Area and conditions of paint application
Polyurethane enamels are used when performing external work. This makes it possible to increase the stability of the structure of some rocks, if initially it cannot boast of stability. The varnish covers the stone with a thin protective film, so moisture no longer penetrates inside.
The place of application of polyurethane paints is also different. The external walls of the house allow the use of conventional types of compounds. Two-component options will be needed for those who seek to create unusual effects.
After drying, the surface acquires an unusual glossy tint. Chips and sudden changes in geometric parameters in this case become unacceptable. Solvent is used if desired. There are also compositions that create a matte finish. A very interesting effect is obtained; the solvent does not affect its production.
When applying such a coloring composition, it is necessary to adhere to a temperature of -10 to +30 degrees. You don't have to think about air humidity. Polyurethane enamel for concrete is easy to apply, even if the humidity level reaches 95 percent. The polyurethane coating itself tolerates temperatures from -40 to +150 degrees.
The surface to be painted must be primed first, otherwise it will be impossible to ensure paint adhesion at the proper level.
Application methods
Polyurethane compounds are divided into groups both according to their composition and according to the materials requiring processing. Application type can be:
- aerosol;
- using a brush or roller.
Aerosol spraying is most often used when processing metal products. Polyurethane paint for cars provides uniform coverage without streaks or smudges. It is also an excellent alternative to conventional balloon compositions due to its safety margin.
Polyurethane paint for concrete floors is evenly distributed using a roller. The result is a smooth and even coating. But polyurethane paints on wood are best applied with a brush.
What surfaces can be painted?
The materials that require processing are also different. Polyurethane paints are suitable for wood, metal and stone. It is these surfaces that most often require additional protection from external factors. The main thing to remember is the need to prime. This is especially true for metal surfaces. But sometimes floor paint for concrete falls under this rule.
And wood requires high-quality drying. In this case, you can do without a primer. At the same time, the material itself is able to absorb any compounds that are applied to it. Therefore, it is necessary to use several layers; one is not enough.
Polyurethane enamels are fully compatible with stone and adhere well to such a surface. Therefore, no primer is required in this case.
Sometimes buyers simply do not have the time to level a layer of paint with maximum accuracy, or they simply do not have the desire to do such work. Then it’s easier to use paint that levels itself.
Immediately after applying such material, so-called tension appears on the surface. It does not matter whether a roller or other device was used during application. Thanks to the tension, the paint spreads easily and all irregularities disappear.
In the video: polyurethane coating of a concrete floor.
Differences in component composition
All paints that are on sale are divided into one-component and two-component. The difference between them lies in the method of curing the composition after application. In particular, one-component enamels do not require the addition of hardeners and other substances. After application, the coating hardens due to moisture coming from the air. In a simplified version: this is a composition completely ready for coloring. So all you have to do is open the can and start painting.
Two-component polyurethane paint cures according to a different principle. Here, evaporation of the solvent is not enough. In order for the composition to harden, it is necessary to start a chemical reaction. A hardener is used for this. As a result, a three-dimensional crystal lattice is formed, which strengthens molecular bonds several times.
The difference between the types considered lies in the scope of application. One-component compositions are usually used for interior work. Two-component paints are more suitable for exterior finishing and help protect the base from environmental influences.
Types of polyurethane paints
There are several types of polyurethane paints on the market. For their manufacture, complex polymers are used, including high-quality polyurethane. There are also several brands, usually everyone knows them. Therefore, it is difficult to make a wrong choice. The solvent is often included initially.
Based on organic solvents
This is a common type of coloring composition, but the main modifier is polyurethane. These materials are one-component. But a couple more components are added to polyurethane: a coloring pigment, a solvent (also known as a thinner). The role of the latter is played by xylene or toluene. Under the influence of atmospheric moisture, processes such as hardening and polymerization occur. Moisture itself reacts with the components that make up the paint.
If the air in the room is too dry, the composition will not set. To dry polyurethane surfaces, it is generally prohibited to use air at too high a temperature. The higher the humidity level, the longer it will take to dry.
After application, the paint gains strength after at least 48 hours. Only after this the coating becomes completely waterproof. In addition, properties such as resistance to aggressive environments and wear resistance appear. This is also different from concrete paint.
Water-dispersed compositions
These materials are also considered one-component, but the place of the solvent for polyurethane compounds is taken by ordinary water. When painting, such paints are harmless. There is no toxic or simply unpleasant odor. In an aqueous environment, other elements of the material are distributed evenly, after which a so-called stable dispersion is formed.
When the water evaporates, the components seem to stick together. After this, they are finally united into a single whole. The result is a transparent thin film, which is endowed with both protective and decorative properties. The solvent component does not affect them.
The presence of water in the composition makes the paint freeze easily at low temperatures. If the paint is defrosted, it will be able to perform its functions, but the technical characteristics will noticeably decrease.
This option of polyurethane paints is excellent for rooms where the humidity level is constantly high. If you need to cover stucco molding or baseboards, then water-dispersive compositions are also suitable. They are distinguished by a high level of elasticity and do not crack even after bending decorative parts.
Alkyd-urethane options
This group includes polyurethane enamel for metal; car paint is no exception. These types of materials consist of the following components:
- pigments;
- solvent;
- driers that accelerate drying;
- alkyd-urethane varnish.
Other components are also included that help improve certain characteristics. No metal enamel is complete without their addition.
Polyurethane paint allows you to create a special film on the surface with increased protective and decorative properties. The degree of gloss along with the texture is determined only by the buyer, depending on preferences in a particular case. The material is suitable for work both indoors and outdoors.
This type of paint is resistant to temperatures in the range from -50 to +50 degrees.
Other positive qualities include:
- abrasion resistance;
- easy application using a roller;
- drying, which takes only a couple of hours;
- anti-corrosion protection if a metal surface is treated.
Manufacturers: review and reviews
The main producers of polyurethane painting compositions are Turkey, Germany, Greece and the countries of the former CIS. However, if there is a need to purchase polyurethane varnish, enamel or paint, you can safely give preference to domestic products in this matter, since these coatings consist of complex polymers that are successfully produced in Russia.
of the Elakor, Krasko, and Promtekhsnab brands performed well There is no doubt about the positive characteristics of Russian paint and varnish products, since they undergo thorough quality control, are certified and have all the permits.
Products made in China are no less popular in the market. It is represented by polyurethane compositions for painting cars, as well as for wooden and concrete bases; there is an assortment of excellent furniture paint.
American products of polyurethane paints are represented by the Valspar . The concern of the same name has been producing paint and varnish products for many years, which are produced using original technology for mixing coloring and binding components. The composition has a lot of positive reviews because it is easy to apply, forming a thin and durable layer with a glossy or matte sheen.
This paint does not crack and does not contain compounds harmful to health. These products are used for painting special equipment, metal structures, boats, as well as interior items and furniture.
The European company Milesi is a leader in the production of high-quality varnishes for wooden surfaces. Most furniture manufacturers prefer to use products from this particular company, since the surface coated with polyurethane varnishes has good physical and chemical resistance and retains its excellent appearance. Milesi varnishes can be used for all types of finishing, including doors and solid MDF. Buyers note a large range of colors, which allows you to choose the desired color.
Sikkens paint and varnish products are popular with Redox two-component paints for metal and concrete surfaces. As a result of using this material, painted objects, structures or bases acquire an excellent matte or glossy appearance.
Features of two-component paints
Most often, polyurethane compounds are sold in two separate containers. One of them contains a hardener, and the other contains a resin. This type of paint can also be produced for concrete. This separation of components has its advantages:
- The ability to obtain a durable, wear-resistant coating. The characteristics are much better than those of standard formulations.
- Humidity does not affect processes such as curing and polymerization.
- It is easy to prepare the solution at once, in the required quantity. With further use, the remaining part does not lose its qualities.
A material such as acrylic paint is perfect for surfaces that are constantly exposed to negative environmental influences. There is additional protection against any acids along with solvents and alkalis. Sea and running water will also not be harmful to the composition. A construction mixer is used to mix the two paint components.
Options for applying polyurethane paint (2 videos)
Various products (26 photos)
Let's look at the most popular two-component metal coatings
"Certacor Zn" . A two-pack heat-resistant composition (one component is a varnish base, the second is pigment zinc) is suitable for painting metal products where there are large temperature differences from –50°C to +400°C. Creates durable protection against corrosive changes. Painted products can be used in sea and fresh water, in oil and petroleum products. The composition can be used under hot water.
"Tsves" . A two-pack composition based on zinc powder with the addition of an ethyl silicate binder. The coating is suitable for anti-corrosion protection of metal surfaces. The primer can be used in the transport, oil, and water industries. The composition is resistant to aggressive atmospheres, ultraviolet rays, and temperature changes.
"Ureplen-Universal" . Protective and decorative coating intended for metal products that are used in harsh atmospheric conditions. The coating can be applied to sewage treatment plants, bridges, basements, swimming pools, tanks and containers in which food products are stored: dairy or juices, etc. The coating reliably protects against corrosion due to changes in temperature and moisture. Extends the service life of metal products up to 25 years.
"IZOLEP-mastic" . A two-pack primer-enamel made on the basis of a suspension of pigments, fillers and functional additives in a solution of modified epoxy resin in a mixture of organic solvents and a hardener (aliphatic polyamide resin). Creates a strong and thick coating on metal surfaces.
coating with good chemical and physical properties, which is reliable anti-corrosion protection. Coating is possible both on new metal products and on products where rust has already formed. Enamel extends the service life of metal products for a long time and prevents corrosion from spreading beyond the already formed corrosion.
Also among the high-quality two-component paints for metal are o (epoxy primer), “CUMIXAN Pro Epoxy” (primer-paint is a Russian analogue of expensive European paints), “CUMIXAN Color UV” (primer-paint based on polyurethane, also a high-quality Russian analogue of European LMB).
