What is polyurea, its varieties, technical characteristics, pros and cons, especially the choice of material and do-it-yourself application.
The Benefits of Polyurea
Polyurea spraying is one of the best modern methods of waterproofing and anti-corrosion protection. The material compares favorably with most other similar polymer-based coatings due to the following qualities:
- High degree of hardening… Polyurea hardens quickly on any surface at any temperature and humidity. At the same time, bubbles or other defects will not appear on the surface of the material. She can perform her tasks almost immediately after application.
- High mechanical properties… Polyurea has a high level of hardness, tensile strength, tensile strength, and excellent flexibility. Due to this, cracks do not form on its surface, it does not settle and retains its original shape.
- Excellent chemical-physical properties… This material demonstrates good adhesion to various surfaces, resistance to a wide range of chemicals and high dielectric properties. Prevents sparking.
- High level of fire safety… Polyurea is much safer than most polymer resins. Due to the special molecular structure, the substance does not burn, does not spread flame.
- Good aesthetic qualities… Aliphatic polyurea coatings retain their excellent appearance, shine and color for a long time, which are not lost even under the influence of weather conditions. Therefore, they can be used as a decorative finish. Aromatic polyurea can only become slightly dull when exposed to UV light.
- Seamless and tightness of the coating… Polyurea can be sprayed onto surfaces of any complex geometric shapes, including vertical ones. It provides a smooth, monolithic, elastomeric coating that does not require fasteners and does not form joints.
- High speed of work with material and productivity… Polyurea can be used in conditions where waterproofing is needed in a short time. The components of the material react quickly, they are also quickly sprayed and hardened. At the same time, one person is enough to work with polyurea - the installation process is not laborious. And two people per shift can apply about 300 square meters of coverage.
- Durability… A polyurea coating can last over 50 years without losing its technical characteristics and without requiring repair.
Disadvantages of polyurea
Ideal building materials and coatings currently do not exist, and polyurea is no exception. This material also has a number of disadvantages that limit its use. Before you buy polyurea, pay attention to the following disadvantages:
- Insufficient UV resistance… This disadvantage is inherent, first of all, in the cheaper aromatic polyurea. This is a purely aesthetic problem, as the technical performance is not affected by the loss of color or gloss. To reduce these negative manifestations when using an aromatic coating, they try to select dark shades as a decorative spraying - gray, brown, black. Aliphatic polyurea is practically unaffected by sunlight.
- Moderate chemical resistance… Concentrated mineral acids, benzene, acetone, toluene, antifreeze, xylene are destructive to polyurea.
- Sufficiently high price of raw materials… The components for the production of polyurea are the so-called "A and B" liquids. They are supplied in separate packaging. In the manufacture of each ingredient, enterprises use about 10-20 components. All of them are quite expensive and, as a rule, of foreign production. Thus, the price of the final product cannot be low.
- Expensive spraying equipment… In most cases, polyurea is applied using special equipment. The two-piece dispenser is available in various models. The performance, power of the device depends on this. Also, the cost of equipment is affected by its configuration. The total price of a kit with the necessary spare parts can fluctuate between 27-40 thousand dollars. Only specially trained personnel can work with such an expensive device, whose functions include not only spraying the substance, but also maintaining the equipment in working order.
- The need to level the working surface before spraying polyurea… The base for application must be carefully prepared - leveled, primed. Polyurea, like any sprayed substance, cannot hide the unevenness of the base. She will only emphasize them after application. Also, do not apply the material to porous surfaces such as plywood or concrete. Otherwise, many "craters" will appear, which cannot be hidden even by repeated sputtering.
Polyurea selection criteria
The high price of pure polyurea, as well as its exceptional technical characteristics, suggest the use of this material in extreme, harsh conditions, where there is low or very high temperature and humidity. At the same time, cheaper and more economical hybrid formulations have found more widespread use. A variety of options for such systems makes it possible to choose the optimal one for various operating conditions.
The choice of polymer determines not only the functions that it will need to perform, but also the application technology. So, for example, if the composition includes surfactants or plasticizing components, then the interlayer adhesion will be rather weak. Therefore, the film coat must be applied in one coat or with a short break between sprays. All these factors must be considered when choosing a material.
When choosing manufacturers of polyurea or ordering services for its spraying, be sure to ask the company's representatives to provide documents that confirm compliance with all technical standards in the manufacture of components of the composition. A high-quality coating can only be obtained if ingredients from proven brands are used, which guarantee stable performance properties of the material.
Brief instructions for the installation of polyurea
For spraying polyurea, special equipment is required. Only professionals can apply the material using this method. You can independently apply polyurea, which is specially designed for these purposes - polyaspartic. When purchasing components for your own installation, be sure to clarify the composition of the polyurea and the methods of dilution. They may differ from manufacturer to manufacturer. It is worth noting that this polyurea contains esters that slow down the curing reaction of the coating, and therefore the mixture can be applied with a brush or roller, without fear of hardening quickly.
Brief instructions for working with the material:
- We prepare the surface for work - we clean it, prime it. If it is moist enough, it is best to dry it before applying the polyurea compound.
- If necessary, level the base to avoid defects on the finished treated surface.
- Using a brush or roller, apply the finished composition to the surface in an even layer.In hard-to-reach places, it is better to use a small brush. In an open space - a roller.
- We wait until the composition is completely dry and, if necessary, apply a second layer.
After complete drying, which in the case of "hand" mixtures occurs within 2-5 hours, you can use the treated surface.
Watch the video review of polyurea:
Polyurea is a relatively new waterproofing material that is becoming more widespread due to its excellent properties and qualities. One of the major drawbacks today is the high price of polyurea. However, manufacturers are developing more economical ways to make components that will reduce material costs in the future.