Alkyd and acrylic compatibility. The difference between alkyd and acrylic paints, are acrylic and alkyd paints compatible? Lacquering technology

The right combination of materials. The difference between acrylic and alkyd enamels and general recommendations by application.

Properties of one-component acrylic enamels

Unlike acrylic emulsions in jars, aerosol acrylic enamels are not water-based, but organic.

Advantages (compared to alkyd spray enamels):

• high drying speed;
• saturated colors;
• high elasticity and high adhesion to plastics (due to these properties, acrylic enamels are preferable for application to plastic surfaces).

Disadvantages (compared to alkyd spray enamels):

• moderate weather resistance;
• moderate adhesion to metals (preliminary priming is required);
• moderate solvent resistance.

Properties of one-component alkyd enamels

The peculiarity of alkyd enamels in comparison with acrylic ones is that after drying chemical processes they don't end there. After the solvent has evaporated, the polymerization process continues in the alkyd enamel under the action of atmospheric oxygen. The molecules “crosslink” with each other and, figuratively speaking, form one large molecule, making the coating more durable and resistant to various influences, but at the same time less elastic and more brittle. However, alkyds have been discovered for a very long time and are very well studied. Modern KUDO formulations take this fact into account, and even after complete polymerization, the paint film remains quite elastic. The polymerization process can last from several days to two weeks. During polymerization, the coating must not be subjected to mechanical stress. For example, an element of an automobile body painted with alkyd enamel cannot be washed and polished for two weeks. Also, during polymerization, alkyd enamel cannot be topcoated with other paints and varnishes, even on an alkyd basis - the coating may be damaged. It is necessary to cover either “wet on wet”, that is, apply the next coating immediately after drying “to the touch”, or after waiting for complete polymerization.

Advantages (compared to acrylic spray enamels):

• high adhesion to metals;
• higher hardness;
• higher weather resistance;
• higher light resistance (less fade);
• higher solvent resistance.

Disadvantages (compared to acrylic spray enamels):

• more long time drying;
• long polymerization process.

Table of correct combinations

* Intermediate drying time between coats, dry-to-touch time, full dry time and time for the base to gain full mechanical strength are indicated in the instructions for use of each specific product.

** We recommend using the color of the primer as close as possible to the color of the enamel.
If the acrylic base is brightly colored, then when applying a thick layer of alkyd coating on it (especially light colors) the bright pigment of the base can “rise”. The same is possible when applying an alkyd coating on an alkyd base "wet on wet".
For example, if a brown-red acrylic primer is painted with white alkyd enamel, then there is a good chance of getting a pink finish.

How to apply an acrylic coating on an acrylic base.

Acrylic coating can be applied to the acrylic base, waiting for the base to dry “to the touch”.
You can also apply the coating after the base has completely dried.

How to apply an alkyd coating on an acrylic base.

An alkyd coating can be applied over an acrylic base, waiting for the base to dry to the touch.
You can also apply the coating after the base has completely dried.
Attention! Do not apply aclide-urethane coatings, in particular yacht varnish, to one-component acrylic primer - the base may swell.

How to apply an acrylic coating on an alkyd base.

The alkyd base must not be covered with paints and varnishes during its polymerization - the alkyd base may swell.
It is necessary to apply an acrylic coating on an alkyd base either “wet on wet”, that is, immediately after the base has dried “to touch” (no later than 1.5 hours after applying the base), or after waiting for complete polymerization, when the coating gains full strength.
When applied “wet on wet”, the adhesion of the applied layer will be higher than when applied after full cure.

How to apply an alkyd coating on an alkyd base.

The alkyd base must not be coated with paints and varnishes during its polymerization - the alkyd base can swell even if the same composition is applied as in the base.
It is necessary to apply an alkyd coating on an alkyd base either “wet on wet”, that is, immediately after the base has dried “to the touch” (no later than 1.5 hours after applying the base), or after waiting for complete polymerization, when the coating gains full strength.
When applied “wet on wet”, the adhesion of the applied layer will be higher than when applied after full cure.

Intermediate drying time between coats, dry-to-touch time, full dry time and time for the base to gain full mechanical strength are indicated in the instructions for use of each specific product.

Alkyd and acrylic paints are among the most common types of paint when it comes to serious painting works: wall painting, metal products etc. Perhaps due to the similarity of the name, they are often confused. Do these types of paints really have something in common?

In fact, the only similarity is that both are paints. Their composition is completely different.

Alkyd type can be called a more modernized option oil paints. They are characterized by a similar mechanism of hardening and the formation of a surface film (which, by the way, is somewhat stronger, but less elastic). Alkyd paints consist of polyhydric alcohols (for example, glycerin) in combination with orthophthalic acid. Actually, the word "alkyd" comes from a combination of the words "alcohol" (alcohol) and "acid" (acid).

Unlike alkyd paints, acrylic paints are made on the basis of acrylic, a polymer better known as plexiglass. The composition of paints may include various additional components designed to improve certain properties (add elasticity, speed up drying).

• Life time. In acrylic paint, unlike alkyd, the surface retains its original appearance much longer. It is advisable to renew alkyd paint about once a year, since oxygen and ultraviolet intensely destroy the surface layer of paint. Acrylic coating, subject to the technology of surface preparation and paint application, can last from 8 (wood) to 20 (plaster) years.
• UV resistant. Acrylic practically does not change the properties of the surface film under the influence of sun rays, that is, it does not fade, does not turn yellow and does not take on a “matte” look. Alkyd compounds in this regard are not so reliable.
• Drying process. But the alkyd film dries relatively quickly, and after a couple of days it fully performs its protective and decorative functions. Acrylic film finishes its formation in about a month after application to the surface. In this case, the coating should be protected from mechanical influences until it is completely dry.
• Mechanical stability. The longer process of acrylic film formation is compensated by more high level resistance to mechanical influences (deformations, scratches).
• decorative properties. Alkyd compositions are distinguished by a more diverse range of shades and halftones, as well as, in general, more bright colors. On the other hand, acrylic paint lasts longer and does not require regular renewal.

Can alkyd compounds be applied to acrylic or vice versa? Neither is recommended, especially if the base has been painted relatively recently or if it is a metal surface. The fact is that the specific composition of the paints may not be completely clear to us. Alkyd compounds may contain components that will show through the layer of acrylic paint as dark spots. If alkyd paint applied over acrylic, it may not be fixed on it, that is, it may peel off.

The only option for applying such paints to each other: applying to the old coating, from which all volatile components have already disappeared. However, even in this case, apply upper layer paint should only be applied after surface treatment with a primer of the same type (i.e. acrylic paint on acrylic primer and vice versa).

Consumers are often faced with a choice: which paint to prefer - acrylic or alkyd? To answer this question, it is necessary to understand the features of these compounds, their advantages and disadvantages.

Alkyd paints

Alkyd paints and varnishes (LKM) can be attributed to an advanced variety oil formulations. For alkyd paints, the same mechanism of hardening and film formation is inherent. Moreover, the film is more durable, although not so elastic. To correct the lack of elasticity, natural oils are added to alkyd mixtures.

The composition of alkyd coatings includes polyhydric alcohols (for example, propane-1,2,3-triol, otherwise called glycerin), as well as orthophthalic acid. The word "alkyd" itself is a construction formed from a combination of the words "alcohol" (alcohol) and "acid" (acid). Depending on the type of alcohol component, alkyd coatings are divided into pentaphthalic and glyphthalic.

Alkyd paints - one of the most common types paintwork materials and there are many reasons for this:

1. Low cost is perhaps the main advantage of alkyd formulations. The availability of paint is especially important with a limited budget or the need to paint large surfaces.
2. Working with alkyd coatings is simple: no special instructions are needed, and all work can be done independently. The composition is diluted with an organic solvent and applied with a brush or roller.
3. The coating dries quickly enough, and the initial polymerization occurs after about 60 minutes. Complete drying occurs in a few days. The dried surface is ready for operation in the conditions of the adverse environment.
4. Alkyd coatings are resistant to moisture.
5. Coatings are neutral to aggressive chemicals(for example, household chemicals).

Disadvantages of alkyd compounds:

1. Insufficient wear resistance and resistance to mechanical stress. The durability of alkyd coatings leaves much to be desired: usually after a year and a half the surface turns yellow and begins to crack. As a result, the product will have to be painted too often. Sometimes such a disadvantage can be ignored, but in most cases it is better to choose a different type of paint for important surfaces.
2. Instability to ultraviolet radiation, due to which the coating soon begins to fade and crack. For this reason, alkyd paints are not recommended for facades.
3. Alkyd mixtures contain harmful human health chemical elements. In addition, a pungent smell emanates from freshly painted surfaces, which disappears in at least a day.
4. Not a very rich color scheme. This shortcoming corrected by purchasing the desired color scheme.
5. Insufficient fire safety.

Acrylic paints

Polyacrylic polymers act as the basis in acrylic compositions. Acrylic paints and varnishes are made on the basis of a polymer, which is also called plexiglass. Special components are added to the composition that improve certain characteristics of the paint, for example, its elasticity, resistance to factors external environment or drying speed.

Advantages of acrylic compositions:

1. Acrylates retain their characteristics even when elevated temperatures. Resistance to high temperatures allows the use of coatings of this group when painting radiators and other surfaces subject to heat. Acrylic paints not only do not crack under the influence of temperature increase, but also do not change the original color.
2. Acrylic compounds are characterized by excellent adhesion (the ability to seize with foreign surfaces).
3. The operation of acrylic coatings can be carried out for at least 8 years in the case of wood and at least 20 years for plastered and metal products.
4. Acrylates are UV resistant, which means they are great for facade works. Acrylic exterior surfaces retain their original appearance for many years.
5. Due to the high transparency and the absence of yellowing of the coating, acrylic paints and varnishes are used for painting light woods. Also, the acrylic group is used in conjunction with pastel stains.
6. Acrylic coatings are non-toxic (unlike alkyd paints), since they do not contain organic solvents. For dissolving acrylic composition the usual one will do water.
7. The paint does not contain hazardous components, as a result of its drying, water evaporates. Therefore, when painting, there is no need for protective clothing.
8. Due to the absence of toxic solvents in the composition, acrylic coatings are devoid of a pungent odor and are suitable for interior work.
9. Acrylic mixtures protect coatings from corrosive processes, and the presence of special additives in them makes it possible to paint even rusty surfaces.
10. The acrylic group is characterized by high fire safety.
11. With a small consumption of paint, high hiding power is ensured.
12. Surfaces painted with acrylic coatings are able to "breathe". Natural ventilation is extremely useful for maintaining the performance of wood products.
13. Acrylic paints dry very quickly - it takes from half an hour to a couple of hours to dry the surface (specific terms depend on the conditions environment and components of the solution). Fast drying is a major advantage when it comes to tight construction deadlines.
14. If paint gets into an undesirable place, it can be easily removed without damaging the surface.

Disadvantages of acrylic formulations:

1. Relatively high cost.
2. Insignificant dry residue. This figure usually does not exceed 30%.
3. The coating takes a long time to gain strength. Final hardening occurs no earlier than 30 days.

Paint compatibility

Acrylic paints are not recommended for use on alkyd coatings, since the result of painting in this case cannot be predicted. After painting, the surface may look like good quality, and bad (if swelling occurs). Alkyd paints and enamels applied to acrylic surfaces, will flake off in most cases.

Please note: if acrylic paint is applied to an alkyd coating, its service life is reduced by at least 2 times.

If you still need to apply acrylic coating to the alkyd coating, the surface must be prepared. First, the product should be carefully cleaned with fine-grained sandpaper, and then treated with primer. Preparatory measures will improve the adhesion of materials and reduce the likelihood of paint peeling.

There are alkyd-acrylic compounds used for painting vehicles. However, their cost is high, and such paints are not used in the construction industry.

So, according to the totality of qualities the best choice- acrylic paint. However, if the budget is limited or the durability of the coating is not critical, you can opt for alkyd paint.

Often, consumers are interested in the question: which paint is better - alkyd or acrylic enamel and what is the difference between them. In order to get an answer to these questions, you need to familiarize yourself with the purpose of each of the options, their differences in composition, as well as positive and negative qualities.

About the composition

Acrylic paint is mostly made up of acrylic, which due to its chemical properties called a polymer emulsion. To give the substance color, color pigments are added. The main difference between enamel is the absence of a pungent odor characteristic of other substances, which is due to the use of water as a solvent. The composition also includes special additions that affect the resistance of the material to temperature extremes and improve its viscosity.

Alkyd paint mostly consists of alkyd varnish, color pigments and a kerosene-based solvent. Some paints contain additives that have fire-fighting, antifungal and antiseptic effects. That is why woodwork is often performed with such enamels.

Learn more about acrylic paint and how to use it

First of all, let's consider positive traits acrylic paints and enamels:

• Retention of original properties even under high temperature exposure. Due to this, the material can be applied to radiators and batteries of heating systems;
• Long service life. The paint used for wood can last up to 10 years, and for metal and plastered surfaces - up to 20 years;
• Differs in resistance to ultra-violet radiation therefore is suitable for external drawing;
• Protection against corrosive effects, which allows you to paint surfaces with already rust;
• Good quality should also be called the fact that you can apply acrylic paint without fear of highlighting harmful substances and bad odour.

But it is also worth considering the disadvantages:

• High cost compared to alkyd paints;
• Long drying time;
• Difficulty in acquiring the right and high-quality material in terms of composition.

In order to use acrylic paints well and efficiently, you must adhere to the following rules:

1. Remove the old coating and clean the surface very carefully sandpaper;
2. Apply a special primer to prevent the process of decay;
3. Add to paint right amount water and mix the composition thoroughly;
4. Spread the mixture over the surface using special brushes and rollers.

Before painting with acrylic red, the surface must be very well cleaned of dust and other contaminants, and also dried no less well.

About the features of alkyd paint

About the advantages of alkyds:

• Low cost, which allows the material to enjoy unprecedented popularity among consumers;
• It is applied very simply and does not require the use of special devices;
• The best choice colors, and an important difference is that all shades are very saturated and pronounced;
• Fast drying.

But alkyd materials also have disadvantages:

• Short service life, which already a year after painting can manifest itself in the form of characteristic yellowness and cracks;
• Instability to ultraviolet and therefore the paint cannot be applied in outdoor conditions;
• When painting with alkyd paints, long-term ventilation of the room is necessary, since the composition contains toxic chemicals.

If there is an urgent need for external use of alkyd paint, you need to purchase a product with special improving additives. And if possible, place the painted surface in a shaded place.

It is also important to remember that applying an alkyd-based varnish to alkyd paint is undesirable, but if it is urgently necessary, you need to clean the surface with sandpaper and only then start work.

The use of car enamels

Now consider what kind of enamel to use for cars: alkyd or acrylic? And what is the difference between alkyd paint and acrylic paint?

The place of superiority in this area is deservedly given acrylic material. This is due to the fact that the tool has good reflective characteristics and resistance to mechanical stress. In addition, the applied agent dries quickly and gives minimal shrinkage at the same time.

Alkyd enamel for a car is not the best, because it has a long period drying and at the same time does not give such a uniform gloss as an acrylic coating. The disadvantages of such autoenamel are compensated by low cost. Also, here it is possible to apply one thick layer of alkyd, while acrylic car enamel needs to be gradually painted in thin layers, each of which must dry well.

Acrylic and alkyd paints: compatibility

Can acrylic paint or enamel be applied over alkyd and vice versa? This question is very interesting and also requires careful analysis.

Experts, in general, do not recommend applying acrylic to alkyd substrates. Without treatment with a special primer and stripping, the service life of the coating can be significantly reduced. There is also the possibility of successful painting. It depends on the unpredictable behavior of the compositions, which can swell or please with an ideal flat surface.

If you apply an alkyd composition on an acrylic base, the result will definitely not please. Through a short time the coating will begin to peel off.

In case of urgent need for staining acrylic paint on an alkyd surface, it is worth performing a few simple preparatory steps:

1. Careful processing with fine-grained sandpaper is carried out;
2. Acrylic primer is applied;
3. On dried soil, alkyd enamel (paint) is applied.

Due to the primer used and other preparatory activities adhesion between materials is greatly improved, which greatly reduces the likelihood of peeling.

When applying acrylic paint on alkyd wear resistance of the new coating is reduced by 2 times.

Conclusion

Acrylic or alkyd paints, which differ significantly in composition and characteristics, are the personal choice of the consumer. Which one to use depends not only on their pros or cons, but also because of the difference in price and application technology. But, judging by the description of both compositions, we can conclude that acrylic paint is of high quality and a large amount of positive properties. Alkyd composition has more low price, and for many it plays an important role.

Based on the foregoing, we can conclude that in pursuit of quality and durability, it is better to choose acrylic paint. But if we talk about beauty and budget savings, then it is better to give preference to alkyd paint. Which of the proposed options to choose is a personal decision of each.

Repairing painted surfaces is an inevitable process. Even under the condition that earlier finishing was done competently and with high-quality materials.

Before repainting the walls, you need to make sure that the new and old coating will be compatible.

On the this moment There are many ways to remove old paint.

• mechanical methods. acrylic enamel and acrylic paint or other coating is peeled off sharp objects or a power tool, such as a drill with a nozzle.
• thermal methods. In this case, the paint is softened, for example, with a building hair dryer, and then removed.
• Chemical methods. The finish is removed with a variety of washes.

However, the process of removing the old coating is long and labor-intensive. Yes, and the price of the issue is quite high, especially if you need to remove paint from large area or complex surfaces. Because of this, many of us prefer to apply the new finish directly on top of the old one. The question often arises as to the compatibility of the finishes.

In this article we will talk about whether acrylic paint can be applied to enamel and vice versa. But first, let's look at the basic concepts.

Varieties of paints and varnishes

The composition of paints and varnishes includes a binder, fillers, pigments, solvents / thinners and additives. In order to correctly apply paintwork materials during repairs, you need to know exactly their composition.

Main Components

Oil paints based on drying oil.

All paints are divided according to the type of binder used and the type of solvent.

1. The binder determines the main qualities of the paint, the service life of the coating and the speed of its drying.. There are 4 types of binders used for paintwork materials: alkyd and epoxy resins, oil (on drying oil), latex, acrylic polymers.
2. Solvent components are divided into actual solvents and diluents.. The former reduce the fluidity and viscosity of the material. Thinners only reduce the viscosity of the paint.
3. To improve the characteristics of paintwork materials, additives are added to their composition.: stabilizers, emulsifiers, fungicides, antiseptics, etc.
4. To separate category relate special paints . These are anti-corrosion coatings, for example, Zinga conductive paint. Analogues with antiseptic properties that protect the base from mold and decay. Compositions for removing small defects (irregularities, scratches, cracks), etc.

Oil and enamel formulations

Pictured is acrylic paint.

Materials based on alkyd and acrylic resins include oil and enamel paints. They are suitable for painting metal, wood and plastered surfaces.

After drying, it is non-toxic, light and moisture resistant.

1. Oil paints are produced on the basis of drying oil. As thinners for them are White Spirit, gasoline, turpentine or solvent naphtha. The price of the compositions is low, but they dry for a long time (up to several days). The main disadvantage is that over time the coating turns yellow.
2. Lacquer is added to enamel compositions as a binder. It gives the coating gloss and aesthetics. The instruction recommends using such paints for external and internal finishing works for metal, wood, concrete, plaster. Enamels are moisture and light resistant. They also have anti-corrosion resistance.

Emulsion and dispersion materials

Water-dispersion composition.

Such paints are diluted, but do not dissolve with water. In them, the binder and pigment particles are distributed in liquid medium thus creating a stable emulsion.

When the coating dries, it does not wash out with water.

1. Emulsion compositions are economical, have environmental friendliness and fire safety.
2. They fit well on almost any substrate.
3. Dries quickly, does not have a strong smell.

Many people think that water-based and water-dispersion formulations are the same.

However, they are different.

1. Matte emulsions are washed off over time. The dispersions are water-resistant and suitable for use in wet rooms.
2. Water-dispersion compositions are usually white, water-based analogues have a variety of color palettes.
3. Dispersions cannot be used at temperatures below +5 degrees. However, when modifiers are added, they are thermally stable. Such, for example, fire-retardant paints for metal Polistil.

Note!
The best analogues from paints diluted with water - based on acrylic resins and polymers.
They have high elasticity and strength.

1. Such compositions are frost-resistant after their complete drying.
2. Possess vapor permeability.
3. Suitable for alkaline substrates (concrete, plaster).
4. These paints are well tinted.
5. Resistant to ultraviolet, retain the original color for a long time.
6. They have the ability to repel water.
7. They have high mechanical stability.

About paint compatibility

First, an epoxy putty must be applied to the old coating.

Based on everything written above, we will answer main question articles - is it possible to paint on enamel with acrylic paint and vice versa.

1. Based on their composition, acrylic coatings fall only on the same old coating. They cannot be applied over alkyd enamels due to thinner/solvent incompatibility. The new coating will simply fold (raise) the enamel.
2. In addition, it is undesirable to apply emulsion and dispersion compositions on old glossy and adhesive paints. The same applies to lacquered bases.
3. But, after emulsion and dispersion materials, any enamels and paints can be used.

Now about how, without removing the enamel, apply a coating of acrylic paint with your own hands.

Note!
To do this, you need to create an intermediate layer, in a stable state, resistant to both acrylic and organic solvents.
It should consist of polyesters, (for example, epoxy resin, polyurethane) on amine hardeners.
Such compounds are dissolved with acetone.

After puttying, acrylic primer is applied.

Now many liquid putties and primers are sold that have the described composition.

One of the best materials is "Inter Troton Spray".

1. First, apply liquid putty over the enamel.
2. Next, cover the surface with acrylic primer.
   
3. Then you can paint the base.

Conclusion

If you are unable to withdraw old paint, then a new coating can be applied to it. However, there are nuances here. Some types of coatings are incompatible, so between them you need to create an intermediate layer of neutral compositions. By watching the video in this article, you will expand your knowledge base.