Peeling skin can be caused by a variety of factors. To deal with ...
Methods for joining bars for carpentry work
The simplest way of corner joining is a mustache trim. Careful adjustment of the planes to be joined, good gluing, the obligatory use of auxiliary fasteners - wooden plates, metal squares, knocking with pins, screwing together - makes this method quite reliable. Miter trim can be significantly enhanced by the use of various plug-in tenons: flat deaf, round deaf, flat through (Fig. 1). In terms of strength, such joints are not inferior to knitting on solid spikes.
Rice. 1 Corner knitting of bars: a - trimming on a mustache; b - with the help of overlays; c - on wooden hairpins; Mr. screws; d-on round plug-in thorns; e - a flat plug-in thorn; g - flat deaf thorn
A common way of corner joints is knitting on a single tenon (Fig. 2). Single spikes can be made through and deaf. A through single thorn is easy to manufacture, more durable than a deaf one. A blind single spike has the advantage that it does not require additional costs to hide the visible parts of the joint.
Rice. 2 Corner joints with a single tenon: a - through; b - deaf
A prerequisite for a high-quality studded joint is correct and accurate marking (fig. 3). Marking is done with a two-line thickness gauge. One of the devils is placed at a distance of 1/3, and the other at 2/3 of the width of the edge of the bar. Considering the front face as the base, risks are carried out on a bar under a thorn, and on another bar - under a nest or eyelet. It is also convenient to mark the nest using a ready-made thorn (this technique is especially convenient for blind knitting). A bar with a spike is placed in the place of the future nest, outlined with a pencil. Then place the block on the shoulder of the spike and mark the depth of the hole. The depth of the socket under the blind tenon should be 2-3 mm more than the length of the tenon for a tight fit of the shoulders and for excess glue.
Rice. 3 The sequence of making the spike joint: a - marking the spike with a two-line thickness gauge; b - trimming the thorn along the contour; c - sawing the thorn with a fine-toothed hacksaw; d - marking the nest for a deaf thorn
Cut the thorn with a fine-toothed saw so that the cut passes near the very risks in the direction of increasing the size of the thorn. When sawing, the block must be well secured in a vice. During gouging, care should be taken to ensure that the risks remain intact. After gouging, the walls of the nest are cleaned with a chisel or knife.
To obtain a strong connection with a single tenon, it is necessary to adjust the tenon with an interference fit of 0.1-0.3 mm, i.e. the thickness of the tenon should be 0.1-0.3 mm greater than the width of the socket or eyelet. If you try to drive a thicker thorn into the nest, then this invariably leads to the splitting of the bar.
When assembling the spike connection, do not hit with a mallet or hammer directly on the part, as chips and dents are possible. For this, an auxiliary block is used, which is placed on the shoulder of the thorn and the thorn is driven into the socket with light blows on it (Fig. 4a). If the thorn, as a result of inaccurate marking, does not have a snug fit of the shoulders, then, without completely disassembling the joints, you can make an undercut, or, as they sometimes say, undercut (Fig.4b).
Rice. 4 Techniques and methods of fastening a single tenon: a - the use of an auxiliary bar during assembly; b - undercut; c - fastening the thorn with wedges; e - correct use of pins
To obtain a stronger connection, it is wedged onto a through single thorn using hardwood wedges. Their taper is small, of the order of 5-8 °. 2 wedges are necessarily wedged into the thorn, stepping back from the edges by 5-10 mm, as shown in Figure 4c. Both wedges are hammered in at the same time by alternating light blows so that the block does not crack. After gluing a single spike, if necessary, it can be additionally strengthened wooden nails(with dowels). Nagels are placed on the diagonal of the corner joint. The hole for the dowel, located closer to the outer edges of the joint, is drilled at a distance of 1/3 of the width of the parts (counting from the edges), and the second hole is drilled, retreating from the inner edges by 1/4 of the width of the parts to be joined. How to use the pins correctly is shown in Figure 4d.
It is even easier to manufacture knitting on a single spike with a shoulder cut on one side (Fig. 5). In this case, the thorn is made with a thickness equal to 1/2 the thickness of the bar with the thorn. The thickness of the part with the socket must be 1/3 greater than the thickness of the part with the spike. One-sided shoulder cutting requires almost 2 times less time than double-sided one.
Rice. 5 Single spike with one shoulder
For the manufacture of frames of hollow panels, thin bars are used, for the connection of which it is recommended to use knitting with an open straight thorn. Nests are cut in the frame of the shield frame. The nests should be no more than 1/2 the width of the bar deep. On the bars of the lattice, open straight spikes are cut, the width of which should be at least 1/3 of the width of the bar of the lattice. This knitting method is simple to manufacture and less laborious than others (Fig.
Rice. 6 Knitting the backboard frame with an open straight tenon
For center or corner connection of bars under a straight or sharp corners one to the other most often use half-tree mating (Fig. 7). With such a knitting, opposite grooves are cut in both joined parts, in depth equal to 1/2 of the thickness of the joined bars. It is always advisable to strengthen a mating in half a tree with dowels. Only in this case will such a connection be strong enough.
Rice. 7 Knitting bars in half a tree with a cross
Carpentry. Mastery lessons. Content
Compound wooden parts requires, first of all, the ability to correctly mark the parts so that they fit exactly and tightly to each other. It is necessary to make it a rule not to make even the simplest connections without marking.
End-to-end connection(fig. 82) - the simplest and most fragile. To increase its strength, the ends of the parts to be joined must be made strictly rectangular. The ends should be processed with a plane, and the squareness should be checked with a square. 
Overlay connection(Fig. 83) is used to connect the ends of two bars at an angle, each end being cut to half the thickness, if they are the same, or the end of one, thicker part is cut off. The parts are glued together and additionally fastened with screws or wooden pins. This connection is also not very strong.
Miter"(Fig. 84) differs from the end-to-end connection in that the mating ends of the parts are cut off at an angle of 45 °.
The marking of the ends is best done with a lance. It is advisable to strengthen such a connection with a plywood plate or a metal square. 
Reinforced mustache connection(fig. 85) is the same as usual, but fortified with inside corner with a square or triangular wooden block.
Overlay "half-wood"(Figure 86) is convenient for a T-shaped connection of two parts. Here, in the same way as when joining "overlay", either cut both parts by half if they are the same in thickness, or make a notch only in the thick part. 
Straight through spike connection(fig. 87) is one of the most durable. Here, depending on the purpose, the parts are glued or fastened with pins.
Connection on two plug-in round tenons(fig. 88) is also very durable. Requires precise hole drilling. It is produced according to a template made of thin plywood or cardboard, cut to the thickness and width of the bar with drilled centers for the holes. The template is applied to both parts and the markings are made with an awl. 
Median single stitch knit can be through and deaf, depending on the purpose. With a through socket for a thorn, it is hammered through. A blind joint is used when it is necessary to hide the end of the thorn. Through spikes are stronger because they have a larger bonding area.
Mid connection with round dowels, as with gussets, requires precise hole drilling.
Cross join(Fig. 89) is carried out "in half a tree" with the same thickness of parts or by forming a corresponding recess in a thicker part. 
The "half-wood" overlay with a paw provides greater strength than the usual "half-wood" overlay, since the mating places are made with oblique sides of the "dovetail" type.
Box connections(Fig. 90) are available with straight and oblique dovetail spines. An oblique tenon is more laborious, but also more durable. 
Splice It is used to obtain long parts by connecting short ones along the length. The simplest methods of splicing are "in a mustache", "half-tree", with a straight and plug-in round thorn.
Nog is a wooden rod made of hardwood. The ends of the dowel are slightly sharpened so that it easily falls into the hole and so that the glue does not rub off by the edge of the hole, but penetrates inside.
The diameters of the dowel and the holes for it must be the same. It is advisable to choose the maximum permissible diameter of the pin, since in this case the gluing area is larger and the connection is stronger. However, it is necessary to leave sufficient wall thickness of the part.
The holes for the pins are drilled after the parts are assembled and glued. The exception is tenon joints: here you can drill holes before gluing. If not large area connections make one dowel in the center. With sufficient area, especially when connecting "overlap", place two pins diagonally.
Sometimes, if necessary for exterior decoration, the outer end of the dowel is slightly drowned and the hole is putty. This method is applicable in products intended for coating with oil or enamel paints.
In products intended for varnishing, holes for the dowels are drilled blind so that the front surface of the part remains intact.
The main types of strong connections wooden products between themselves is their gluing and gluing fastening along the fibers. Subject to all gluing rules, strength glue line more than the adhesion of wood fibers to each other.
The bond strength depends on the quality of the glue, its correct preparation, correct methods gluing and subsequent holding of the glued parts. An indispensable condition for high-quality gluing is the use of dry wood. The wood is usually glued with carpentry or casein glue.
The quality of gluing with wood glue is largely influenced by the thickness of the glue. For hard wood, a thinner glue is required, for soft wood, a thicker one, because. soft wood absorbs it more strongly. A completely liquid glue is used to fill the pores of the wood when gluing the ends.
Carpenter's glue should be applied to the surface of both parts to be bonded, this will ensure greater strength.
Then the parts to be glued, depending on their size and location, are compressed with clamps, by imposing weights, temporarily knocked down with nails, etc. Pressing in the parts is not required only when gluing the spikes in the nests, since they sit there quite tightly. If the spike enters the eyelet, then additional compression is desirable. Expose details further processing can be done in at least a day, when the glue finally hardens.
Joiner's glue adheres well to wood, but has a significant drawback - it intensively absorbs moisture. Therefore, the parts glued with it cannot be kept in an environment with high humidity.
Casein glue became more widespread due to the fact that it is cheaper, easier to manufacture, is not afraid of moisture, sometimes even surpasses carpentry in adhesion strength.
When gluing parts with a longitudinal direction of the fibers with casein glue, you can limit yourself to applying glue to one of the surfaces. If at least one of the parts is glued with the butt end, both surfaces are greased with glue.
The glued surfaces are kept for 5-10 minutes, and then squeezed, depending on the glued area, for 3-6 hours and kept for another day. Casein glue should not be applied too thickly, as it forms crusts when squeezed out, which can be difficult to remove when sanding. If the glue is still squeezed out, the excess must be removed immediately with a damp cloth.
If, in addition to gluing, the parts are fastened with nails or screws, then pressing is not necessary.
Before applying the adhesive, it is necessary to prepare the surfaces to be glued. Preparation consists in a good fit of the joint planes to each other and roughening them with a rasp: rough surfaces stick together better.
Required condition good adhesion- cleanliness of surfaces. They should be free of dust, dirt, grease or oil stains. The thickness of the adhesive layer is of great importance for the adhesion strength. The connection will be fragile, both with a too thick layer of glue, and with too thin. Therefore, the glue should be applied in a thin, but dense and uniform layer.
For all its apparent simplicity fastening parts with nails, screws or bolts these operations require compliance certain rules, the implementation of which ensures the strength of the joints. Great importance has also correct selection nails, screws and bolts in length and thickness.
The longer and thicker the nail or screw, the greater the area of contact with the wood it has and the correspondingly higher the strength of its fastening. Therefore, the length of the nail or screw is selected so that it is 3-5 mm less than the total thickness of the parts to be joined. The nails and screws themselves should be as thick as possible, as far as the width of the part and the location of the nail or screw from the edges allow.
It should be borne in mind that a nail hammered across the fibers holds the details well; a nail driven into the end holds much weaker. The same applies to screws.
If hardwood parts need to be fastened with thin nails or close to the edge, then a hole with a diameter less than the thickness of the nail is pre-drilled.
It should be remembered that several closely spaced nails hammered into one layer of wood can split the part. The same can happen when driving a nail too close to the end, especially if the nail is thick and the details are thin.
When fastening parts of different thicknesses, always a thin part is nailed to a thick one, and not vice versa. The length of the nails should be 2-4 times the thickness of the thin piece.
Screw connections are more durable than nails. Thanks to the screw thread, the contact surface of the screw with the wood is greater. In addition, there is a great deal of friction between the screw and the wood and mechanical resistance to the reverse movement of the screw.
First, with a pencil or an awl, mark the places where you need to screw the screws. Then a hole is drilled with a diameter slightly smaller than the cylindrical part of the screw and half its length. For small screws, the hole can be pierced with an awl. It is much more difficult to screw screws into a whole tree without punching holes, and you can also split the part.
The end of the screw is inserted into the hole, holding it with the fingers of the left hand and slightly driven in with a hammer, making sure that it stands upright. Then the screw is screwed in with a screwdriver until the head rests on the surface. The slot of the head is installed parallel to the grain of the tree.
When screwing several screws in a row, it is desirable that their splines are directed in one straight line or parallel to each other.
The strength of the connection with nails or screws also depends on the hardness of the wood. The harder the wood, the stronger nails and screws sit in it.
The most durable type of connection, which does not depend on the direction of the fibers or on the hardness of the wood, is obtained by using bolts with nuts.
The holes for the bolts must be equal to their diameter. The length of the bolt is selected so that the part extending beyond the part is slightly greater than the thickness of the nut. Washers are placed under the heads of bolts and nuts to protect the wood from dents.
Bars of joinery are interconnected by a tenon joint, which consists of two elements - a tenon and a socket or eyelet. Thorn - a protrusion at the end of the bar, included in the corresponding
Rice. 42. Types of thorns:
a- single, b- double, v- multiple, G- round, d- "dovetail", e- one-sided "dovetail", g, h- toothed, and- nest, k, l- eyelets, m- a deaf thorn, n- thorn in the dark, O- thorn in
semi-darkness
nesting socket or eyelet of another bar. Thorns are single (Fig. 42, a), double (Fig. 42.6), multiple (Fig. 42, c), that is, more than two.
A solid thorn is a thorn that is integral with the bar. A plug-in thorn is a thorn made separately from the bar. A thorn with a cross-section in the form of a circle is called round (Fig. 42, G).
The dovetail spike (Fig. 42.5) has a profile in the form of an isosceles trapezoid with a large base on the end face of the thorn, the one-sided dovetail spike is in the form of a rectangular trapezoid with a large base on the end face of the spike (Fig. 42, e).
The toothed spike has a profile in the form of a triangle or trapezoid, the smaller base of which is the end face of the spike (Fig. 42, h), a two-sided toothed spine (Fig. 42, g) -isosceles triangle.
Single and double spikes are used in the manufacture of windows, frame doors, furniture; dovetail thorn - in the manufacture of boxes, boxes; serrated spikes - when gluing parts (splicing) along the length.
In addition, round plug-in thorns are used when joining plots (blanks) in width. Thorns in the dark and semi-dark (Fig. 42, but), used in the manufacture of frames, me-
Rice. 43. The shape of the processed bars:
a- chamfer, b- headquarters (headquarters), v- edge rounding, G- fillet, d- fold-quarter, e- kalevka, f- Thorn, s- eyelet, and- profiled edge, To- bar, l - nest, m- layout, n- Platicker, O- overhang; / - shoulders, 2 - lateral edge of the thorn, 3 - end face of the thorn, 4 - panel, 5 - edge, b- butt, 7 - face; / - the length of the thorn, B- stud width, s - stud thickness
whites, etc. In addition, they use sockets and lugs, a deaf thorn, shown in Fig. 42, and, k, l, m.
A thorn in the dark is made not only at the end connection, but also in those cases when it is required that the edges of the nest be invisible, since it is not always possible to get smooth edges of the nest. To hide this defect, a darkening is cut out from the thorn, that is, a part of the thorn is removed in width from one or both sides.
In order to form a thorn, an eyelet, processed bars, that is, planed from four sides to the required size, -f- pre-marked.
Structural parts and elements of joinery. Joinery has the following main structural parts and elements.
Bar- the simplest detail; comes in different sizes, sections and shapes (Fig. 43). The narrow longitudinal side of the bar is called the edge, and the longitudinal wide side is called the face, the line of intersection of the face with the edge is called the edge. The end transverse side of the bar, formed when trimming at a right angle, is called the end.
In the manufacture of window and door blocks, small-section bars (vertical, horizontal sash sash)
they are made of solid wood, and large cross-sections (boxes) are made glued.
Layouts are called bars intended for fixing glass in sashes, doors or panels in door leaves frame structure.
Panels represent a rectangular shield made of joinery, chipboard or fiberboard. Panels are flat in shape, with beveled edges and profiled edges. The panel within the doors is installed in a groove, rebate and fastened with layouts or applied to the bars and fastened with screws.
Fold called a rectangular notch in a bar. If the notch has equal sides angle, then it forms a quarter.
Platik- a ledge formed to hide the gap; used in cases where the flush fit of the part is difficult. The use of a plastic plate simplifies the assembly of products. It is used in the manufacture of furniture.
Overhang- protrusion beyond the base. Used in the manufacture of furniture.
Galteli called a semicircular notch on an edge or face of a part.
Frame consists of four bars forming a square or rectangle. In addition, separate frames have internal middle bars (frame doors, window sashes with slabs).
The frames are assembled on a tenon connection. A small frame is assembled on a single open through thorn or thorn with semi-darkness or darkness. In the manufacture of joinery, predominantly rectangular frames are used, very rarely (for unique buildings) - polygonal or round. Casement, a window, a transom, a box - all these are frames.
All connections in window blocks are made on thorns. The strength of the finger joint is determined by its dimensions and the area of the glued surfaces. To increase the strength, the spikes are made double (in the windows).
Shields are made massive (board) or with voids. In order to avoid warping, massive shields should be collected from narrow slats (parts) with a width of no more than 1.5 thicknesses, with a selection of fibers, moisture up to (10 ± 2)%.
When gluing parts in width, the same (sapwood) faces of the battens to be connected should be facing in opposite directions, and the edges of the same name - towards each other.
It is allowed to dock the slats along the length if the joints are staggered and the distance between them in adjacent slats is at least 150 mm. In panels intended for load-bearing structures, the slats are not joined along the length. Wall panels, vestibules, etc. are made of shields.
To avoid warping, the shields are made with dowels.
Rice. 44. Types of shields:
a- with dowels, b- with tips in the groove (tongue) and ridge, v- with a glued rail at the end, G- with glued-in triangular strip, d- with glued triangular strip, e-
multilayer
(rice. 44, a), with tips (Fig. 44.6), with glued and glued strips (Fig. 44, c, d,e). The dowels in the shields are made flush with the plane or protruding. At least two dowels are placed on each shield. Shields with dowels are intended for doors of temporary buildings, etc.
a) S) v)
Rice. 45. Ways of connecting shields:
a- for a smooth joint, b- on the rail, v- in a quarter, G- in the groove and comb, d- in the groove and triangular ridge, e- in "dovetail"
Rice. 46. Adhesive joints of bars, boards along the length:
a- end, b- on the "mustache", v- on a stepped "mustache", G- on a stepped "mustache" with bluntness, d- toothed, e- vertical toothed, w - horizontal toothed, s- toothed on the "mustache", and- stepped; в - bevel angle, L- the length of the "mustache" of the thorn, t- connection pitch, 6 - bluntness, 5 - gap, V- thickness, i- the angle of the tenon
In addition to planks, multilayer shields are made, glued from three or five single-layer shields with mutually perpendicular direction of fibers (Fig. 44, e).
Massive shields are glued on a smooth joint (Fig. 45, a), on a rail (Fig. 45.6), in a quarter (Fig. 45, c), in a groove and a ridge (Fig. 45, d, e) willow "dovetail" (Fig. 45, e).
Joining wood parts. Splicing of segments along the length can be face, on the "mustache", toothed, stepped (GOST 17161-79).
End adhesive bond (fig. 46, a)- this is an adhesive connection with the end surfaces of the gluing. Under the end glue connection "mustache" (Fig. 46.6) is understood as the glue connection with flat gluing surfaces located at an acute angle to the longitudinal axis of the workpieces. Adhesive bondingon a stepped "mustache"(Fig. 46, c) is a joint in which the gluing surfaces have a protrusion that prevents the workpieces from displacing in the longitudinal direction when stretched. A joint in which the beveled ends of the workpieces have a bluntness, which prevents the workpieces from displacement in the longitudinal direction during tension and compression, is called a joint with a stepped "mustache" with a bluntness (Fig. 46, G).
Serrated adhesive bond(fig. 46, e)- this is a connection with profiled surfaces in the form of toothed spikes, twirlglue joint(fig. 46, e)- connection with the outlet of the profile of the studs on the face of the workpiece. In a horizontal toothed joint (Fig. 46, g), the profile of the spikes extends to the edge of the workpiece.
Serrated glue joint with "mustache"(fig. 46, h)- connection
on the "mustache" with profiled gluing surfaces in the form of toothed spikes.
Stepped adhesive bonding(fig. 46, and)- end connection with profiled gluing surfaces in the form of a step, the height of which is equal to half the thickness of the workpiece.
The most durable is glued joint on a toothed spike. This type of connection is used for splicing sash bars, transoms, window and door frames and other building elements.
Serrated adhesive bond(see fig. 46, e) manufactured in accordance with GOST 19414-90. The workpieces to be glued should not differ in moisture by more than 6 %. In the joining zone of the workpieces, knots of more than 5 mm are not allowed. Roughness parameter of gluing surfaces of toothed spikes Rmmax according to GOST 7016-82 should not exceed 200 microns.
The dimensions of the spike joints are given in table. 1.
tableI. Dimensions of finger joints
Rallying consists in joining bars, planks, plots along the width of the edge into shields or layers into blocks. Each workpiece connected to a shield is called plot.
In accordance with GOST 9330-76, it is recommended, depending on the purpose of the products, to make the connection along the edge on a rail, in a quarter, in a rectangular and trapezoidal groove and a ridge, and on a smooth joint.
When making connections on the K-1 rail (Fig. 47, a), at / equal to 20 ... 30 mm, do 1\ 2 ... 3 mm more; S \ take equal to 0.4 So for timber battens and 0.25 5 0 for plywood battens. The size S \ should be equal to the nearest dimensions of the slotted disc cutter, i.e. 4, 5, 6, 8, 10, 12, 16 and 20 mm. One- and two-sided chamfers are allowed on the edges.
For connection of type K-2 along the edge in a quarter (fig. 47, b):ho= 0.5 So - 0.5 mm, b is dependent on S 0 :
S 0 , mm I2 ... 15 15 ... 20 20 ... 30 30
B, mm 6 8 10 16
Rice. 47. Schemes of joining boards (plots) along the edge:
a- along the edge on the K-1 rail, b- in a quarter along the edge of K-2, v- into a rectangular groove and a ridge along the edge K-3, G- in a trapezoidal groove and a ridge along the edge of K-5, d- on a smooth joint K-6 (along the edge), e- along the edge into a rectangular groove and K-4 ridge
For connection of type K-3 in a groove and a ridge (fig. 47, v) radius of curvature G make 1 ... 2 mm, and the size 1\ - 1 ... 2 mm more size/ (Table 2). One- and two-sided chamfers are allowed on the edges.
Table 2.Dimensions of the K-3 connection, mm
|
S, | ||
Dimensions of connections K-4 (fig. 47, e) are given in table. 3. Table 3.Dimensions of the K-4 connection, mm
|
Sa |
B | |||||
The dimensions of the grooves and ridges of the K-5 joint (Fig. 47, d) are determined according to table. 4.
table4. Dimensions of the K-5 connection, mm
|
St |
I | |||
The seam formed when joining the plots is called fugue. Plots from which the shield is glued onto a smooth joint type K-6 (Fig. 47, e) must have smooth and even edges forming a right angle with the plane (face) along the entire length. If there are no gaps when connecting the plots, then the jointing (fitting) of them is performed efficiently. Shields are glued in clamping clamps, wi-max, presses.
In addition to gluing, shields can be assembled from plots into round plug-in thorns, while the diameter of the thorn should be 0.5 of the thickness of the plot, and the length should be 8 ... 10 diameters. The spikes are installed with a step of 100 ... 150 mm.
The connection in the groove and the ridge, as well as in the quarter, is made by culling along the entire length of the edge (plot) on one side of the groove or quarter, and on the other - the ridge or quarter. This compound is used in the manufacture of panels, planking of wooden floors, the device of joinery partitions, and the filing of ceilings. A smooth reveal is more economical than a quarter or groove and tongue.
When connecting to a rail along the edges of the plots, grooves are selected into which wooden or plywood slats are inserted.
The reliability and aesthetics of complex wood structures largely depend on the right choice the way of connecting its constituent parts. This is especially true for frame products, load-bearing structures where safety parameters come to the fore.
A high-quality connection of wooden parts is a guarantee of durability, the basis for an attractive appearance of a product, an indicator of the skill and professionalism of a carpenter and joiner.
Choice of connection type
In general, there are types of joints of wooden blanks great amount, therefore, it is possible to tell only about some of them, the most common.
One of the most simple ways build up a wooden part (timber, log, board), increase its width is the end connection. There are several options for its implementation. A simple and functional half-thickness (half-tree) method is often used. Depending on the expected load on the part, the cut can be flat 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.
The creation of volumetric frames or timber 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 structure requires high tensile strength, the cutouts are trapezoidal.
Additional connections of frame products, which impart rigidity to the structure, are implemented using T-shaped or cruciform joints. The main stress at the joints is compression, displacement and rupture. In special cases, the structure is additionally reinforced with metal corners, screws or nails.
It is convenient to use a special box groove to connect the boards to each other in box structures at right angles. 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. While creating wooden furniture often use a connection on dowels, dowels and dominoes (when the groove has an oblong shape, as opposed to a round dowel).
Spike connection (spike-groove)
The simplest and one of the most reliable is the tongue-and-groove connection. It is widely used in joinery. In a similar way, wooden parts of window frames are assembled into a single whole, a variety of cabinet furniture parts, plywood sheets are made. The essence of this method is that a spike is made at the end of one part to be connected, which is inserted into the groove of the other part and fixed in it.
For work, it is convenient to use a special lamellar cutter, in the absence of one, you can do with a simple hand tool... You will need:
- hand-held shank saw with a fine tooth;
- electric or hand drill;
- several chisels of different widths;
- sandpaper;
- measuring tool, square and pencil.
First, the workpieces are marked out. The parameters of the spike 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. The 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 caused by the fact that the tenon 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
Quite often, in carpentry, various options for half-wood joints (simple or straight lock) are used. This type of assembly wooden structures characterized by simplicity of manufacture and high reliability. There are the following varieties:
- cross connection;
- half a tree - dovetail;
- gusset;
- on a mustache;
- splicing in half a tree.
The first two methods are used to connect parts that intersect at right angles. Particularly popular is the dovetail, in which the shape of the neckline is a trapezoid and the sides are not at right angles. The slot of the lock expands slightly from the end, providing a more secure fit. It should be noted that a tenon joint can also be called a dovetail if the tenons are cut in the form of trapezoids.
The second and third modes form a complete corner. Splicing is used if it is necessary to increase the length of the workpiece.
How to make a cross connection
One of the simplest is the cross connection. It is distinguished by its simplicity of manufacture, even a novice carpenter can master its wisdom. The work is done in the following order:
- markup is done. The parts to be joined are superimposed on each other. Use a ruler to draw a cut line. A thickness gauge is used to mark the thickness;
- the first part is clamped in a vice. With a hand saw, carefully, along the lines, a cut is made to the mark left by the thickness gauge. The workpiece turns. The second cut is made;
- the workpiece is removed from the vice. With the help of a sharp chisel and a wooden mallet, part of the wood is removed between the cuts;
- the second part is processed;
- planes are aligned with sandpaper or an abrasive bar.
Now you can dock wooden blanks... The connection must be tight, without backlash and gaps. If the product is one-piece, the joints are coated with wood glue, the structure is additionally reinforced with screws.
Forming corners on a mustache
One of better ways creating corners of various volumetric products is a mustache joint. It allows you to create a monolithic structure, hide the fibers of the end, thereby providing an attractive appearance. 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 performed at 45 degrees, however, the angle can vary widely. The work is performed according to the following algorithm.
First, the details are marked. It is important not to forget that the markings are carried out along the long side, otherwise you may not guess with the dimensions.
On the edges to be connected, draw a line at the required angle. With a combined square, the markings are 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 cutting angle; it will be useful to use a bar as a guide.
Finished parts are applied to each other, checking the accuracy of the fit. Irregularities will have to be smoothed out with a hand plane, to bring the angle with the help of a sandpaper. Joiner's glue is applied to both surfaces, and the product is fixed with the help of clamps. Additional strength can be achieved with studs. When working with a hammer, it is important to control the force of the impact so that the workpieces do not move.
Particularly critical connections are reinforced with bars that are glued into the inner corner. A joint that will not be visible can be additionally reinforced with a metal square.
As a result of well-done work, you will get a perfect seam. If a small gap has formed, then it can be hidden by straightening the adjacent wood fibers using a smooth cylindrical surface. To do this, use the stem of an ordinary screwdriver.
Thorn in the eyelet
Corner and T-joints (example: T-joint window frame) it is convenient to perform intersections using the tongue-and-groove method. V this case the eyelet is made at the end of the vertical part, the cuts for the thorn are made in its horizontal component.
Work begins with marking the eyelet. The thickness of the workpiece is divided by three. With a thin hacksaw, cuts are made to a depth equal to the width of another workpiece. With the help of chisels, excess wood is removed, the walls of the eyelet are leveled with sandpaper.
The second workpiece is marked out. The width of the tenon must be equal to the width of the first workpiece, the thickness must be equal to the thickness of the tenon. The cuts are made with a hand hacksaw, the depth and angle of inclination are carefully controlled. The excess is removed with a chisel.
The final finishing in thickness is carried out using sandpaper. The parts should be connected with light effort and not disintegrate under their own weight.
Thorn in the socket
A more complex connection is the tenon-to-socket method. 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-joints. The difference between this method is that the spike is made at the end of the vertical part, a socket is cut out in the body of the horizontal part.
This is one of the most common furniture connections. Distinguish between connection with a through thorn and a blind. The difference is that in the first case, a through socket is cut, in the second, a slot is made to a certain depth.
Features of Japanese joinery
Japanese craftsmen have reached unprecedented heights of carpentry. Using traditional techniques, combining Various types connections, they create accurate and reliable joints without the use of nails and other fasteners. The joining of various wooden parts is carried out solely due to the frictional force.
The reliability of these connections is based on an accurate cut. Perfectly matched lock lines on both mating parts create a connection with impeccable precision. Complex lock configurations require great experience, knowledge and ability to own the instrument, but if you wish, you can learn all this.
Pulling planks together
High-quality wood is expensive, it is not always possible to buy a good board with the required parameters, and it is not always necessary. To make, for example, a tabletop, it is not at all necessary to look for a board as wide as a table, having the skills of carpentry, you can create an ideal wooden canvas with the necessary parameters.
There are many options for rallying. A board with a spike and a groove, the so-called lining, is widespread. It allows you to create even wooden surfaces large area. A simplified version of it is often used - a board with a quarter joint.
Rallying on a smooth puffer (butt)
The easiest way not requiring additional elements... The side edges of the boards are planed, it is better to do this in pairs, clamping both adjacent boards in a vice and at the same time processing them. This will create a precise surface on which the unevenness of one board will be compensated by the unevenness of the other. Both boards are coated with glue and fixed until it hardens completely.
Consolidation of load-bearing elements
There are several ways to lengthen (build up) a board that is part of the supporting structure. The simplest and most reliable is a half-wood connection with subsequent overlay on the junction of the reinforcing strips. Non-critical areas can be reinforced with plywood.
The same method is used to join the boards at different angles. Precisely made cuts of the articulated parts make it possible to do without reinforcing linings, it is enough to fix the boards at the junction with screws.
Cutting without residue means that the laid logs will form an even angle, their ends will not protrude beyond the structure, a separate variety of it - warm corner... The cut with the remainder, in turn, means that an interlacing of protruding ends will form at the corners of the building. The second method is more costly in terms of the amount of material, but the building retains heat better and is more stable.
Exists different ways joining parts made of wood, the ability to determine the optimal one for a particular type of work will significantly diversify the range of products that a master can make. The right way will provide an attractive appearance the product and guarantees the reliability of the volumetric design.
Timber such as beams, planks, or planks is generally produced in a specific size, but often construction may require material that is long, wide, or thick. For this reason, in order to achieve the required size, several types of joints are used using cuts made by specialized equipment or by manual marking.
Width connections
After bonding boards with a small width, a shield is obtained with the dimensions required for production. There are several methods for docking:
1)Docking on a smooth joint;
in this method of joining, any board or rail is referred to as a plot, and the formed seam is referred to as a fugue. The jointing can be considered qualitative only when there are no gaps between the edges of adjacent boards.
2)Rail fastening;
grooves are selected along the edges of the plot and slats are inserted into them, fastening the boards between each other. The indicator of the thickness of the lath and the indicator of the width of the groove itself cannot exceed 1/3 of the indicator of the thickness of the timber used
3) Binding in a quarter;
in abutting plots, completely along the entire length, quarters are selected. With this method, quarters cannot exceed 50% of the thickness of the plot itself.
4) Docking type in groove and ridge (rectangular and triangular);
this type of joining provides for the presence of a groove on one edge of the plot, and on the opposite edge of the ridge, the shape of which can be either rectangular or triangular. Moreover, the latter is rarely used, due to the lower level of fortress. This kind of joining is quite in demand and is often used in the manufacture of parquet. Lack of bonding - less economy due to the use of more boards
5) Dovetail fastening;
This type of docking is somewhat similar to the previous version, but only the ridge here has a trapezoid shape, similar to the tail of swallows. Hence the name of the fastening method.
Joining the boards into shields: a - on a smooth joint, b - in a quarter, c - on a rail, d - in a groove and a rectangular ridge, e - in a groove and a triangular ridge, e - in a “dovetail”.
Also, in the production of wood panels, dowels, a ridge glued into the end strip and tips in the groove are often used. Reiki for insertion may have rectangular shape or triangular. When using dowels, it is better to prefer a dovetail groove. All this is necessary for the manufacture of high quality wood panels.
Shields: a - with dowels, 6 - with a tip in the groove and ridge, c - with a glued strip in the end, d - with a glued triangular strip, e - with a glued triangular strip.
Length splice
The most popular methods of joining along the length are: close, such as groove and comb, fastening on the "mustache", serrated type of glue fastening, on a quarter, and also fastening on a rail. The docking of the toothed type is most actively used, due to its extremely high level of strength.
The connection of the bars along the length: a - end-to-end, b - in the groove and comb, c - on the mustache, d, e - on the toothed glue joint, e - in a quarter, g - on the rail.
Also, the boards can be joined by the splicing method, when the segments of the timber dock together in length. This is done in several ways. For example, in half a tree or with a cut of an oblique type, an overhead lock of an oblique type and a straight one, close, as well as a tension lock of both a straight type and an oblique one. When splicing using the half-tree method, the required length must be 2-2.5 times the thickness of the bar. To increase the level of reliability, dowels are used. For example, a similar option can be observed when building log cottages.
When using an oblique cut with cutting ends, the size should be equal to 2.5-3 of the thickness of the bar. It is also fixed by means of pins.
Fastening with an oblique or straight type overhead lock is used in those structures where there is a tensile force. The direct-type overhead lock is placed directly on the support itself, and the oblique type lock can be placed at the support.
If you made a decision to use an oblique cut with trimming the ends, then the fastening must be 2.5-3 of the bar thickness indicator. In such situations, you can also use a dowel.
When fastening by means of a tension lock of an oblique or straight type, high level strength. But at the same time, such a docking is notable for the complexity of manufacturing, and the wedges are somewhat weakened when the tree dries out. For these reasons, this method of fastening will not work for structures that carry high loads.
Side-by-side splicing involves moving both ends of the bar onto a support and then stapling it together.
Splicing: a - half a tree, b - with an oblique cut, c - a straight patch lock, d - an oblique patch lock, d - a straight tension lock, e - an oblique tension lock, g - end-to-end.
The fastening of logs or beams can be observed during the construction of walls frame houses, at the top or bottom of the strapping. The key types of fasteners are: half-wood, corner pan, spike type and half-leg.
Docking in half a tree - direct cutting or cutting off 50% of the thickness at the edges of the bars, as well as their subsequent fastening at a right angle.
The half-leg docking is formed by cutting at the edges of the beams of the inclined planes, as a result of which a tight connection of the beams is obtained. The slope must be determined using a special formula.
Cutting by means of a corner frying pan is extremely similar to the cutting by the half-wood method, but differs from it in that when this type fastening one of the bars loses a little in width.
The connection of the bars at an angle: a - half-wood, b - half-leg, c - spike, d - angular.
Height connection
Cross-shaped fastening of the bars is often observed during the construction of bridge structures. With this option, you can use the docking in half a tree, by a third and by a quarter, and also by notching only one of the bars.
The cross-shaped connection of the bars: a - half a tree, b - in a third of a tree, c - in a quarter of a tree, d - with a notch of one bar.
The method of building boards or bars in height is called bonding materials in height, which is very actively used when erecting poles or masts.
Build-up is subdivided into the following types:
- Tightly with a secret type thorn.
- Tight with a through-type ridge.
- Half-wood bolted.
- Half-tree with fastening on clamps.
- Half a tree with a steel strip.
- An oblique cut with fastening on clamps.
- Tightly with overlays.
- Fastening with bolts.
The length of the joints themselves, as a rule, is equal to 2/3 of the thickness of the joined bars or 2/3 of the diameter of the logs.
Connection of logs when building up: a - end-to-end with a secret spike, b - end-to-end with a through ridge, c - half-wood with fastening with bolts, d - half-wood with fastening with strip steel, d - half-wood with fastening with clamps, e - oblique cut with fastening with clamps, g - end-to-end with pads and bolts.
Spike connection
When fastening the bars by means of thorns, a direct thorn is cut on one of them, and an eyelet or a nest is made on the other. Knitting of beams with a thorn method is actively used in the production of such joinery as doors, windows or transoms. Each fastening is carried out on the basis of glue. It is allowed to use not only one spike, but several. The larger the number of spikes is planned to be made, the correspondingly and larger the gluing area will be.
This type of docking is subdivided into: corner end type, corner middle type and corner box type.
When the end-type corner fastening is used, unclosed through thorns (no more than three), thorns with darkening through and blind type, as well as a plug-in dowel. Corner docking of the middle type is quite often found on doors. For corner fasteners of the middle and end type, you can additionally use screws, nails or bolts.
Corner middle joints on a tenon: a - blind type US-1, b through US-2, c - through double US-3, d - blind into the groove and comb US-4, e - blind into the groove US-5, e - blind on round dowels US-6.
That's all the key information about existing types connections. This does not include nails, screws or bolts. Pure wood and a little glue. 🙂
It will be useful for novice home craftsmen to learn about the methods of joining wooden parts. We devote a short educational program to this topic, which will describe the main types of joinery joints and rallies with the use of glue, nails, screws or dowels, or without them at all.
Rules for choosing a connection depending on the type of load
The simplest are end connections, they are used when it is necessary to build up a part. These joints are best suited to withstand compressive loads, but good resistance to twisting, stretching and bending can be achieved by cutting down specially shaped locks. Standard Option end connection - with undercut to half the thickness of both parts. The cut can be straight or oblique, if necessary, to prevent bending, stretching or twisting, a thorn is cut at the end of each cut or obtuse angle, or make a step cut, forming a kind of "lock".
1 - a straight overlay in a half-tree; 2 - oblique pad; 3 - straight strip with a stepped joint; 4 - half-wood overlay with an oblique joint; 5 - oblique patch lock; 6 - half-wood connection with an oblique thorn
Corner and side joints are used to connect straight parts into a truss or frame. Usually, this part of the structure is a supporting one, so the main loads fall on displacement and compression. If the structure is subjected to the stipulated static load, a rectangular spike is cut on one of the parts, and a groove or eyelet of appropriate dimensions is cut on the other. If action to break the structure is possible, the tenon and groove are cut in the form of a trapezoid.
Corner joints: 1 - with an open through thorn; 2 - with a deaf closed thorn; 3 - with a through oblique thorn
Overhead cross and T-shaped connections are used, as a rule, for additional connections between critical structural parts. The main load in them is on compression, displacement and rupture. The first two types of load are eliminated by cutting half a tree or less, followed by aligning the parts. The shoulders of the notches take the main load on themselves, it remains only to secure the connection with screws or overhead brackets. In some cases, a dowel is used to strengthen the connection or a thorn with a wedge is cut out.
1 - cross connection with a half-wood overlay; 2 - cross connection with landing in one socket; 3 - T-shaped connection with a hidden oblique thorn; 4 - T-shaped connection with a straight stepped plate
A separate type of connections is box-type. They are intended for joining boards at right angles. Usually, for a box connection, teeth are cut on each board, the width of which is equal to the distance between them. On different boards the teeth are cut with an offset, so when connected, the angle from the boards looks like one whole. The teeth can also be wedge-shaped, which prevents the angle from breaking in one direction, or they are additionally fastened with glue or nails.
Box corner joints: 1 - with straight through thorns; 2 - with oblique through thorns
How to make a spike connection
To make a spike connection, you need to circle both parts with a marking line on all faces at a distance from the end equal to the width of the connection. On two opposite sides and the end line marks the body of the thorn, the markings on both parts are completely identical.
The thorn is trimmed from the sides with a hacksaw for a cross-cut and the wood is chipped with a chisel. The width of the stud is made 2-3 mm larger for subsequent precise processing with a knife or chisel. The groove is cut with a hacksaw for longitudinal cutting and chipped with a chisel, also leaving a small allowance for processing. This is followed by fitting, in the process of which the parts are combined and achieve the most snug fit.
With a T-shaped spike connection, a central spike or groove is cut on one of the parts, and an eyelet is hollowed out on the other or two side cuts are made, depending on the type of the first part. To make the eyelet, a chisel is used, turning the inclined part of the blade into the hole. If the eyelet is not solid, I make the spike 8-10 mm more depth and cut off its end in the form of a deployed wedge. So, when hammering, the spike will open itself, and the part will be firmly seated.
To connect wide parts, you can use the box connection by cutting several pins and grooves. The easiest way to secure a tenon joint is to drill through the tenons and hammer a wooden dowel into the hole (window gusset).
How to splice boards with glue
A very popular method of joining boards and bars is longitudinal and transverse gluing. When joining the boards with the wide side, the end can be even, although in most cases a tongue-and-groove profile is used. A tight fit of the parts is very important so that the adhesive layer is as thin as possible, this is the only way to achieve maximum strength. Sometimes a small amount of cotton fiber is applied to the butt, greased with glue, this improves the quality of the adhesion.
The boards can also be connected in profile, but this will require wedge-shaped toothed cutting of both ends with an offset to the floor of the tooth for different parts. At home, such an operation can be performed using a hand-held router.
For gluing parts, casein glue or high concentration PVA is used; sifted wood flour is added to the adhesive to give strength. The surfaces are covered with glue and kept in air for 3-5 minutes, after which they are placed under oppression or squeezed with clamps. Such a connection turns out to be stronger than the wood itself and never breaks at the joint.
How to weld structural members
For supporting structures, two types of connections are used - extension and articulation. The easiest way to fuse the two pieces together is to make a half-thickness cut with a hacksaw at the same distance from the ends, and then chop off the excess wood with an ax. After matching the two parts, the connection is usually fastened with two overhead strips nailed to the side of the cut. Bonding is also possible, but only with a tight fit of the parts.
The ends cut into half a tree can be brought together at almost any angle, this is the main method of connecting roof trusses. For fastening the parts, an additional tightening bond is required: the bar is applied to the connected parts from the side at a distance of 30-50 cm from the corner and cut in half the thickness at the points of contact, and then the structure is fastened with nails.
Often vertical and inclined structures need support, for example, when connecting a rafter system to floor beams. In this case, a notch is made of the landing nests on the horizontal beam, into which the racks will be inserted. It is very important to observe the angle of inclination and make the undercut by no more than a third of the thickness of the timber.
Connections with ad hoc links
Almost all joinery joints are made with additional reinforcing ties. In the very simple example the role of such is played by nails or screws.
When building up parts, the unit can be strengthened with a through bolt connection, clamps, brackets and wood grouses, or it is simply wrapped with cold-rolled wire. It is enough to fasten the spliced vertical supports with two overhead strips - wooden or metal.
Corner joints are most often fastened with staples, patch plates or corners. In cases where it is necessary to maintain a small mobility of the connection, one through bolt is used, which either stitches across the place of the overlay of the parts, or pulls them in the longitudinal direction with a minimum indent from the overlay.
The attachment point of the special connection must be at least 10 diameters of the fastening element from the edge and must not have any defects. It is important to remember that often the bonds do not provide the overall strength of the connection, but only compensate for the unaccounted load.
