- Composition and properties of rubber paints
- Decorative properties
- Application area
- Preparation and application rules
- Reviews, recommendations, warnings
Paintwork materials with a high content of rubber polymers occupy a separate niche among the paints for household use. Today our site will figure out what is the difference between liquid rubber and materials containing latex, for what purposes different types of paints are used, as well as how to properly prepare and apply.
Composition and properties of rubber paints
Latex and its synthetic counterparts form the basis of any rubber. Being a water-soluble substance, it becomes hydrophobic after drying and polymerization, preventing the penetration of moisture and partially restricting the diffusion of water vapor and atmospheric gases.
Most of the so-called rubber paints are water-borne, they do not contain organic solvents and do not emit volatile substances when dry. However, there are also paintwork materials based on organic solvents:
- Two-component – compositions are a black polymer-bitumen water emulsion with a hardener, which is applied by a mechanized method and hardens in the first few seconds after spraying. This material is called liquid rubber and is used to create seamless waterproofing..
- One-component bituminous paints have a longer drying time. Unlike an emulsion, the composition is initially transparent and can be tinted with pigment dyes, which expands the list of decorative properties and scope.
Most of the paints containing latex and rubber are distinguished by high protective properties, reliably protecting the product covered with them from negative environmental factors. After polymerization, the coating retains its elasticity, which favorably affects the wear resistance and resistance to vibration of the base.
Rubber paints differ greatly in the content of rubber polymers. Compositions for interior and facade decoration have surface hydrophobicity and high crack resistance. Outdoor materials that cover metal and wood structures provide comprehensive protection against corrosion and decay. The more latex the paint contains, the more pronounced the protective properties, but at the same time, the specificity of product preparation and coating is enhanced.
After drying, the rubber paint remains matt: due to the peculiarities of the chemical composition, a glossy surface cannot be achieved. Paints based on both an aqueous emulsion and organic solvents are easily tinted, but bright saturated colors can be achieved only by using a thickener for acrylate paints and applying a layer of over 1 mm..
The main negative feature of latex-containing paints is the same as that of other water-dispersion compositions – low resistance to fading. Indoors, they show normal light fastness, but in direct sunlight, bright and dark colors lose saturation in a season or two. High-quality paints based on organic solvents are devoid of this drawback: they include fixers and color stabilizers, as well as a UV filter..
The ability to paint a product with rubber paint depends on how confident the adhesion between the coating and the surface is. The fact is that most paints with rubber-polymer components provide only surface hydrophobization, but with abundant wetting or complete flooding, they still retain the ability to pass water.
The simplest example is concrete products, which in themselves are quite hygroscopic. Moisture saturation in concrete leads to surface erosion, which causes paint flaking, blistering and cracking. Another example is steel structures for which water-based rubber paint is not suitable as a primary protective coating. Permeation of atmospheric moisture and oxygen causes corrosion, which manifests itself in the form of rusty spots and streaks.
In fact, rubber paint can be used to paint metal products, even rims that are operated in very harsh conditions. But this is done either to increase resistance to abrasion and mechanical stress, or to give a characteristic aesthetic effect. In any case, the metal is first coated with a primer with corrosion inhibitors and a film-forming enamel, and then with a rubber paint. In this case, it is imperative to take into account the incompatibility of acrylate and alkyd bases. You will either need to use acrylic enamel or apply a special intermediate primer for acrylate-based paints and varnishes.
Separately, it is worth considering the possibility of using rubber paint for facades. This is advisable only if the material of the enclosing structures does not provide for gas exchange with the outdoor environment. Otherwise, the diffusion of water vapor through the wall will be limited and moisture accumulation inside the carrier layer or insulation is possible. There are no other restrictions on the use of rubber paint on the facade, this is one of the best coating options, but only if it is properly prepared.
It is most advisable to cover untreated sheet materials with rubber paints: CBPB, OSB, GVL, plywood, especially in IAF systems. Due to its high hiding power and the ability to stretch up to 400-600%, the paint is able to reliably hide the joints between the plates and minor defects of unpolished surfaces.
This is not the case with natural wood: due to its ability to limit gas exchange with the environment, rubber paint coating can cause excessive moisture, rotting and warping. The use of rubber paint is advisable only if the wood has undergone complex bioprotective treatment and is used in conditions where the risk of dampness is minimal.
There are a number of restrictions for certain types of rubber paints, all of which are indicated in the application instructions. So, the paint may be unsuitable for covering ceilings, doors, floors or terraces, therefore, when buying, you must definitely study the label of the selected paintwork.
Preparation and application rules
The safety of the paintwork depends to a greater extent not only on the quality of the materials, but also on the correct preparation and adherence to the application technique. In the case of rubber paint, the latter is especially important. To understand the principles of preparation for painting, we will analyze the three most typical examples..
1. Concrete fence. The so-called “Euro-fences” are characterized by low frost resistance, which can be partially compensated by preventing the concrete from saturating with water. This is done in two stages: first, the product is thoroughly impregnated with a surface water repellant on a silicon-organic basis, or with ordinary sodium silicate. After drying, the concrete should be covered with a primer such as “Betonkontakt”, which increases adhesion, and then 1-2 layers of rubber paint. In the case of eurofences, the processing and painting of sections with pillars should be carried out separately, having previously disassembled the structure.
2. Roof. Iron and slate roofs are often covered with rubber paint to increase durability and aesthetics. This can be done most simply with galvanized iron: since the base does not corrode, it is enough to apply an adhesive acrylic primer, and then the topcoat. The situation with slate is a little more complicated: it, along with concrete, requires careful hydrophobization.
In the case of standing seam or sheet roofs made of black iron, the coating can also be protected with rubber paint. Due to the increased film thickness and the ability to withstand cyclic temperature fluctuations, the coating service life can be 10-15 years before restoration. However, steel sheets are the most difficult to prepare. They must first be treated with an acid-free zinc-containing rust converter. Such compositions are used to treat reinforcement before concreting. After that, the surface of the iron must be thoroughly washed with a solvent, apply acrylic primer and 2-3 layers of rubber paint with a break of 1 day.
3. Plaster facade. The ability to hide the opening of cracks in façade plaster makes rubber paint an extremely attractive type of coating. However, for the preservation of aesthetic properties, it is required not only to properly prepare the surface, but also to impeccably observe the finishing technique using the “wet facade” technology. If no correction and leveling is required after applying the base plaster coat, the paint can be applied immediately. In this case, it is imperative to treat the surface with a primer containing stone flour, thoroughly dry and clean the surface of the walls, avoid carrying out work at the maximum permissible temperatures.
Reviews, recommendations, warnings
Rubber paints are one of the most controversial modern finishing materials. Judging by the reviews, the same composition under different conditions of application and operation can both demonstrate excellent qualities and become unusable in 1-2 years..
It is very important not to neglect the rules of preparation. Since rubber paints themselves are much more expensive than conventional paints, it makes no sense to save on a quality primer and protection against corrosion and decay. Time cannot be saved either: before application, efflorescence, greasy streaks and dust should be carefully removed.
If the preparation is carried out correctly, it is enough to simply follow the rules for working with the selected material:
- Check the pictograms on the label to determine if roller, brush or spray application is acceptable.
- Make sure the temperature and humidity are within the recommended.
- Allow the required time to dry before applying the next coat.
If you are considering applying rubber paint for any purpose, your best recommendation is to contact the manufacturer for first-hand information. Rubber paints differ in composition and content of latex polymers: for example, those that are suitable for roofing will last no more than a year on the facade. On the other hand, a direct recommendation for use from the manufacturer serves as a kind of guarantee and a reason for filing a complaint in case of damage to the coating..