Overview of rust primers for metal

Anti-corrosion primer action

After application, the primer begins to transform the rust into a compound that is not able to oxidize, and a strong film appears on the surface. If the corrosion spot is too thick, a preliminary cleaning is carried out, removing the most fragile layers, otherwise the quality of the coating will be low.

If a metal and rust primer is used for outdoor work, then processing can be carried out regardless of the level of atmospheric humidity and temperature. In the case of application of the internal composition, it should be ensured that the working conditions are suitable. The duration of soil hardening depends on the thermal regime and the individual properties of the substance itself.

Corrosion product modifiers

Today on sale you can find many metal primers for metal for rust, which differ in the active substance, reaction rate and other properties. The most popular formulations are based on phosphoric acids; there are also products based on tannin and other components in the assortment of stores. Classification of modifiers:

• Stabilizers. They convert iron oxide hydrates, which have an unstable structure, into compounds that are more resistant to attack, for example, into magnetite.
• Converters. As a result of a chemical reaction of a product with corrosive spots, poorly soluble salts appear on the surface. These include all iron, zinc, barium and manganese phosphates.
• Rust penetrating primers. They are distinguished by high penetrating properties, after impregnation, the composition seals the corrosive product, making it resistant to external influences.
• Modifiers that create a solid base: it serves for the subsequent treatment of a metal surface with paint or varnish.

Where should a primer-modifier not be applied?

In some cases, it is impractical to use compositions that form a base on metal with rust stains:

1. Corrosion spots occupy more than a third of the entire surface.
2. The dross has a thick layer with a loose texture.
3. The foci of rust are through, in this case the use of a primer is ineffective: first you need to remove the holes.

Most often, such problems arise in structures that are in contact with a humid environment on a permanent basis. Rusting of the surface goes faster if it has not been protected with special means, and after a few days such a product begins to become stained. The longer the surface is in contact with water, the more it will be damaged, respectively, the effectiveness of the use of primer compositions greatly decreases.

Composition and specifications

The primer for the facade differs from other types of external coatings, given the increased requirements for them. The necessary qualities are provided by the chemical and physical composition. The presence of certain components depends on the type of construction impregnation. The main options are represented by the following primers.

1. Acrylic - a solution of polymer resin acts as the main substance. Additional elements are water, vegetable components, sand, abrasive particles, and dyes. The mortars are versatile, suitable for most exterior walls. They have practically no toxic effect, odorless. Dry very quickly upon application. Well diluted with water.
2. Alkyd - the base substance is a synthetic polymer that dries quickly and prevents corrosion.Therefore, it is successfully used for starting processing of wood and metal structures. Possesses high hygroscopic properties. Relatively inexpensive kind of base. Excellent base for ceramic tiles.
3. Mineral - the composition includes components such as lime, cement, gypsum. The mortar serves as a base when working with wet mineral materials - concrete, brick, plaster. The thick consistency evens out the outer coatings. However, an external primer should be selected taking into account the type of base coat.
4. Universal two-component based on a polyurethane component - suitable for most walls as a starting mortar. Convenient to use, dries quickly, has high resistance to external factors. The only drawback is the high price of a universal primer.
5. Base mortar with alkali-resistant quartz sand - creates an outer surface with a rough texture. Due to its special composition, it has unique properties that promote adhesion of materials.

Given the variety of facade primers, before purchasing, you must read the instructions for use.

Consumption for 1 m 2

For different types of mixtures, certain criteria are provided for the volume that is required for application. The composition of the outdoor primer determines the amount of substance required to sufficiently impregnate the walls. The calculation is carried out per square meter of coverage.

• If an acrylic facade primer is used, take up to 120 - 150 ml.
• Alkyd mixtures for wood, chipboard, MDP are used from 100 to 120 ml.
• When you need to prepare metal surfaces for painting, you will need 80 - 120 ml of starting composition.
• When using primers for deep penetration of the facade, take about 100 ml.
• The amount of the mineral solution is 300 ml.
• Most anti-corrosive primer external mixtures are calculated on the basis of an amount of 60 to 80 g per square meter.

However, before buying, you should read the information on the label, where the manufacturer indicates the exact amount of outdoor mixture required for processing external surfaces. In this case, it is imperative to take into account the type of material on which the primer will be applied. The more pores and small cracks, the more the mixture will be needed.

Hygroscopic, loose material may require multiple layers. The volume of the consumable solution is influenced by environmental conditions and the type of decorative coating. If the main walls of the building are subsequently covered with siding, porcelain stoneware, stone, then one layer of the base solution is applied. For painting, the surface should be primed at least twice.

Secondary primers

The functions of fillers are diverse, since they are the final stage of work before applying the enamel and are designed to eliminate all existing surface defects, align surfaces and joints, isolate problematic materials and ensure a tight adhesion of paint. When working with them, it is required to exclude the slightest risks and carefully grind the surfaces (to a depth of 30 microns). Alignment should remove all defects and pores remaining after the putty, level the transitions from one plane to another.

Colored, paintable

The use of colored soils became popular in the 80s and 90s. last century. Few imagined that such a simple know-how as adding coloring pigments to a mixture would become widespread and would give such great savings in material consumption. This is especially true for the interior and under the bonnet. The Japanese, Koreans, and, more recently, AvtoVAZ refused to paint them, considering it sufficient to process them with a colored (tinted) primer coating.

High-build primers

The standard thickness of primers applied in 2-3 layers is 100-140 microns.However, a number of manufacturers (Liqui Moly, AUTOP) produce formulations that when applied, form a layer of 260-300 microns. They are convenient to use on large surfaces for major refurbishment. The use of such primers provides high-quality leveling and allows you to exclude the putty stage from the processing process. These primers are most commonly sprayed and exhibit good wet adhesion.

Firms of soil-aerosols

The convenience of using the formulations in aerosol cans, their ability to dry quickly and the ability to save time and effort (no dilution of the mixture and work with a spray gun is required) were highly appreciated by the repairmen. The Russian market today is dominated by such manufacturers as Kudo, Sadolin, Loctite, Jeta Pro, Brulex, NOVOL and many others. The price is also attractive - from 250 rubles. up to 800 rubles for a can with a capacity of 0.5 liters.

The main types of primers

Let's consider the main types of primers suitable for application to a metal surface.

Phosphating

The mixture is based on solvents and orthophosphate acid. This type of primer is a universal solution that is suitable for the treatment of any metal structures. The composition is recommended to be applied to objects that are not subject to corrosion.

Phosphating primers have good adhesion; during operation, they create a porous layer on which the paint and varnish material can easily be applied. Typically, these solutions are used to treat steel, aluminum and galvanized surfaces.

The compositions are well combined with paints with alkyd, ethanol and epoxy bases. The phosphating primer is characterized by high temperature resistance, it can withstand the temperature range from +150 to +220 degrees Celsius. After applying the mixture, the surface acquires dielectric properties. The disadvantages of the soil include low corrosion protection.

Passivating

The main components of the composition are chromic acid salts: chromates of strontium, barium, calcium, lead, zinc. Moreover, chromates are widely used passivators. They tend to make the transition of metals from an active state to a passive one. The coating after priming will not interact with the environment.

For the protection of aluminum structures, compositions are well suited, the main part of which is dichromate salts. When working with ferrous metals, conventional chromates are sufficient. As a rule, stronz and zinc compounds become components of the passivating primer.

The high concentration of salts provides a high-quality protective coating.

Isoning

The base of the primer is called neutral pigments, such as red lead iron, which creates a film on the metal that is resistant to moisture. Unfortunately, the mixture has a short duration of this effect and the liquid seeping through the coating starts the rusting process.

Transformative

The primer solution for metal products can be applied to a surface that contains traces of corrosion. The composition converts rust into a kind of compound, which undergoes rapid destruction.

The components of the mixture are surfactants that provide easy penetration of soil particles through corrosion layers.

The combination of a converting composition with a passivating material is optimal.

Protective

Products containing magnesium, zinc and aluminum powders fight rust. Soil quality is in direct proportion to the concentration of the above components. The higher their number, the better the soil.

The most popular material used for the pretreatment of metal structures is a composition with zinc dust.

Inhibitory

This metal primer is widely used to protect surfaces from corrosion. The metal processing process creates an enamel-primer on the surface of the product.Inhibitors can dissolve in both water and oil.

Alkyd

The product belongs to insulating and passivating soils. Its main purpose is to combat corrosion.

The components of the soil are fillers based on iron red lead, white, etc.

Tips and tricks for use

Any construction work has its own specifics and fundamental principles of implementation.

For work with a primer on metal, a number of general recommendations can be distinguished:

• it is best to use liquid formulations with a spray gun;
• mixtures on a water-dispersion basis dry very quickly, therefore, the surface is covered with a second layer immediately;
• for small designs or products, you should choose a spray. The aerosol is very convenient to use, but on condition that it is required to apply the composition on a small plane;
• surface treatment should be carried out without interruption. Therefore, the calculation of the amount of the required composition should be performed without fail;
• two or three thin layers will form much better than a thick one;
• a sanded surface makes it possible to obtain a better result from priming;
• coloring compositions are required to be applied immediately after the primer has dried. Due to delay, dust will appear on the coating, which will lead to a decrease in adhesion to the paint.

Competent observance of all the preparatory stages preceding the application of the primer, the choice of suitable products, carried out taking into account all the nuances related to the specifics of the surface and the means for applying an anti-corrosion coating, will ensure an attractive appearance of the product or the whole structure. This will significantly extend the service life and postpone the need for repair work for a sufficiently long period.

A properly primed and painted product, facade, structure, detail or surface in the room will be reliably protected from negative environmental influences, mechanical contacts, and will also give a certain aesthetic pleasure from contemplating a fresh and neat surface.

For information on how to apply a primer on metal, see the next video.

Technology: how to paint metal surfaces on the street

It would seem that there is nothing difficult - take a brush and apply a layer. But much depends on the preparation of surfaces and the correct choice of paints and varnishes. If you pick up a paint that is not suitable for a certain type of metal, then it will quickly crack.

Paint for painting metal surfaces outdoors should contain anti-corrosion agents, preferably with rust converters.

How to determine the quality of metal

Most often, fences and other structures are made of black iron, which quickly rusts. In order to slow down the oxidation process, cover the parts with an alkyd primer.

Galvanized metal parts, especially roofs, are painted with alkyd paint.

As for non-ferrous metals (for example, copper is a red metal), they are almost never painted; in extreme cases, they are varnished (epoxy or polyurethane).

Work order

If the damage is minor, before starting work, treat the metal surface with a degreasing solution, then the paint will "lie" well and adhere to the base material.

If the metal is covered with a thick layer of rusty coating, remove it with a special locksmith tool (scraper). With a pointed tip, layers up to 0.01 mm thick can be removed.

It is not necessary to clean everything to the ground, a thin, even layer of rust is acceptable.

If there is no scraper, you can use an emery cloth, a brush with metal teeth. For cleaning slightly damaged parts, a simple metal sponge is suitable.

You can not remove rust, but treat it with phosphoric acid (included in some solutions) and apply a layer of paint on top. Phosphoric acid is best used in advanced cases.

Important! Wear gloves and a respirator mask before handling metal with any chemical agent. After removing rust and treating parts with solvents and degreaser, wait until the structure is dry

Do not apply paint to a damp structure

After removing rust and treating parts with solvents and degreaser, wait until the structure is dry. Do not apply paint to a damp structure.

Designs are advised to wash with plain water and soap.

What paint is suitable for untreated surfaces:

• The composition contains corrosion inhibitors, substances that slow down the formation of rust.
• The thickness of the protective film is not less than 150 microns.

The next step after drying is priming the surface. The primer provides additional protection, enhances adhesion to the material (it is recommended to apply 2 layers).

For ferrous metal, take an anti-corrosion primer, for non-ferrous metal a mixture with good adhesion or varnish.

After the primer is dry, paint can be started.

The nuances of staining

It is more convenient to paint twisted fences, enclosures or decorative iron figures with a brush - it will crawl into all hard-to-reach places and paint over small details.

Apply several coats (before applying the second, wait for the first to dry).

The number of coats depends on how well the surface was processed and what compounds were used. If there was no pretreatment or cleaning, then more paint will be needed.

It is easier to paint small areas with an aerosol can, the main thing is not to be interrupted during application - the jet should go continuously, and the distance of the spray from the surface is no more than 20 cm.At least 3-4 layers will be required.

Wait until the previous coat is dry before re-spraying (about 15 minutes).

It is better to paint metal surfaces on large areas (for example, roofs) with a wide, but not very hard roller. If you paint with hard, then you have to go back and paint over the missing areas.

In the enamel for outdoor use, you need to add a solvent (10% of the volume of the can).

The maximum number of layers is 3.

Only a flat surface is painted with a roller, the corners and joints are painted over separately with a brush. Immerse the roller in a tray of paint, squeeze lightly on the mesh (so as not to splatter) and hold it against a wall or metal covering. Movements need to be done up and down, and overlap the stripes themselves with a slight overlap.

The most popular grades of primers for aluminum

Hand sanding or grinder is used when sanding to solve problems with aluminum surfaces. Due to the protection against acidic substances, it is permissible to carry out etching with their help. The correct choice of formulations also plays a role.

Hand sanding or grinder is used when sanding to solve problems with aluminum surfaces.

Primer brand VL-02

Manufactured taking into account all the requirements described in GOST 12707-77. A two-component composition based on thinners. To create a base for this primer, other types of components can also be used:

• Acidic additives that dissolve the surface. Usually these are water-alcohol solutions, to which phosphoric acid is added;
• Polyvinyl butyral. Formed when oily aldehydes react with polyvinyl alcohol. Ensures increased adhesion to non-ferrous metals. Resistance to mechanical damage after application is guaranteed;
• Zinc crown with high concentration. Pigmented yellow-colored substance, protected from corrosion.

A two-component composition based on thinners.

Body brand primer

A foreign company that has released its own alternative for domestic developments. In the case of non-ferrous metals, the variety marked 969 is used.There is an acid etching primer from the same manufacturer, with its own characteristics and scope.

In the case of non-ferrous metals, the variety marked 969 is used.

VL-08

Forms a greenish-yellow protective film. Retains its properties for at least 6 months, requires a minimum of two-layer application. Forms a semi-matte glaze coating, refers to elastic types of protection.

Retains its properties for at least 6 months, requires a minimum of two-layer application.

GF 031

Glyphthal paint and varnish material. Designed to protect structures, which are also operated at elevated temperatures. The main thing is to mix the composition thoroughly before a homogeneous mixture is formed. The brush or pneumatic method is best for spreading over the surface.

Designed to protect structures, which are also operated at elevated temperatures.

Zinc-based white

Absolutely white product with a slight bluish tint when it comes to its original form. Absolutely free of any odors. Protected from the effects of harmful microorganisms and bacteria, does not degrade if present.

They differ in the following positive properties:

• Resistance to weathering;
• Compatible with different types of paints;
• Easy application;
• Sun protection;
• Low toxicity.

Protected from the effects of harmful microorganisms and bacteria, does not degrade if present.

EP-51

Enamel intended for painting primed products made of metal, which includes aluminum. The suspension must be thoroughly mixed prior to application, until the sediment is completely removed. In this case, the surface to be treated must be dry and even, free from serious contamination. Then it will be easy to paint everything.

The surface to be treated must be dry and level, free from serious contamination.

Types of rust primers

Product classification is possible according to several criteria, from the type of metal and processing conditions to the period for hardening. The scope and effectiveness of such compositions depends on this.

By composition

Depending on the base, the substances can be oily, aqueous or combined. According to their structure, they are divided into paints, enamels and varnishes. The composition also allows you to classify products according to additional criteria:

• Scope of use (indoor, outdoor).
• Hazard class (if the rust primer contains toxic substances, it is prohibited to use it on indoor surfaces).
• Substance consumption per square meter.

By properties

According to the method of action, primers are passivating, phosphating, isolates, converters and protectors. With regard to compositions designed to affect corrosion, the following varieties are distinguished:

1. Primary composition. Its effect is to transform the oxidized fragments into a protective shell.
2. 2 in 1 - a product that combines the properties of a filler and a primary substance.
3. 3-in-1 primer is similar in rust to the previous type, but also has the qualities of a composition for the final coat. It is its application that provides the greatest effect.

Choosing the right soil mixture

When buying a primer, there are several main factors to consider:

• what metal will be processed: black or non-ferrous;
• the presence of a quality certificate in the product, which guarantees its safety;
• a kind of topcoat that will eventually fall on the surface;
• parameters of composition consumption per 1 m2 of surface;
• what load will be on the surface, the primer will be applied from the outside or from the inside.

Considering all these parameters, it is possible to choose the ideal composition for a specific type of work. Each type of metal has its own types of primer. There are compounds for cast iron, zinc, non-ferrous alloys, steel and iron.

Be sure to take into account the tool that will be applied. If a spray gun is used, then the composition must be liquid. If you use the powder version of the soil mixture, then it must be diluted strictly according to the instructions.

When applied with a roller, any form of mixture release is perfect. When applied correctly, this is an economical way to use material.

Small areas and hard-to-reach surfaces are treated with a brush.

Aerosol formulations are more expensive.

Temperature norms

Heat-resistant soils have special formulations adapted to strictly defined conditions. When choosing a product, you need to have an accurate idea of ​​the planned regime of thermal loads, inquire about the recommendations of the manufacturers displayed on the labels.

Heat-resistant primer is available for use in the following temperature ranges:

• from room temperature to 60 ° C;
• no more than 100 ° С;
• up to 300 ° C;
• more than 300 ° C.

Products of the first group are used for water heating systems in apartments or houses; the second is for steam systems, fireplaces, ovens' outer surfaces.

Soils with higher fire-retardant properties are designed for powerful household heaters, industrial installations operated in severe mode.