Polyurethane varnish: types, benefits and application

Polyurethane-based varnish is widely used for the treatment of wooden structures. Such paintwork material emphasizes the structure of wood and makes the surface more attractive visually. After the solution dries, a strong film is formed on the surface, which protects the tree from the effects of external negative factors. Types, advantages and features of the application of polyurethane material will be discussed in more detail in this article.

Polyurethane varnish is one of the most popular materials in construction and repair. Created coating has excellent performance. The solution based on polyurethane surpasses others in many ways.varnishes varnishes.

Polyurethane mixture has the following advantages:

• Resistance to temperature fluctuations. The coating can be operated in the temperature range from -50 to +110 degrees Celsius.

• Long service life. Quality coverage can last more than ten years.

• There is a high level of adhesion.

• An important role is played by the moisture resistance of the coating.

• The material is resistant to direct sunlight.

• The varnish maintains various mechanical loadings.

• The wear resistance of the material is significantly higher than that of the alkyd coating.

• Good elasticity, due to which the varnish layer is not covered with cracks after drying.

However, like all coatings, polyurethane varnish has its drawbacks. The main disadvantages include:

• The composition of the two-component solutions, as a rule, include organic solvents, which may not be the best way to affect human health.

• Not all types of polyurethane mixtures are of high quality. The composition of the material depends on the manufacturer. Poor quality coating may turn yellow over time.

• The cost of high quality polyurethane varnish is quite high.

Polyurethane varnish is mainly used for wooden surfaces. However, the solution well protects not only wood, but also many other materials.

There are the following applications of varnish.

• Creating a reliable protective coating on walls, floors and ceilings and wooden furniture. A durable polyurethane lacquer film protects surfaces from mechanical stress and also prevents the formation of damage from chemical agents.

• Mortar well impregnates surfaces such as concrete, brick, roofing material in the form of slate tiles.

• Polyurethane varnish is one of the most popular materials for parquet processing.

• Varnish is used to create a “wet stone” effect.

• It is applied both to internal, and to exterior finish.

• The composition is ideal to prevent rust on metal and concrete.

Polyurethane-based varnishes may have a different composition, which will affect the properties of the future coating.

The chemical composition of the following types of mixtures:

• single component;

• two-component.

One-component solutions are made on a water basis and are produced ready for application.

The advantages of this composition include:

• Health safety. The one-component mixture does not contain toxic substances and organic solvents.

• When drying, the varnish does not emit harmful substances into the air.

• The material is fireproof.

However, one-component compositions are inferior in quality to two-component mixtures. A two-component solution is made immediately before the start of finishing work. This composition includes the base and hardener.

To prepare a mixture ready for application, the two components must be mixed together. The disadvantage of this composition is quite small permissible shelf life of the prepared solution. The mixture can be used within five hours after its manufacture.

Two-component varnish has a higher technical characteristics than the one-component composition.If the surface is subjected to high mechanical loads, then it is necessary to use only two-component solutions for its processing.

Polyurethane-based mixtures are classified not only by chemical composition, but also by application.

Depending on the scope of use, the following types of manufactured varnishes are distinguished.

• Yacht This type of paint product was originally intended to cover wooden yachts. However, now the material is actively used for interior and exterior of various designs of wood. The advantage of this varnish, above all, is a high moisture resistance.

• For plastic. For the processing of plastic products are produced compositions without the content of latex components.

• Parquet.

• Furniture.

• Universal (for various types of surfaces).

Polyurethane-based lacquer is most often produced in a colorless transparent form, which makes it possible to emphasize the natural structure of wood when applying the composition to the surface. According to the degree of gloss, glossy and matte coatings are distinguished. Such differences in shade have no influence on the technical characteristics of the material.

The difference will be in some operational features.

• Glossy finish is most prone to scratches. In addition, defects on a shiny surface are more noticeable than on a matte finish.

• Matt varnish better emphasizes wood texture.

• Matte coating is most resistant to ultraviolet radiation. For outdoor work it is better to use this kind of paintwork material.

Some manufacturers of finishing materials produce varnishes based on polyurethane, which include dyes. Pigmented blends allow the surface to give the desired shade.

The quality of varnish based on polyurethane directly depends on the composition of the mixture and its manufacturer. It is better to purchase material produced by a company that has established itself as a manufacturer of paint and varnish coatings.

The history of the company Petri has more than fifty years. The company occupies a leading position in America for the production of polyurethane varnishes. All products manufactured under the Petri brand are of high quality and excellent strength indicators.

The line of polyurethane-based varnishes has ten different modifications of the material, different in composition and some properties.The use of any kind of mixture from Petri guarantees a high-strength coating with a diamond hardness effect. Such material is perfect for treating floors in high-traffic areas where the surface load will be high.

The company Polistuc is one of the leaders in the production of paints and varnishes in Italy. Italian polyurethane varnishes are used in both domestic and industrial construction. Basically produced mixtures for processing metal and wood structures.

Polistuc polyurethane varnishes are highly resistant to abrasion and scratches on the surface. With the help of this material creates a high-quality and durable coating that does not yellow over time.

The company "Irakol" is one of the largest manufacturers of professional paints and varnishes in Russia. The products of the Russian company "Irakol" are not inferior in quality to the products of world manufacturers of paints and varnishes.

In the production of polyurethane varnishes on the basis of using only high-tech modern equipment and the best raw materials.The price of the products of the company "Irakol" is significantly lower than foreign analogues.

The technology of applying polyurethane varnish to the surface will depend on the composition of the mixture itself, as well as its scope. However, it must be remembered that in any case, before carrying out finishing work, it is necessary to carry out the procedure of preparing and cleaning the surface.

Before carrying out repairs, the wooden base must be well cleaned of dirt and, if necessary, sanded. If there are grease stains on the wood, they must be removed. When wet cleaning does not help to get rid of such contaminants, the surface can be degreased with a solvent.

If the construction of wood will be used outdoors or in conditions of high humidity, then it must be treated with a special solution to improve antiseptic properties. To emphasize the natural wood structure of the surface or to give the material the desired shade, before applying the varnish, the product is coated with stain.

If it is necessary to cover the floor with paintwork material,then there is a need to protect the lower part of the walls from pollution. To this end, the walls below are covered with masking tape around the perimeter of the room.

After the wooden surface is ready for processing, you can begin to manufacture a solution for application. Single-component formulations are sold in ready-to-use form.

However, in certain cases it is necessary to add a solvent to one-component mixtures:

• If the solution will be distributed with a brush, it is not necessary to dilute it with a synthetic solvent.

• When working with a roller, you need to enter from five to ten percent solvent.

• When a paint sprayer is used for applying lacquer, the consistency of the mortar should be quite liquid. Therefore, in the composition you need to add up to twenty percent solvent.

Two-component mixtures are made strictly in the proportions that were specified by the manufacturer. Instructions for the preparation of the mixture is always indicated on the packaging of the material. Apply a two-component solutions better with a fur roller.

Surface treatment should be carried out along the direction of the wood fibers.It is recommended to apply a polyurethane coating in at least two layers. In certain cases, four layers of the mixture may be required. The varnish is spread over the surface with slow and smooth movements. During careless work on the coating may form bubbles.

The last layer of the mixture is applied only on the dried and clean coating. The time interval before the subsequent surface treatment can be from two to six hours. From the surface it is necessary to remove all accumulated dust with a vacuum cleaner or a damp cloth. It is also recommended to walk on the first layer with sandpaper. The drying time of the finishing layer depends on the type of polyurethane varnish used and averages eight hours.

For improvement of operational qualities of bulk concrete floors often use varnishes on the basis of polyurethane. In order for the coating to turn out to be of high quality, the floor must be as even and clean as possible. If polymeric substances were not part of the self-leveling floor, then such a surface should be primed.

To create an original decorative coating, various patterns can be formed on the surface with varnish using special stencils. The rest of the technology of applying a polyurethane mortar to concrete does not differ from similar work on wooden floors.

Repair work indoors should be carried out at a certain temperature. The air temperature in the room should not exceed twenty-five degrees.

When using a two-component solution, you need to remember some additional precautions.

• If finishing work is carried out indoors, then the room must be well ventilated.

• It is necessary to work with such material in a respirator.

• After all repairs, it is advisable not to use the premises for two days. During the specified time, all harmful substances should come out and evaporate from the coating.

When a roller is used as a tool for working with paintwork material, the mixture should be distributed cross-wise on the surface.This method will allow you to create a smooth coating without the formation of stains.

The consumption of aerosol mixtures is usually higher than that of conventional liquid formulations; therefore, it is recommended to purchase material with a margin.

The process of applying polyurethane varnish, see the following video.