The tree is widely used in various areas of human household activities. Especially widely wooden structures are used in construction. However, any wooden structures consist of separate parts that must be connected together in one way or another.
There are several types of connections. But you need to learn one rule: before starting work, you need to carefully mark out future cuts and always follow the markup. In the final product, the parts must fit exactly and tightly.
Methods for connecting boards and bars of small length: 1 - "butt" (butt); 2 - "in the groove and crest"; 3 - "on the mustache"; 4, 6 - "toothed" adhesive; 5 - "half a tree"; 7 - "on the rail"; 8 - "direct lock" overhead; 9 - "oblique lock" overhead; 10 - "straight" and "oblique" tension locks.
The simplest and relatively fragile is the "butt" connection. For this connection, the ends of the fastened parts are made clearly rectangular, and the ends are processed with a planer.
The mustache connection is similar to the butt joint, but here the ends of the parts are beveled at an angle of 45o. For accurate marking, a device called a yarunok is used. Such a connection is strengthened with a plywood lining or a metal square. Strengthen the connection "in the mustache" with fastening with inside square or triangular beam.
More durable connections include “overlay” connections by making saw cuts. If the parts to be joined are of the same thickness, then cuts are made on both parts for half of their thickness. In the case when one part is thicker than the other, then the cut is made only in a thicker part. To enhance the strength of the parts are glued and additionally fastened wooden dowels or screws.
If it is necessary to obtain a T-shaped connection, a half-tree overlay is used. In this case, both parts are cut if they are of the same thickness, or a thicker part is cut off with different thicknesses of the fastened elements.
The most durable connections that have come down to the present time from ancient times are connections with through spikes, on two plug-in round spikes and in the middle knitting method with a single spike. Details connected by a straight through spike are additionally fastened with dowels and glued. To make a connection on two round plug-in spikes, use a template pad made of plywood or thick cardboard to accurately drill the holes for the spikes. The median knitting with a single spike is deaf if you need to hide the end of the spike on front side, and through, which is much stronger than deaf.
For box joints, spiked joints with straight and oblique ("dovetail") spikes are used. Despite the higher labor intensity, the connection with oblique spikes is more durable and reliable.
For reliability, all joints can be strengthened with dowels, gluing, nails, screws, bolts, and a combination of these joint strengthening techniques.
Nagel is made in the form of a wooden rod with slightly pointed ends from hardwood. If the product will subsequently be painted or varnished, then the outer end of the dowel is recessed and puttied or a blind hole is drilled for the dowel.
Before gluing, the parts are thoroughly dried, the surface is cleaned of dirt, grease and oil stains, dust and roughened with a rasp for better adhesion. Moreover, hardwood parts are glued more liquid composition, and soft wood is denser because it absorbs moisture much better. The surfaces to be glued must be carefully smeared with glue, which significantly increases the strength of the connection. The adhesive layer should not be too thick or too thin. This will significantly degrade the quality of the connection. The adhesive is applied in a uniform, dense, non-breaking layer. For reliable bonding, the product must be kept for at least a day before being subjected to further processing.
For gluing, carpentry or casein glue is used. Wood glue is not waterproof and high humidity finished products may be sticky. Therefore, it is recommended to use casein glue, devoid of this drawback. In addition, casein glue is somewhat cheaper, and the bonding strength is slightly superior to carpentry.
For extra strength joints wooden structures fasten with nails, screws and bolts. The length of the nail or screw is selected 3–5 mm shorter than the total thickness of the parts to be joined, and when connecting parts of different thicknesses, the length of the fasteners should be 2–4 times the thickness of the thinnest part.
It should be borne in mind that screws and nails screwed or hammered across the fibers hold the parts better.
The part of the bolt that extends beyond the parts to be joined should be slightly larger than the thickness of the nut. Washers are placed under the bolt heads to protect the wood from crushing. The slots of the screw heads are parallel to the wood fibers. It is desirable to place the slots of all screws on one straight line or parallel to each other. Before screwing in thin screws or driving in thin nails, it is recommended to make signal holes with a smaller diameter.
Screw connections are considered the strongest. You need to be careful not to split the tree. For this purpose, screws and nails should not be driven in and driven close to the edge and to each other.
Often, during the construction of frames for roofs of complex configuration, there is a need to use elements custom size. Typical examples include hip and half-hip structures, the diagonal ribs of which are significantly longer than ordinary rafter legs.
Similar situations arise in the construction of systems with valleys. So that the created connections do not become the cause of the weakening of the structures, you need to know how the rafters are spliced along the length, in what way their strength is ensured.
Splicing the rafter legs allows you to unify the lumber purchased for the construction of the roof. Knowledge of the intricacies of the process makes it possible to almost completely build a truss frame from a bar or board of one section. The construction of a system of materials of the same size has a positive effect on the total cost.
In addition, a board and a bar of increased length, as a rule, are produced with a larger cross section than that of the material standard sizes. Along with the cross section, the cost also increases. Such a margin of safety when constructing hip and valley ribs is most often not needed. But with proper splicing of the rafters, the elements of the system are provided with sufficient rigidity and reliability at the lowest cost.
Without knowledge of the technological nuances, it is quite difficult to make joints of lumber that are really rigid in bending. Rafter junctions belong to the category of plastic hinges that have only one degree of freedom - the ability to rotate in the connecting node when a vertical and compressive load is applied along the length.
In order to ensure uniform rigidity when a bending force is applied along the entire length of the element, the pairing of the two parts of the rafter leg is located in places with the smallest bending moment. On diagrams showing the magnitude of the bending moment, they are clearly visible. These are the points of intersection of the curve with the longitudinal axis of the rafter, at which the bending moment approaches zero values.
We take into account that during the construction of the truss frame, it is required to ensure that bending resistance is equal over the entire length of the element, and not the same opportunities to bend. Therefore, the junction points are arranged next to the supports.
As a support, both an intermediate rack installed in the span, and directly a Mauerlat or a trussed truss are taken. The ridge run can also be assessed as a possible support, but it is better to place the rafter legs joining areas lower along the slope, i.e. where the minimum load is placed on the system.
Splicing options for rafters
In addition to accurately determining the location for pairing the two parts of the system element, you need to know how the rafters are properly extended. The method of forming the connection depends on the lumber chosen for the construction:
- Bars or log. They are built up with an oblique cut formed in the connection zone. For reinforcement and to prevent rotation, the edges of both parts of the rafters cut at an angle are fastened with a bolt.
- Boards sewn in pairs. They are spliced with the location of the docking lines apart. The connection of two parts superimposed on each other is made with nails.
- Single board. The priority is splicing with a frontal stop - by joining the trimmed parts of the rafter leg with the imposition of one or a pair of wooden or metal linings. Less commonly, due to the insufficient thickness of the material, an oblique cut is used with fastening with metal clamps or a traditional nail fight.
Let us consider in detail these methods in order to understand in depth the process of increasing the length of the rafters.
Option 1: Bevel cut method
The method involves the formation of two inclined cuts or cuts, arranged from the side of the pairing of parts of the rafter leg. The cutting planes to be joined must be perfectly aligned without the slightest gaps, regardless of their size. In the connection area, the possibility of deformation must be excluded.
It is forbidden to fill cracks and leaks with wedges made of wood, plywood or metal plates. It will not work to fit and correct flaws. It is better to accurately measure and draw cutting lines in advance, according to the following standards:
- The depth is determined by the formula 0.15 × h, where h is the height of the beam. This is the size of the area perpendicular to the longitudinal axis of the beam.
- The interval within which the inclined sections of the cut are located is determined by the formula 2 × h.
The location for the docking area is found according to the formula 0.15 × L, which is valid for all types of truss frames, in which the value of L displays the size of the span covered by the rafters. The distance is measured from the center of the support.
Details from a bar, when making an oblique cut, are additionally fastened with a bolt passing through the center of the connection. The hole for its installation is drilled in advance, its Ø is equal to the Ø of the fastener rod. To prevent the wood from being crushed at the place where the fastener is installed, wide metal washers are placed under the nuts.
If a board is connected using an oblique cut, then additional fixation is carried out using clamps or nails.
Option 2: Rallying the boards
In the case of using rallying technology, the center of the connected section is located directly above the support. The joining lines of the trimmed boards are located on both sides of the center of the support at a calculated distance equal to 0.21 × L, where L denotes the length of the overlapped span. Fixation is carried out with nails installed in a checkerboard pattern.
Backlash and gaps are also unacceptable, but they are easier to avoid by carefully trimming the board. This method is much simpler than the previous method in execution, but in order not to waste hardware and not to weaken the wood with extra holes, the number of points of fasteners to be installed should be calculated with accuracy.
Nails with a stem section up to 6 mm are installed without pre-drilling the corresponding holes. For fasteners larger than the specified size, it is necessary to drill so that when connecting, the board does not split along the fibers. An exception is cross-section hardware, which, regardless of size, can simply be hammered into wooden parts.
To ensure sufficient strength in the rally zone, the following conditions must be observed:
- Fasteners are placed every 50 cm along both edges of the boards to be joined.
- Nails are placed along the end joints in increments of 15 × d, where d is the diameter of the nail.
- For rallying the board at the interface, smooth round, screw and threaded nails are suitable. However, threaded and screw versions are preferred because they have much higher pull-out strength.
Note that the connection of rafters by rallying is acceptable in the case of an element of two sewn boards. As a result, both joints are overlapped with a solid piece of lumber. The advantages of the method include the size of the overlapped span, which is impressive for private construction. Similarly, rafter legs can be increased if the distance from the top to the bottom support reaches 6.5 m.
Option 3: Frontal stop
The method of frontal extension of the rafters consists in the butt joining of the connected parts of the rafter leg with the fixation of the section with nails, dowels or bolts through the lining installed on both side planes.
To exclude backlash and deformation of the extended rafter leg, the following rules must be followed:
- The edges of the board to be joined must be perfectly trimmed. Gaps of any size along the connection line must be excluded.
- The length of the overlays is determined by the formula l = 3 × h, i.e. they must be no less than three board widths. Usually the length is calculated and selected based on the number of nails, the formula is given to determine the minimum length.
- Overlays are made of material, the thickness of which is not less than 1/3 of the same size of the main board.
Nails are hammered into the overlays in two parallel rows with a checkerboard "scatter" of fixing points. In order not to damage the overlay, which is thin in relation to the main lumber, the number of attachment points is calculated based on the resistance of the nails to the transverse force acting on the legs of the hardware.
When the junction of the rafter parts is located directly above the support, there is no need for nailing calculations to fix the overlays. True, in this case, the docked leg will work as two separate beams for both deflection and compression, i.e. according to the normal scheme, it is necessary to calculate bearing capacity for each of the constituent parts.
If steel rod bolts or rods without thread, dowels are used as fasteners, when joining a thick board or beam, then the threat of deformation will be completely eliminated. In fact, even some gaps in the joining of the ends can be ignored, although such flaws are still best avoided.
When using screws or screws, holes are pre-drilled for their installation, the Ø of the holes is 2-3 mm less than the same size of the fastener leg.
In the production of frontal joints of rafters, it is necessary to strictly observe the estimated installation step, the number and diameter of fasteners. If the distance between fixing points is shortened, splitting of the wood may occur. If the holes for the fasteners are larger than the prescribed dimensions, the rafter will be deformed, and if less, the lumber will crack during the installation of the fasteners.
Extension with composite rafters
To connect and increase the length of the rafters, there is another very interesting way: building with two boards. They are sewn to the side planes of the single element being extended. Between the extended parts there is a gap equal to the width of the top board.
The clearance is filled with trimmings of equal thickness, set at intervals of not more than 7 × h, where h is the thickness of the board being extended. The length of the distance bars inserted into the clearance is at least 2 × h.
Extension using two stackable boards is suitable for the following situations:
- The device of a layered system along two side runs, which serve as a support for the location of the docking area of the main board with the attached elements.
- Installation of a diagonal rafter that defines an inclined edge of hip and half-hip structures.
- Construction broken roofs. As a support for the connection, the strapping of the lower tier of rafters is used.
Calculation of fasteners, fixation of remote bars and connection of boards is carried out by analogy with the methods described above. For the manufacture of remote bars, trimming of the main lumber is suitable. As a result of the installation of these liners, the strength of the prefabricated rafters significantly increases. Despite significant material savings, it works like a solid beam.
Video about how to build rafters
Demonstration of basic splicing techniques structural elements truss system:
A video with a step-by-step process for connecting rafter parts:
Video example of one of the ways to connect lumber:
Compliance with technological requirements, according to which the rafters are spliced along the length, guarantees trouble-free operation of the structure. Elongation methods allow you to reduce the cost of building roofs. You should not forget about preliminary calculations and preparation for making connections so that the result of the effort becomes ideal.
Making furniture with your own hands is becoming increasingly popular due to the high cost of finished products, and thanks to a large number source materials that appeared in the public domain. At home, with a minimum set of appropriate tools, it is realistic to assemble viable furniture that will serve properly and please with its appearance. One of the most popular joining methods is gluing, which makes it possible to obtain strong, monolithic parts. Gluing can be used as an independent fastener or as a duplicating one, when using external elements, such as dowels, dowels or self-tapping screws.
Do-it-yourself glued wood
Before gluing, the parts are processed, this is done not only to clean the surface, but also allows you to open the wood pores. When applied, the adhesive composition penetrates through the pores into the wood structure, into the intercellular space, and when solidified, it forms a multitude of the thinnest threads (cobwebs) that reliably “seam” the workpieces together. The strength of a correctly made seam exceeds the strength of the wood itself; when testing for fracture, the part breaks not at the place of gluing, but along the whole tree.
Gluing a tree allows you to get products with better parameters than massive ones. In the process of gluing, elements that are suitable in texture and shades are selected, damaged, cracked and knotty areas are rejected. As a result, the strength of the glued parts is greater than that of the usual one, and by gluing the thinnest veneer onto the front surfaces, the products are given the appearance of the most valuable rocks. Wood glued according to all the rules warps, cracks and cracks much less than solid wood.
How to glue wood. Technology
There are several ways to connect parts when gluing.
- Gluing wood onto a smooth joint - joining smooth details without increasing the penetration area.
- Gluing on a microthorn - an increase in the penetration area by 2.5 - 5 mm due to the creation of a jagged relief on the part (using a milling cutter).
- Bonding on a toothed spike – increase in the penetration area by 10 mm due to the creation of a toothed spike.
- Gluing on a tongue-and-groove (thorn-groove, dovetail, oblique tenon) - additional grip due to the groove connection.
Although in certain situations where special conditions of use are expected, tongue and groove joints are relevant, in most cases the parts are glued to a smooth reveal. Modern adhesives penetrate deep into the structure and create a strong seam without additional sampling of wood.
How to glue boards together. Options
The wood to be glued must have a moisture index in the range of 8 - 12%, maximum - 18%. If there is a need to glue wet parts, use special compound, during the hardening process, it draws moisture from the wood. When gluing blanks with different humidity a difference of more than 2% is not allowed in order to avoid internal stress in the glue line due to deformation of the wetter part. The temperature of the glued workpieces varies between 15 - 20⁰С, so the work is carried out in warm rooms (18 - 22⁰С). In the cold, most compositions crystallize, which leads to a deterioration in the quality of gluing and makes the process difficult.
The final preparation of wood (planing, jointing, sanding) is carried out immediately before gluing in order to increase the permeability of the adhesive and avoid warping. It is important not only to select parts according to their dimensions, structure and external data, but also to arrange them correctly.
- When gluing along the length, only one type of sawing is used - tangential or radial;
- When gluing, both in length and in width, alternation is not allowed different parts wood - the core is laid with the core, sapwood (young, extreme part) with sapwood;
- Annual rings of adjacent blanks from boards or bars should be directed in different directions or at an angle to each other from 15⁰.
The standard thickness of furniture boards is 2 cm, but in order to glue wooden boards at home, when choosing boards for a board, the estimated waste during processing is taken into account, so the workpiece is selected with a thickness of up to 2.5 cm. The excess will be removed during the primary processing, when defects are eliminated, and after gluing, when grinding the shield. If you dissolve a board 5 cm thick for a furniture board, you get two blanks with the same texture and shade, which increases the decorative effect of the product. For shields, boards of wood of the same species are selected, up to 120 mm wide, so that it is possible to process the edges of the shield with high quality, the length of the blanks should have a margin (2 - 5 cm).
Adhesives
Adhesives used for the manufacture of laminated wood fall into two main groups.
Synthetic - obtained on the basis of resins or polyvinyl acetate dispersions (PVA). They are characterized by increased strength of the resulting connection, moisture resistance, biostability. The disadvantages include the presence harmful substances, which may stand out in environment during operation and further operation. This is "famous" for compositions based on phenol-formaldehyde resins. Modern PVA dispersions and their derivatives are non-toxic and are commonly used in the domestic area and are considered universal for wood. The bulk of synthetic mixtures are ready for use. The epoxy adhesive needs finishing, to work with it the hardener included in the kit is mixed with epoxy resin.
Natural mixtures - animal, vegetable, mineral. They are safe, give a strong connection, but are produced in the form of semi-finished products that are prepared before use. How to glue a tree with them: when preparing, you must strictly follow the instructions and observe the dosages, otherwise the quality of the glue will not allow you to get a strong connection. To prepare the adhesive, it is usually necessary to dilute the powder concentrate with water to the desired consistency (may require a certain swelling period) or to melt the solid particles. Direct exposure to fire is not allowed, apply " water bath”, on which the mass with the addition of water after swelling melts to a homogeneous consistency.
How to glue a tree
When gluing wooden surfaces glue is applied to both parts in an even layer. The thickness of the layer depends on the type of glue, its consistency and the type of surfaces to be glued - the thinner the wood, the thinner the layer. The glue should moisten the part, but not excessively; when connecting the elements, an even roller should stand out. Adhesive streaks are removed from the surface as soon as they grab a little, with a scraper or spatula. Cured excess glue greatly spoils appearance details and complicates their further processing.
How to glue a wooden blank.
After applying the adhesive, the parts withstand a certain period of time, this allows the composition to penetrate deeper, at the same time excess moisture evaporates, the concentration of adhesives increases. During exposure, it is not allowed to air the seam in a draft or dust it. Some varieties natural glue(bone, skin) must be applied hot, instantly fastening the parts without aging, as the composition loses its properties as it cools.
Wood Gluing Tool
To get the maximum strong connection, when glued, the wood is pressed in - compressed by means of special presses. At home, for these purposes, improvised tools and means are used - a vice, clamps, cam devices, frames made of metal corner with clamping mechanisms. The pressure during wood pressing is maintained in the range from 0.2 to 1.2 MPa. possible in production large quantities, at home, such indicators are enough for the structural details to stick together.
Glued wood with your own hands.
Subject to the gluing technology, the adhesive seam is strong and reliable, and, unlike the method of connecting parts with metal fasteners, does not spoil the appearance.
For fans of creating household items on their own, a topic is open on FORUMHOUSE. How to organize a convenient corner for working with wood can be found in the article. The video about wooden elements in a country house shows interesting products made by users of the portal.
Joinery bars are interconnected with a spike joint, consisting of two elements - a spike and a socket or eye. Spike - a protrusion at the end of the bar, included in the corresponding
Rice. 42. Types of spikes:
a- single, b- double, in- multiple G- round, d- dovetail e- one-sided dovetail f, h- serrated and- nest, k, l- eyelets, m- deaf thorn n- thorn in the dark, about- spike in
semidarkness
vuyuschie nest or eyelet of another bar. The spikes are single (Fig. 42, a), double (Fig. 42.6), multiple (Fig. 42, c), that is, more than two.
A solid spike is a spike that is integral with the bar. A plug-in spike is a spike made separately from the bar. A spike 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 spike, a one-sided dovetail spike - 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), bi-oblique serrated spike (Fig. 42, g) of an isosceles triangle.
Single and double spikes are used in the manufacture of windows, frame doors, furniture; spike "dovetail" - in the manufacture of boxes, boxes; jagged spikes - for glued joining of parts (splicing) along the length.
In addition, round plug-in spikes are used when connecting plots (blanks) in width. Thorns in the dark and semi-darkness (Fig. 42, but), used in the manufacture of frames, me-
Rice. 43. The shape of the processed bars:
a- chamfer, b- headquarters (shtap), in- edge rounding G- fillet, d- fold-quarter, e- kalevka, well- thorn, h- eye, and- edge with profile processing, to- bar, l - nest, m- layout, n- plastic, about- overhang; / - shoulders, 2 - lateral edge of the spike, 3 - end face of the spike, 4 - panel, 5 - edge, b- butt, 7 - face; / - spike length, b- stud width, s - stud thickness
leucorrhea, etc. In addition, sockets and eyes are used, a deaf spike, shown in fig. 42, i, k, l, m.
A dark spike is made not only at the end connection, but also in cases where it is required that the edges of the nest be invisible, since it is not always possible to obtain even edges of the nest. To hide this defect, a darkness is cut out from the spike, that is, a part of the spike is removed along the width from one or both sides.
In order to form a spike, an eyelet, processed bars, i.e. planed from four sides to the required size, -f- pre-marked.
Structural parts and elements of joinery. Joinery products have the following main structural parts and elements.
Bar- the simplest detail; it happens in different sizes, sections and shapes (Fig. 43). The narrow longitudinal side of the bar is called the edge, and the wide longitudinal side is called the face, the line of intersection of the face with the edge is called the rib. 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, bars of small sections (vertical, horizontal sash sashes) are
they are made of solid wood, and bars of large sections (boxes) are made glued.
layouts are called bars intended for fastening glass in sashes, doors or panels in door leafs of a frame structure.
Panels represent a shield rectangular shape, made of joinery, chipboard or fiberboard. The shape of the panels are flat, with beveled edges and with profiled edges. The panel within the doors is installed in a groove, rebate and fastened with layouts or placed on bars and fastened with screws.
folded called a rectangular recess in the bar. If the recess has equal sides of the angle, then it forms a quarter.
Platik- ledge formed to hide the gap; used in cases where fitting the part flush is difficult. The use of platik simplifies the assembly of products. It is used in the manufacture of furniture.
Overhang- protrusion beyond the base. Used in the manufacture of furniture.
Galtelyu called a semicircular recess on the edge or face of the part.
Frame consists of four bars forming a square or rectangle. Separate frames have, in addition, internal mullion bars (frame doors, window sashes with slabs).
The frames are assembled on a spiked joint. Small-sized frames are assembled on a single open through spike or spike with a semi-darkness or darkness. In the manufacture of joinery, mainly rectangular frames are used, very rarely (for unique buildings) - polygonal or round. Casement, window, transom, box - all these are frames.
All connections in window blocks are made on spikes. The strength of a spiked joint is determined by its dimensions and the area of the bonded surfaces. To increase the strength, the spikes are made double (in the windows).
Shields are made massive (plank) or with voids. Massive shields in order to avoid warping should be assembled from narrow slats (parts) with a width of not more than 1.5 thickness, with the selection of fibers, humidity up to (10 ± 2)%.
When gluing parts along the width, the same (sapwood) faces of the joined rails should face in opposite directions, and the edges of the same name should face each other.
Joining rails along the length is allowed if the joints are spaced apart and the distance between them in adjacent rails is at least 150 mm. In panels designed for load-bearing structures, the rails do not join along the length. Wall panels, vestibules, etc. are made from shields.
To avoid warping, shields are made with dowels
Rice. 44. Types of shields:
a- with dowels b- with tips in the groove (tongue) and comb, in- with a glued rail at the end, G- with glued triangular rail, d- with a glued triangular rail, e-
multilayer
(rice. 44, a), with tips (Fig. 44.6), with glued and glued rails (Fig. 44, c, g,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 designed for doors of temporary buildings, etc.
a) S) in)
Rice. 45. Methods for connecting shields:
a- for a smooth fugue, b- on the rail in- in a quarter G- in a groove and a comb, d- in a groove and a triangular comb, e- in dovetail
Rice. 46. Adhesive joints of bars, boards along the length:
a- end, b- on the "must", in- on a stepped "mustache", G- on a stepped "mustache" with blunting, d- jagged e- vertical gear, w - horizontal gear, h- jagged on the "mustache", and- stepped; c - bevel angle, L- the length of the "mustache" of the spike, t- connection pitch, 6 - bluntness, 5 - gap, AT- thickness, i- spike angle
In addition to boards, multilayer shields are made, glued together from three or five single-layer shields with mutually perpendicular direction of the fibers (Fig. 44, e).
Massive shields are glued onto a smooth fugue (Fig. 45, a), on a rail (Fig. 45.6), in a quarter (Fig. 45, c), in a groove and a crest (Fig. 45, d, e) willow "dovetail" (Fig. 45, e).
Connecting wood parts. Splicing of segments along the length can be end, on the "mustache", serrated, stepped (GOST 17161-79).
End glue connection(Fig. 46, a)- this is an adhesive connection with end surfaces of gluing. Under the end adhesive connection on the "mustache" (Fig. 46.6) is understood the adhesive connection with flat bonding surfaces located at an acute angle to the longitudinal axis of the workpieces. Adhesive connectionon a stepped "mustache"(Fig. 46, c) is a joint in which the bonding surfaces have a protrusion that prevents the workpieces from moving in the longitudinal direction during tension. A connection in which the beveled ends of the workpieces have a bluntness that prevents the displacement of the workpieces in the longitudinal direction during tension and compression is called a connection to a stepped "whisker" with a blunt (Fig. 46, G).
Serrated glue connection(Fig. 46, e)- this is a connection with profiled surfaces in the form of toothed spikes, twirlhot glue joint(Fig. 46, e)- connection with the output of the profile of the spikes on the face of the workpiece. In a horizontal gear connection (Fig. 46, g), the profile of the spikes goes to the edge of the workpiece.
Serrated adhesive connection on the "mustache"(Fig. 46, h)- connection
on the “mustache” with profiled bonding surfaces in the form of jagged spikes.
Step glued joint(Fig. 46, and)- end connection with profiled bonding surfaces in the form of a step, the height of which is equal to half the thickness of the workpiece.
The most durable is adhesive connection on a toothed spike. This type of connection is used for splicing bars of sashes, transoms, window and door frames and other building elements.
Serrated glue connection(see fig. 46, e) are manufactured in accordance with GOST 19414-90. The workpieces to be glued should not differ in moisture content by more than 6 %. Knots larger than 5 mm are not allowed in the workpiece joining area. The roughness parameter of the bonding surfaces of toothed spikes Rmax according to GOST 7016-82 should not exceed 200 microns.
The dimensions of the spiked joints are given in Table. one.
TableI. Stud sizes
Rallying consists in connecting bars, boards, plots along the width of the edge into shields or in layers into blocks. Each workpiece connected to the shield is called plot.
In accordance with GOST 9330-76, the connection along the edge is recommended, depending on the purpose of the products, to be made on a rail, in a quarter, in a rectangular and trapezoidal groove and comb, and on a smooth fugue.
When making connections to the K-1 rail (Fig. 47, a), it should be done at / equal to 20 ... 30 mm 1\ 2...3 mm more; S\ take equal to 0.4 So for wood laths and 0.25 5 0 - for plywood laths. 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. On the edges, one- and two-sided chamfers are allowed.
For a K-2 type connection along a quarter edge (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. Connection diagrams of boards (plots) along the edge:
a- along the edge on the rail K-1, b- a quarter along the edge of K-2, in- in a rectangular groove and a crest along the edge of K-3, G- in a trapezoidal groove and a crest along the edge of K-5, d- on a smooth fugue K-6 (along the edge), e- along the edge into a rectangular groove and crest K-4
For connection type K-3 in the groove and tongue (Fig. 47, in) rounding radius G make 1 ... 2 mm, and the size 1\ - 1 ... 2 mm larger than / (Table 2). On the edges, one- and two-sided chamfers are allowed.
Table 2.K-3 connection dimensions, mm
|
S, | ||
Dimensions of connections K-4 (Fig. 47, e) are given in table. 3. Table 3K-4 connection dimensions, mm
|
Sa |
b | |||||
The dimensions of the grooves and ridges of the K-5 connection (Fig. 47, d) are determined according to Table. 4.
Table4. K-5 connection dimensions, mm
|
St |
I | |||
The seam formed when connecting plots is called fugue. Plots from which the shield is glued onto a smooth fugue type K-6 (Fig. 47, e) must have smooth and even edges forming a right angle with the plane (plate) along the entire length. If there are no gaps when connecting the plots, then their jointing (fitting) is done with high quality. Shields are glued together in clamps, wai-maxes, presses.
In addition to gluing, shields can be assembled from plots into round plug-in spikes, while the diameter of the spike should be 0.5 of the thickness of the plot, and the length should be 8 ... 10 diameters. The spikes are set in increments of 100 ... 150 mm.
The connection into a groove and a ridge, as well as into a quarter, is made by selecting along the entire length of the edge (plot) on one side of the groove or a quarter, and on the other, a ridge or a quarter. This compound is used in the manufacture of shields, laying plank floors, carpentry partitions, filing ceilings. A plain joint is more economical than a quarter or tongue and groove joint.
When connecting to a rail along the edges of the plots, grooves are selected into which wooden or plywood rails are inserted.
Wooden parts are used in many products. And their connection important process on which the strength of the entire structure depends.
For the manufacture of furniture and other wood products, dozens of various compounds. The choice of how to connect wood parts depends on what the product should be in the end and what load it should carry.
Connection types
When connected wooden parts need to remember important point- always a thin part is attached to a thick one, but not vice versa.
According to the relative position of the elements, the following methods of connecting wood parts are distinguished:
- extension - increasing the height of the part;
- splicing - elongation of the workpiece;
- rallying - increasing the width of the element;
- knitting - connection at an angle.
The methods of joining wooden parts in the manufacture of furniture are most often used as follows:
- gluing;
- "dovetail";
- butt;
- grooved;
- overlap;
- deaf on thorns;
- through spike.
Let us consider the technologies of some compounds in more detail.
Splicing to length
Such wooden parts have some nuances. At its core, this is the elongation of elements in the horizontal direction. Splicing can be:
- End-to-end - cuts of the ends are made at a right angle and are combined with each other. A bracket is hammered into both beams (logs).
- Oblique butt - the cuts are made at an angle, and the ends are fastened with a pin or nail.
- End butt with a comb.
- Direct overlay - the length of the cutting is 1.5-2 times greater than the thickness of the beam (log).
- Oblique overlay - the ends are cut at an angle and fixed with bolts.
- Overlay with an oblique cut - end ridges are made at the ends of the parts, having a width and length of one third of the thickness of the timber.
Height extension
From the name it is clear that the essence is to lengthen the bars or logs in the vertical direction. The axes of the elements are on the same vertical straight line. Extension types are:
- End-to-end extension. To perceive random loads, a spiked pin is inserted on the sides.
- Extension with one or two spikes. The width and height of one spike must be at least one third of the timber thickness. Nest depth - a little more height spike.
- Growing in half a tree. The ends of both logs must be cut to half their thickness by 3-3.5 diameters in length.
- Tongue extension. In one beam, you need to cut a fork into which you need to insert the correspondingly cut end of the other workpiece. The connection itself must be wrapped with tin.
Width payment
Used to increase the product in width. When using rallying methods, it is important to pay attention to the location of the annual rings of the tree. It is important to alternate boards depending on their direction. The payment options are:
- Butt - the details need to be trimmed and milled on a square.
- In tongue and groove - the height and width of the ridge is equal to 1/3 of the thickness of the board.
- In a hacksaw - the edges must be trimmed at an acute angle to the wide plane of the board.
- Comb with a height of 1/3 to half the board.
- A quarter with a ledge equal to half the thickness of the board.
- In the tongue with rails - in each board, select the grooves into which you need to insert the rail, which has a width twice the depth of the groove.
knitting
Knitting is used when it becomes necessary to connect parts at an angle. The types of knitting are:
- knitting in half a tree using a hidden spike;
- knitting in a semi-paw;
- single and double slotted spikes;
- slotted paw.
butt
The easiest way to join two pieces together. Joining wooden parts at right angles is done using this method. The surfaces of the two parts are carefully adjusted to each other and pressed tightly. There is a connection of wooden parts with nails or screws. Their length should be such that they pass through the first part and go deep into the second one by about 1/3 of the length.
For the fastening to be reliable, it is necessary to drive in at least two nails. You need to place them on the sides of the center line. The thickness of the nail should not cause cracking of the wood. Therefore, it is recommended to pre-make holes with a diameter of 0.7 of the thickness of the nail used.
To enhance fixation, lubricate the surfaces that are connected with glue. For rooms that will not be under the influence of moisture, you can use carpentry, casein or skin glue. In the case of using the product in high humidity conditions, it is better to use a moisture-resistant adhesive, for example, epoxy.
Overlay T-connection
To perform such a connection of wooden parts, you need to lay one workpiece on top of another and fasten them to each other using bolts, screws or nails. You can arrange wooden blanks both at a certain angle to each other, and along one line.
So that the details do not change, use at least 4 nails. If there are only two nails, then they are driven in diagonally. To make the fixation stronger, the nails must pass through both parts, and the protruding ends must be bent and deepened into the wood.
Half tree connection
To perform such a connection of two wooden parts, certain skills and experience are required. It is performed as follows. In both workpieces, samples are made with a depth that corresponds to half of their thickness. The width of the sample must be equal to the width of the part.
The method of joining wooden parts in half a tree can be performed at different angles. In this case, it is important to ensure that the angle is the same on both wooden blanks, and the width corresponded to the width of the part. Due to this, the parts are tightly pressed against each other, and their edges are located in the same plane.
In addition, such a connection may be complete or partial. In the case of a partial connection, the end of one workpiece is cut at a certain angle, and an appropriate sample is made at the end of the other. Such connections include angular in the mustache of a half-tree. The bottom line is to trim both spikes at an angle of 45 o, as a result of which the seam between them is located diagonally. When using this method, you need to be especially careful, and make corner cuts with a special tool - a miter box.
Cleat
Such wooden parts are used for fastening planks or when laying the floor. The edge of one board has a spike, and the edge of the other has a groove. Accordingly, fastening occurs when the spike enters the groove. Such a connection looks very neat, since there are no gaps between the boards.
Doing tenons and grooves requires some experience. And besides, for the manufacture will require special machine. Therefore, it is easier to purchase ready-made parts.
Connector "socket-thorn"
The most commonly used method of joining wooden parts. Such a joint is strong, rigid and looks as neat as possible. To make such a connection, you need to have some skills and experience, as well as be careful. An incorrectly made socket-thorn connection is fragile and looks ugly.
Its essence is the following. At the end of one workpiece, a groove is drilled or hollowed out, and at the end of the other, a spike. It's better when the elements have the same width. If the thickness is different, then the spike is made in a thin part, and the groove, respectively, in a thick one.
Spike connection sequence:
- Using a thickness gauge, draw two risks parallel to each other on the side of one workpiece. The distance should be the width of the future spike. For its evenness, markings should be made on both sides.
- The most optimal tool for making spikes is a hacksaw with a narrow blade and fine teeth, or a bow saw. During operation, the teeth of the tool should pass along the inner edge of the marking line. For convenience, it is better to clamp the part in a vice. It is best to make the spike a little larger than the required size. Then, if necessary, you can remove the excess. But if the spike is shorter, then the whole process will need to be repeated again.
- Using a chisel or chisel, a nest (groove) is made in the second part. Naturally, the dimensions of the groove must correspond to the dimensions of the spike. It is best to drill holes around the entire perimeter of the groove before proceeding with chiselling. The edges are carefully processed with a chisel.
If the connection of wooden parts is done correctly, then the surfaces of the edges of the spikes fit snugly against the walls of the socket. This gives good adhesion when gluing. In order for the spikes to be tighter, their dimensions should be 0.2-0.3 mm larger than the dimensions of the socket. If this value is exceeded, the bowstring may split; if the tolerance is less, the fastening will lose its strength during operation.
In addition, such a connection also involves gluing and fastening with screws, nails or wooden dowels. To simplify the work, holes should be drilled before screwing in the screws. The heads of the screws are hidden in a secret (made using a countersink). The pilot hole should be equal to 2/3 of the screw diameter and less than 6 mm (approximately) of its length.
Gluing
Bonding wooden parts is carried out as follows:
- The surfaces to be glued are cleaned with a lint-free cloth, and the roughness is cleaned with fine emery.
- Using a cardboard stick, apply wood glue in an even thin layer on all necessary surfaces.
- The surfaces smeared with glue must be rubbed against each other. This will ensure smooth contact and strong bonding.
- The parts must be pulled together so that the retention at the joints is reliable. Measuring the diagonals will make sure that the corners are straight. They must be equal. If this is not the case, the position of the elements needs to be corrected.
- The connection is strengthened by drilling pilot holes into which finishing nails are driven in or screws are screwed in. The heads of the screws must be recessed, for this the holes must be bored. The nails are deepened using a punch.
- Holes with nails are covered with putty for wood. Holes bored for screws are closed with hardwood plugs lubricated with glue. When the glue or putty is dry, the surface is sanded so that it is smooth, and then varnished.
Necessary tools and fixtures
Implementation tools are very diverse. They are selected depending on the type of work performed. Since in carpentry the processed elements are larger than in carpentry, respectively, the tool must be suitable.
To connect wooden parts, use the following:
- axe;
- planer, straight and curved plows, bear, sherhebel - more thorough surface treatment;
- chisel - chiseling holes and nests;
- chisel - for cleaning cuts;
- drills with various tips - for through holes;
- various saws - for sawing up and down;
- hammer, hammer, sledgehammer, mallet;
- square, compasses, level and other auxiliary tools;
- nails, metal staples, bolts with nuts, screws and other fastening products.
Conclusion
In fact, there are many more ways to connect wooden parts of furniture or other structures. The article describes the most popular methods and implementation technologies. It is important to remember that the connection of wooden parts for painting or varnishing must be carefully prepared, and all fasteners must be strong and made to last.
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