Spike connection dovetail. "Dovetail" fastening, connection. Cleaning cutouts between spikes

From different kind connections of two removable parts to each other in mechanics and the wood industry, dovetail fastening is the strongest and most reliable. In woodworking, this type of connection or lock is used in all forms of production.

Ways to use the dovetail mount:

1. furniture manufacture;
2. connecting workpieces to each other;
3. connection of bars;
4. fastening timber in the construction of houses.

With large-scale production, the design of this lock is quickly and successfully performed by a dovetail cutter. At home, in the absence of milling equipment, it is easy to make a dovetail with your own hands. At the same time, the ability to produce this design with high quality is considered a high-class craftsmanship.

This article provides detailed description the manufacturing process, with a step-by-step listing of all the techniques, so that a master of any level understands how to make a dovetail.

Preparation for work

Before starting, prepare the following materials and tools.

materials

Name	Type and dimensions, mm	Quantity
Wooden bars - blanks	40x40x500	2
Wood glue	—	1

Tools

The list of tools that are used in the manufacture:

• a circular saw;
• belt sander;
• manual eccentric sander;
• Miter saw;
• band-saw;
• manual frezer;
• workbench with clamping vise;
• straight chisel;
• jigsaw manual;
• finger cutter 10 mm;
• clamp;
• joiner's square;
• ruler:
• pencil;
• file;
• sandpaper grit 100.

Description of the manufacturing process

The design of this carpentry lock is a tight joint of two parts. At the end of one bar, a V-shaped protrusion is made, resembling a dovetail (where the name comes from). On the second bar, a cut is made according to the shape of this protrusion. The thickness of this spike can be the full width, and the floor of the tree. The spike and cut are made at an angle of 10-12 degrees.

This article describes the manufacturing process of this joinery joint in a wood floor. The type of product that should be obtained as a result is shown in the figure.

1. By using circular saw cut out 2 identical bars.
2. They are processed on a grinder.
3. Trim the ends of the bars with a miter saw.

Advice! In the event that several connections are required, it is recommended to make a dovetail template from a thin, dense material, which increases productivity. In the described example, a single production of this design is given.

When the protrusion is ready, a slot must be made under it on the second workpiece. To do this, markup is made on the second blank, using the first as a template. It is necessary to make the markup as accurately as possible, since any play between the parts is not allowed. The design will be unreliable. For this reason, the top lines are drawn with a cutting knife. The middle is marked with a pencil.

Next, you have to choose in the bar, according to the marks made with a jigsaw, a slot for a spike. This can be done in two ways. In the first case, the slot is selected using a chisel, cutters, file and sandpaper. Here it is necessary to show extreme accuracy, because. it is necessary to maintain a perfectly flat surface for joining and gluing parts.

If a hand router is available, then it is much easier to make a dovetail with a router, since in this case it is much easier to get a perfect result than manually.

In order to complete the connection of the dovetail, and to ensure a tight and reliable connection of the parts, on the workpiece 2, using a chisel, carefully trim the edges of the sides, periodically trying on the spike and trying to insert it into the slot. The spike should be inserted tightly, but without excessive force.

Important! After the spike has entered the intended place, the parts should be separated. In order to do this, it is necessary to clamp the workpiece 2 in a vise, and using a wooden hammer, carefully knock out a bar with a spike from the slot, as shown in the figure. If you try to do it by hand, you can break the spike.

Finally, wood glue is applied to the surface of both parts to be joined. The parts are connected to each other and pressed tightly with a clamp.

After a certain time, necessary for the glue to harden, the part is cleaned of adhesive residues using a chisel. With a manual eccentric grinder, the surface of the finished structure is brought to an ideal state. The structure is ready.

Conclusion

Practice shows that the dovetail connection is the most common reliable wooden castles in carpentry. At proper manufacture and reliable bonding, it is able to withstand heavy loads of tearing, shock and vibration. It has been used since the construction wooden houses. In the old days, this castle, common in carpentry and carpentry, with the name dovetail, was called a frying pan.

At present, this type of wooden castle is ubiquitous in all countries, in any kind of wooden connections.

Video

Detachable fastening of parts using the “dovetail” method is carried out by installing a trapezoidal spike, cut at the edges of another element, arranged on one side of the workpiece, into the groove. The type of connection of parts is used in many designs that require the creation of a rigid one-piece frame: small arms, furniture production, mechanical engineering, wooden capital construction.

After the drawing is drawn up, the dimensions of the dovetail are selected individually. The master proceeds to perform preparatory operations, during which the frame and sled take part. The material used in the process of solving the problem with loaded nodes can be steel, cast iron, bronze. In other cases, connection types can be made from light non-ferrous metals and plastics. The surface of the product is processed with a profile cutter with finishing with a scraper or a polishing disc.

Before you make a dovetail with your own hands, you should create a drawing, the dimensions of which must withstand the allowable operational loads. When making a cut, it is necessary to correctly select the angle of inclination of the sides of the trapezoid, the standard value of which is 45 0, 55 0 and 60 0. The connection by the selected method is applied in the system:

1. canopy of small arms;
2. metalworking machine;
3. optical device;
4. "In the paw" and "frying pan" in wooden housing construction.

TO positive properties technology includes high structural strength. The application of the method allows you to fasten elements without nails, screws, self-tapping screws and chops.

Application of the method with wood

The wooden spike and the mounting groove must have an identical shape and be connected into a tight tight knot. The dovetail connection, the drawing of which is intended for different products, helps to form a T-shaped and angular fastening of boards, beams or logs without overlaps at the installation sites of internal partitions. The technology of assembling wooden structures makes it possible to use for interior partitions construction material smaller diameter. If necessary, protection from wind and drafts, the corner joints of the structure of the capital structure are sealed with jute fibers.

A classic example of using the connection of elements is a drawer of a furniture set. The electric carpentry equipment used in the construction of the tenon and groove system for a hand router allows the interlacing of tenon elements using the natural resistance of the articulation to the force applied to the front of the product during extension.

The connection, the drawing of which is drawn up for each item individually, can be performed in different ways.

Most of the craftsmen working in furniture production and housing construction prefer the method of end-to-end connection of joints because of the decorativeness of the repeating pattern. Preparation of elements is carried out on a milling machine with a special device.

Marking the connecting spikes

The preparation of the material for connecting the tongue and groove with your own hands according to the template is carried out after marking the “tails” with a thickness gauge, pencil or marker on the sides and edges of the part with sockets or partitions. The dimensions and number of elements depend on the type of material, the width of the board and the way the spikes are arranged. To give decorative look the connection lines of the spikes must be of the same size, located at the same distance from each other.

Before starting work on the machine, the material is equipped with markings across the workpiece with a deviation of 6 mm from the edges. The rest of the board must be divided into an even number of spikes, measure 3 mm from each side of the marks, draw a marking line perpendicular to the end. Using a stencil or bevel, apply the contours of the slope of the spikes for the dovetail joints.

Cutting trapezoidal spikes

To form the connecting elements, the box blank is placed in a vise in such a way that one side of the spikes is located vertically. On the side face of each spike, cuts are made that do not reach the shoulder line, the workpiece is reinstalled, and other side faces are processed in a similar way. After that, the part is fixed horizontally, the lateral waste is cut off at the level of the shoulders. Excess wood between the spikes must be removed with an openwork saw.

Marking and sawing out the landing nest

For accurate marking of the seat, the workpiece is placed on a carpenter's table in a vice in a vertical position, the end of the board is rubbed with chalk to obtain an imprint on the part with the spikes already cut. With help special device the edges, the line of the shoulders of the lateral side are aligned in the form of spikes and the end of the blanks with sockets.

After finishing preparatory work you can begin to form a groove at the corners of the workpiece next to the shoulder line in accordance with the spike markings. The cut, for which the thorn groove cutter for a hand router is used, should be made in the waste part of the board so that the groove is parallel to the marking line. Excess wood between the partitions of the nest is removed with an openwork saw, cleaned with a chisel or chisel with a beveled edge. The movement of the tool should be directed from the edges to the center.

Assembly of connecting joints

For the production of products, the connection of parts of which is carried out by the dovetail method, almost all types of wood, plywood, and plastic are used. A feature of the method is non-separable technology with the use of fasteners (carpenter's glue). Checking the accuracy and fitting parts is carried out after:

1. preliminary "dry" assembly of the final product;
2. removal of excess material;
3. cleaning or sanding tight spots.

The adhesive is applied to the adjoining sides of two pieces of wood. For a tight connection of the parts of the structure, a hammer and a wooden gasket are used to protect the product from accidental damage.

After tapping the joint along the entire line, it is necessary to remove excess glue, the product is sent to dry, followed by cleaning with a jointer in the direction from the edge to the middle.

The shape and solution of the angle of cut

Standard bonding angles should not be sharp or obtuse. The large slope of the milling cut promotes the formation of short fibers in the corner. Insufficient slope of the groove reduces the strength of the connection of the elements. To solve the problem, experts recommend using bevel markings, templates or stencils. For hardwood, it is necessary to choose the optimal cut slope, which should be 1/8, for soft wood, the slope is milled by 1/6.

Decorative connection of elements

A neatly made grooved dovetail can serve as an additional decoration for household and office furniture. Design options for furniture design allow you to emphasize the beauty of wood and appreciate the skill of a specialist. The selected type of assembly of the product corresponds to the indicators of the standard proportions of the structure.

A feature of the "dovetail" is the possibility of cutting a log or beam into a half-tree in the shape of a trapezoid when corner mount details. IN wooden construction often used is the method of joining beams using the “radical tenon” method, when two elements are spliced ​​with a rectangular tenon and a groove of a similar shape. Sawing parts for connection is carried out with a cutter according to drawings, diagrams and dimensions.

The reliability and aesthetics of complex wood structures largely depend on right choice way to connect it constituent parts. This is especially true for frame products, load-bearing structures, where safety parameters come to the fore.

Quality connection wooden parts- a guarantee of durability, the basis of an attractive type of product, an indicator of the skill and professionalism of a carpenter and joiner.

Connection type selection

In general, there are a huge number of types of joints of wooden blanks, so you can only talk about some of them, the most common.

One of the most simple ways to build up a wooden part (beam, log, board), to increase its width is the end connection. There are several options for its implementation. Often a simple and functional half-thickness (half-tree) method is used. Depending on the expected load on the part, the cut can be even or oblique. In some cases, the joint is strengthened with curly cutouts - locks. This type of connection prevents stretching, twisting, bending. So the timber is spliced ​​together for the purpose of lengthening.

Creating three-dimensional frames or wooden frames requires reliable connections at various angles. In this case, it is rational to use a thorn-groove or thorn-eye connection. The nodes at the junction of the parts withstand the load of displacement, bending and compression. If the design requires high tensile strength, cutouts are made in a trapezoidal shape.

Additional connections of frame products, giving rigidity to the structure, are implemented using T-shaped or cruciform connections. The main load at the joints is compression, displacement and rupture. IN special occasions the design is additionally reinforced with metal corners, screws or nails.

To connect the boards to each other in box structures at a right angle, it is convenient to use a special box groove. As the name implies, this method is often used to create three-dimensional structures, including furniture boxes. A well-made box joint looks monolithic, has an attractive appearance and can withstand impressive loads. When creating wooden furniture, a connection is often used on dowels, dowels and dominoes (when the groove has an oblong shape, as opposed to a round dowel).

Spike connection (thorn groove)

The simplest and one of the most reliable is the thorn-groove connection. It is widely used in carpentry. In a similar way, wooden parts of window frames are assembled into a single whole, a variety of parts of cabinet furniture, plywood sheets are made. The essence of this method is that a spike is made at the end of one part to be joined, which is inserted into the groove of another part and fixed in it.

For work it is convenient to use a special lamellar milling cutter, in the absence of such, you can get by with a simple hand tool. You will need:

• hand saw with a fine tooth;
• electric or hand drill;
• several chisels of different widths;
• sandpaper;
• measuring tool, square and pencil.

First mark the blanks. The parameters of the tongue and groove depend on the parameters of the wooden parts and the configuration of the product, however, it is worth considering a few general recommendations.

Important! The thickness of the spike should be about a third of the thickness of the part, the width should be 70-80% of the width, the length should be equal to the thickness of the workpiece to be joined.

The groove parameters must also meet these criteria. In any case, it is important to ensure that the dimensions of the tongue and groove match. Parts should be connected easily, without pressure, but not fall out under their own weight. There should be no backlash, cracks and distortion.

The groove is cut first, this sequence is due to the fact that the spike is much easier to fit under the groove than vice versa. With the help of a saw, cuts are made, excess wood is removed with a drill, the bottom of the groove and the walls are leveled with chisels.

In most cases, only wood glue is enough to fix the parts; screws or nails will help to ensure maximum strength.

Half tree connection

Often used in carpentry various options half-wood joints (simple or straight lock). This build type wooden structures characterized by ease of manufacture and high reliability. The following varieties are distinguished:

• cross connection;
• half a tree - dovetail;
• gusset;
• on the mustache;
• half-tree splicing.

The first two methods are used to connect parts that intersect at right angles. Especially popular is the dovetail, in which the cutout shape is a trapezoid and the sides do not go at a right angle. The groove of the lock slightly expands from the end, providing a more secure fit. It should be noted that a spiked joint can also be called a dovetail if the spikes are cut in the form of trapezoids.

The second and third ways form a finished corner. Splicing is used if necessary to increase the length of the workpiece.

How to make a cross connection

One of the simplest is the cross connection. It is easy to manufacture, even a novice carpenter can master its wisdom. The work is done in the following order:

• marking is done. The parts to be joined overlap each other. Draw a line with a ruler. Thickness markings are applied with a thickness gauge;
• the first part is clamped in a vise. hand saw, carefully, along the lines, a cut is made to the mark left by the thickness gauge. The workpiece is rotated. A second cut is made;
• the workpiece is removed from the vise. With the help of a sharp chisel and a wooden mallet, part of the wood is removed between the cuts;
• processing the second part;
• the planes are leveled with sandpaper or an abrasive bar.

Now you can join the wooden blanks. The connection must be tight, without backlash and gaps. If the product is one-piece, the joints are coated with carpentry glue, the design is additionally reinforced with screws.

Formation of corners on the mustache

One of better ways creating corners of various volumetric products is a joint on a mustache. It allows you to create a monolithic structure, hide the fibers of the end, thereby providing an attractive look. This method is suitable for a wide variety of products, but is most often used for the manufacture of frames and cabinet furniture parts.

To create a connection in each of the wooden parts, cuts are made at an angle equal to half the angle at which the workpieces meet. Most often, this angle is straight, therefore, the cuts are made at 45 degrees, however, the angle can vary widely. Work is performed according to the following algorithm.

First mark out the details. It is important not to forget that the markup is carried out along the long side, otherwise you can not guess with the dimensions.

On the edges to be connected, draw a line at the required angle. With a combined square, the markup is transferred to each side of the workpiece. Then a cut is made, for which it is better to use an electric miter saw, but you can also work with a hand tool. When working with a hacksaw, it is important to control the angle of the cut; it would be useful to use a bar as a guide.

Finished parts are applied to each other, checking the accuracy of fit. Irregularities will have to be smoothed out with a hand planer, bring the angle with a sandpaper. Carpentry glue is applied to both surfaces, and the product is fixed with the help of clamps. Additional strength can be achieved with the help of carnations. When working with a hammer, it is important to control the force of impact so that the workpieces do not move.

Particularly important connections are reinforced with bars, which are glued into the inner corner. The joint, which will not be visible, can be further strengthened with a metal square.

As a result of high-quality work, a perfect seam will turn out. If a small gap has formed, then it can be hidden by straightening the adjacent wood fibers using a smooth cylindrical surface. For this, the rod of a conventional screwdriver is suitable.

Spike in the eye

Corner and tee (example: T-shaped connection of a window frame) intersections are conveniently performed using the tongue-and-groove method. In this case, the eye is made at the end of the vertical part, cuts for the tenon - in its horizontal component.

Work begins with the marking of the eye. The workpiece thickness is divided by three. With a thin hacksaw, cuts are made to a depth equal to the width of the other workpiece. With the help of chisels, excess wood is removed, the walls of the eye are leveled with sandpaper.

Mark the second blank. The width of the stud should be equal to the width of the first workpiece, the thickness should be equal to the thickness of the stud. The cuts are made with a hand saw, the depth and angle of inclination are carefully controlled. Excess is removed with a chisel.

The final finishing in thickness is performed with sandpaper. Parts should be connected with light force and not fall apart under their own weight.

Thorn in the jack

More complex connection is the way the thorn in the socket. It requires more skill, but is much more reliable and durable. The scope of use is the same as in the previous case, namely, T-shaped joints. The difference of this method lies in the fact that the spike is made at the end of the vertical part, a nest is sawn out in the body of the horizontal.

This is one of the most common furniture joints. There is a connection with a through spike and with a deaf one. The difference is that in the first case, a through nest is cut out, in the second, a slot is made to a certain depth.

Features of the Japanese carpentry connection

Unprecedented heights of carpentry art were reached by Japanese masters. Using traditional techniques, combining Various types connections, they create accurate and reliable joints without the use of nails and other fasteners. Docking of various wooden parts is carried out solely due to the force of friction.

The reliability of these connections is based on an accurate cut. Perfectly matched lock lines on both mating parts allow you to create a connection with impeccable precision. Complex lock configurations require a lot of experience, knowledge and ability to use the tool, but if you wish, all this can be learned.

Rallying boards

Quality wood is expensive, buy good board with the necessary parameters is not always possible, and not always necessary. To make, for example, a tabletop, it is not at all necessary to look for a table-wide board; with carpentry skills, you can create the perfect wooden canvas with the required settings.

There are many payment options. A board with a spike and a groove, the so-called lining, is widespread. It allows you to create smooth wooden surfaces large area. A simplified version of it is often used - a board with a quarter joint.

Rallying for a smooth fugue (butt)

The easiest way that does not require additional elements. The side faces of the boards are jointed, it is better to do this in pairs, clamping both adjacent boards in a vise and simultaneously processing them. Such processing will create an accurate surface on which the irregularities of one board will be compensated for by the irregularities of the other. Both boards are smeared with glue and fixed until it is completely solidified.

Rallying load-bearing elements

Lengthen (build up) the board, which is part of load-bearing structure possible in several ways. The simplest and most reliable is a half-tree connection, followed by an overlay on the junction of reinforcing strips. Non-critical areas can be reinforced with plywood.

The same method is used for articulating boards at different angles. Precisely made cuts of the articulated parts make it possible to do without reinforcing pads, it is enough to fix the boards at the junction with screws.

Cutting without residue means that the laid logs will form an even corner, their ends will not protrude beyond the building, its separate variety is a warm corner. Cutting with the remainder, in turn, means that an interweaving of protruding ends will form at the corners of the building. The second method is more expensive in terms of the amount of material, but the building retains heat better and is more stable.

There are various ways to connect wood parts, the ability to determine the best one for a particular type of work will significantly diversify the range of products that a master can make. The right method will provide an attractive appearance product and guarantees the reliability of the three-dimensional design.

How to make a spiked box connection with a hand tool.
Multi-thorn box connections are classic carpentry technologies. They are still used in the production of high-quality furniture. Of course, in our time, more simple and quick ways box assemblies. I myself usually assemble boxes on self-tapping screws, but I will write about this in another article. Here I propose to remember how this was done from time immemorial with a hand tool.

Actually, the questions of making spikes by hand sometimes arise if you don’t have special tools and fixtures at hand. And buying an expensive machine for one-time work does not make sense. True, you must understand in advance that manual work requires care and accuracy.

From the tools you will need a hacksaw-award, a set of chisels, a mallet. For marking a pencil and a metal ruler. The award differs from a regular hacksaw not only with a small tooth, but also with a special “back” overlay on the upper edge of the saw. This overlay provides additional rigidity of a cloth.

Spikes can be made self-gripping, i.e. dovetail or straight. It is better to start with straight lines, dovetail can be used when some experience appears. The details of the box in the photo are from MDF, but this is not the point, the wood blanks are processed in the same way.

1. Let's start with marking the ends of the parts. Drawer slats 100 mm wide. divided into five equal parts. Let's break them into squares 20/20 mm. , then we will combine the ends of the parts and shade the squares with a pencil through one.

That is, a clean square should be located opposite the shaded one. When making spikes, we need to remove the painted areas.

2. For ease of use, the part must be clamped vertically. If you do not have a carpentry workbench, then fix the part with two clamps to the desktop. To do this, clamp a wooden block on the edge of the table with one clamp, and pull the part to the bar with the other.

3. We cut the spikes along the markup, and note that you need to cut not along the line, but so that the marking lines remain on the side of the saw. If the cuts are made exactly along the line, the spikes will be loose and assembly of the box will become a problem. You will have to glue veneer or chips into the gaps, in general, hemorrhoids and poor-quality work. We are sawing out the areas shaded with a pencil, so the saw must be inside the shaded sector. We make cuts to a marking depth, in this case 20 mm.

4. With a chisel or cutter, select the segments between the cuts.

We take the part out of the clamp and lay it flat on the table. With a chisel we align the shoulders between the spikes. In order not to spoil the table, it is better to put a planed board or a piece of plywood under the workpiece. A wooden mallet may be needed, see .

5. When all the spikes are propylene and decorated, we carry out the initial assembly. If during assembly the spikes do not fit into place, it's okay, you need to fit the parts using a chisel or cutter (knife). For a quality assembly, fractions of a millimeter matter, therefore, for an accurate fit, it is better to work the spikes with a file or a large sandpaper on a long bar.

I once had to make not only boxes on spikes, but also knit wooden window frames using hand tools. There, the principles of work are the same, the spikes and lugs were first cut out according to the markings with a saw - an award, and then cut down the excess in the lugs with a chisel.

If you need to make a lot of spiked boxes, then it's better to think about purchasing a power tool. Such spikes can be made manual router mounted on a "table", or on a small stationary circular with a variable saw height. For both options, you will need to make a device for precise cuts. But it seems to me that making such a device is no more difficult than manually preparing parts for several boxes.

Wooden and veneered furniture, as well as others, assembled from individual structural elements made of solid wood, unfortunately, cannot serve indefinitely. And this is quite understandable. In addition to natural aging and various “diseases” of wood, there are loose adhesive joints, traces of careless storage, unskilled repairs, restorations, and others. Most often, furniture with a weakened strength of structural joints comes into restoration. individual elements, in particular studded joints.

1.1. Strengthening of the socket-spike, dovetail connections

It should be noted that over the past two centuries, furniture has been assembled using various tenon joints. Most often, a socket-thorn connection or similar hidden connections were used, in which wooden dowels (rods) were used. Such connections hold the base of the frame of many tables, armchairs, chairs, sofas and other furniture products. This position remains unchanged in the practice of restoration of structural elements made of solid wood at the present time.

The tongue-and-socket connection is a rectangular variant of the structural assembly of furniture and has two main connection methods. First, when the socket is with a ledge and a tenon - one end of the wooden element is cut and fitted in such a way as to fit into a socket carved in another element. In another way, the spike is at the same level on one side of the planar strapping of the furniture part, for example, a drawer of a table.

Rice. 1. Dovetail connection

The dovetail connection (Fig. 1) is a complicated version of the socket-thorn connection. The spikes should fit snugly into the nests, which are shaped like a swallow's tail, which increase the strength of the connection; they only separate in one direction.

« Dovetail”, as well as the “thorn socket”, are used to connect two wooden flat elements converging at a right angle, for example, in drawers tables, cabinets and other products.

Rice. 2. Strengthening the dovetail connection with inserts

Rice. 3. Strengthening the connection "socket-thorn" with inserts

With a rod (initial) connection, one structural element (detail) of furniture, with a dowel glued into the socket, is inserted into the socket on the second element with pre-applied carpentry glue.

Strengthening of dovetail and socket-thorn joints is shown in fig. 2 and 3, respectively.

IN wooden chairs, armchairs, sofas, there are many connections, more than in other types of furniture. The connections discussed above must withstand significant loads, although sooner or later in any furniture they are weakened or completely destroyed. One loose connection puts more stress on good connections, so the weak one needs to be strengthened - the sooner the better.

In cases where disassembly of furniture is undesirable, and its spike joints are greatly weakened, the adhesive joints are strengthened by injecting liquid fresh wood glue with a medical syringe and kept until the glue dries completely. The place of gluing is fixed with clamps.

If it is necessary to provide increased strength of the joints, then the structure of the furniture frame is reinforced with additional details: cut-out plates from ordinary multi-layer birch plywood, glued with hot wood glue inside the frame and fixed with screws; wooden lugs, also glued in inside corners tsargo belt of chairs, armchairs, tables; wooden dowels, which are driven with an interference fit and glue into holes drilled at the places of tenon joints.

During restoration work, when the spiked joints are disassembled, the spikes are cleaned of old glue. To remove glue from the surface of the spike, use a knife, scraper, coarse sandpaper. Hold the knife almost perpendicular to the wood of the thorn, exerting force on the blade so as to remove the dried glue without pressing the knife into the wood. The nest is cleaned of old glue with a chisel by scraping, while it expands slightly to make room for an expanded tenon due to an additional lining of a thin veneer plate. This will provide increased bond strength with new gluing. In addition, if there is a gap in the “socket-thorn” connection, then a wedge is sometimes added for tight joining, and in some cases, for greater fixing, a bevelled key is driven into the edge of the connection.

If the spike has a crack, then it is sawn through with a spiked saw and a slightly beveled wedge is inserted into the cut.

In case of destruction of the spike, it is replaced with a new one. To do this, in place of the old spike, a nest is made with a chisel 2-3 cm deep, into which a new spike is glued.

After eliminating all defects on the parts and checking the fit of the studs and sockets, the stud joints are again glued with wood glue. To do this, glue is applied to the spikes, dowels and gaskets, as well as to the sockets. After assembly, placing the spike in the socket, tighten the spike joints with a clamping device and hold them until the glue dries completely.

1.2. Strengthening joints in "tongue and ridge"

The tongue and groove connection (Fig. 4) is used when the structural elements to be connected are rectangular, for example, two folding boards.

Rice. 4. Tongue and tongue connection

This connection is weakened as a result of the simultaneous shrinkage of the tongue of the furniture element and the comb in thickness. Restore the thickness of the comb on both sides with thin veneer pads. If the comb has cracks or is broken off, then it is cut off with a planer. In its place, a recess is made, that is, a tongue of the same width and depth as that of the attached board. Boards are rallying on a spike. The plug-in spike is glued into the groove, and the direction of its fibers should be perpendicular to the direction of the fibers of the parts to be joined. The stud can be made from plain birch plywood with a thickness of at least 5 mm if the connected tongue ribs are of sufficient thickness.

1.3. Strengthening the connections on the dowel

To connect individual elements, dowels of circular cross section are widely used (Fig. 5). So, for example, a dowel is used to connect two broken parts of the legs of a chair or armchair. Nests for dowels are drilled with a drill desired diameter. Nagel is not necessarily made from the same material as the furniture. The best pins are made from beech, which is less brittle than oak. The pin should penetrate deeply (up to 5-6 cm) into the parts to be joined.

Rice. 5. Dowel connection

1.4. Strengthening joints on a "smooth fugue"

The connection of boards to a smooth fugue (Fig. 6), weakened as a result of warping of the shields and shrinkage, is strengthened with transverse dowels of a trapezoidal or rectangular cross section.

Rice. 6. Connection to the "smooth fugue"

They are inserted into the grooves made on the inside (non-front) side of the part. The dimensions of the keyway for thin boards must be at least half of their thickness. Glue the boards along the edges and glue the dowels at the same time. To do this, after applying the glue, the bonded boards are placed face down on a dense and even backing board, the dowels are inserted and placed under the press. At the same time, with the help of a clamp, the boards are squeezed from the edges. This eliminates the slight distortion of the overall surface.

Strengthening joints on a smooth fugue can be carried out with inserts in the form of a dovetail spike (Fig. 7) - this is the traditional method.

Rice. 7. Strengthening the joints with a dovetail spike

"Dovetail", which is sometimes called "butterflies" by restorers, is an insert in the form of double spikes. After the parts of the boards are connected, grooves are cut in the tree for about a third of its thickness in the form of an insert, into which they must fit tightly. Inserts are made from the same type of wood as the exhibit, or from durable wood (oak, beech); their fibers should be perpendicular to the direction of the fibers of the joined edges. The dovetail should be wide enough at the lintel (center). Due to its shape, such an insert provides a strong connection, but some restorers consider it insufficient.

1.5. Strengthening connections on the "mustache"

Restorers quite often come across with joints of furniture elements on the "mustache" (Fig. 8), which consist in the imposition of one element on another at an inclined cut. The parts to be joined should, if possible, have the maximum contact surface, then the reliability of gluing will be the greatest. The glued place is strengthened with dowels or plug-in spikes.

Rice. 8. Strengthening the connections on the "mustache"

1.6. Strengthening joints with "breadcrumbs"

This method of strengthening the elements of the furniture structure and their connections is used when the furniture cannot be dismantled. Strengthening can be carried out with connecting plates of any shape (Fig. 9).

To close the crack from the inside and prevent it from spreading, you can use the overlay to fix the connected place vertically and horizontally. The overlays are made of wood of the same species as the exhibit itself. When sticking them on a crack, it is necessary that the fibers of the linings be perpendicular to the fibers of the parts to be joined. Often the cracks to be bonded are not straight, in which case it is preferable to make not one overlay, but several smaller ones next to each other. After coating with good wood glue, if possible, they are pressed with screws. The advantage of this strengthening of the connections is that the linings can be removed if necessary.

One of the types of overlays are "crackers", which strengthen the connection of the side with the leg. Some restorers object to the use of "crackers", considering them irrational. They prefer to dismantle the furniture, redo the drawer side with a new internal connection. This violates the principle of maximum preservation of the original. In addition, sometimes it is harmful to remove the upholstery and then dismantle the exhibit. "Crackers" compensate for the "fatigue" of the wood side, caused by numerous renovating upholstery. "Crackers" are especially useful when the bars of the seat side are curved and have longitudinal cracks.

"Crackers" are made from soft, well-adhesive wood species (linden, poplar). Their height should be equal to the height of the king. From the inside, they are given a concave line, because this shape facilitates the upholstery and the final fastening at the corners of the junction of the side and leg. "Crackers" are installed after fixing the legs. If they fit well and are glued on, then there is no particular need to screw them in with screws. But some restorers, nevertheless, during gluing, press the “crackers” with clamps, and after gluing they screw in the screws. Nails are not allowed.

Rice. 9. Strengthening the joints with "breadcrumbs"