Wood is a naturally occurring material with high porosity and a large number of natural enemies. Mold, algae, fungi, and insect pests quickly render wooden buildings unusable if they are not properly protected.
Adverse weather conditions - precipitation, temperature changes, sun and wind also negatively affect wooden building. The most loaded structures especially need protection - the base, window and door frames, and the overhang of the cornice.
A primer for wood reduces the porosity of the material, reduces the absorption of compounds, protects against pests of all types, reduces the influence of precipitation, impregnation with a fire retardant increases resistance to fire.
Primers for various purposes They can be transparent, matte with great coverage, or revealing the structure of the wood. Opaque compounds are often tinted to match the color of the topcoat to obtain a more uniform color.
By chemical composition wood primer for exterior painting is made on the basis of:
- acrylic resins;
- alkyd resins;
- silicone acrylic;
- shellac;
- epoxy resins.
Let us consider the properties of primer compositions in more detail.
Acrylic based
An acrylic-based primer successfully protects wood from mold, bark beetles and discoloration. It is resistant to UV radiation, temperature changes, dries quickly and has no unpleasant odor, it is applied in 2–3 layers.
This primer is especially suitable for painting on wood. acrylic paint, but can also be used for other types of painting. Acrylic primers are low cost, effective, environmentally friendly and harmless to humans.
Based on alkyd resins
Alkyd primer is used for painting alkyd paints and enamels, creating a water-repellent layer on the surface. Alkyd primer is an ideal coating for previously painted surfaces.
The alkyd composition can be diluted with water, it is an economy class primer with a service life of 3–5 years, the disadvantage is that it takes a long time to dry, each layer takes from 10 to 18 hours, and has an unpleasant specific odor.
Silicone acrylic primers
Silicone-acrylic compounds are one of the most durable and effective, penetrating deeply into the pores of wood, strengthening and protecting against absorption atmospheric moisture and sunny color, resistant to all negative factors, harmless, but expensive. They are used for painting with latex, alkyd, silicone and water-based varnishes, azures and paints.
Shellac
Shellac primer is used on knotty softwood to neutralize the natural resin released through the knots and to isolate a layer of water-soluble stains. Shellac levels the surface of the wood, thanks to which the finishing paint layer applies easily and reduces paint consumption.
Epoxy
A two-component primer for wood for painting based on epoxy resin forms a protective film on the surface of the wood that is resistant to abrasion, mechanical damage and weather conditions. The primer is expensive and is more often used indoors for furniture or parquet.
By functional features
The construction chemicals market offers primers of various compositions and purposes, both from famous brands and little-known manufacturers. Functionally, wood primer before painting is divided into the following types:
- anti-corrosion, protecting against cracking, drying out, and falling out of knots;
- antiseptics that prevent biological damage;
- hydrophobic, preventing the absorption of moisture;
- flame retardants that increase the degree of fire resistance;
- universal formulations containing all previous components.
There are surface protection compositions and compositions deep penetration providing long-term protection, best manufacturers They promise the effectiveness of the composition for up to 25 years.
Anti-corrosion and antiseptic primers
Anti-corrosion and antiseptic primers protect the wood structure from cracking and other types of corrosion; the presence of fungicides in the composition guarantees protection against pests, fungi, and mold. They are also used on old paint coatings to harden the surface.
Deep penetration
The main advantage of deep penetration primers is long-term protection and reduced consumption of finishing paint material, that is, direct savings.
If the composition contains linseed oil, such a primer will protect against moisture and protect against pest damage. Deep penetration primers protect wood from fading, and therefore require paint or varnish with a UV filter.
It is especially important to use deep penetration compounds on hard surfaces. wood materials artificial origin - chipboard, fiberboard, OSB, plywood.
Primer with varnish
Compositions that simultaneously protect wood and form a varnish finishing layer on the surface are more often used for processing wood materials indoors. Unfortunately, a two-component composition is always inferior to two one-component ones in terms of the quality of protective properties.
Product with waterproofing properties
Waterproofing (or water-repellent) compounds are used for wood exposed to atmospheric conditions or high humidity, for example, in baths and saunas. They form a film on the surface that prevents moisture absorption.
Universal primers
universal primer compositions have all the properties listed above and are used when quick processing is necessary, but their effectiveness is lower than specialized compositions.
Average cost and where to buy
The cost of primers depends on many components:
- chemical composition;
- appointments;
- validity period;
- hiding power;
- manufacturer.
Of course, the cost of an acrylic primer from a domestic manufacturer with a working life of 5 years will be significantly lower than the cost of a primer based on epoxy resin from a world-famous foreign brand.
And yet, despite the high cost, you need to purchase products from companies that have been proven for at least 10 years of producing quality products and specialize in construction chemicals:
- Tikkurila (Finland);
- Pinotex (Estonia);
- Biofa (Germany);
- Belinka (Slovenia);
- Unibud (Belarus);
- Neomid (RF).
The average price is 300 rubles. per liter
The best choice is to purchase both primer and finishing paint from the same manufacturer from an official dealer or representative office of the company, this guarantees compatibility and better job different layers.
Application technology
Applying a primer to an external wooden surface is not difficult, but it will require preparatory work, the composition of which depends on the time of construction - it is a new building or a house with history, repeatedly painted in the past.
Over old paint
Before priming, it is necessary to remove the old paint layer and assess the condition of the wood. When peeling old paint it is removed with a spatula, heating it with a hair dryer.
- In case of damage by pests or disease, remove the damage and fill the uneven areas with putty.
- Check the tightness of the seams between the crowns and, if necessary, re-caulk the seams.
- The walls are being sanded.
- Dust the surface with a vacuum cleaner or a damp cloth or sponge, and wash off oil stains.
- Dry the surface.
- Paint it.
Painting is carried out in dry, windless weather, preferably without sun, at temperatures from +5 to +30°C. For priming, you can use a brush, roller or. Don't forget a set of protective clothing and equipment personal protection- glasses, respirator, gloves.
Solutions ready for use are mixed, concentrates are diluted according to the manufacturer’s recommendations.
Apply the primer using hand movements from top to bottom or from left to right, as convenient, in the direction from the eaves to the base. For large areas it is more convenient to use a spray gun; it can be rented to minimize costs; for small areas a spray gun is more convenient.
The primer is applied in 2–3 layers, according to the manufacturer’s instructions, over the dried previous layer. When using several compositions, they start sequentially with a fire retardant, then an antiseptic, and the last one is to apply primer under the finishing paint.
There are several types of primer that can be applied over the old paint layer if it has not lost bearing capacity and does not peel off, and the surface of the walls is healthy and without defects.
On fresh wood
Fresh wood is treated at logging sites with temporary compounds with a validity period of about six months. Even if you purchased primed wood, protecting the surface before finishing is a must.
- The walls of a new building must be scraped or sanded.
- Check the tightness of the seams and smooth out the defects with acrylic putty.
- The walls are dusted.
- Apply sequentially 2-3 layers of fire retardant, antiseptic, and primer tinted to match the color of the finish coat for adhesion.
- Watch a video about priming wooden walls.
Conclusion
Appearance wooden house will largely depend on the quality of the preparatory work and application of the primer. Priming the walls before painting means protecting the wood from destruction for a long time and making your home durable.
An important step when working with wooden surfaces is their pre-processing primer. Primer for wood is called liquid formulations, which are applied under varnish or covering paint. As a rule, manufacturers add components to these impregnations that form a film on the surface or harden deep in the pores of the wood material.
Don't forget that 75% of success in painting wood is pre-treatment. The primer itself is not a panacea if it is used without taking into account the characteristics of the wood, if it is not compatible with the paintwork material with which it will be coated, and also if the surface of the wood is not sanded.
In this article we will look at a number of important issues about priming wood before painting, we learn not only about the compatibility of products, but also about systems and their service life. In principle, in this material we have collected all the experience of working with the compositions of Renner, Teknos, GNature and Remmers.
Do I need to prime wood bases before painting?
The service life of paintwork materials indicated by the manufacturer on the packaging and the paint shades in the catalog correspond to reality only when applied correctly, that is, using a primer with preliminary and intermediate sanding. All test reports are always completed in the system. The manufacturer's claim of 10-15 years of service life is always based on tests of the entire system. Otherwise the following happens:
- the operating time of paintwork materials is reduced by half;
- the consumption of paint or varnish is very high;
- unsightly spotting appears on the surface (especially when using dark paints);
- lack of proper adhesion leads to premature peeling and peeling of paint.
Each manufacturer of paints and varnishes creates special, adapted primers for them. Without a primer, the quality of painting (visual and operational) is much worse.
The advantages of primers for treating wooden surfaces are obvious:
- allow you to save paint and varnish for the finishing coating;
- extend the service life of wooden structures;
- improve technical properties Paintwork materials, including durability;
- adds aesthetics to the finish;
- protect wood from fungi, mold and diseases inherent to it;
- smooth the surface, hiding any defects;
- promote good adhesion (adhesion) between the base and the paint/varnish layer.
Types of primers for wood
Based on their composition and penetration depth, primers are divided into two categories - adhesive (alkyd) and leveling (acrylate). Alkyd - deep penetration compositions are made on an alkyd basis. Alkyds (polyesters) consist of very small molecules, due to which they are able to be deeply absorbed into the wood structure and harden within it, holding the fibers together and making the material stronger.
Photo 1. Teknos soil 1881
Alkyd primers are used where high adhesion is important. Being absorbed into the wood, the adhesive composition provides strong adhesion between the layers. Alkyd primer has another significant advantage - from the moment of its application to painting with the finishing layer it can take from several months to 1 year. During this time, the dried substance does not lose its adhesive and protective properties.
Photo 2. Leveling primer Teknos 3130
Leveling primer is made on the basis of acrylate-polymer dispersions, including latex, styrene, vinyl. Acrylates have a large molecule, so the substance leaves a large dry residue on the surface. Acrylate primer is not absorbed, but spreads over the surface, filling all its pores, leveling out any defects, forming a smooth film. This ability of leveling primers is indispensable where translucent painting is planned. Acrylate impregnation prevents the appearance of spotting on the finishing surface and greatly reduces the subsequent consumption of paintwork materials.
Which primer to choose, taking into account the purpose and application conditions
The choice of primer depends on the operating conditions of the surface to be coated and the composition of the next layer. Operating conditions mean exterior or interior (external and internal work), humidity level. On the street wooden structures and sheathing are exposed negative impact natural factors: dampness, sun, frost, high temperature. Accordingly, maximum protection and high adhesion are required here, which can be provided by soils with a high content of alkyds.
Photo 3. Primed auqa primer 2900 planken
For interior decoration, aesthetics are primarily important, so acrylate-based primers are used for interior work. They ensure ideal leveling of the absorbent capacity of the lining surface, giving it a special attractiveness and a shine that is pleasing to the eye. In the rooms protective film is not exposed to aggressive atmospheric influences, therefore it retains its integrity for a long time and adhesion plays a secondary role here.
Technology of applying primer to wood
The key to high-quality painting is pre-treatment of wood and the correct application method. Wood can be sawn (edged), planed and sanded.
- Sawn material (edged) has high porosity and fluffiness, therefore its absorption is high; here an antiseptic is needed rather than primer.
- Planed board is smoother, but its pores are closed with resins and smoothed by planing. Such a board will not be able to absorb alkyd primers, and acrylate primers will have too large and hard pile that intermediate sanding will not help.
- In sanded wood, the pores are open and ready to be filled with primer, which will harden over time and turn into a root, holding the paint on the surface and preventing it from peeling and peeling. Accordingly, this is wood ready for priming. It is important to know that the pores are filled with resins in just 48-72 hours, so you need to prime immediately.
Sanding is important stage staining, without which there will be no good adhesion. It is carried out before priming and in the intervals between layers. For primary grinding, an abrasive material with 80 grit (coarse) is used, which removes lint and smooths out cracks and chips. Next, primer is applied, and it, in turn, raises the pile again. The dried fibers are subjected to intermediate grinding with 150 grain (fine abrasive). After this treatment, the absorbency of the wood sharply decreases, it becomes perfectly smooth and ready for painting.
Photo 4: Spraying wood primer
Different primers are applied in different ways: brush (maklovitsa), rags, air and airless spraying, dipping. This point must be clarified when purchasing a primer. Deep penetration compositions are best applied with an airless spray under pressure.
Photo 5. Intermediate sanding of wood
The air temperature should be in the range of +5-+30℃. If impregnation is carried out in several layers, which is practiced outdoors, the primer for the first layer can be diluted with water (as indicated by the manufacturer) so that the composition acquires maximum fluidity and penetrates deeper.
How long does it take for primer to dry?
The manufacturer specifies the drying time of the composition on the packaging. Boundary fluctuations depend on humidity environment and air temperature. In a warm room and with good ventilation, the soil dries faster. For water materials it takes about 2 hours (the exception is Teknol 1881, which takes a day to dry). Oily soils dry in 12 to 24 hours. The time for complete polymerization also depends on the number of layers applied. The first layer dries faster than subsequent ones. For most soils, one coat is more than enough.
Service life of material treated with primer
- hydraulic oil Renner YS M300 + 101 primer = 15 years of service;
- Teknos Nordica ECO + Teknol 1881 = 8-15 years of service;
- varnish Aquatop 2600 + Aquaprimer 2900-02 = 6-8 years of service.
These parameters may have slight deviations, depending on the conditions and intensity of operation of the coating.
The LesoBirzha company owns its own carpentry production, including painting shops finished products. In this regard, our specialists know the properties of primer compositions first-hand, but from their own experience, and have the right to recommend tested primers to the consumer.
Photo 6. Antiseptic primer for hydraulic oil
- For Teknos NORDICA EKO 3330 covering paint, use adhesive impregnations Teknol 1881, Teknos AQUA PRIMER 3130.
- For translucent painting with Teknos AQUATOP Varnish 2600, you should buy glaze primer from the same manufacturer, Teknos AQUA PRIMER 290-02.
- For RENNER brand YS M300 hydraulic oil, it is recommended to apply Renner YM M101 aqueous antiseptic primer.
- To paint with natural oils from the GNature series, purchase Gnature 870 Schutz Grund-Ol primer-oil.
We are confident that carefully reading this article and following our recommendations will help you choose the right primer for wood and achieve high-quality painting. And we are happy to continue sharing our experience.
How to prime wood before painting? Is this operation always necessary? Are any more needed? preparatory work before applying paint? Let's try to answer these questions.
Why is this necessary?
First, let's find out why you need a primer for wood before painting.
- For disinfection. Cheap (and therefore popular) types of wood are susceptible to rotting. It is promoted by high atmospheric humidity, the appearance of condensation, water leaks and other minor household troubles.
Antiseptic impregnation can prevent the appearance of mold, which rapidly destroys organic fiber.
Useful: if the fungus has already started, you can use any chlorine-containing solution for initial disinfection. detergent. “Belizna”, the price of which is approximately 20 rubles per liter, is quite suitable for this purpose. However, only specialized antiseptic impregnation can provide long-term protection.
- To strengthen the surface. First of all, this applies to old, drying wood. The resins contained in the soil penetrate between the fibers and glue them together, preventing accelerated destruction of the material.
- To reduce the absorbent properties of wood. Structurally, wood resembles a sponge: the same abundance of large pores in a relatively small volume solid. When applying any coating, most of the first layer will be uselessly absorbed into the pores - provided that they are not filled with a primer.
- Finally, wood primer for painting acts as a protective and separating layer. Not clear? Let's try to explain.
We're getting a little ahead of ourselves; However, we note that the paint can be applied to an old coating of the same type without first cleaning the surface. Acrylic over acrylic paint, oil over oil paint, and so on.
However, differences in color may cause the old coating to show through due to it being partially dissolved when the new paint is applied. A primer of the appropriate type will act as a separator that will prevent the paints from mixing ().
In addition: wood contains tannin, a natural dye that often bleeds through water-dispersed coatings in untidy spots. The primer traps it inside the wood.
Types of primers
What types of primers are there for wood before painting?
Functionality
Antiseptic primers provide antibacterial protection. They kill microorganisms that have already settled in the wood and create an environment that prevents their further reproduction. Antiseptics, as a rule, also prevent the appearance of wood-eating insects; many contain fire retardant (fire retardant) additives.
Strengthening (primers, or deep penetration primers) serve, as can be easily concluded from the category name, to increase mechanical strength grounds. Most primers of this type are universal: compositions intended for brick and plastered surfaces are perfect for wood, plywood, hardboard and chipboard.
Finally, hydrophobic primers are needed to protect wood from excess humidity. They are used primarily for wooden facades.
Compound
The choice of primer composition is determined by what type of paint is intended to be used.
- Penetrating soils based on acrylic resins are the most versatile. They are used under any type of paint, since they are almost completely absorbed into the wood, without leaving a film on its surface with the possibility of subsequent delamination.
- Silicone-acrylic primers characterized by pronounced water-repellent properties. After their application, the moisture content of the wood is stabilized and practically does not change with fluctuations in atmospheric humidity. It is clear that for complete protection from dampness, a water-repellent primer is applied over the entire surface of each element of a wooden structure.
- Alkyd primers are used, respectively, for painting alkyd enamels(PF-115 and its imported analogues). In essence, primers of this type are identical in composition to enamels, but contain a larger amount of solvent, dry faster and contain the cheapest possible pigments.
In addition: primers make the surface rough after drying. Thanks to this feature, the adhesion of the paint to the base is made more reliable.
- Polyurethane primers are characterized by a relatively high cost and are intended for preparing wood for coating with parquet varnishes based on polyurethane synthetic resins. As in the case alkyd primers, they differ from varnish only in the large amount of solvent and the absence of tinting additives.
- Drying oil is traditionally used as a primer for oil paints. By impregnating the wood to a depth of several millimeters, it not only ensures the most reliable adhesion of the paint to the base, but also protects the wood from dampness and rotting.
Preparing a wooden surface for painting
We found out how to prime wood before painting. How can you completely prepare a wooden surface for painting with your own hands?
Over old paint
If the type of old paint matches that which is intended to be used, complete stripping of the coating is not required. Oil, alkyd or nitro enamel is sanded with sandpaper or a sanding mesh to obtain a rough surface; peeled areas of the coating are removed with a spatula and thoroughly sanded.
If the color does not match, as already mentioned, apply separation layer primers of the appropriate type. You can paint it after it has completely dried.
If the old coating has a different composition from the new one (for example, instead of oil paint wooden lining It is supposed to be painted with water-dispersion acrylic paint), the coating is heated with a construction hairdryer and removed with a hard .
Remains of paint are removed with solvent. Then the base is primed - first with an antiseptic, then with a suitable primer for painting.
The photo shows stripping the paint with a hairdryer and spatula.
Tip: Many all-purpose penetrating primers already contain antiseptic additives. In addition, a concentrated antiseptic can be independently added to water-based soil.
On fresh wood
Here, the instructions for preparing the surface are relatively simple.
- The base is sanded or scraped.
- Defects and cracks are filled. This type of putty is quite elastic and does not crack when the linear dimensions of the wood fluctuate.
- The surface is swept away from dust and primed. As a rule, a wide brush or spray is used on wooden surfaces; penetrating soils on acrylic base For better impregnation, apply twice.
As always, the video in this article will offer the reader additional information. Good luck!
In the era of metal and plastic, which surrounds us everywhere - on the street, at work, at home, does not go out of fashion and natural wood. At the same time, wooden products require careful care, and only then will they serve us as long as possible. Natural materials have always been popular, despite the fact that they are more expensive: wooden furniture, window frames, doors, flooring - we live among all this every day. After all, they are environmentally friendly and do not emit any toxins, unlike artificial materials.
But at the same time, wood is very susceptible to damage and destruction under the influence of various factors. So, with excessive humidity or direct contact with water, the wood swells and becomes deformed. If protective measures are not taken in time, it will simply collapse. When exposed to the sun, the material burns out and dries out, which also has a detrimental effect on its structure. Wood is a favorite place for insects, mold and mildew.
The substance tannin, which is contained in wood, often appears on the surface, thereby deteriorating appearance wood covering. Therefore, wooden products must be periodically treated with protective agents.
To protect wood as much as possible would be better suited primer and varnish or paint. The soil will help protect the surface from fungal formations, fill all cracks and roughness, and in this way make it more durable. And it will fulfill its main task - it will help the varnish or paint to adhere well to the wooden base.
Why prime wooden surfaces?
A primer for exterior woodwork is mandatory, because it is the outdoors that affects the material the most natural factors: rain, moisture, temperature changes. Various elements Roofs, façade design, fences and railings must be protected from damage by priming and painting.
Tip: The main criterion when choosing a primer for exterior work is that the composition should create a waterproof coating.
Also, such treatment requires wooden structures that are located indoors, but are in contact with the facade walls. Indoors, you need to take care of the wood products that are available in rooms with high humidity or unheated: bathrooms, loggias, balconies.
Types of primers
There are a variety of primer compositions, which are classified according to different criteria. So, the choice of primer depends on the following factors:
- The surface material that we will process (metal, concrete, gypsum board, plastic, brick, etc.);
- What kind of work is it intended for - interior or façade;
- Method of application to the surface - roller, brush, spray.
A high-quality composition should have the following properties: absorb well into the surface and dry quickly. So, for porous surfaces such as gypsum or wood, a material is needed that penetrates deeply into the structure of the base and creates good conditions to interact with finishing material. For these purposes, penetrating soil is used. At the same time, the composition partially fills the pores, thereby reducing consumption finishing composition.
But for concrete slabs, tiles you need a composition that will promote the adhesion of putty, plaster and other solutions to the base. Indeed, due to the smoothness of the coating and the practically absence of pores, the solutions adhere very poorly to such walls. In this case, use an adhesive primer.
This type of soil is also called Concrete contact. Due to the content of quartz sand in the composition, it creates a rough coating on a smooth surface. And due to this, the solution adheres better to the surface. Consumption rate different types soil is specified in SNIP, these are average figures. In practice, there may be other material costs.
Primer for walls is available on a water, organic and mineral basis.
Water-soluble products include acrylic, latex, silicate and silicone products. In alkyd compositions, organic components act as solvents. In mineral formulas, the base is cement, gypsum and lime.
Primer consumption according to GOST:
| Type | Consumption in g per 1m2 |
|---|---|
| GF-021 | 60-100 |
| GF-115 | 110-130 |
On the market today building mixtures presented to the buyer huge assortment materials. And compositions, both imported and domestically produced, are popular.
According to the type of primer base, there are the following:
- Acrylic primer for wood – due to its component composition have excellent technical characteristics. This type of soil is suitable for processing bases made of any material - from plastic to concrete. And at the same time creates optimal conditions for applying putty. In turn, primers based on acrylic additives can be both universal and narrow-purpose - for wood, metal, plastic, concrete, etc.
- Alkyd primer - used for treating wooden bases, concrete, and metal. Contains components that serve as protection against fungal growths and mold. It will protect the wood from swelling, and concrete coverings from moisture.
Alkyd enamel for interior and exterior use:
- Latex type - used in rooms with high humidity: kitchen, bathroom, swimming pool. A film is formed on the treated surface that will protect the coating from moisture.
- Polyvinyl acetate composition - this primer is used to treat walls that will then be painted.
- Polyurethane based primer is used for impregnation parquet board before painting with polyurethane resin compositions. Its composition is similar to varnish - it contains a solvent and gives a colorless coating.
- Shellac primer smoothes the surface and prevents resin from leaking out. Shellac in the stain plays the role of an insulating additive.
- Drying oil is used for oil-based coloring compositions. This coating protects the wood from moisture and improves its adhesive properties.
Anti-corrosion and antiseptic primer
A primer for wood with an antiseptic effect will protect the wood coating from various pests and insects, fungal growths and mold. Anti-corrosion compounds will prevent corrosion from damaging the surface.
Mistakes when applying primer for wood (video)
Deep penetration primer
Deep penetration soil is used to strengthen the structure of old and loose wood. Thanks to this coating, the base will become stronger and will last for some time. Also, this type of composition will help protect products from pests and rotting. Deep penetration soil Ceresit has proven itself to be of excellent quality.
Primer with varnish
Varnished primer is a dual action product. It is used for processing wooden floor coverings. This option is more affordable than purchasing two products separately.
Waterproofing agents
Compositions with waterproofing properties are used to treat wooden products in rooms with high humidity and outdoors. Inside I process wood in baths, swimming pools, kitchens and kitchen utensils. Waterproofing primer for wood Alpina is an excellent option for treating wood products.
Universal primer
Universal formulations have excellent characteristics, suitable for any type of surface: from wood to concrete. Such soil for preparing the foundation for decorative finishing will create optimal conditions for putty, plaster, paint and other materials. The universal primer Capalac Classic is ideal for processing wooden products for further finishing.
How to prime wooden surfaces?
Wood primer for painting has its own rules and characteristics. Priming and painting must be carried out at air temperatures from 5 to 30 degrees. At low temperatures the composition will simply lose its properties, and at high temperatures it will dry out quickly and the surface will not be properly saturated. Before you start applying paint and varnish, you need to decide on the composition of the soil and prepare the base for treatment. Preparation consists of cleaning from dirt and grinding with an abrasive material.
If we paint over the old paint with a composition similar to the previous one, then there is no need to completely sand the wood. old oil paint and clean the nitro enamel with sandpaper. We need to get roughness on the wood for adhesion to the materials. Apply the primer composition in two layers.
When processing fresh wood, the best composition would be acrylic primer and paint. This primer needs to be applied in 2 or 3 layers. Can be used as liquid primer, and aerosol - in cans. In order not to spend money on buying a primer, you can prepare it yourself from starch.
Priming wood before painting saves paint
Wood is a very popular material for construction, decoration, furniture and household items. Over many centuries of use, it not only has not lost its relevance, but has also become even more popular, and the methods of its processing have become even more advanced.
One of them - priming before painting wood - allows you to extend its service life and make the finishing process simple and economical.
Depending on the operating conditions, wooden structures are subjected to various kinds external influences. Some of them only affect the appearance of the wood, others can destroy its structure over time, and others, among other things, negatively affect human health.
These include:
- Direct sun rays– dry the wood, change its color;
- Air humidity and precipitation cause swelling, deformation, trigger the processes of rotting and mold growth;
- Insect pests sharpen wood and destroy its structure.
To protect structures from these harmful factors and give them aesthetic appearance, they are subjected to painting, varnishing and other types of external finishing. But first the wood is primed before painting. Why is it needed?
Primers fill all the pores and cracks in the wood, so that fungi and mold do not develop in them. And if the primer for wood for painting contains fungicides and insecticides, then this becomes impossible in principle, and will also protect the material from pest invasion.
But this is not the only purpose of the primer; special protective impregnations can also cope with such tasks. And with the help of priming, the surface of the wood acquires strength and smoothness, becomes less permeable, so the paint lies on it in an even layer, is not absorbed, and therefore is used more economically.
In addition, it provides better adhesion of the finishing composition to the surface of the wood, so it will last longer without peeling or crumbling.
Considering that the price of the primer is significantly lower than the cost quality paint, then the benefits and benefits of its use become obvious. Especially if you have a large area to paint.
How and with what to prime wood
For those who are superficially familiar with wood processing technology and are planning to build with their own hands for the first time wooden fence, sheathing walls or, for example, making a crib, the following information will be useful.
What wood needs priming?
If you are doing interior work, want to preserve the natural beauty and structure of the wood and are not going to paint it, there is no need for priming. It is enough to treat it with impregnation - transparent or tinted - to simply protect it from changes in humidity, mold, bugs and achieve color harmony with other interior details.
The wooden rack in the photo is tinted to match the color of the trim and baseboards
But in the following cases, this step absolutely cannot be skipped:
- If wooden structures will “work” in the open air. They are more exposed to changes in temperature and humidity, as well as to rot and insects. These are fences, entrance doors, windows, roofing elements, external cladding buildings, etc.;
Wooden elements in contact with the external environment need reliable protection
- If the wood is finished with wet or unheated premises– bathrooms, balconies, terraces, verandas;
- If internal structures are in contact with external walls;
- If there are noticeable defects on the surface that need to be sealed with putty;
- If wooden surface Regardless of the purpose and operating conditions, it is intended for painting or opening with varnish.
Types of primer for wood
Before priming the wood before painting, you need to choose the right composition, meeting your requirements. There aren't many of them.
| Type of primer | Properties | Purpose | Note |
| Alkyd | They strengthen the pores of wood, reduce the absorbency of the treated surface, and prevent swelling of the fibers. | Designed for initial application on fresh untreated wood, chipboard, fiberboard. | They contain organic solvents, so they are not recommended for use in residential areas. |
| Acrylic | They have the same properties. | Preparation wooden base for painting with water-based, alkyd, latex paints. | They dry quickly, can be diluted with water, and are safe for health. |
| Antiseptic | They prevent and eliminate fungal infections and preserve wood. | Used to protect structures operated in difficult conditions. | Unpainted surfaces should be treated every 3-5 years. |
| Shellac | Neutralizes the effect of resins that can discolor the finish coat. | Used for wood coniferous species, processing of knots. |
Pay attention! When working with primers containing toxic insecticidal or fungicidal additives, safety rules must be followed.
Application
Applying a primer layer is an elementary task that even a child can handle. The product is always accompanied by instructions for use indicating the method and conditions of application. It is more important to properly prepare the surface, especially when processing old wood.
To do this, it is cleaned of all possible contaminants: dust, greasy stains, bitumen, old paint. Remove unnecessary nails and screws.
If necessary, sand with sandpaper or special tool. If water was used for cleaning, the surface must be thoroughly dried.
Only after this can you begin priming, using a brush, roller or spray gun.
The sprayer gives a high flow rate, but allows you to treat the most inaccessible places
Please note. The first layer of wood primer before painting should be as fluid as possible so that the composition fills all microcracks. Dilute it according to the manufacturer's directions.
You can see how this process is performed from start to finish by watching the video posted on this page.
And to avoid mistakes, try to follow the following rules:
- Any surface, including wood, should be treated with a primer at low humidity and positive air temperature. The composition dries best in the temperature range from 5 to 30 degrees;
Important. In extreme heat, the primer will dry very quickly, but will not have time to penetrate to a sufficient depth, which will reduce the quality of the treatment.
- For processing materials such as plywood or particle boards, you should use a deep penetration primer and apply it in 3-4 layers;
- Each layer must completely dry before applying the next;
- The more layers of soil you apply, the deeper the material will be saturated;
- It is not necessary to apply expensive primer for subsequent painting. The quality of processing can be improved by increasing the number of layers.
Conclusion
Now you know how to prime wood before painting, why and how to do it. Even if the wood does not need protection and will be used in a dry and heated room, a primer layer will improve the quality finishing and will allow you to save on expensive materials.
