Sodium silicate, known as water glass, whose use in construction, as in many other areas, has become the norm, is a chemical compound of sodium oxide (Na2O) and silicon dioxide (SiO2). The result is a glassy substance with the very useful property of solubility in water, due to which the material can be in the form of both solid crystals (or powder) and brownish syrupy liquid.
Crystals born in fire
The production technology of the material is a process of baking soda ash and quartz sand in a furnace at a temperature of 1000 to 1400°C. As a result, carbon dioxide is released and sodium silicate is formed (Na2SiO3).
Possible forms and types of sodium silicate
To the end user it isthe silicate compound can be realized both in the original form of large glass crystals and in the form of a crushed powder. To obtain liquid sodium glass, reactors are used, where solid silicate particles are dissolved under pressure in hot water. After cooling, the finished product, which has the form of a viscous liquid, is packaged in containers of various sizes. Liquid sodium silicate can also be obtained by directly dissolving quartz sand under pressure in a heated aqueous solution of caustic soda.
With any production technology, the finished solution will be the more viscous, the higher the concentration of its constituent elements. High-viscosity liquid glass is used to form glass granules obtained by spraying and drying a hot solution. The resulting beads are packed and shipped in the same way as the solid form of sodium silicate, but (unlike anhydrous formulations) they dissolve several times faster, greatly simplifying the process of using the material.
Fire, water and water pipes
Let's find out what makes this product so special. High alkalinity, corrosion resistance, excellent binding capacity combined with natural (read: safe) components are the main properties of liquid glass, its use is fully based on the use of these unique qualities. Products and surfaces treated with sodium silicate acquire moisture resistance, heat resistance, protection against fungus and bacteria, and compositions based on it are used for sealing and protection againstcorrosion of metal water connections.
Liquid armor
The use of liquid glass in the repair and construction work is very effective and expedient for a number of reasons. Concrete, as the main building material, is most susceptible to all kinds of aggressive influences, both operational and natural, therefore its protection and strengthening is almost the main “headache” of any homeowner. It is for the solution of this difficult task that sodium liquid glass can serve. Its use as an additive in a concrete mortar or plaster mixture has a complex effect on the consumer characteristics of a building material:
- Due to high adhesion, the surface strength of concrete increases, reducing the risk of microcracks.
- The refractoriness of sodium silicate gives the structure high heat resistance, which allows the successful use of materials and solutions based on it for the construction of stoves and fireplaces.
- As a result of reducing the porosity of the concrete solution, the corrosion resistance of all elements containing liquid glass from moisture, temperature extremes and other natural influences increases many times over.
- Concrete becomes bactericidal.
When choosing improving additives, these factors, combined with the low cost of the material, make liquid glass attractive.
For concrete, the instructions for use from the classic composition (3 parts of sand, 1 - cement) differ onlythe fact that a certain amount of liquid sodium sulfate is added to the finished sand-cement mortar (approximately 20% of the volume of the dry mixture).
A fly in the ointment in a barrel of viscous brownish substance
The only serious disadvantage of using such an additive is a significant reduction in the setting time of concrete. Therefore, this technology is used in small areas (for example, for laying refractory bricks during the construction of stoves and fireplaces) or the volume of the batch is calculated so that the concrete does not have time to set. For this reason, many builders are more likely to use another option for using liquid sodium silicate.
"Raincoat" for concrete
This method is based on the characteristics of the material to form a monolithic film after drying. This property (together with the hydrophobicity and high adhesion of the composition) determined its active use in protecting buildings and structural elements from moisture by direct application to the treated surface, that is, priming.
Why, among the many ways and types of waterproofing, it is worth paying attention to liquid glass? Application on concrete sets it apart from its competitors in a number of ways:
- Ease and speed of application. To work, it is enough to have a wide paint brush, spatula or spray gun.
- High adhesion. After application, the material does not peel off, firmly bonding to the base.
- Highfluidity. Qualitatively covers all depressions and microcracks.
- Antiseptic treatment. The surface becomes invulnerable to fungus and mold.
- High environmental friendliness of the binding material. Allows the use of liquid glass inside residential premises. Being non-toxic and one of the most common chemical compounds in nature, sodium silicate has no harmful effects on the environment. It eventually returns to its natural state as silica (SiO2) and soluble sodium compounds.
- In addition to improving the moisture-proof properties, as a result of processing, the surface layer is strengthened, which increases the wear resistance of the base and serves as protection for the decorative coating.
- Economical use of material.
- Availability and economical cost.
Clinging to everyone, does not allow himself to be pestered
Before processing, it is necessary to clean the surface well from debris and dust, and plaster large cracks and chips. With a single application, the concrete screed is reliably impregnated with liquid glass to a depth of two to three millimeters. Re-coating with the composition is carried out only after the previous layer has solidified. After several treatments, it is possible to achieve impregnation of the base material up to twenty millimeters.
The disadvantage (or features of this coating) is the impossibility of painting or pasting after application. Surface smoothness, as well as highthe temperature and chemical stability of sodium silicate prevent the diffusion of third-party solvents into its internal structure.
Ideal proportions depend on the desired result
For construction work, there are several ways to use liquid glass. Instructions for use for each of them has its own characteristics:
- The solution for waterproofing consists of one part of liquid glass and two parts of water. With this proportion, it takes about 300 ml of the resulting composition to cover 1m2.
- The primer is used for preliminary preparation before wallpapering or painting. In this case, cement, pre-mixed with water, is mixed with liquid glass in equal proportions.
- In the manufacture of waterproofing plaster, a sand-cement mixture is prepared with a silicate additive in equal proportions of all ingredients (1 x 1 x 1).
- An antiseptic solution is created by mixing water and liquid glass in equal proportions.
Unusual possibilities of unusual glass
Sodium silicate's alkaline properties of removing fats and oils, neutralizing acids, and breaking down starches and proteins make it ideal for use in one of the most common consumer products: washing machine and dishwasher detergents.
Small amounts of water glass are used in wastewater treatment, where it adsorbs metal ions and helps in the formation of loose particles,filtering water from unwanted suspended materials.
A solid version of sodium silicate is widely used to make silica gel, a commonly used drying agent.
This is an excellent adhesive for glass or porcelain.
The traditional use of water glass is as a preservative for eggs, which can be stored in a viscous silicate solution for several months under cool conditions.
Liquid sodium silicate is added to a car radiator to seal the engine head.
There are many variants of silicate compounds in which sodium is replaced by other alkali metals, such as potassium or lithium. Each is suitable for its own needs, but they all share the same property of being a glassy solid that dissolves in water to form an alkaline solution.
