How to choose the right glue for wood?

When choosing a suitable glue for wood, you should take into account the specifics of the upcoming work and pay special attention to the properties and characteristics of the composition. The decisive factors are the types of materials to be glued, the conditions where the work will be carried out and the finished structures will be used.

Selection of basic properties of the adhesive composition

There is no universal glue for any type of work; each has certain properties. To figure out which glue is best for wood and which one is best for gluing other materials, you should study the characteristics and composition of the selected product.

What you need to pay attention to:

1. degree of moisture resistance - indicated by the letter D and divided into classes (2 - minimal, 3 - sufficient, 4 - increased);
2. toxicity;
3. strength of the adhesive joint (kg/cm³) and density of the composition;
4. adhesion to other materials - fabric, metal, plastic, rubber, ceramics, glass;
5. complete drying time;
6. heat resistance;
7. resistance to bacteria and fungi.

Secondary characteristics include color; it can also be different: transparent, white, black, or imitating the natural shade of a certain type of wood.

Types of wood glue

Manufacturers have developed many different compositions for woodworking, and if you turn to the experience of carpentry masters, you can identify a number of the most suitable types. It should be noted that some types of glue can be divided into several subtypes, each of which has a narrow specialization, special color or composition.

PVA glue or compositions based on it

PVA glue remains the undisputed leader; many users prefer it, despite hundreds of new products with unique compositions. Glue is produced by almost all brands, and the average price for 1 kg varies from 80 to 400 rubles. The best furniture glues are often PVA based.

Pros:

• environmental friendliness - the composition does not release dangerous toxins before or after drying;
• leaves no traces;
• Complete drying time – up to 24 hours;
• high adhesion to various materials.

Minus:

• The water-based composition is not intended for use in rooms with high humidity.

Advice

You can add crushed wood shavings to PVA glue for better fixation of the elements.

Epoxy two-component adhesive

Familiar to many, glue made on the basis of epoxy resin is widely used for a variety of purposes, including for joining wooden structures. The kit includes two components: glue and hardener.

Pros:

• high adhesion to all known materials;
• does not leave marks on the product, does not change the color of the wood;
• epoxy glue is very strong and ideal for fixing even moving parts;
• resistant to water, oils and various aggressive solutions;
• has electrical insulating properties.

Minuses:

• when using, you must wear protective gloves, the composition may provoke an allergic reaction;
• With little experience in use, it is very difficult to calculate the proportions, which sometimes leads to overspending.

Casein glue

Universal glue is often used to connect small elements when constructing various models of buildings or vehicles, repairing furniture or interior items.

Pros:

• provides a very strong connection;
• complete drying time less than 20 hours;
• more resistant to humidity and elevated temperatures than wood glue.

Minuses:

• complex preparation process - glue powder is mixed with cold water and mixed thoroughly. It will take about 1 hour to get the glue ready.

Cyanoacrylate compounds

Cyanoacrylate mixtures are considered universal and are very popular. Experienced craftsmen have long been convinced of the effectiveness of such compositions. Glue is most often sold in small containers: given that the cost of such goods cannot be called low, it is rational to use them for small amounts of work.

Pros:

• high strength;
• minimum setting time is about 10-15 seconds;
• the glue does not change the color of the products and does not leave marks;
• resistant to various liquids;
• The minimum density of the composition allows it to be used for decorative work or joining small parts.

Minuses:

• relatively high cost (for example, Cosmofen instant glue, 20 g - 120 rubles);
• requires extreme care during operation.

Glue BF

Among the many types of BF glue, two products are suitable for wood: BF2 for interior use and BF4 for exterior use. The multi-purpose composition is suitable for gluing various materials to wood, is easy to use and is sold in almost every specialty store.

Pros:

• BF2 – moisture resistant, BF4 – moisture resistant, frost resistant;
• dries completely in 1 hour;
• Great for gluing metal to wood.

Minuses:

• effective only after careful preparation - the products should be thoroughly cleaned.

Advice

If you heat the gluing area to 80°C, the complete drying time will be reduced to 15 minutes.

High temperature adhesive

Heat-resistant compositions are highly specialized; they are used when the workpiece is subjected to firing or other exposure to high temperatures. The glue does not dry out, crack or peel off.

One type of high-temperature composition is adhesive sticks. This composition is applied using a glue gun, where the rod gradually melts. The intensity of application is adjustable by the user.

Wood glue

Wood glue is only suitable for gluing wooden pieces. Powdered glue is poured with water 3-4 cm above the level of the powder and the mixture is kept for 6 to 12 hours, depending on the manufacturer’s recommendations. Then the adhesive composition is brought to a state of readiness in a water bath, mixing thoroughly. In this case, the temperature of the mixture should not exceed 70°C. If you add natural drying oil to the composition, the glue acquires waterproof properties. By adding salicylic acid or borax, the glue will be resistant to all types of bacteria, mold or fungal spores.

Pros:

• used for all types of wood;
• has sufficient strength.

Minuses:

• long and relatively complex cooking process.

How to glue wood to wood or other materials?

Determining which glue to glue wooden products with is quite simple. First of all, you should analyze what kind of work will be carried out: gluing wood products or gluing other materials to wood.

You can glue wood to wood or other material using any of the types of glue listed above. When working with small parts, it is better to use a quick-drying cyanoacrylate compound or casein glue. When it is necessary to carry out a large amount of work, for example, gluing linoleum to a plywood base, covering wooden furniture with leather, or finishing walls, PVA is most suitable. If the structure will be outdoors all year round and subject to temperature changes, BF4 is needed.

Fastening wooden elements to each other also involves a medium or large amount of work, therefore, carpentry or epoxy glue, as well as PVA, are used. The compositions have a neutral color and are outwardly invisible; as a result, you can get a durable monolithic structure. Which one is better to use is a subjective question; these compositions have a big difference in moisture resistance, but similar bond strength.

General rules for using glue when working with wood

The maximum effect can be achieved if the design details are properly prepared. The wood should be treated; to do this, the surface is cleaned with fine abrasive sandpaper and all dust is removed. Other materials, such as porcelain, glass or plastic, are degreased with acetone.

According to the technology, the glue is applied in an even thin layer on both surfaces.Gluing with BF glue is carried out in two stages with a break of 15 minutes. When using two-component compositions, they are either mixed or one component is applied to one side, the other to the other and fastened.

When joining the end parts, carpenter's glue for wood is applied in two layers, allowing the first to dry slightly. A second one is applied on top, the glue is allowed to soak in a little, and the parts are then sealed together. When flat pieces are joined, the mixture is distributed along the fibers in one layer.

After applying the composition, the elements should be tightened using a press or clamp. If this is not possible, then only quick-drying “second” types of glue are used for gluing. If the composition dries for longer than 4 hours, the clamps are held for about 2 hours. Excess glue protruding between the workpieces must be quickly removed before the composition sets.

The last point is compliance with safety measures. Sometimes even simple compounds can provoke an allergic reaction. To protect your eyes and skin, it is enough to use rubberized gloves and goggles.

Only popular and relatively safe types of adhesives and mixtures are presented here. There are other types that will cope well with their task - for example, Moment Joiner glue is quite effective, but has increased toxicity and is applicable only for technical purposes. Other types often require long preparation of the mixture or are intended only for production work.