To protect surfaces from negative influences, including atmospheric, today polyurethane enamel is widely used, which is offered for sale in a wide range. This mixture is a variety of polymers with protective properties. If we compare this composition with other paints, then no other option can compare with polyurethane enamel. Quite often, this composition is used as a protective coating, since the film has a high margin of safety.
Classification of polyurethane enamels
Polyurethane mixtures are divided by the material to be coated, as well as by type of application and composition. You can use for application a brush or a special aerosol spray. The scope of use of polyurethane enamel is quite wide, different types can be applied to stone, wood or metal. Before using the polyurethane mixture, the wood does not need to be primed, it should only be well dried.
Specifications
Unicomponent polyurethane enamel is a composition that is made from polyurethane, pigment and solvent. Among the main characteristics of this mixture should be highlighted:
- wear resistance;
- elasticity;
- harmless after evaporation of the solvent;
- chemical stability.
Polyurethane compounds perfectly adhere to the most difficult surfaces.
Varieties of polyurethane enamels
Polyurethane enamel may be water dispersible. Among the advantages are harmlessness at the staining stage and the possibility of dilution with ordinary water. Hydrophobic surfaces with such enamels are not recommended. This should include concrete, stainless steel and plastic.
Polyurethane is represented by a unique chemical modification, which allows the composition to be stored in the form of an aqueous non-hardening dispersion. This allows you to get a durable wear-resistant coating. If it is necessary to paint the floor in the production room, it is recommended to give preference to a composition with organic solvents.
Organic solvent based polyurethane enamel
Polyurethane enamel can be made on the basis of organic solvents, for example, xylene or toluene. For dilution, it is better to use numbered solvents that are recommended by the manufacturer. After gaining strength, which takes two days, such a coating acquires the qualities called the main advantages: wear resistance, water resistance, resistance to aggressive environments.
Polyurethane enamel paints are still alkyd-urethane, they are used to create an elastic and durable coating that cures slowly and also has a mild odor when stained. The price of such mixtures is significantly lower compared to single-component urethane enamels.
Description of two-component polyurethane enamels
Two-component polyurethane enamel consists of a hardener and enamel, the first of which is added before use. The mixture remains viable for 3 hours, and drying lasts 6 hours. The cost of this material is high, as is the strength of the coating. Such polyurethane enamel for metal can be used for metal structures that will be loaded in production conditions and operated in hot shops with an aggressive atmosphere.
The upper limit of the working temperature of this mixture is +80 ° C and can reach 100 ° C. If there is a need to cover the structure, which will be operated in fire hazardous conditions, then special compositions should be purchased. For example, the paint on the metal "Polystyle" when exposed to temperature will form a carbon foam, which reliably insulates and resists the flame for up to 1.5 hours.
The use of polyurethane enamel "Elacor-PU"
If you need polyurethane primer-enamel, pay attention to "Elacor-PU", the cost of which per kilogram is 275 rubles. This composition should be used under certain conditions, which are expressed in the absence of capillary rise of water from below. It is also important to have a waterproofing base. Residual surface moisture should not exceed 5%. Before applying the composition, the surface gets rid of oily areas. If we are talking about a concrete base, then it should be sanded using a special machine to remove the remnants of old paint, dirt and cement milk.
Before using polyurethane enamel for concrete, the surface must be dusted with an industrial vacuum cleaner, and then coated with a primer from the same manufacturer. Before use, the mixture is well mixed, and it must be applied with a polyamide roller in 4 layers. The minimum number of layers is 2, the final number will depend on the task being pursued. Between layers it is necessary to wait about 4-8 hours.
The use of enamel for concrete "Elacor-PU Enamel-60"
This enamel is a one-component color moisture-curing semi-gloss mixture, the main advantage of which is the possibility of application at low temperatures. After polymerization, a wear-resistant solid plastic polymer is formed on the surface, which will be distinguished by chemical resistance.
Preparation consists in cleaning and priming the surface, which is then coated with enamel at a temperature of from -30 to +25 ° C. The temperature of the material itself can vary from +10 to +25 ° C. It is also important to consider the relative humidity, it should not exceed 80%. Before application, the composition is mixed until a uniform color and consistency. To do this, you can use a paint mixer, which is set to revolutions in the range from 400 to 600 per minute.
For work, you can use rollers or brushes that are resistant to solvents. Airless spray technology can be applied. On one layer, the area of which is a square meter, it will take about 150 g of enamel. The final result will depend on the smoothness of the surface. Layered drying lasts the same amount of time as in the above embodiment.
Conclusion
If you decide to use a two-component polyurethane composition, you should take into account that its application is not carried out on wet surfaces. This requirement is due to the fact that the hardener will react with the liquid by the release of carbon dioxide, which contributes to the foaming of the surface.