Drying oil is a substance that, when applied to the surface of wood or metal, forms protective film. Drying oil is produced from natural oils. The technology involves filtration of the oily component and its heat treatment, as well as the addition of a drier - a substance that accelerates the drying process.
With the advent of a huge variety of paints and varnishes on the market, natural drying oil has not lost its popularity, since it does not contain chemical solvents and is an environmentally friendly product. It is part of oil paints and is used for the manufacture of primers, paste putties, and oil-resin varnishes.
Along with the natural product, synthetic and semi-natural versions of the material have appeared, each of them has its own characteristics, so drying oil covers a fairly wide range of solutions that are used to treat wooden, metal and plastered surfaces.
What is drying oil: classification and properties
All drying oils produced by industry are divided into several main types:
- natural;
- semi-natural;
- synthetic;
- combined;
- alkyd.
The oldest and most time-tested drying oils include natural options produced on the basis of linseed, tung, hemp and other oils. Cobalt, lead, manganese and other components are used as additives to speed up drying. According to current standards, the percentage ratio of oil and drier is 97 to 3.
According to the production method, a distinction is made between polymerized (standard) and oxidized natural drying oil. The first is produced using heat treatment technology without purging, the second method involves the process of long-term simmering of the oil at high temperatures (300 degrees) with purging.
Oxol is a semi-natural type of material. According to GOST, this drying oil contains 55% vegetable oil (most often linseed), 5% drier, the rest is solvent. Basically, oxol is used to treat surfaces and structural elements indoors and is used for outdoor work in order to improve adhesion during further painting and putty.
Combined drying oil differs from oxol in the ratio of components; this product contains about 30% solvent. The material is obtained by polymerizing and removing moisture from drying oils capable of forming a strong, infusible film. GOST grade K-3 combined drying oil can be used for the production of paste-like thickly grated oil paints.
Composite versions of drying oil are produced on the basis of synthetic substances obtained as a result of oil refining, so they are distinguished by their sharp persistent odor, which remains for a long time after drying. Since the material is toxic and harmful, it is not used for interior works Oh.
Another type of drying oil is made up of a mixture that includes an alkyd resin as a base, solvents, modified versions of oils and auxiliary components - driers.
Using drying oil for wood
Drying oil is one of the popular and traditional materials for wood processing. It allows you to preserve the beauty of the texture of wood and its energy. Under the influence of factors such as heat and oxygen, the vegetable oil that is part of the drying oil applied to the wood surface polymerizes as it dries. In this case, part of the substance impregnates the wood, penetrating its porous structure, while the other forms a thin protective film on the surface. This explains what drying oil is and why it is needed. Thus, natural drying oil is used:
- for surface priming various elements, pre-treatment before painting, increasing adhesion;
- processing wooden elements in order to extend their service life, restoration of furniture;
- as finishing wooden surfaces of walls, floors inside the house and further care after them.
Wood treated with a natural composition breathes and aromatizes the air, which is why this type of drying oil is chosen by lovers environmentally friendly materials, absolutely safe for environment and human health. The material is included in oil paints, mixtures intended for priming and filling wood, and serves to dilute them to the desired consistency.
How long does it take for natural drying oil applied to a wooden surface to dry? It all depends on the ambient temperature and the vegetable oils used in the material. If we focus on the average temperature regime at 20 - 22 degrees, then it will take about a day for the solution, which is based on linseed and hemp oil, to dry completely. Impregnation with a component made from sunflower raw materials takes longer to dry.
When processing the surface of wooden elements, you should wear rubber gloves, but if you haven’t done this, the question arises of how to wash drying oil from your hands. It is best to use organic solvents.
Drying oil based on natural vegetable oils is inferior in strength of the protective layer, penetration depth, and durability to combined and semi-natural impregnations. Therefore, often for carrying out internal and external finishing works choose oxol. The best variety It is considered a product containing linseed oil. This semi-natural drying oil creates, after complete drying, an elastic and fairly strong moisture-resistant film.
How to dilute drying oil
Mixtures containing oils tend to thicken over time. It is not possible to use drying oil in this form; it needs to be diluted. How? It depends on the type of drying oil. It is generally not recommended to dilute a natural product, but many people neglect this advice. In this case the best option turpentine or white spirit is considered. The same thinners are suitable for semi-natural formulations. Other types of drying oil are usually diluted with a solvent, which is a component of their composition.
Be careful: there are fakes
Today you can hear from people who covered window frames, plywood and other wooden objects with drying oil, because it does not dry for a long time, they ask what to do in this case? Experts say that if the material does not dry within the period stated by the manufacturer, then it is a low-quality product, most likely an oil composition sold under the guise of drying oil. Material High Quality, applied in a thin layer, polymerizes by interacting with oxygen, so natural drying oil, according to technical specifications, dries within 24 hours at room temperature with an air humidity level of 60%. Drying oil that does not dry is most likely defective or fake. Therefore, you should clean it off, rinse it off, using a solvent that is used to remove stains of vegetable oils and resin. It is better to choose solvents of organic origin, such as white spirit, solvent. In any case, the substance is partially absorbed, so only the top layer can be removed.
In order not to get into trouble when purchasing a material, it is advisable not only to familiarize yourself with information about the manufacturer and clarify the composition of the drying oil, but also to check the availability of a certificate of conformity, which is issued for natural drying oil and oxol. If you purchase a composite type of material, then require a hygienic certificate.
During some construction and repair work often a material such as wood is used. Wood has a porous structure and therefore needs additional processing more than others.
In order to protect this valuable and not entirely cheap material use drying oil "Oxol".
What it is?
Drying oil is a thick oily liquid primarily Brown, consisting of a mixture of different components, is intended for painting wood and preparing plastered surfaces for painting, and is also used as a solvent for oil paints.
Like any other product intended for processing, drying oil consists of basic and auxiliary substances. The basis of Oxol drying oil is vegetable oil, the share of which is in the range of 54-55% of the total mass.
Different oils can be used to make the product: flaxseed, hemp, sunflower, grape, soybean, corn or camelina. The base contains either one type or a mixture of several oils.
The share of additional components in the composition of "Oxol" accounts for 45% of the total mass, of which 40% is the solvent (white spirit is most often used), and the remaining 5% is driers. Each of them has certain properties that affect the composition as a whole.
The solvent gives the drying oil the desired consistency, and driers contribute to the rapid drying of the composition on the surface. Salts are called driers different metals, or, more precisely, compounds of iron, cobalt, lead, lithium, strontium and many others with organic acids.
The film formed on the surface prevents paint or varnish from penetrating deep into the wood structure, which means less material is required. In addition, the use of drying oil as a preparatory layer when painting can improve the adhesion of varnish or paint to a wood surface.
In order to understand how and due to what a film is formed on the surface, it is necessary to consider the principle of operation of drying oil, based on the properties of the components. Many types of vegetable oils used as a base are capable of thickening under certain conditions (oxygen, heat, light), and when applied to the surface in a thin layer, they can polymerize (dry out).
The formation of a semi-solid mass occurs due to polyunsaturated fatty acids present in some oils of plant origin. The rate of hardening on the surface is directly dependent on the size of glycerides of unsaturated fatty acids and such an indicator as iodine number. The higher the percentage of fatty acids in the oil and the higher the iodine number, the faster the polymerization process occurs.
But the natural oxidation process occurs slowly, and therefore drying oil is subjected to heat treatment along with the driers added to its composition. Heating of this composition leads to the decomposition of substances that slow down the formation of the film, and due to the presence of metal salts, the oxidation process occurs faster.
Drying agents affect the composition not only during the drying process, but also after it. It lasts as long as the layer remains on the surface, their share should not exceed 5%; a higher percentage of their content in the composition leads to darkening and then destruction of the film coating.
The formation of an elastic film on the surface occurs, as a rule, within 6-36 hours. This time difference is due to many factors: composition, preparation technology, presence of additives. Almost all drying oils known today take about a day to dry..
Kinds
Today, manufacturers produce several varieties of oil-based drying oils, differing in the presence of additional components and the percentage of the main substances.
Natural drying oil is basic basis for "Oxoli", but differs from it in the percentage of components and the absence of additional substances in the composition. The oil, most often linseed or hemp, accounts for 97%, and the remaining 3% is driers.
This type of drying oil is suitable for treating surfaces located only indoors, and therefore it is used infrequently, and the cost of this type is quite high due to the large percentage of oil in the composition and its original price.
Drying oil "Oxol" It costs much less than natural, because the share of oil in its composition is only 55%. But the reduced proportion of oil and the solvent included in the composition do not this type drying oils are worse than natural ones. It is in no way inferior in properties and appearance to its natural analogue and even surpasses it in some ways.
“Oxol” can be used to cover wooden structures and plastered surfaces not only indoors, but also outside, which is its undoubted advantage.
On a surface treated with drying oil A stable coating with a gloss effect is formed no later than 24 hours. It is distinguished by elasticity, water resistance and maximum durability compared to other types. The only disadvantage of “Oxol” is its harsh odor compared to its natural analogue due to the presence of a solvent, which is most often used white spirit.
The division of "Oxoli" into brands is due to the use of different oils that make up the base. For grade “B”, either hemp or linseed oil is used. The best drying oil is considered to be made on the basis linseed oil , it is this that forms a more durable coating on the surface.
The composition of the PV brand is based on other types of oils (soybean, sunflower, camelina, grape, corn).
A surface treated with a composition based on sunflower oil is less resistant to various influences compared to a base made from linseed oil.
Combined drying oil unlike other types, it contains several types of oils that pass through various processing. In particular, if rapeseed oil, which is cheaper in cost and does not dry well, is added to the composition, then it is first subjected to oxidation. This process is necessary so that the drying oil with cheaper oils used as a base approaches the properties of the original version.
The composition of the combined drying oil also includes synthetic substances and a solvent. Such drying oil is marked with the letter “K”, and the number following the letter indicates for what types of work the composition can be used. Even numbers indicate drying oils intended for treating surfaces indoors, and odd numbers indicate compositions that can be worked with outside.
Alkyd drying oil has some similarities with Oxol. Vegetable oils are present in alkyd species, but their share is insignificant. This type of drying oil is produced on the basis of alkyd resins, which are diluted with solvents, most often white spirit. In addition, the composition includes driers.
Specifications
Drying oil "Oksol" is produced in accordance with GOST 190-78, which sets out the standards various indicators for grades “B” and “PV”. There are eight basic standards that determine whether drying oil belongs to one type or another.
They vary depending on the type of oil used and the brand of drying oil itself:
- The color indicator is listed first in the table. For both brands, this value is identical; the color should be no darker than 800 mg J/cm³ (on the iodometric scale). But there are exceptions for drying oil, where the base is camelina oil (brand “PV”), this indicator has a different numerical expression. The color of such drying oil should be no darker than 1800, while for drying oil made from soybean oil, this indicator is 1100 J/cm³.
- Conditional viscosity indicators, measured using a viscometer, differ slightly for the two brands. For brand “B”, the flow time of drying oil through a funnel with a diameter of 4 mm (at t = 20°C) is within 18-22 seconds, and for brand “PV” – within 19-25 s.
- Acid number, measured in mg KOH/g, for different brands is different. For brand “B” this figure should be no more than 6, and for brand “PV” it is slightly higher - 8. If sunflower oil is used as a base in drying oil, whose acid number ranges from 8-15 mg KOH/g, the total acid number should not exceed 10.
- Mass fraction of non-volatile substances, measured in%, for both brands should be in the range of 54.5-55.5. If there is petroleum-polymer resin in the drying oil mixture, the mass fraction of non-volatile substances can fluctuate between 55-59%, provided that the viscosity index complies with the standards determined by GOST.
- Indicators such as sediment volume and transparency both brands have the same values. Sludge by volume – 1%, transparency – complete. The flash point in a closed cup for both brands should not exceed 32°C.
- There is another important indicator characterizing drying oil by drying time. For grade “B”, a stable coating (up to degree 3) is formed no later than 20 hours from the moment of application, and for grade “PV” - no later than 24 hours.
According to GOST 190-78, there are strict requirements that dictate which containers drying oil can be poured into, at what temperature the liquid can be safely stored and what precautions to take when opening a jar of the composition. All safety requirements are described in detail in this document.
When purchasing drying oil, sellers must have a quality certificate.
Consumption per 1m²
There are standards for the consumption of drying oil per 1 m². As a rule, these indicators are not very different from the consumption values of oil paints. To apply drying oil in one layer per 1 m², it will take from 80 to 130 g. This spread is determined by factors such as the type of surface being treated (wood or plaster), the porosity and hardness of the material, the type of solution, as well as the effects of temperature and humidity.
For fresh wood, consumption can be increased to 200, and in some cases up to 250 g per 1 m². According to some sources, the average consumption of drying oil for a single-layer coating ranges from 150-200 g per 1 m².
Drying oil or "boiled oil" (as it was called in ancient times) is liquid composition forming a film that is formed as a result of processing vegetable oils (by oxidation or prolonged heat treatment) or fatty alkyd resins, also called driers. Drying oil is used as a protective impregnation for a variety of surfaces, as a primer before painting, as a base for different types of paint, and even acts as a coating for interior decoration.
Based on its components, drying oil is classified into the following types:
- natural;
- semi-natural;
- synthetic.
The most widely used types at the moment are: natural, oxol drying oil and combined. In addition, alkyd and even composite ones are often used.
According to GOST, the product in question must consist of at least 97% natural vegetable oil(drying or semi-drying, as well as mixtures thereof, mainly flax oil, occasionally sunflower, soybean, hemp oil).
During production, oils are exposed to prolonged exposure to high temperatures (at least 300°C) for 12 hours; the next step is the use of air blowing.
As a result, we get an oily, opaque, thick liquid consistency of a rich brown and sometimes greenish color with a slight smell of the base oil.
Drying oil based on flax oil looks like a light-colored liquid, transparent and oily.
Its main purpose is to perform the following tasks:
- primer various surfaces: wood, metal or previously plastered;
- manufacturing and obtaining the required consistency of thickly rubbed paint in light colors, putty, paste for lubrication;
- as a paint composition light color used indoors and outdoors for painting metal structures, window and door openings, flooring.
For complete drying room temperature it will take no more than a day.
Drying oil from hemp oil is dark in appearance and due to this it is mainly in demand, just like drying oil from flax oil, but when you need to get dark colors. It dries similarly in no more than a day.
Drying oil made from sunflower oil dries much worse and will require much more time than a day to dry completely. In addition, although the film turns out to be quite elastic, it is inferior to the drying oils discussed above according to such indicators as:
- hardness;
- strength;
- water resistance.
Table 1. Indicators of oil drying oils.
| Indicator name | Meaning for drying oils | Test method | |||
|---|---|---|---|---|---|
| natural | oxol | combined | |||
| linen | hemp | ||||
| 400 | 1600 | 800 | 800 | ||
| 1 | 1 | 1 | 1 | According to GOST 5481 | |
| 26-32 | 26-32 | 18-25 | 20-60 | According to GOST 8420 | |
| 6 | 7 | 8 | 10 | According to GOST 5476 | |
| Full | Full | Full | Full | According to GOST 5472 | |
| 24 | 24 | 24 | 24 | According to GOST 19007 | |
| 7 Mass fraction of non-volatile substances, % | - | - | 54,5-55,5 | 70 ±2 | According to GOST 17537 and 9.9 of this standard |
| - | - | 32 | 32 | GOST 9287 | |
| 9 Density at temperature (20 ± 2) °C, g/cm 3 | 0,936-0,950 | 0,930-0,940 | - | - | According to GOST 18995.1 |
| 10 Iodine number, mg iodine per 100 g, not less | 155 | 150 | - | - | According to GOST 5475, section 2 |
| 11 Mass fraction of phosphorus-containing substances in terms of P 2 O 5,%, no more | 0,026 | 0,026 | - | - | According to GOST 7824, section 2 and 9.13 of this standard |
| 12 Mass fraction of unsaponifiable substances, %, no more | 1 | 1 | - | According to GOST 5479 | |
| 13 Mass fraction of ash, %, no more | 0,3 | 0,3 | - | - | According to GOST 5474 and 9.15 of this standard |
| 14 Resin acids | Absence | - | - | By 9.16 | |
| Note - It is allowed to use oxol-type drying oil with other indicators of the mass fraction of non-volatile substances and conditional viscosity, provided that this brand of drying oil meets all the standard requirements for this group of drying oils. | |||||
Representatives of this species also received their second name “oxol”; technologically they are also made from oils, but subjected to oxidation, with the addition of solvents and driers. In this case, the percentage of oil is 55%, the solvent (white spirit is most often used) is at least 40%. Due to this composition, the liquid is quite unpleasant and pungent odor, which can last for some time even after drying.
In terms of cost, oxol is much more economically profitable than natural, but at the same time it has practically no differences in basic properties and is almost identical in appearance.
The most valued is oxol made from flax oil - the film of such a product is hard, elastic, water resistant and, notably, has the greatest durability.
To reduce the cost even further, it is also produced from sunflower oil, but its film characteristics are significantly lower than those made from flax oil.
Drying oil combined
This type of drying oil is almost identical to semi-natural ones, except for the percentage: the percentage of oil is about 70% and 30% remains as a solvent. They are obtained by polymerization and dehydration of drying and semi-drying oil. The main direction for using this product is the production of thick-based paints. Brands K-2, 3, 4, 5 are commercially produced. Complete drying time does not exceed a day.
Table 2. Indicators of combined drying oils.
| Indicator name | Meaning | Test method |
|---|---|---|
| 1 Sludge, % (by volume), no more | 1 | According to GOST 5481, section 2 |
| 2 Conditional viscosity according to a VZ-246 type viscometer with a nozzle diameter of 4 mm at a temperature of (20 ± 0.5) °C, s | 15-50 | According to GOST 8420 |
| 3 Acid number, mg KOH, no more | 10 | According to GOST 5476, GOST 23955, method A |
| 4 Transparency after standing for 24 hours at a temperature of (20 ± 2) °C | Full | According to GOST 5472 |
| 5 Drying time to degree 3 at temperature (20 ± 2) °C, hours no more | 24 | According to GOST 19007 |
| 6 Mass fraction of non-volatile substances, %, not less | 50 | According to GOST 17537 |
| 7 Flash point in a closed crucible, °C, not less | 32 | According to GOST 9287 |
Alkyd drying oils
Thermochemical processing of semi-drying and non-drying oil gives the resulting alkyd drying oil a high drying ability. In addition, in terms of the totality of its properties, it has higher values for hardness, durability, water resistance and weather resistance than oxol drying oils. Thanks to this, this type is considered more promising, since it allows reducing the cost of vegetable oil for production. The only drawback can be called thickening during storage, which is due to the fact that free fatty acids, of which large quantities react with mineral pigments and insoluble metal soaps appear. This does not allow the product to be used for the production of thickly grated paint, but does not prevent it from being used en masse for diluting them to the required consistency.
This type is currently considered the cheapest and this is what has made it quite widely used. After all, the main component is not natural oil or resin, but their substitutes, most often various products obtained from oil refining. The composition of such drying oils may be different, since they are produced not on the basis of GOST, but according to technical specifications. They also differ significantly in appearance - the color is often light, and transparency is much higher than that of oil-based compositions. Also, the disadvantages include very Strong smell and a longer drying process. The most common representatives are slate drying oil and, of course, ethinol.
Shale drying oil looks like a darkish liquid, as noted, there is a pungent odor and is a derivative of the process of oxidation of shale oil with further dissolution in xylene. It dries in a little over a day. It has good weather resistance. The main direction of use is dark tinting, diluting paints to the required consistency, which are used mainly for outdoor work and sometimes indoors for painting metal, wood and plaster surfaces. It is prohibited to use this drying oil for application to sexual materials and household items.
Drying oil ethinol, on the contrary, looks like a transparent liquid of a lightish tone, with the same specific odor and is produced from waste obtained from the production of chloroprene rubber.
After application, the film dries quickly, shines, is very hard, resistant to alkali and acid, but, unfortunately, has low weather resistance.
Often this type is used as an additive to other drying oils, but not more than 15%. The main direction was the production of paint and primer for metal based on it.
Table 3. Indicators of synthetic drying oils.
| Indicator name | Meaning | Test method |
|---|---|---|
| 1 Color on the iodometric scale, mg I 2 /100 cm 3, not darker | 700 | According to GOST 19266 and 9.3 of this standard |
| 2 Sludge, % (by volume), no more | 1 | According to GOST 5481, section 2 |
| 3 Conditional viscosity according to a VZ-246 type viscometer with a nozzle diameter of 4 mm at a temperature of (20 ± 0.5) °C, s | 18-25 | According to GOST 8420 |
| 4 Acid number, mg KOH, no more | 12 | According to GOST 5476 |
| 5 Transparency after standing for 24 hours at a temperature of (20 ± 2) °C | Full | According to GOST 5472 |
| 6 Drying time to degree 3 at temperature (20 ± 2) °C, h, no more | 24 | According to GOST 19007 |
| 7 Mass fraction of non-volatile substances, %, not less | 50 | According to GOST 17537 |
| 8 Flash point in a closed crucible, °C, not less | 32 | According to GOST 9287 |
Applying drying oil
Work order
- Before starting work, it is necessary to clean and degrease the surface to be treated.
- If the work uses a composition based on semi-natural drying oil, then application is recommended only on a dry surface.
- Using drying oil and paint and varnish products based on it, it is recommended to apply using a brush, roller or spray gun.
The average working consumption when using semi-natural drying oil is from 150 to 200 g. per cubic meter. As already noted, drying time with natural drying will take no more than a day.
Drying oil storage
Based on the fact that drying oil contains oil and solvents, it belongs to explosive and fire hazardous materials, therefore, in the room where work is carried out, natural ventilation or equipment must be provided forced ventilation in explosion-proof design. If material gets on human skin, wipe it off and rinse well with soapy water. When storing drying oil, you must ensure that the container is tightly closed and protected from moisture and sun rays, was far from the fires and electrical appliances. When thickening, you can dilute the drying oil with any solvent available to you, suitable for oil paints in a ratio of 1:10.
Selection of drying oil
Before purchasing drying oil, you need to take a good look at what’s in the container. First, you should determine by color whether it corresponds to the declared type of product. In addition, you should carefully read the description of the components and check whether it complies with GOST if you purchase semi-natural or natural drying oil. They will have a certificate of conformity, but the composite ones will only have a hygienic certificate. In general, you should be careful when using the latter, since it is toxic and it is important to note that there should be no oil residues (the so-called fus) and osprey (oil refining residues) in it, otherwise the drying process will become endless. And finally, it should be noted - carefully inspect the liquid for homogeneity; there should be no sediment or mechanical particles present.
As noted earlier, the main purpose of these products is to process various surfaces; they are also indispensable in the production of paints. If you focus on surface treatment, then drying oil for wood is excellent. It is used both for impregnation of products and walls in general. But to carry out external works It is recommended to apply drying oil only for preparation before further painting. And it would be more optimal to use oxol or alkyd drying oil. Natural would be better suited for interior work (due to environmental friendliness and lack of odor) and to obtain the required consistency of paints.
Almost all types are used in the manufacture of paints. So, natural becomes the basis for thickly grated ones, and alkyd is an excellent base for oil-based ones. Only composite is not used due to low quality.
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The fashion for natural materials in construction, furniture production, and interior decoration has already become a tradition. And it is wood that continues to be in trend due to its environmental and aesthetic properties. But, unlike artificial materials, wood coverings and structures can deteriorate under the influence of unfavorable factors external environment such as moisture, direct sunlight.
The modern market offers a wide variety Construction Materials, however, the old and time-tested drying oil, natural, linen, does not lose its position. We'll tell you about specifications, composition and use of this product.
Composition, GOST and types of natural drying oil
Natural linseed drying oil contains linseed oil that has been processed at high temperatures. The finished oil is an almost transparent liquid with a light yellow tint. According to GOSTs, natural drying oil should contain only two components:
- 97% linseed oil;
- 3% driers - metal particles or carbon salts that accelerate the drying process of drying oil.
Also, according to GOSTs, lead, cobalt and manganese act as driers, the use of which greatly reduces natural time drying time - from a week to literally one day. If the natural drying oil, for which we just talked about GOST standards, contains any additional substances, you should not take it. Most likely, it will be a low-quality product. Also divided into 2 types:
- standard (polymer), which is manufactured using heat treatment without blowing;
- oxidized, created by simmering the oil for high temperatures with purging.
Technical characteristics of linseed oil - what are its features?
The production of natural drying oil must be carried out according to the standards of GOST 7931-76. According to the requirements, the characteristics of the oil must meet a number of indicators:
- drying speed - about a day at an average temperature of 20 ° C;
- pleasant aroma;
- the density should be a maximum of 0.95 g/m 3 ;
- transparency of the composition after settling for 24 hours;
- presence of phosphorus-containing elements in the composition - no more than 0.02%.
Now let's look at why many people choose natural drying oil. Technical characteristics distinguish it from oxols, combined solutions - substances that are included in many other compositions, for example, white spirit.
If we talk about the advantages of drying oil, they are as follows:
- mechanical stability;
- wide range of uses;
- almost 100% impervious to moisture;
- opportunity to save consumables(for example, during final finishing with paint).
But you need to remember that everyone is yours positive sides Drying oil can only develop if its technical characteristics and composition comply with GOST standards.
Where is drying oil used - we protect various coatings
Drying oil can also be treated metal surfaces, in this case the composition acts as a primer. If you are going to restore furniture or paint wood products, the oil will protect against moisture and restore color. By the way, drying oil is also used to create a finishing layer when finishing floors, since it will protect coatings from mechanical damage and moisture, which wood is very afraid of.
Before telling how to use the composition correctly, you need to understand the principle of action of the substance. Thus, the oil polymerizes when exposed to light and oxygen, after which part of the product penetrates into the material, and the other part creates the thinnest layer. It is this that protects the processed material from moisture and damage. Even if drying oil meets all standards and GOSTs, its improper use can lead to loss of oil properties .
So, before applying the composition, it is necessary to clean the surface from dust and dirt, it must also be dry, and the wood should be sanded.
Apply the oil in 2-3 layers, everything will depend on the requirements for the appearance of the product being processed and the required level of protection. For processing, either a brush or a large brush is used. Approximate consumption per one square meter– about 80 gr. After completing the work, throw away the rags and roller, and ventilate the room. If allowed weather, in the room where processing is carried out, you need to open windows and doors. Products treated with oil can be used after a day.
Thus, drying oil, which complies with all GOST standards and contains natural ingredients, becomes an alternative to many modern protective equipment. If you still can’t choose what to use to finish and protect the wood, then linseed oil will become ideal solution.
The use of wood as a building material is becoming fashionable again - having become saturated with various types of plastic, synthetics and substitutes, people are beginning to appreciate natural purity, safety and incomparable appearance. But the tree needs serious processing. Should I use drying oil or give preference to more modern materials?
Natural materials – in search of safe ones!
If you have chosen wood for finishing your house, guided primarily by its environmental friendliness, then it will probably be important for you to comply with this condition to the end. After all, an environmentally friendly tree can be coated with so much chemicals with your own hands that any sense in using this material is lost.
And here a slightly forgotten drying oil enters the arena. Of all the film-forming materials that are on the market today, it is, objectively, the most natural. This statement can easily be confirmed by the fact that most drying oils consist of natural oil(hemp, flax, sunflower, etc.) – the percentage of natural components is from 45 to 95%.
Drying oil or, as it was called in the old days, “boiled oil” was known to master painters several centuries ago. Already in the 17th century, every artist used this material. Today, the technology for producing natural drying oils is practically no different from the methods known in ancient times. Exist different types this film former, the properties of which differ quite significantly.
Drying oils – what you need to know?
No matter how many manufacturers there are, the production technology is generally the same for all - vegetable oil, subject to heat treatment, is mixed with driers after filtration. Driers are metal compounds that accelerate the polymerization process of the oil film. Cobalt, lead, manganese, iron, lithium, strontium - the very name of these metals raises serious doubts about the safety of the resulting compounds. It should be noted that GOST, which regulates the production of this material (GOST 7931-76), was developed back in the USSR, and has long required a thorough revision.
If you choose a composition, then look for the necessary information on the label, which specific drier was used - cobalt drier is considered relatively safe. According to GOST, it should be from 3 to 5%. Exceeding this figure leads to too high a rate of polymerization of the drying oil, and the process does not stop even after drying, which subsequently leads to darkening and cracking of the layer. This is why artists today still use oils and paints without driers.
Is it possible to do without driers? Of course it is possible. Although this is rare, if you wish, you can still find such compositions, or compositions with a minimum content of this component. In fact, they are the ones who can best protect wooden structures from the occurrence of rot. Conventional drying oils with drying agents completely harden in 24 hours, and in hot and windy weather even faster, while compositions without drying agents can harden up to 5 days. If you dissolve oil paint with this composition, its drying time will also increase.
Such a long polymerization period allows the oil component to penetrate as deeply as possible into the wood fibers, which is why the wood will better repel moisture and resist fungus and wood-boring beetles.
In the case of driers, oils do not penetrate as deeply within 24 hours. The film formed on the surface of the wood can peel off and collapse over time, causing all your efforts to go down the drain. That is why ancient wooden buildings, treated with drying oils without drying agents, have been perfectly preserved to this day, while modern wooden buildings require constant care with your own hands.
The natural rate of polymerization of natural vegetable oils depends not so much on the production technology, but on the quantitative content of glycerides of polyunsaturated fatty acids, such as linoleic and linolenic acids. Flaxseed (GOST 5791-81) and hemp (GOST 8989-73) oils boast the highest glyceride content - 80% and 70%, respectively. For comparison, sunflower oil, which is also often used for inexpensive drying oils, contains about 30% linolenic acid glycerides, and therefore, even in the presence of drier, dries several times slower. Olive oil practically devoid of the ability to harden, over the years it will only thicken, and Castor oil and does not thicken at all.
According to existing GOST, natural drying oil should consist of 97% natural vegetable oil. However, manufacturers often break this rule in an effort to improve the hardening speed. It is easy to determine this with the knowledge gained - if the drying oil is on sunflower oil, according to the manufacturer, hardens faster than in 24 hours; the amount of driers in its composition clearly exceeds the 3% established by GOST. And therefore, from the point of view environmental safety, it will be more harmful than drying oil based on linseed oil, which hardens in the same period.
The requirements for production technology are also described in GOST 7931-76 and have also not been revised for a long time. During the cooking process, vegetable oils undergo simmering at high temperatures - at a temperature of about 300 ° C they are heated and kept for about 12 hours. Further, the technology may differ - drying oil obtained by heat treatment without blowing with air is called standard (polymerized), and compositions that have undergone blowing are called oxidized, or oxidized. Natural oil drying oil has a sweetish aroma of vegetable oil, its color varies from light brown to dark brown, almost black, and it takes a long time to dry.
Not natural - drying oils are different!
The closest to natural drying oil is the combined one - these compositions contain about a third of the solvent, often white spirit. This makes it possible to reduce the cost of production and offer the buyer a product that dries in less time. high speed. The use of solvent-based drying oil fits perfectly into exterior repairs - it’s both quick and reliable, and the smell will quickly disappear.
If you dilute vegetable oils even more, you get the so-called oxol, the production of which is regulated by GOST 190-78. – this is the obligatory 55% of natural oil, the remaining 45% is divided between solvents and driers. Oxol dries much faster due to the active evaporation of the solvent, and therefore it is convenient to use it in outdoor work with your own hands. In internal use, its use, as in the case of a combined one, is not recommended - due to the solvent, the composition has a sharp, bad smell, which can persist even after the layer hardens.
The low cost of oxol makes it popular among the masses. Oxol is used to dilute oil paints and enamel, since by itself it cannot adequately protect wooden structures. If you choose oxol, we recommend giving preference to more expensive compositions based on linseed oil - they create a strong and elastic film on the surface of the wood, and such drying oil dries faster.
Alkyd drying oil is a film-forming composition, the main component of which is alkyd resin (glyphthalic, xyphthalic or pentaphthalic), as well as modified oils and solvents. Objectively, this is the most acceptable combination of price and quality - alkyd compositions withstand temperature changes well, withstand the effects of atmospheric conditions and are little susceptible to ultraviolet radiation. Is post-processing necessary? Necessarily! This drying oil dries for about a day, after which at least two layers of varnish or paint should be applied.
The last place in terms of the quality of the created coating and its characteristics is occupied by composite drying oil. However, it is difficult to call it drying oil - it is a petroleum product that has a similar purpose, for example, to thin paint. There is not even a corresponding GOST for the production of such compositions. In appearance, such compositions are easy to distinguish by their high degree of transparency. Composite drying oil takes longer to dry and is poorly absorbed into the surface of the wood. This material should only be used for covering temporary structures or to dilute inexpensive paint.
Natural drying oil can be easily identified by its dark brown color and characteristic sweetish aroma of heat-treated vegetable oil. If there is a strong smell of chemicals, it is no longer a natural drying oil, but a combination or oxol. There should be no sedimentary formations, stains or lumps inside the jar in all cases. You have every right to demand a certificate of conformity from the seller.
You should be doubly careful with composite drying oils, since such compositions can be toxic, and therefore high-quality drying oils are accompanied by a hygienic certificate. Different shades in the composition may indicate the presence of oil residue (fuse) - composite drying oils should not have any color at all. Fuzz is the reason that drying oil takes a very long time to dry. If the so-called osprey (an oil refining product) also penetrates into the composition, then the drying oil will simply never dry out. The presence of such inclusions can also give off a pronounced odor.
It should be remembered that all drying oils are fire hazardous. Their use and storage should be away from sources of fire and heat. While the drying oil is drying, do not use electronics or smoke indoors. Don't forget to purchase a fire extinguisher and other safety equipment.
