Coatings based on silicate paints have several unique properties: they have high vapor permeability and dry quickly. The moisture that builds up inside the wall in winter does not destroy brick and plaster. They pass carbon dioxide well and do not delay the hardening of the plaster. The coating does not burn; in addition, it does not emit various harmful substances. Such silicate paints are well applied on surfaces with highly alkaline components (lime plasters). These qualities ensure a long surface life.
The disadvantages of these paints include the impossibility of applying them to old coatings on an organic basis due to the complete lack of adhesion.
Silicate paints are suspensions of fillers and pigments in aqueous solutions of sodium and potassium silicates . Silicates are salts of very weak silicic acid. They are much weaker than coal, therefore, they are easily displaced by interaction with carbon dioxide, which is contained in air. The resulting silica sol rapidly loses water and forms a porous coating that consists of silicon oxide. During the formation of silicic acid and its dehydration, an interaction of the formed coating with particles of pigments, fillers, and an inorganic substrate is observed. Silicic acid and silicates are especially active in interacting with zinc and calcium compounds. Given that calcium hydroxide is the main component of plasters and concrete, the processing of such surfaces with silicate paints leads to the creation of a monolithic layer of a chemically bonded coating.
Silicate paints, or rather their properties, largely depend on the properties of the liquid glass used. The most waterproof high-quality paints can be obtained using potassium glass. There are other silicates, but they are too expensive for the production of paints and varnishes. In order for silicate paints to retain their advantages and to be able to be applied to coatings on an organic basis, then acrylic dispersions are added to their composition, due to which paints are obtained that have high vapor permeability, excellent adhesion to old organic-based coatings and mineral surfaces .
A new type of paint coatings - silicate paints - are now widely used. When aluminum or zinc is added to them, they acquire anti-corrosion properties. This type of coating is used on plastered walls. In addition, they perfectly interact with stone, concrete, ceramic, slate and other surfaces, penetrate well into the structure of the processed surface, but at the same time they have poor hiding power, and therefore an increased consumption of paint is required .
Care must be taken when handling silicate paints. They include up to ten percent of alkali. If paint gets on the skin or eyes, inflammation may occur. Therefore, when working with these paints, it is necessary to protect the eyes. It will not be superfluous to use a respirator. If paint gets into your eyes, rinse them immediately with cold water and wash yourself with soap at the end of work.