Miter splicing of plywood. Types of glue for plywood and features of its use. What glue is best for plywood

Choosing glue for plywood, in most cases, is not difficult. In this case, you need to start from what the plywood is attached to. In construction, this multilayer wood material is used as a subfloor under linoleum, laminate or parquet. In everyday life, you may need to glue plywood sheets together or mount them to another wooden surface. For each type of work, glue is selected individually.

What types of glue are there for plywood?

The range of glues is quite wide. Most compounds on the market are suitable for plywood, taking into account their purpose. The following groups of mixtures can be distinguished:

On water based or water-dispersion adhesives. A prominent representative of this group is PVA. It has no pungent odor and is non-toxic, easy to use and has low cost. It must be applied to both surfaces to be bonded. Differs in drying time - up to 7 days.
Wood glues of animal origin. For plywood, casein and albumin are often used. The inconvenience lies in the complexity of preparation. The compounds must be boiled to achieve the effect.
Based on urea and phenol-formaldehyde. To make them, manufacturers use appropriate resins. Such adhesives are more environmentally friendly and less toxic than epoxy adhesives. Often used for gluing wooden elements and designs.
Epoxy and polyurethane. These are solvent-based formulations. They have a pungent odor and are toxic in liquid form. Work must be carried out in a ventilated area, using respiratory and skin protection. Once dry, they are generally harmless.

Epoxy and polyurethane, in turn, are divided:

to single-component adhesives - these are ready-to-use adhesives that can be used immediately after opening the package;
two-component - in the package the adhesive comes separately from the hardener. Before use, you must mix the ingredients together. Such compositions are called “reactive”, since the adhesive properties appear during chemical reaction between components. They are characterized by rapid drying, which is not always convenient - you often have to re-mix a new batch.

How to glue plywood together

Plywood consists of several layers of wood veneer, their number can vary from 3 to 20. In production, gluing is done using urea or phenol-formaldehyde compounds, and pressing is used.

The best option for gluing finished plywood are considered to be adhesives that are already present in the material. But this is not a prerequisite. If the sheet does not have water-repellent properties, aqueous compounds can be used. For products that do not absorb moisture, you can use epoxy or plywood.

Gluing can occur end-to-end or miterwise. In any case, the adhesive must be applied to both surfaces. After this, the sheets are pressed tightly against each other and left in this position until dry. Excess must be removed immediately.

How to glue plywood to a concrete floor

Plywood as a subfloor - best option. Almost any coating will fit perfectly on it. At the same time, the material is environmentally friendly, inexpensive, and easy to work with. The surface of the base must be flat, with differences in height up to 2 mm. Often, to achieve this, cement or concrete screed.

Before laying plywood on a concrete floor, you need to cut it into squares. Recommended dimensions: 60x60 or 75x75 mm. The sheets are laid with a shift. A gap of 2 - 5 mm is left between them. This method allows you to hide possible irregularities, and the wood practically does not deform during the drying process. For gluing, you can use almost any composition, following the manufacturer’s recommendations.

Advice
Work can begin only after the concrete has completely dried. An exception is PVA glue and its derivatives - the composition is also applied to a wet concrete screed.

Features of working with plywood glue

There are some rules that must be followed when gluing plywood:

Before applying glue, surfaces must be cleaned of debris and dust.
Before gluing using water-dispersed compounds, a primer is applied to the concrete screed. This can be either a special mixture or the glue itself, diluted with water.
Work with toxic substances should always be carried out in a ventilated area.
Laminated plywood must be sanded, otherwise it will not stick well.
PVA glue is not suitable for outdoor work due to changes in weather conditions and temperature changes.
Water-based compounds have a long drying time, so it is necessary to fix the plywood with self-tapping screws until it hardens completely.
Epoxy glue is most suitable for outdoor work; it can withstand adverse conditions better than others.

Famous manufacturers

When gluing small-sized elements, you can use both regular “Moment” and PVA. Adhesives are produced for large volumes of work for various purposes and composition.

The most common and famous manufacturers:

(Poland)- the company produces professional . The range includes synthetic, polyurethane mixtures, two- and one-component. Among them are waterproof and quick-hardening.
(France)- a world-famous company that produces a wide variety of construction products. For gluing plywood, glues based on PVA (polyvinyl acetate), two-component polyurethane and others are used.
"Rogneda" (Russia)- domestic manufacturer, the produced mixtures have affordable price and, in many ways, are not inferior foreign analogues. The company manufactures as universal adhesives, and special parquet for floor coverings.
(USA)- produces a line of products for gluing wood, parquet and floor coverings in general.

Plywood - unpretentious for construction work material. High-quality glue for plywood will undoubtedly increase its service life and reduce the likelihood of deformation. If the rules are followed, the connection will be reliable. However, if you use cheap, low-quality compounds, there is a high probability of sheets peeling off on the sides and unevenness appearing. Gluing plywood together is not that difficult, and in most cases there are no operational problems.

When buying glue, it is important to pay attention to the labels on the packaging - special glue for plywood is better than universal glue. It is also important to make sure that the mixture is environmentally friendly - if the work is carried out in a residential area, it is desirable that the glue contains a minimum content of toxic substances.

You will need

- roller or brush;
- clamps or clips;
- drying oil or vegetable oil;
- low-fat cottage cheese;
- ammonia;
- sandpaper

Instructions

Select adhesive

Adhesives used for gluing plywood can be divided into two groups. Protein adhesives are based on animal products. The casein version of protein glue is obtained from low-fat cottage cheese. Albumin - from animal blood. There is also a combined albumin-casein option. In all cases, the starting material for the production of adhesives of this group is protein, which is found in the blood or milk of animals.

Synthetic adhesives are made from artificial phenol-formaldehyde and urea-formaldehyde resins.

It should be remembered that the choice of glue brand depends on the air humidity in the room where it will be used. finished design, as well as the required degree of strength of the finished product.

Apply a layer of glue evenly and carefully onto the surfaces to be glued using a brush or roller. Press them tightly together using clamps or clamps. Remove excess glue.

If for some reason you do not have the opportunity to purchase ready-made glue, it is quite possible to make casein glue in. To do this, you need to take low-fat cottage cheese and mix it with ammonia in a ratio of 4:1. Spread the mixture onto the parts and press them tightly together.

For gluing surfaces exposed to moisture, glue of a different composition is made. Take wood glue and heat it up. Add drying oil or vegetable oil in a 4:1 ratio.

You should know that gluing laminated plywood is not recommended - its film layer, due to its physical characteristics, is not suitable for such an operation. If it is necessary to glue laminated plywood, it is necessary to remove the laminate layer to the wood using sandpaper. Dry and clean the surface thoroughly. Use epoxy glue.

What are the ways to join plywood?

Wow, that's a question! This, dear friend, on the one hand is not difficult, but on the other hand, it depends on where this connection is established! If there are no special loads, then you can simply put the ends on glue and fix the sheets with screws using self-tapping screws. If there is a connection where there will be loads, then there are a lot of options and they are very different; plywood, like solid wood, is connected almost the same way:

a) connections with ties, working in compression - with keys and blocks; b) connections with ties, bending - with dowels, bolts, nails, screws, pins; c) connections with ties, working in tension - bolts, screws, clamps; d) connections with shear bonds - adhesive seams.

Here are some types of joints most common in the construction of a house as well as in the construction of motor plywood boats.

Plywood gluing technologies

The main technologies for gluing plywood are shown in the picture below:

These are not the only methods, you can come up with your own, but the figure shows the main ones, in addition to which you can also do this:

Or you can make some “keys” with teeth:

and a more detailed diagram:

From the above, I think everyone can choose the method that is most suitable for a given situation.

In general, it all depends on what goals you are pursuing.

Algorithm for gluing plywood

The planes that are planned to be glued must first be carefully treated with sandpaper or emery, in this way we will remove all irregularities for better gluing. Then you need to remove dust from the surface and, to ensure maximum adhesion, degrease it.

After this little preparatory stage you can apply glue to both planes (it is better to use special glue, and there are a variety of glues, and dilute it according to the instructions). After application, the glue must be allowed to sit for some time, and then connect the two parts, pressing them tightly against each other. It would be better to secure the pieces with clamps.

The drying process will usually take about a day, but it is often recommended that after removing the clamps, do not subject the plywood to any pressure for another day or so.

Tenon connection of parts. How to make high-quality tenon joints in wooden furniture yourself.

Chapter: Country construction and improvement

When making homemade wooden furniture The master is faced with the need to make high-quality tenon joints.

The tenon connection of parts is the highest quality and most reliable. And although recently more and more more furniture made and assembled using metal corners, the tenon does not lose its position. Not many people can simply make high-quality spikes. If a person can do them, we can say that he has already established himself as a carpenter.

In industry, studs are said to be “cut” using special precision equipment. At home, it is, of course, not available. Therefore, many craftsmen who make simple garden and country furniture sacrifice quality in favor of simplicity. Let me also remind you that in the vast majority of cases, tenons are cut only along the wood fibers. If the tenon is made narrow and across the fibers, it will definitely chip. To prevent it from chipping, the width of the tenon should be at least 15-20 times the thickness of the part. This requirement does not apply to plywood. You can cut tenons of any width into plywood, but it is desirable that the outer layers are also oriented along the tenon.

Meanwhile, for a long time there has been a fairly simple method that allows you to quickly and efficiently make tenon joints wooden parts even a novice carpenter. This method was proposed by Yu.A. Egorov. The essence of the method is quite simple and understandable.

Let's say we need to make a finger joint between two parts. For convenience, in the drawings I colored them in different colors.

A prerequisite for quality tenon joint production is the fact that each saw has a specific cutting width. It is determined by the size of the tooth set. It can be measured by making several cuts in some piece of wood. Or you can directly use the saw to take measurements when making tenons.

On each part we apply a mark to the depth of the cut; it is equal to the thickness of the parts. If the parts are the same in thickness, then the depth of cut in each part will be the same. If the parts have different thicknesses, then the depths of the cuts will be different. In a thin part the cuts are deeper (equal to the thickness of the thick part), in a thick part they are shallower.

The parts are folded face to face so that the ends coincide, and relative to each other along the side edges they are shifted to the width of the cut of the saw that we will use to make tenons. (Not the thickness of the saw blade, but the width of the cut!). We secure the parts in a vice or workbench and make random cuts evenly across the entire width of the parts. If the parts are of different thicknesses, we make cuts to a depth equal to the thickness of the thin part. (We will finish the thin part separately later). We try to make the cuts as much as possible along the axis of the part, avoiding the taper of the tenons.

After this, we release the parts and again shift them relative to each other by the width of the cut, but only in the other direction. By the way, if we now make a shift by an amount slightly less than the width of the cut, then we will subsequently obtain a tight tenon joint, which is important for furniture. And if we move the parts a little more than the width of the cut, we will get a free tenon joint. The tenons of the parts will fit freely into the grooves of the other part. This circumstance is important in the manufacture of detachable connections (on a stud) or rotary connections.

Ignoring the old cuts, we make new ones, approximately in the middle of the existing tenons. We also observe the depth of the cuts and especially carefully their length.

After this, we free the parts and adjust the depth of the cuts to the required value (for a thin part, if the parts are of different thicknesses). Using a chisel, we carefully remove excess tenons (look carefully and do not remove the ones you need!), and clean the ends in the grooves.

After this, the parts can be joined.

Permanent connections are usually made with glue.

We work with plywood correctly

For wooden parts, wood glue or PVA glue are perfect. They will maintain a reliable connection even if the parts get wet or the moisture content of the wood increases. If the parts will be used in a dry room, epoxy resins (adhesives) can also be used.

After the glue has hardened, the joint is cleaned, sanded and processed in the same way as the entire product.

If the connection is planned to be detachable or rotating (for example, you are making blinds or an accordion door from boards or panels), then before starting assembly, you need to round the ends of the tenons so that their corners do not rest against the grooves when turning. In non-rotating but detachable connections, this is, of course, not necessary.

Having connected the parts, all the tenons are simultaneously drilled with a long thin drill. Its diameter should be equal to the diameter of the pin (nail) that you will use as an axis or fastening.

Using this method of making tenon joints, you can quickly, easily and most importantly, make very high quality tenons on the parts of your garden furniture.

Konstantin Timoshenko.

3 ways to connect plywood parts

Plywood is popular building material, possessing such qualities as environmental friendliness and plasticity. Furniture and decorative items are made from its sheets, and it is used in interior decoration. When creating structures, both gluing plywood and fastening the material with bolts or nails are used.

How to join plywood?

When choosing a method for fastening plywood products, you should take into account the characteristics of the material and the method of its operation.

Plywood pieces can be bolted, nailed, or glued together.

Compositions

For gluing plywood parts you can use different types glue. For interior works PVA composition is used, which is an aqueous emulsion of polyvinyl acetate. Protein options adhesives are based on products of animal origin. These are casein, albumin, albumin-casein types of glue. For the production of synthetic adhesives, urea-formaldehyde and phenol-formaldehyde artificial resins are used. The urea-formaldehyde base creates a colorless seam, while phenol-formaldehyde resins are water-resistant.

The brand of glue for plywood must be selected taking into account the required strength, as well as the degree of humidity of the room in which the structure will be used:

The choice of adhesives depends on the brand of plywood.

Products that are installed in ventilated areas can be joined using PVA, protein or synthetic glue.
During production country furniture, which is planned to be transferred from the room to the air, synthetic compounds are used to connect the parts.

Moisture-resistant plywood (grade FK) for interior spaces glued together with compounds based on urea resins. Sheets of material with increased moisture resistance (FSF brand) and bakelized plywood (FB) are joined with compounds containing phenol-formaldehyde resins. If unlined sheets of material are used, then plywood can be glued with any type of glue. The surface of laminated sheets with a film coating must be cleaned down to the wood layer before joining. Plywood should be sanded in a direction perpendicular to the wood grain.

Operating instructions

Before gluing plywood, you need to prepare the following tools:

Before gluing, the plywood parts are sanded.

foam roller;
clamps;
hammer.

Materials:

blanks;
sanding paper;
nails.

Glue the plywood together, working in this order:

The surface of the plywood sheets is cleaned of dust and dirt is washed off from it. For laminated material using sanding paper remove the laminate layer.
The sheets are thoroughly dried.
Using a roller, spread the glue in an even layer on the surface to be glued.
Using clamps, the plywood parts are pressed tightly against one another. Any excess glue that has come out should be carefully removed so that it does not get on the front side of the product using a knife and a rag.
Details large sizes if necessary, they are additionally connected with nails, evenly distributing them over the surface in increments of 40-50 cm.
After the adhesive mass has dried, the clamps are carefully removed.

If you need to glue plywood with metal part, then the use of epoxy glue is recommended. Tools needed:

Materials:

Types of plywood gluing.

plywood and metal parts;
epoxy glue.

They work in the following order:

The workpieces are cleaned with sandpaper, then the parts are freed from sawdust and dust.
Apply the epoxy mixture evenly to clean and dry surfaces with a brush.
The blanks are combined and fixed using clamps, excess glue is removed.
After the seam has dried, the parts are freed from the clamps. If delamination occurs plywood sheet, then you can glue its layers, laying them with paper.

If you need to glue plywood, you can use a channel (U-shaped profile) as a clamp.

Threaded holes are made in its upper and lower parts and the workpieces to be glued are fixed point-blank with bolts through a gasket. The bolt pitch must correspond to 10 workpiece thicknesses. The spacers between the bolts and the plywood should be 3 times the thickness of the parts. The edges of the channels are connected with bolts through bosses. Pressing is done evenly, with medium tightening, so that enough glue remains in the seam.

//moyafanera.ru/youtu.be/LNAXQmNeaxE

Plywood can be used in interior decoration, to create household or country interior. To work, you need to know how to connect plywood parts. Before gluing plywood, you should carefully study the instructions and select adhesive composition, prepare everything necessary to work with the material. With a high-quality seam, self-made products will look attractive and remain durable for a long time.

We work with plywood correctly

Home — Instructions — Repair and interior decoration— Using tools — Working with plywood correctly

We work with plywood correctly

Plywood can be processed in a variety of ways, both with standard hand and power woodworking tools. However, it should be noted that the glue in the plywood board causes rapid wear and tear. cutting tools Therefore, it is recommended to use carbide tools. Plywood can also be cut using modern laser cutting systems and hydraulic systems under a pressure of 3500 bar.

Sawing

Best result sawing is obtained when using a band or circular saw. Sawing must be done correctly to get a clean cut. First, sawing is done across the direction of the fibers of the front side, then along. This method avoids splitting corners. On the best front side of the plywood, sawing is done with a hand or band saw, on the back side - with a circular or contour saw. When cutting with a circular saw, we recommend high speed and low feed rate. The penetration limit of the saw blade teeth should be small.

Drilling

Holes with smooth edges are obtained if the drill bit is sharp enough and equipped with a front cutter. Drilling should begin from the front side. Splitting on the reverse side of the slab can be avoided by using a backing sheet.

Using nails

For wall, ceiling and floor panels, threaded nails or special screws are best, preferably with the head hidden or pressed in. Regular wire nails are also suitable for concealed nailing. Acid-resistant nails are recommended for nailing exterior cladding panels as they provide better protection against rust on the panel surface.

The length of the nails should be 2.5-3 times the thickness of the panel. The interval between nails for panels under walls and ceilings is considered suitable - 10-20 cm along the edges, 20-30 cm in the middle, depending on the load and type of nails. In floor panels, the interval should be 20-30 cm along the edges and 40-50 cm in the middle. Due to the fact that the structure of the plywood board consists of strips of veneer with a transverse grain pattern, nails can be driven close to the edge. A distance to the edge of the panel of 12-15 mm is considered suitable.

In load-bearing structures, the strength and fixation of nails plays an important role in their integrity. The nails must be driven in in the correct order; they must be long and have large heads. Screws can be used. As noted above, the fixation of the structure can also be improved by using glue at the joints.

Screw connections

In many applications, plywood panels are secured with screws. In finishing, in the manufacture of cabinet furniture, exhibition stands and shipbuilding, preference is given to screws. Auxiliary holes can be pre-drilled, with the hole in the panel matching the diameter of the screw and the smaller hole in the frame; the diameter of the latter will be half that of the previous one. The screw head should not penetrate the face veneer. If domed nails are used, washers must be used. When attaching sheathing plywood to metal structural components, you can use special screws to secure the plywood board with reverse side without damaging the front side.

The underfloor panels of cargo containers and trailers are usually attached to the metal chassis using self-tapping threaded screws. For example, plywood boards with a thickness of 27 mm can be fastened with M6x40 mm screws. The screw first penetrates the plywood board and then cuts threads into the metal. This method is quite fast.

Thin plywood panels for transport engineering are also easy to attach to metal structure using the above self-tapping screws. Plywood boards are easily bolted. The hole for the bolt should be 2 mm larger than the diameter of the bolt itself. There should be washers and nuts under the bolt heads to protect the panel surface. To avoid damaging the wood under the bolt, do not over-tighten the bolt. Where plywood is used outdoors, an over-tightened bolt can press into the surface of the board, causing it to swell with moisture. This will cause cracks to form in the surface of the plywood around the bolt.

Locks, hinges, shelves, etc. can be easily and securely attached to the plywood surface from any side or edge. The most durable fastening is using clamping fixtures. If it is necessary to place screws along the edges of panels, holes for them must be pre-drilled.

Installation

Plywood can be secured to the structure using glue, nails, staples, screws, rivets or bolts. When choosing a fastening method, it is important to consider the operating conditions, required strength and appearance. Before installation, the plywood board must be prepared for the final operating conditions, and precautions must be taken to prevent possible expansion or contraction of the board as a result of exposure to moisture or temperature changes. A gap of 2 mm at the joints is considered necessary. Elastic filler can be used, for example, between the edge of the panel and the steel frame of the structure. In heated structures, it is necessary to ensure proper ventilation of the plywood board.

Types of connections

Joints and joints are important components of plywood structures. There are many types of connections for plywood boards: tongue-and-groove, tenon and others. When performed correctly, they ensure the reliability of the structure of walls, floors and supporting elements. The ends of the plywood board are usually the most sensitive part, so special attention should be given to the treatment of joints, especially if the plywood is intended for outdoor use.

In walls and ceilings, butt, open, tongue-and-groove, seam and strip connections are recommended. In outdoor applications, various connections stripes are provided the best protection from external influence. Vertical and horizontal profiles made of aluminum, effectively protect the edges of the plywood board. Their resistance to rust makes them suitable material for facades. However, if for architectural reasons an open connection is preferred in an outdoor application, the edges must be properly finished. Approximately 2 mm/m should be maintained for panel expansion. In butt joints this distance should be 3-6 mm. Tongue and tongue joints are commonly used for floors and panels that go under roofs.

How to glue plywood together: rules and methods of adhesive bonding

It effectively prevents panels from lifting and damaging roofing materials, can withstand greater loads than a conventional butt joint. The panel is secured by secret nailing.

The best load-bearing capacity is achieved by using a stepped profile or similar special profile with flanges supporting the edges of adjacent panels. Such profiles are used, for example, in the construction of floors of cargo containers or trailers.

Bonding

Unveneered plywood is usually glued together with any wood glue. The choice of adhesive depends on the method of operation, the moisture content of the end use and the required strength. Common types of glue: PVA, phenol, epoxy resin, polyurethane, etc. PVA glue is suitable for indoor use. This glue is colorless and has good adhesive strength. Phenol and epoxy adhesive have high adhesive strength that can withstand harsh conditions external environment. When gluing plywood to metal, an epoxy type adhesive is recommended. Contact adhesives are typically used for bonding large surfaces and for veneered plywood intended for indoor use.

It is not recommended to glue laminated plywood. Film-coated plywood is not capable of long-term bonding. If film-coated plywood is attached with glue, the glued surface must first be cleaned down to the wood layer, for example, using sanding paper. It is advisable that the glue be epoxy. The surface to be glued must be dry and clean.

The glue must be applied evenly to both surfaces to be glued with a roller or brush. The desired pressure force is achieved using clamps, screws or nails. A suitable interval between nails is 1 nail per 40 cm2. Any excess glue should be removed before it hardens. You should always read the adhesive manufacturer's instructions carefully.

Grinding

The surface of the plywood is usually sanded with relatively coarse abrasive paper (No. 80 - 100) perpendicular to the grain of the wood. If an exceptionally smooth finish is required, for example for high-quality varnishing, sanding with fine-grain paper in the longitudinal direction of the wood grain is recommended.

Surface finishing

polished, flat surface plywood provides an excellent basis for subsequent finishing. Plywood can be laminated, laminated, painted, impregnated with special paint or solution, etc. When choosing a paint or primer, it is important to consider the cracking tendency of veneer veneers. The surface can also be covered with laminate or veneer made from valuable wood. It is possible to use thin film. Plywood can also be covered with wallpaper. If plywood boards were stored in conditions high humidity, then before finishing they must be dried to normal moisture content. The surface should be thoroughly cleaned of dust resulting from previous processing. This procedure must be repeated before each finishing stage. Depending on the required quality, 1-2 layers of coating are applied.

Edge processing

To align the edges of the slab after sawing, they can be lightly planed. The best results are achieved by planing from the corners towards the middle, thereby avoiding splitting at the corners. The edges of the panel can also be sanded. The ends are painted 2-3 times acrylic paint with special additives.

Primer

Wood belongs to natural materials, which expands and contracts depending on the complex effects of temperature and humidity environment(despite the transverse layers of veneer inside the slab). Cracks are observed on the inside of the face veneer, which expand and contract under the influence of changes in humidity. Due to these reasons, a preliminary primer is necessary for subsequent painting. Flexible paints are used, and the correct combination of paints is important.

Painting paper base completely prevents the formation of cracks in the paint layer due to humidity. In conditions of high humidity and outdoor use, plywood boards must also be painted on the reverse side. In such conditions, finishing of the ends is important and must be done especially carefully and several times. Plywood intended for outdoor use must be painted with special paints.

Painting

The application of paint gives the plywood a natural textured pattern. The surface of the board can also be painted completely, without showing the wood texture. The paint is applied with a brush or spray. Colored plywood is acceptable for both interior and exterior exterior finishing. But before final painting, the surface must be treated with a special solution to prevent the appearance of blue stains and fungi, since the biological resistance of transparent paints is limited due to the minimum content of the binding substance.

Varnishing

Birch plywood with a varnished surface is pleasant to look at and easy to keep clean. Before varnishing, the surface of the panel must be sanded with fine-grained sand. sandpaper. Dust generated during sanding must be carefully removed and the surface coated with diluted varnish.

S. Vetrov

Pioneer Shipyard

File from the bookshelf of Alexey Nesenenko
OCR: Nesenenko Alexey February 2004

The “procurement shop” also continued to operate.

Three parts were prepared here external cladding. Since the length of the dinghy exceeded the dimensions standard sheet plywood (most often 1.5X1.5 m), there was a need to connect - join - the sheets. Zhores Ivanovich explained that the most reliable option for butt joints of plywood would be “miter” gluing and showed how this operation can be performed simply and accurately.

— The strength will depend on the length of the “burr”—the bevel of the edge at the joint. Usually this is 12 - 20 sheet thicknesses. Our skin thickness is 6 mm. This means that 80 mm will be enough.

The chief foreman examined both surfaces of the sheets being joined and chose those with fewer knots for outside sheathing and marked them. One of the sheets was laid on the workbench with the marked side up and a line was drawn parallel to the edge that was to be processed at a distance of 80 mm from the edge. The second sheet was placed on top of the first with the marked side down, aligning its processed edge with this line. Then a line was drawn on it, 80 mm from the edge, limiting the “burr” strip.

Now, having adjusted the plane to the thinnest shavings, Zhores Ivanovich began to plan both edges of the sheet at once “in one pass.” Wood plank, which he secured with four nails to the workbench, kept the sheets from shifting and gave the correct slope to the plane. The result was one inclined plane 160 mm wide; all layers of plywood are marked on it in the form of straight and parallel lines. When the sheets were then laid with joined edges on top of each other, the joint turned out tight and even.

They placed a wide board under the joint, covering it with paper so that it would not stick to the plywood. Having smeared the surfaces to be joined with glue, Zhores Ivanovich put them together, and immediately hammered two small nails into the edges so that when pressing, the sheets would not move relative to each other. A second board was placed on top, also placing paper between it and the plywood. The guys began to place different weights on this board to ensure the required pressure.

The blanks of both transoms were cut out of a sheet 12 mm thick, they were placed in their places on the outside and traced with a pencil along the contour of the frames. Zhores Ivanovich made from thin plywood a small template that helped, when filing the bow transom with a hacksaw to a clean size, to simultaneously remove the small parts from its bottom and side edges. So when the transoms were put (with glue and screws) in place, all that remained was to cleanly plan their edges flush with the surfaces of the frames.

The guys then started installing the sheathing.

We started from the side. The blank was placed on the set and secured with a pair of clamps to the fender beam at the bow and stern. From the side of the set, the outer edges of the fender, bilge stringer and transoms were outlined. In addition, we marked the position of both edges of all toptimbers and the inner edges of the transom frames. This was necessary to know where to pre-drill holes for screws and apply glue.

The workpiece was removed from the set and cut around the perimeter, leaving an allowance of 3 - 4 mm for final gouging. Guided by the lines showing the position of the transverse set, we marked the double-row staggered seams and drilled small holes for the screws. Having smeared glue on the edges of the set adjacent to the skin and the corresponding strips on the sheet itself, it was again put in place, pressed against the set (going from the middle to the bow and stern) and secured with several nails to the frame and transoms.

“Now, guys,” said Zhores Ivanovich, “we need a surface planer.” Set 8 mm on it and draw a line of the first row of nails along the top and bottom edges of the sheet. We mark the line of the second row at a distance from the edge equal to 17 mm. So, being staggered, the fasteners will more evenly press the sheet to the slats of the set. However, we have already talked about this. And don’t forget: we must have time to completely secure the board to the set before the glue sets!

Then the work went very quickly. One of the guys walked with a drill and drilled holes - 75 mm alternately in each row. His partner inserted 2.5X20 nails into these holes and, holding the set rail with inside steel blank, hammered them into place with a hammer. Immediately, using a punch, the nail heads were recessed approximately 0.5 mm into the wood and, at the same time, the glue protruding from under the plywood along the cheekbone and fender was removed with a rag (otherwise, when the glue hardens, the tool will quickly become dull during subsequent gouging).

Nails were driven along the longitudinal set, moving from the frame to the bow and stern, alternately along the chine and fender. If you start from the transoms, a bulge may form in the middle of the boat - the skin will not fit the frame. On the Optimist there is little cross-section, so drilling out the holes and installing screws did not take much time. On the same day they managed to install the second side, and began installing the bottom the next morning, giving the glue time to gain strength.

We started by removing the bait from the bottom edge of the bilge stringer along with the lower edge of the sides.

“A little subtlety,” said Zhores Ivanovich, picking up the plane, “you need to plan, holding the plane at an angle to the cheekbone and so that the blade first begins to cut the plywood of the sheathing, as if pressing it against the stringer.” If you do the opposite, you can easily peel off the outer layer of plywood.

When the sheet was laid on the hull and the bottom set began to be outlined, at the same time the marks of the beginning and end of the centerboard well were placed on the plywood. This made it possible, in a convenient position, when the sheet was removed, to mark and cut a slot for the centerboard to pass through. The pins for installing nails along the cheekbone were marked using the same simple rimus as used when installing the sides. When the nails were being driven in, one of the guys had to climb inside the boat and support the longitudinal slats under the place where the next nail was driven in with a massive blank.

When the edges of the bottom sheet were planed - now flush with the surface of the sides and transoms, Zhores Ivanovich said that the boat could be removed from the slipway. They quickly pulled out the nails that held the toptimbers to the slipway, removed the braces, and now the hull of the future "Optimist", unanimously picked up by all the participants in its construction, was turned over and placed on an even keel - the way it would float. One of the guys was already trying to climb into the boat, but he was stopped by the voice of Zhores Ivanovich:

- Eh, no! Let's do everything like at a real shipyard! First, let's put the boat on the keel block, otherwise we'll ruin the bottom.

Zhores Ivanovich sketched a sketch of a square box without a bottom, which the guys immediately put together from four boards, strengthening the corners with pieces of plywood.

How to glue plywood sheets together

Pieces of felt were nailed along the upper edges of the transverse supports of the keel block so that the bottom would not rub against the wood. Four blocks nailed to the ends of the supports reliably fixed the boat's hull from moving sideways.

Despite the significant popularity of leaf wood material, many craftsmen do not have a clear idea of how to glue plywood together. This is most likely due to the fact that such a need arises quite rarely, and therefore information about the technology of adhesive joining of plywood sheets is not very widespread.

However, if you are making furniture or decorative items (for example), then sooner or later you will still have to master the basic methods. Well, if you decide to take up aircraft modeling or self-construction boats, then you simply cannot do without the skills of splicing wooden sheets.

Gluing Basics

Production technology

When talking about gluing plywood sheets, they most often mean either the production technology of the material itself, or the connection of several fragments in the manufacture of various products. We will talk about splicing sheets in detail below, and in this section we will try to pay attention to the subtleties production process.

Most often, gluing veneer to make plywood is done using the hot dry method. Today the following technological schemes are relevant:

The connection of the prepared veneer plates is carried out using a press while maintaining constant pressure in the working gap. This technology is used for the production of slabs whose thickness does not exceed 8 mm.
Alternate gluing of veneer at constant pressure with heat treatment. By alternately joining, thicker plywood is made - usually from 10 to 18 mm.
Multi-stage sizing of workpieces with cooling of the press after each operation makes it possible to increase a significant thickness of the slab. This technique used for the manufacture of sheets with a thickness of 20 mm or more.

Pay attention! Gluing veneer sheets one at a time ensures a higher quality of the finished product, as it promotes the most uniform distribution of temperature and pressure. Also, layer-by-layer pressing practically eliminates delamination of the material during processing, which is also very important.

However, these technological schemes are of interest only to those who plan to engage in industrial production veneer boards. For us, first of all, information on how you can connect several pieces of plywood with your own hands, without the use of presses and thermostats, will be important.

Adhesives used

When choosing what to glue plywood with, you should carefully study everything available options. On modern market There are many compositions, and therefore it is worth choosing exactly the one that will best meet our requirements.

The bulk of plywood adhesives are represented by two categories - protein (of animal origin) and synthetic. We will talk about the most popular varieties from each category.

Protein groups include the following:

Casein - made from cottage cheese that has undergone a defatting procedure. Adhesives are sold in the form of a dry powder; before use, they are dissolved in water and mixed thoroughly.
Albumin - made from protein obtained from animal blood. The dry component is mixed with water in a ratio of 1:9. The glue curls at a temperature of 70 0 C, which is why albumin compounds are used for hot gluing.
Combined– combine components of casein and albumin compositions.

Synthetic adhesives are mainly represented by resinous substances. The most commonly used:

Urea-formaldehyde resins (KF-MT, KF-Zh, etc.). They provide a colorless seam, therefore they are practically indispensable in the manufacture of decorative elements that imitate natural wood.

Pay attention! Urea-based mixtures contain a minimal amount of volatile phenols, so their use is preferable from a hygienic point of view.

Phenol-formaldehyde resins (SFZh-3011 or 3014). They are highly water resistant and not damaged by bacteria.

Almost any adhesive for gluing plywood includes:

Main adhesive.
Solvent.
Filler: wood dust or flour.
Additives that control the rate of hardening and ensure maximum adhesion.
Plasticizers.
Antiseptics.

Substances such as acids or ammonium chloride are used as hardeners, and to ensure resistance to wetting, tannins (formalin, copper salts, etc.) are added to the composition.
Photo - quick-hardening composition in a tube.

In order for the glue to retain its adhesive properties for as long as possible, either ethyl alcohol or acetone is used to dissolve the adhesive component.

Glue requirements

Many joining technologies, such as miter gluing of plywood, can only be implemented if high-quality adhesive compounds are used.

It is for this reason that the following requirements are put forward for most types of plywood adhesives:

High quality connections of materials.
Ease of use at home.
No volatile toxins in finished product after the composition has dried.
Resistant to moisture.
Not susceptible to decomposition by bacteria and fungi.

It is very important that the adhesive does not destroy the wood veneer during application and does not change its color.

The affordable price is also important, since when actively working with plywood, the glue is consumed quite quickly.

Pay attention! At the moment, there is no composition that satisfies absolutely all the requirements, so you will have to choose according to those parameters that are most important for you.

Gluing technologies

Gluing sheets

There are two ways to glue plywood sheets - gluing and splicing. The difference between them is as follows:

When gluing, the plates are connected by planes, and a ledge is formed at the junction.
Splicing is used when it is necessary to connect two slabs end to end. In this case, they usually try to fit the planes as accurately as possible so that when sealing the seam the gap is minimal.

We glue the plywood using this algorithm:

The planes intended for connection are carefully processed using sandpaper or emery, removing all irregularities.
We dust the surfaces, removing the slightest dirt.
To ensure maximum adhesion, plywood sheets can be additionally degreased.
Apply the plywood glue prepared according to the recipe to both planes.

Advice! As we noted earlier, there are a variety of adhesives. As a rule, the instructions for use contain sufficient information on proper dilution and glue application technology.

Let the applied adhesive remain in place for some time (the duration depends on the type active substance), after which we connect the strips of plywood together.
Pressing the parts to be glued tightly against each other, we fix them with clamps. To avoid damage to the veneer, wooden strips can be placed under the clamps.

We remove any excess glue with a rag, then leave the parts until the composition is completely polymerized.
After keeping the plywood under pressure for the set time (as a rule, the drying process takes about a day), remove the clamps.

Advice! To avoid delamination, it is advisable not to subject the adhesive joint to stress for at least 24 hours after removing the clamps.

By gluing strips of thin plywood sometimes connect two quite large sheets, adjusting them to each other “butt”. In this case, glue is applied to the pre-aligned ends, and a strip of veneer is placed over the seam on one or both sides.

Plywood splicing

Two technologies are used for splicing plywood - miter jointing of plywood and butt gluing.

A butt joint is used if in the future the seam between the slabs will not experience operational loads. An example is a situation in which several sheets of fairly thin plywood are spliced for multi-layer laminated veneer sheathing. plywood boat.

The technology for such gluing is as follows:

The ends of both plates are carefully aligned and polished. The most convenient way to do this is with a router or a stationary grinding machine.
Thoroughly degrease surfaces.
Apply contact glue to the plywood and press the planes together.
On top of the resulting seam we apply a fairly thick layer of glue, into which we embed a strip of fiberglass. We roll the fiberglass fabric with a roller, ensuring its tight fit to the plywood.
After the glue has completely dried, we clean the glued seam, removing as many irregularities as possible. When cleaning, we try not to damage the fiberglass so as not to reduce the mechanical strength of the connection.

Miter gluing of plywood ensures almost complete absence of seams, and therefore is used very widely. To do this, the ends of the connected plates are cut at an angle:

At the first stage, we lay the plywood sheets on top of each other, and using a jointer, we begin processing the ends at an angle, forming a mustache.
The length of the mustache for maximum effective gluing should be 10-12 thicknesses of the plywood sheet.
To ensure that the planes are as even as possible, we carry out the processing in two steps: first we set the jointer knife to 1-1.5 mm, and then to finish smoothing the plane we reduce it to 0.75 mm.

Advice! If you don't have a jointer at hand, you can improve the plane by attaching a temporary backdrop of wooden planks to it.

After processing, we clean the mustache using a tape grinder. First we go through all the planes with a grain of 40, and then - 80.

Having formed a mustache, we fold them with the processed planes facing each other. Apply glue and secure the plywood with clamps.
As in previous cases, remove the protruding drops of glue and leave the workpiece to dry.
After removing the clamps, keep the spliced sheet for 24 hours.

Of course, the strength of such a connection is inferior to monolithic plywood, but such a slab will be quite suitable for work.

Conclusion

We hope that thanks to this article, you will no longer have questions about how to glue plywood on edges and butt joints, as well as what glue can be used for this. Of course, gluing slabs from wood veneer– a labor-intensive task, but with a serious approach and strict adherence to technology, the result can be considered guaranteed.

Similar materials

I always use “epoxy”, that is, epoxy glue, or as it is also called, epoxy resin. The adhesive is quickly prepared for use, consisting of a resin and a hardener, and is easy to apply. The result is a beautiful, translucent, amber-like seam. The packaging is convenient, compact, and the price is not expensive.

True, at the present time the market is filled with all kinds of glue for gluing plywood, although in my opinion, if you follow the instructions on the packaging, you can always glue plywood using the ordinary and popular “Moment” glue. The decisive factors when using these types of glue are the compression force of the surfaces to be glued, as well as the duration of gluing. The moment is quite elastic, unlike solid epoxy resin, and is well suited where there is vibration or deformation.

As for modern species, then these include synthetic glue based on PVA emulsion, resins and other components. Here is his photo:

The following specialized rubber adhesive, which is called “For plywood”, is also suitable:

It is noteworthy that all these types of glue are used for both parquet and plywood. Therefore, by and large, you Any will do adhesive for parquet or flooring.