One of the most controversial materials, about which even experts do not have a clear opinion, iswood glue: which one is better, more reliable and easier to use? The question is very interesting, requiring knowledge of the features and properties different types glue.
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What is it needed for
Wood glue is used everywhere and constantly. Everyone at least once in their life has glued some wooden parts together or repaired broken things or pieces of furniture.Wood gluingproduced by slightly different methods than joining, for example, rubber or plastic products. There is no need to perform standard operations: applying the composition, drying for about 10-15 minutes and firmly pressing the parts against each other.
Wood requires a different approach, which is determined by the structure of the material and the individual properties of each species. It requires a different adhesive composition that can be absorbed into the material and create a durable film. Currently, many compounds have been created, from ancient traditional wood glues to the most modern synthetic compounds. Question,how to glue wood, not at all simple.
Varieties
Wood gluing materials have different composition and purpose.
Some of them are universal, connection wooden parts for them, just one of many use cases.
Others are intended only for gluing wood and have no other uses.
Choosing how to glue wood to wood, you should decide on the type of composition and its properties, which should be discussed separately:
PVA
One of the most common compositions, familiar to everyone since school days. Polyvinyl acetate dispersion, as this composition is correctly called, can be used for gluing paper, wood and other materials. The main condition is the ability of the bonded material to absorb moisture. It has the appearance of a milky-white thick liquid. When dry it becomes transparent. Mostly, PVA glue is used for gluing wood , since it is very convenient for this. Its features:
- Available in ready-to-eat form;
- dries quite quickly;
- does not stain the gluing, the glue squeezed out when squeezing the parts can be removed without consequences;
- diluted with water; any glue that gets onto a clean surface can be easily washed off or wiped off with a damp cloth.
There are different brands of PVA glue designed for construction work, universal or carpentry compounds. Setting time is about 20 minutes (depending on the brand), complete drying is 24 hours.
Attention!If PVA glue was stored in unheated room and frozen, then after thawing it cannot be used.
Epoxy
This is a two-component composition consisting of epoxy resin and hardener. Being mixed in the required proportion, the material hardens into a strong solid mass.
The curing process of the composition is purely chemical in nature, so the presence of air is not required for this.
It is noteworthy that epoxy adhesive not intended exclusively for wood , it can glue a variety of materials that do not have chemical conflicts with the adhesive components.
For him it has important correct dosage of components when mixing: if there is too much hardener, the mixture “boils”, bubbles and quickly turns into a solid foamy mass. If there is a lack of hardener, the mass does not gain the required strength. Freezing time different brands can vary from several minutes to one day, most often - several hours.
BF
BF glue appeared in widespread use in the late 70s and early 80s of the last century. It was believed that this was the most universal and reliable composition, capable of tightly connecting anything. In fact, this is not the case; the material has a lot of restrictions or conditions for use.Designed for gluing metals to non-metals, plastics and other materials.Wood is not exactly absent from this list, but it is far from being in first place. However, if neededwood glue, waterproof and frost-resistant, then the BF-2 or BF-4 brands fully correspond to this definition. The gluing technology is quite inconvenient: it requires applying an adhesive layer, drying it “tack-free” and compressing the parts for a while to gain strength of the adhesive layer.
Heat-resistant compounds
Wood in its own way technical properties is not subject to heat treatment. Therefore, there are simply no specialized thermal adhesive compositions for gluing wooden products., but some types of heat-resistant compounds can be used for these purposes.
Exist different kinds such compositions. These can be synthetic mixtures, various modified varieties of epoxy glue.
This group can include special material, produced in the form of rods, which are applied using an adhesive gun. The material, melted to a liquid state, is applied to the surface to be glued and pressed tightly against the second part. This method is simple and convenient, but requires the constant purchase of adhesive rods and connection to the power supply.
Carpentry
Carpentry (gluten) glues are one of the oldest groups, used back in ancient times. In our timewood glueused primarily for restoration of antique furniture or repair of acoustic musical instruments. The reason for this limited use is the difficulty of working with wood glues, which are sold dry and require preparation for use.
There are several types of wood glues:
- bone;
- fleshy;
- sturgeon.
The first two are made from horn plates or animal skins, the latter is made from the skin of sturgeon fish. It is believed that the bone composition is better than the flesh one, but sturgeon is very difficult to find; it is used mainly by violin or guitar makers.
Important!The main feature of wood glue is its reversibility. The glue can be soaked in hot water, pulled apart for repairs, and put back together without causing damage to the material of the part.
Syndeticone
Syndeticoneglue for gluing wood to wood- modification of wood glue, invented in 1878.
Since then, this composition has been widely used for a long time, but today its use is almost complete.
It is noteworthy that the name of the glue does not indicate any original composition, it is only a reference to the original name of the glue - “Syndeticon”, as the inventor called it.
The composition includes the following components:
- wood glue;
- sugar;
- slaked lime.
Its production takes about a day, which was also the reason for refusing to use it.
Polyurethane
Polyurethane wood gluedistinguished by high performance qualities and high cost. The composition is suitable for gluing damp wood and can be used for both interior and exterior work. The glue foams when it dries, filling possible cavities and stopping moisture or cold from reaching them. The adhesive joint can be used at temperatures from -30° to + 100°, in addition, polyurethane is the bestwaterproof wood glue.
Casein
Another very old natural composition. Its main component is casein, a milk protein obtained from low-fat cottage cheese. Available in the form of granules from brown to white- the higher the quality, the lighter the granules.
The material is truly universal - in addition to gluing wood, it is used in manufacturing, painting, and printing.
Traditionally used as environmentally friendly furniture glue high class. At the same time, the surfaces to be glued must be protected from glue getting on the front parts of the parts, as it is quickly and deeply absorbed, leaving dark spots. In addition, the material is hygroscopic and can deteriorate: become moldy, and there is a possibility of insects appearing. It must be stored in a tightly closed container.
Pasty
Paste-like adhesives are used to join poorly formed parts. Thick material fills small voids like putty, sealing the seam and stopping the access of moisture, cold or other unwanted influences. Typically, wood gluing is not one of the main specializations of such compounds, but for uneven surfaces this choice is quite justified.
Basic properties
Good glue for wood it must have a number of specific qualities:
- strength;
- resistance to water;
- good adhesion to any type of wood;
- non-toxic composition;
- versatility of use;
- high drying speed;
- the composition must be sold ready-to-use;
Many modern compositions have such properties, for example,wood glue "Joiner". Most traditional adhesive compositions, for all their advantages, require too long and labor-intensive preparation, which makes work inconvenient and reduces productivity.
When choosing wood glue, you should pay attention to some points:
- If gluing is permanent, then it is best to use some kind of synthetic irreversible compound. To connect parts that can later be disassembled, for example, musical instruments, it is better to choose traditional types - bone, casein and the like.
- When gluing light wood, you should not use casein glue. The seams will darken and the work will look sloppy. The best choice is Joiner glue, which dries to approximately the same color as the wood.
- When buying PVA glue, pay attention to its consistency. If there is a separation of the material into more liquid and thicker fractions, it means that the glue was frozen during storage or transportation. Such material cannot be used, it has lost its qualities.
Homemade recipes for preparing the composition
Some traditional types glue can be prepared independently, at home:
- Casein glue is made from low-fat cottage cheese, which is soaked in soda solution and washed under running water. Then the mass is dried to a dry powder, which is diluted with water immediately before use.
- Sometimes an ordinary paste helps to get out of the situation. It is brewed from flour (6 tablespoons per 1 liter of water) by adding an aqueous solution of flour to boiling water. The mixture is brought to a boil, cooled and used for its intended purpose.
- Wood glue is made in a water bath: in a container placed in a container with hot water, heated on a tile. Ready-made wood glue has a liquid and flowing consistency and is used asfurniture wood glue.
Important!Wood glue has a strong, stale smell, sometimes even too strong. Before preparing it, you should consider whether to use a ready-made composition.
General gluing rules
Each type of glue has its own specific methods of use. TO general rules This may include the need to clean and dry the surfaces to be glued, and first do a dry assembly without glue to check the accuracy of the fit. If the parts cannot be pressed together with a little manual effort, then you need to put off gluing and fit them better. The connected parts are pressed and fixed with clamps until the glue dries completely (usually it is recommended to keep them for 24 hours).
Using glue to join wooden parts is an old but effective technology. Modern synthetic compounds can greatly enhance the strength and stability of the joint, ensuring high-quality service of the glued parts.
For carpentry work and furniture repair, adhesives based on polyvinyl acetate are used - PVA, PVA-A, PVA-B, PVA-E, EPVA, and "Casein glue" , "Bone glue", "Synthetic joinery". Polyvinyl acetate adhesives form a clean and durable seam, although with low water resistance. More water resistant "Casein glue" And "Synthetic joinery". The latter is two-component, consists of resin - a viscous mass from white to brown colors and hardener - white oxalic acid powder. The hardener is dissolved in half a glass hot water(a 10% solution is obtained), then the resin and solution are thoroughly mixed until a homogeneous mass is obtained. The time during which the prepared portion must be consumed is 20 minutes.
"CASEIN GLUE" sold in the form of a white powder. 250 g of it are dissolved in 1 cubic dm of water heated to 60...70 degrees and kept for at least one and a half hours. It is best to apply the glue with a brush or brush made from bast fibers.
Glue "BONE" sold in tiles, which are crushed and poured cold water and stand for about a day. Then the water is drained and the swollen glue is boiled “in a water bath” - in a pan placed in another, large one, into which water is poured. When the mass acquires a homogeneous consistency, the glue is ready.
Compounds based on polyvinyl acetate, casein and bone adhesives are very strong and can withstand loads of up to 50...60 kgf/sq.m. cm.
This figure is much lower for adhesives AGO(30 kgf/sq.cm), "SYNTHETIC JOINERY"- (up to 25 kgf/sq.cm), BF-2 (20 kgf/sq.cm), "KITTIFIX" And "MEKOL"(10 kgf/sq.cm) and "MARS"(5 kgf/sq.cm).
When gluing, the wood must be sufficiently dry, and the moisture content of the connecting parts should not vary greatly, otherwise the structure will inevitably “lead.”
The glue fills the pores of the wood, opened during planing and sawing, which ensures the strength of the seam. If the pores are closed, for example, with an old layer of putty, glue or paint, the connection will not be strong. Therefore, it is important to clean surfaces properly.
Their increased roughness will only benefit.
Old layers of polyvinyl acetate and animal glues can be removed with water heated to 60...70 degrees. To do this, it is enough to place a cloth moistened with warm water on the cleaned area for 2...3 hours. The swollen layer of glue can then be easily cleaned off. Other adhesives, as well as paints, are removed with special removers - for example, AFT-1, BEM, R-4, SD special, SP-7. If one is not effective enough, another is used. BF and casein glues have to be removed with a rasp or sandpaper.
Paradoxically, the thinner the adhesive seam, the stronger the bonding will be. Therefore, when fixing furniture tenons in the eyes, the old coatings are cleaned very carefully so that unnecessary gaps do not appear. If the tenon sits loosely in the eye, you need to insert spacers made of veneer or a layer of wood separated from the plywood.
When they glue wooden blocks, for their extensions it is better to make a “mustache” or “toothed” connection. In the first case, the bevels of the bars are prepared so that the parts fit tightly to one another; the length of the connection should be 8...12 times greater than the width of the part. This ratio must also be adhered to when making a “toothed” connection: the teeth (length about 40 mm, width about 10 mm) in the parts are cut out according to a template with a hacksaw.
The glue is applied to both surfaces to be joined. For strength, the seam must be loaded or clamped with a clamp for 25...30 minutes. After the seam has hardened, you should not load the product for 24 hours.
A special issue is gluing broken skis or parts wooden boat. The best ones for this are epoxy adhesives - "EPOXY PUTTY", EDP, EPO. The main thing is that the seam is thin, and the product in the place to be glued must be tightly clamped or well bandaged while the glue is setting.
This is how skis are repaired. Before introducing the hardener into it, the main component of epoxy glue is diluted with acetone to such a consistency that it flows into the crack. A thin wooden wedge is inserted into the crack and the top side of the damaged ski is sealed with wide adhesive tape. After this, a hardener is introduced into the glue and the crack is quickly filled with it. Then the wooden wedge is removed and the ski is tightly bandaged. The excess glue squeezed out of the crack is removed with a spatula or a piece of plywood. The lower surface of the ski at the gluing site is wiped with acetone. The ski is left in a horizontal position for a day bottom side up.
And now - about gluing metals to wood. It is best to use rubber adhesives here - 88N, KR-1, "ELASTOSIL-2", Zh-3. They are also applied to both surfaces to be glued (this increases the strength of the connection by 5...7 times compared to one-sided application), and the seam is loaded with a pressure of 4...5 kgf/sq.cm or clamped in a clamp for 3...5 min.
Wood and metals can be bonded with adhesives 88N, 88NP, KR-1, Zh-3 and contact method. To do this, glue is applied to both surfaces and allowed to dry for an hour. After this, they are wiped with a swab moistened with acetone, the parts are connected and the seam is loaded, providing a pressure of approximately 7 kgf/sq.cm. After 10...12 hours, an adhesive joint is formed that can withstand loads of up to 5 kgf/sq.cm.
Approximately the same result is obtained by using glue. "Moment", but at a shutter speed three times less. True, the seams formed by these adhesives often turn out to be creeping - when loaded along the seam, the parts may move, but the seam will nevertheless remain strong.
For covering wood with veneer (single-layer plywood, or veneer), glue is most suitable "SYNTHETIC JOINERY", since it forms a completely colorless seam. Can also be used "CASEIN". But polyvinyl acetate glues are less suitable here due to low water resistance, while bone glue is simply inconvenient to work with, in addition, it forms a colored seam.
If glue is applied to both surfaces - both the wooden base and the veneer - then the veneer will immediately curl into a tube, and when straightening the junction of the individual sheets, they will separate, and cracks will appear around them. Therefore, only the surface is coated with glue wooden base and place dry veneer sheets on it. For 40 minutes, press with a load so that the pressure in the seam reaches 6...8 kgf/sq.cm. The seam is completely cured in 6 hours.
When using glue "SYNTHETIC JOINERY", which, as already mentioned, is two-component, you do not need to mix the resin and hardener in advance, but apply them to the product one by one: first a layer of hardener solution, and then a layer of resin. Then apply a sheet of dry plywood and press it with a weight. The resulting adhesive seam is quite strong, but fragile. He withstands the action cold water, but in warm weather (60 degrees) it quickly collapses.
Decorative films made of polyvinyl chloride and laminated paper plastic are best glued to wood using rubber adhesives "ELASTOSIL-2", 88N, KR-1, Zh-3. Bottom side planks useful
sand with fine sandpaper. Adhesives are applied to both surfaces to be joined, film or plastic is placed on wooden product, carefully “squeezing” it out of the seam air bubbles, and apply a load for 20 minutes (about 3...4 kgf/sq.cm). The seam is completely cured within 10 hours, and the glue "ELASTOSIL-2"- in 3 days. When gluing the latter, it is necessary that the surfaces are completely dry, and that no moisture gets into the seam during setting.
Fabrics are firmly connected to wood using polyvinyl acetate and BF-6. However, both are not without drawbacks. The first is characterized by low water resistance, the second forms a seam painted in yellow. When using polyvinyl acetate glue, coat fabric and wood with it and apply a small weight for 10 minutes. After 12 hours, the seam is completely cured. Glue Bf-6 also applied to both surfaces, but in two layers. The first one is dried, and then the second one is applied to it. When it is not yet completely dry, the fabric and wood are applied to each other and the glue seam is ironed through a wet rag with a hot iron until it becomes dry.
Experts who work with wood know that the glue for this material must be reliable, durable, and waterproof. Moreover, non-toxicity and versatility, as well as cost, play a big role. As we see, there are many factors influencing the buyer’s choice. But how can an ignorant person determine which glue to choose so that the purchase meets all the requirements? Considering that today the widest range is offered on the market, it is difficult for a potential consumer to make the first right choice. Therefore, in order not to make a mistake when purchasing wood glue, it is necessary to study the features of this material.
How to glue wood?
The retail network offers a wide variety of wood adhesives that have individual characteristics and characteristic differences. Most popular types wood adhesives:
- PVA. Everyone has been familiar with this composition since childhood. It perfectly glues wood surfaces and requires 24 hours for final drying.
- BF adhesive compositions. The main advantage is high strength and durability. It takes no more than an hour to completely dry. If necessary, speed up the hardening process, the mixture can be heated.
- Waterproof glue for gluing wood - t It contains one component that is suitable for gluing any wood.
- Adhesive syndeticone composition. Before use, you need to heat and wait for the composition to swell. Complete drying time is at least 24 hours.
- The best glue for wood, which is widely used among people, is “Moment”.
- If it is necessary to use a moisture-resistant adhesive, we recommend epoxy, which exhibits high stability to oily compounds.
- The best material for joining wood is Kleiberit. It is waterproof and reliably connects layers of wood.
- A polyurethane-based composition allows you to fill the structure of the wood, creating a complete product.
- Casein glue is waterproof and heat resistant.
Characteristics
One of the most common adhesive compositions is PVA glue for wood. It's non-toxic, absolutely safe material, which has an unlimited shelf life. PVA is easily applied to the surface and reliably bonds the wood. This type of glue is used in furniture production. However, you need to know that PVA has low water resistance and moisture resistance. Therefore, it is not recommended to be used for gluing materials that are intended to be used in wet rooms and outdoors.
To reliably join wood with adhesives, compounds from the BF series are often used. These types of adhesives are frost-resistant and elastic. Thanks to these characteristics, BF adhesives can be used with your own hands for exterior work, as well as for joining wood with metal, glass, and plastics. BF compositions should be applied to a previously cleaned and degreased surface. The initial layer, which acts as a primer, is left to dry for an hour. Afterwards, a second layer is applied and the two halves of the glued product are connected and left until completely dry.
Syndeticone glue is an excellent tool for gluing wood to other materials. This composition includes dry wood glue, slaked lime and sugar. It has high strength characteristics and resistance to atmospheric influences.
Adhesive composition based on polyurethane is very popular because it is highly resistant to temperature changes, humidity, and is suitable for gluing hard wood.
Today, more and more often, professionals working with wood with their own hands use assembly adhesive for wood. It is versatile, heat resistant, can withstand low temperatures. The assembly adhesive composition includes acrylic on water based, which indicates its safety for the environment.
Casein glue is moisture resistant. It is excellent for gluing wood, paper, fabrics, cardboard, and leather. To obtain an adhesive composition, powdered casein should be mixed with water and brought to the state of sour cream. To achieve the desired consistency, the composition must be stirred for an hour. After this, the mixture can be applied to the surfaces and, after waiting for five minutes, they can be combined. Using casein glue for gluing wood products, you need to remember that this composition leaves stains on the surface. Therefore, you need to work with it very carefully.
To summarize, we see that there are many adhesive compositions for gluing wood. Choosing suitable look glue, water resistance, versatility, reliability and resistance to temperature changes should be taken into account. If wood needs to be spliced, best choice is Kleiberite. In other cases, you can use PVA, BF, “Moment”.
Before coating paint and varnish compositions the wood is sanded and primed. This will give greater adhesion to the base coating with wood, and the consumption finishing reduced by 40%. You can buy a ready-made primer for wood or make it from available and inexpensive adhesives. We will tell you how to make a PVA primer for wood at home in this article. We will also consider what disadvantages and advantages a homemade coating has.
The basis of a homemade primer is PVA glue, which is an aqueous emulsion of polyvinyl acetate. PVA is used for gluing various materials made of wood and cardboard. When applied to the surface, the glue dries and forms a dense film. When making a primer, the glue is diluted with water, so the film on the treated surface is thin. When applied thickly, the adhesive primer is poorly absorbed and forms a thick, uneven film, which over time easily peels off along with the paint. A PVA-based primer has advantages that are inherent in ready-made professional products:
- Adhesion increases.
- Wood gets additional protection from water.
- The paint goes on smoother.
- The consumption of decorating composition is reduced.
- The primer composition has a low cost.
Despite the many advantages, the homemade composition has disadvantages. Therefore, it is recommended to use homemade products based on PVA only in cases of savings. Disadvantages stand out:
- The primer does not penetrate deep enough into the wood and improves the structure by only 0.2%. If we talk about other materials that do not have the hygroscopic properties of wood, then PVA coating is ineffective.
- Does not have antiseptic properties. Wood is afraid of mold and mildew, and PVA will not be able to resist the proliferation of microorganisms.
- Over time, the glue changes its color, turns yellow, and if you cover the wood with light paint or varnish, then appearance the finish will be ruined.
- The coating is resistant to steam and water. It is not recommended to use for covering walls, floors and ceilings in damp rooms and baths.
Some disadvantages can be avoided if you know the intricacies of the work. We will talk about this below. But most of the disadvantages are difficult to correct, so the PVA priming method is economical, but not always effective. The funds that were saved during the repair will be used to correct the defects. Therefore, it is necessary to weigh the pros and cons several times. In most cases, it is more profitable to immediately use a professional wood primer. For those who like to save money, here is a table where we will reveal in detail the secret to solving some problems:
Priming with PVA is suitable for painting wood with inexpensive dark-colored paints. On light colors appear over time yellow spots, the paint will have to be removed and the wood will have to be re-treated. It is not recommended to use primer under varnishes at all. In this case, various impregnations are used that do not harm the appearance and will not spoil the natural pattern of the wood.
The effectiveness of a primer depends on two factors: application technique and proper preparation facilities. Below we will consider each factor in more detail.
Mix and apply
A primer for wood for painting is prepared from the following components: glue (sold in any construction stores, average price from 60 rubles for 0.9 liters) and warm water(40-45 degrees). Adhesive the composition is suitable construction or carpentry work. The price is lower for the first option. You will also need an empty plastic container, a small bucket and a spatula for stirring will do. Below is a table of prices for various glue manufacturers:
| Manufacturer and name | Peculiarities | Price |
| “Super PVA” moment | Quick-drying, viscous. | 145 rub. for 250 g. |
| “Carpenter” moment | Moisture resistant, viscous. Doesn't mix well with water. | 190 rub. for 250 g. |
| White House “PVA universal” | Construction, easy to install. | 60 rub. for 900 g |
| White House “PVA super” | Waterproof, viscous, suitable for all surfaces. | 75 rub. for 900 g |
| Expert “PVA carpentry glue” | Waterproof, viscous, contains antiseptic additives. | 116 rub. for 900 g |
| Expert “Universal PVA Glue” | Easily diluted with water and applied to any surface. | 83 rub. for 900 g |
| Text “Universal joiner! | Moisture resistant, quick drying. | 90 rub. for 900 g |
You should not buy the advertised Moment or Titan. When choosing, you do not need to pay attention to the manufacturer, since it is suitable for the primer composition inexpensive option from White House or Expert. Essentially the composition of the emulsion is the same. A waterproof composition will be more difficult to dilute with water, so for quick woodworking it is better to use classic PVA glue. But waterproof gives the wood additional waterproofing and protective properties, How acrylic primer. Diluted in small portions. Cook immediately a large number of adhesive primer is not recommended, as the mixture left loses its quality characteristics.
It is more profitable to purchase glue for preparing primers in volumes of 0.9 liters or more, since the price for small packages is higher. If you need to treat a small surface, then 250 g is enough, so there will be no unused residues.
Preparation
You can make a primer with your own hands using the following ratio: 1 part PVA - 2 parts water. But the ratio depends on the viscosity of the glue. After mixing, the DIY wood primer is checked for thickness using a test application. A small amount is applied to the wood, the mark should remain whitish, but not too dense. When drying, the film should not peel off from the wood. If the composition turns out to be thick, add a little more water. IN ready mixture an antiseptic or a small amount of lime or crushed chalk is added. Lime and chalk are sifted so that there are no large inclusions during application.
Water is poured into the glue in small portions, the composition is stirred all the time. If, on the contrary, you pour glue into water, it will be more difficult to mix the primer.
The finished primer will be well absorbed into the wood and applied evenly using a brush or roller. But before application, the wooden surface is sanded and leveled. If there are cracks or chips, the wood is puttied using special compounds.
Application
Instructions for applying PVA glue primer to wooden surface, consists of the following stages:
- The wood is being prepared. To do this, the surface is ground and leveled. The accuracy of further work will depend on the quality of preparation.
- Using a brush they are processed hard to reach places: corners, near baseboards, places behind radiators and pipes.
- The remaining surface of the wood is covered with a roller or a wider brush. The first layer should dry within 1-2 hours.
- The wood is inspected for the presence of “fringe”. If the surface has lost its evenness, it is sanded again using sandpaper the smallest caliber. It is more convenient to carry out sanding by placing a piece of paper on a small block.
- A second coat of primer is applied. Just like the first time, hard-to-reach areas are coated first, then the main surface.
- The treated surface must dry (for 24 hours), after which the paint and varnish coating is applied.
The finishing is considered complete after complete drying.
It is possible to use PVA glue as a base for wood primer, but the result is not always positive. If the primer is not diluted correctly, then over time the finish will peel off from the wood and renovation work will have to do it again. Under light paints and varnishes, the PVA emulsion turns yellow and the appearance of the wood deteriorates. Therefore, it is recommended to use professional primers for finishing, which are available in every hardware store and the price for them is not off the charts.
In everyday life you have to do various works with wood products - to repair, restore, or even make something with your own hands. The use of traditional fasteners (nails, screws, or other) is not always possible or advisable.
In most cases best option– gluing of structural parts. But is every composition suitable for working with wood? How to choose the right glue for wood, what to consider? This article will answer all such questions.
Any glue is selected based on the specifics of its application. Therefore, before you buy the composition, you should familiarize yourself with its properties:
- Final drying time.
- Bonding density.
- Moisture resistance.
- Universality of use, that is, adhesion to other materials, not just wood.
- Connection strength, ability to withstand dynamic loads.
- Degree of toxicity.
From these positions, we will consider the features of all commercially available compositions for working with wood, as well as those prepared independently.
Types of adhesives
PVA
Such products are also called dispersed, polyvinyl acetate.
Main characteristics
- There is no toxicity. Consequently, such glue can be safely used for working with wood indoors, without taking any precautions (hood, etc.).
- Performance. Primary setting - after about ⅓ hour, final hardening - within a day.
- Any surface can be processed.
- The shelf life of the glue is unlimited.
Minus - since PVA is diluted with water, in rooms with excess humidity the reliability of gluing gradually decreases.
Epoxy glue
A set familiar to many, consisting of two components (resin + hardener), which must be mixed in a certain proportion before use.
Main characteristics
- Connection strength.
- Versatility of use.
- Epoxy adhesives are resistant not only to water, but also to fuels and lubricants, and a number of aggressive reagents.
- Guaranteed drying time (depending on layer thickness) up to 24 hours.
- When working with such adhesives, you need to take care of protection skin. The ingredients are irritating.
- Increased consumption. In practice, it is impossible to determine exactly how many components should be diluted for a specific job. Some of the glue remains unused and is discarded.
BF
Several varieties of the product are sold under this brand. The “2” and “4” series are suitable for gluing wood, including other materials.
Main characteristics
- Quick drying - no more than 1 hour at normal temperature and humidity.
- For interior works It is advisable to use “BF-2”, external ones – “BF-4”.
- Such adhesives are applied in 2 layers, with an interval of 15 minutes.
- High moisture resistance, and the 4th series can withstand low temperatures.
The downside is that it is somewhat relative, but sometimes it matters. Before using such adhesives, the wood needs high-quality cleaning and degreasing.
Heat-resistant compounds
Such adhesives are sold in the form of rods, so you will have to additionally purchase a special “gun”.
The main characteristic is clear from the name - increased resistance to high temperatures. Given the specific nature of the application, such compositions are used mainly for fastening small parts and for sealing cracks in wood.
Wood glue
They do not refer to ready-to-use products. Before gluing, it is necessary to prepare the composition.
Specifics of preparation
- The dry mass is poured warm water and is aged from 6 to 12 hours, depending on the size of the dishes and the amount of glue. It should be completely saturated.
- "Water bath. The liquid is drained from the container and heated with steam until a homogeneous mass is obtained. During the preparation process, the glue is periodically stirred until all solid particles are completely dissolved. It is necessary to ensure that the composition does not boil! This required condition to obtain high-quality glue.
How to use
The segments to be glued are coated in an even layer in the direction of the wood grain. After this, tightly press the parts and fix them in this position. After 7–8 hours, the composition completely hardens.
The downside is that the gluing efficiency decreases sharply when the wood moisture content is more than 10%.
Syndeticone glue
It is prepared on a carpentry basis by adding lime (slaked) and powdered sugar.
Main characteristics
- High adhesive strength.
- Resistant to liquids and aggressive chemical compounds.
The downside is the lengthy cooking process. Before use, the dry mass is kept in water for at least a day.
Adhesive paste
It is obtained by adding chalk or powder crushed to a powder into hot wood glue. wood ash. Such compositions are excellent for puttying or priming wood. Sticks well with it following materials: glass, metal, stone.
Polyurethane compositions
They are more expensive than many types of wood glues, and this is understandable.
Main characteristics
- The gluing area can withstand increased dynamic loads. For example, a repaired chair leg will not become loose over time.
- Inertness to low and high temperatures, humidity, ultraviolet radiation and so on. If a wooden product is used in extreme conditions, such glue is the best choice.
Casein glue
Anyone involved in aircraft modeling is familiar with it. This composition can be used to secure leather, paper, and fabric to wood.
Main characteristics
- Inert to dampness.
- Connection strength.
- Complete drying - no more than 18 - 20 hours.
The downside is that cooking requires care and time. Water (cold) is poured into a portion of the powder, after which the mixture is constantly stirred. It is brought to the state of sour cream, and for the dry composition to completely dissolve, it will take at least 1 hour.
Wood adhesives are sold in various packages. For the convenience of the reader, the average price in rubles/kg is indicated in parentheses after each item.
According to reviews from those who often have to deal with wood, it is worth using adhesives of the brands “Jowat” (204), “Casco” (502 - PVA), “Kleiberit” (439), “Titebond” (from 260 for 310 ml), "Moment-joiner" (478). It is with them that most professional craftsmen work, especially since you can choose any modification, since their compositions vary depending on the series.
The water resistance class can be easily determined by the markings on the glue package. Indicated by the letter “D”. The number behind it gives an idea of the stability of the composition in front of liquids: 2 – low, 3 – sufficient, 4 – very high. But D4 class adhesives are quite expensive, so their use is justified only in cases where the product will be used in conditions of constant dampness.