueness of its composition, it can be used to seal systems and assemblies of water and gas pipelines, heating pipes. The composition provides reliable protection against corrosion, is suitable for the elimination of pores and small cracks.
Among other brands of sealants that deserve attention, it is worth noting the domestic "Unigerm" and imported compositions Abro, Quickseal, Uni-Fitt.
Typically, the glue is sold in flat-necked tubes. This allows even small threaded connections to extract the correct amount of sealant. With the same neck, if necessary, it is distributed over the surface. Some manufacturers attach a small brush to the tube, which further simplifies the process of using the composition.
The procedure for using the gel looks like this:
- shake the package before use;
- open the tube and apply glue at the joints;
- fix the parts and hold them in this position for 20-30 seconds;
- remove any excess sealant that has come out by wiping the surface with a clean cloth.
In plumbing, as, indeed, in other areas, it is important to apply the sealant from the inside and outside, ensuring an even distribution of the composition over the entire working base. This is the only way to guarantee a permanent and complete seal. To obtain a better fastening, work should be carried out on a dry and degreased surface. For these purposes, a solvent can be used, which should be allowed to dry completely.
The curing time of the sealant is usually 15 minutes. For formulations from different manufacturers, the polymerization time may vary (from 5 minutes to an hour, depending on the brand and purpose of the gel). The optimum temperature for work is + 15 … + 25 ° С.
The system can be used in 3-4 hours, the final polymerization takes place a day after application.
The sealant demonstrates its maximum properties on pipe joints with a diameter of no more than 8 cm. Better adhesion is demonstrated when applied to roughened rather than smooth and polished surfaces. It is possible to apply over contaminated surfaces, but if possible it is still better to clean and degrease them.
If it becomes necessary to separate the parts glued with sealant, you should prepare special keys and a construction hair dryer. The latter should be turned on and the sealant layer should be warmed up. After that, it will begin to crumble. When the threaded connection is freed from the bulk of the glue, the parts are disconnected using a plumbing wrench. If further use of the parts is expected and their fixation with an anaerobic sealant, the old layer of the composition can not be completely removed, but a new one can be applied on top of it.
You can learn how to use anaerobic sealants in the video below.