Preparation of new wooden surfaces for painting. Painting of wooden products: technology, tools, types of paints and varnishes Cleaning of old paint and preparation for coating paintwork

TYPICAL TECHNOLOGICAL CARD (TTK)

1. APPLICATION AREA

A typical routing is designed for painting, for preparing surfaces for painting (preparation of wooden surfaces).

SURFACE PREPARATION FOR PAINTING.

When painting the surface, a number of operations are performed, which are reduced to four soils: I - surface preparation; II - surface treatment; III - surface color; IV - painted surface finish.

Preparation of wooden surfaces of carpentry for oil painting

Joinery products must arrive at the construction site prepared for painting. Before painting, they must be cleaned of dust, dirt, spray and wiped with a dry cloth.

Cleaning is carried out with a steel spatula. The knots and tar resulting from wood drying are cut down to a depth of 2 ... 3 mm using a chisel. At the same time, surfaces are cleaned from roughness. Major defects are fixed by the joiner. Doors and windows must be fitted and glazed.

Preparation of wooden plank floors for painting

The floor surface is cleaned of debris and dust. Small areas of floors are cleaned with hazel, dust is swept. For large volumes of work, the floors are cleaned with a parquet grinder tucked with a coarse sandpaper. The dust is removed by a vacuum cleaner. It is not recommended to wash wooden floors for cleaning, since wet floors significantly delay the execution of subsequent technological processes.

The list of operations for finishing with water, emulsion and anhydrous paint compositions is given in Table 1.1, 1.2. The number of technological operations performed, first of all, depends on the type of paint and varnish coating and the requirements for its quality, as well as on the quality of the surface and the material of the finished structure. The consumption of paint compositions is determined by the type of finish coating and the surface quality of the finished structure.

Table 1.1

Technological operations carried out during surface finishing with water and emulsion paint compositions inside buildings

Technological operations	Painting the facade with water compositions	Facade painting with emulsion compositions
					Calcareous		Polyvinyl acetate
			High-		On plaster and concrete	On brick and wood				High quality
Surface preparation
Water wetting
Surface smoothing
Crack splicing
Surface treatment
First priming
Partial primer with primer
Grinding greased areas
The first solid putty
Grinding
Second putty
Surface painting
First coloring
Grinding
Second color
Fluting, trimming, knurling, splashing, etc.

When preparing the surface for painting, the following operations are carried out: cleaning, smoothing, cracking, cutting knots and smudges, as well as (if necessary) drying the plaster, concrete and wood (Table 1.1, 1.2).

Manually smooth the surface with a hazel (sand stone, brick), pumice stone or the end face of a piece of wood. For mechanized smoothing, universal trowel-grinding machines based on pneumatic and electric drills are used (Fig. 1).

These machines have interchangeable working equipment: discs with liners made of pumice, wood, flaky or emery stone for smoothing and cleaning plastered or polished putty surfaces; disc with felt overlays for smoothing freshly applied putty; a disk with a steel brush to clean the surface from rust and old paint, etc., providing a number of operations related to the preparation of surfaces for painting.

Table 1.2

Technological operations performed during surface finishing with oil and synthetic compounds inside buildings

Technological operations		Type of coloring
		On wood
		Improved	High quality
Surface preparation
Surface smoothing
Cutting out knots and pitches with cracking
Crack splicing
Surface treatment
Proliferation primer
Partial grease with primed grease spots
Grinding greased areas
Solid putty
Grinding
Second solid putty
Grinding
Proliferation primer
Surface painting
The first painting of the facade
Flanging
Grinding
Second color
Painted surface finish
Fluting, cutting, knurling, spraying

Surface cleaning.Removing splashes, drips of the painter's solution is performed with a metal scraper, spatula and brush. Dust is removed from the surface with a hair brush (brush) or vacuum cleaner. First prepare the ceilings, and then the walls.

Surface smoothing.Painters using devices equipped with a flask, a metal mesh, pumice or a bar of wood, process individual sections or completely finished surface. In the case of using dry mixes and mortars in fine sand in the grout, the surface smoothing operation is not performed.

Breakdown of cracks.The painters examine the surfaces and open the cracks visible with the naked eye with a metal spatula or plaster knife to a depth of 2 mm. This operation is performed by moving the spatula or knife blade along the crack.

Cutting out knots and pitches.Drop-out knots of the painter are removed by drilling or chiseling with the subsequent sealing of a wooden cork on glue. Jams are removed carefully with a chisel.

Drying of the surface layers.Reducing the moisture content of the material in the finished structure to the required values \u200b\u200b(Table 1.3) is carried out by the heat or heat ventilation method.

Table 1.3

Permissible material moisture W%, in the surface layers of the finished structures

In the heat-ventilating method of drying, the air heater is placed outside the building and heated outside air is supplied to the premises. USV-type air heaters have a heating capacity from 42 to 420 thousand kJ / h, air capacity from 250 to 4500 m / h. During the drying process, the air temperature in the room and the moisture content of the material of the finished structure are measured.

Properties of wood materials.

Wood as a building material lends itself well to processing, has high tensile, compression and bending strength, low bulk density, heat and sound conductivity. However, this material has several disadvantages: it is easily exposed to fire and decay, absorbs moisture, and is heterogeneous in structure.

For the correct and appropriate application and increase the service life of wood, it is necessary to know its properties.

The main part of the tree is the trunk, the lower part (of a larger diameter) of which is called the butt, or lower cut, and the upper - the top, or upper cut.

Wood is the densest and strongest part of the trunk. It consists of a series of concentric annual rings especially pronounced on coniferous trees. Each annual layer consists of spring (inner), lighter wood and summer (outer), darker. The larger the percentage of summer wood at the edge of the trunk, the more durable the material is considered.

In the center of the trunk section is the core - the earliest part of the trunk formation. In technical terms, it is much worse than wood, consists of thin-walled cells and is a loose tissue.

There are two main groups of tree species: coniferous (pine, spruce, larch, fir, cedar) and deciduous (oak, beech, hornbeam, maple, ash, birch, alder, chestnut, linden, walnut, etc.).

In construction, conifers are most widely used. Deciduous is more used in the manufacture of furniture and other wooden products.

Hardwood.Oak.Solid, durable, viscous, rot-resistant material. It is mainly used for the manufacture of underground structures. It has a beautiful texture, is well processed, due to which it is widely used in the furniture industry and for expensive finishes in construction (parquet, panels, intra-apartment stairs, etc.).

Beech.It has hard and strong wood, but it is easy to rot. It is used mainly for the manufacture of carpentry and during finishing work.

Hornbeam.When drying, the wood warps heavily, the trunk in its cross section is irregular in shape and rarely straight, so it is almost never used in construction.

Such breeds as birch, linden, maple, alder, walnut are almost not used in construction. The main purpose is for the manufacture of furniture and expensive finishes. Aspen is used for the manufacture of shingles for roofing.

Conifers.Pine.The most common material in construction. Its wood is mainly strong, flexible, resinous, well resists decay, with intensive drying warps, but does not crack much. Due to the small amount on the main part of the trunk branches makes it possible to get good lumber.

Spruce.The wood is less strong and resistant than pine, less resinous, so it is better for bonding. However, due to the large number of strong knots, it is more difficult to process.

Larch.More resinous than pine, stronger than it, much more resistant to decay. Wood cracks during drying, which limits its use in nail structures and carpentry.

Fir.It has light, soft and resilient wood. There are no resinous substances in the wood, which makes it unstable to decay. It is used in open (non-plastered) structures protected from atmospheric precipitation. Application in the manufacture of carpentry is limited.

Cedar.It has light resinous wood with a beautiful texture (arrangement of annual layers on a longitudinal section). It is weaker than pine in strength. It is used for the manufacture of carpentry.

Vice of wood.During growth, as well as during felling, transportation, storage and drying, a tree often has a number of defects that limit its use in construction.

The main defects of wood are the following.

Slanting -helical placement of fibers around the longitudinal axis of the trunk. It is found in all breeds. Sawing such wood into boards is undesirable. With a significant slanting logs, they are used as a whole in secondary structures.

Silence -wavy or tangled arrangement of fibers, making wood processing difficult.

Cracksdistinguish between frost, core, shaky and airy. All of them contribute to premature decay of wood and damage to structures.

Knots- the foundations of tree branches found in wood. Knots are fused (healthy) and non-fused (falling out); painted, friable and tobacco (depending on the degree of decay).

Fused knots have little effect on the quality of wood, and falling knots limit its use in structures working in tension and bending. Wood with painted, and especially with loose and tobacco knots before the removal of the location of the knot in construction is not used. As a rule, such knots not only rot themselves, but also cause rotting of healthy wood.

Worm-hole- damage to wood by pests, mainly their larvae. The greatest harm is caused by the bark beetle, which spoils the wood directly under the bark; barbel beetle, which damages wood at a depth of more than 5 cm; weevil beetle, which makes a large number of moves in the wood.

Decaywood is the decomposition of its cells, accompanied by a color change, cracking in the longitudinal or transverse directions and turning the wood into a brown mass that crumbles when touched in dust. Rotting is caused by a fungus that infects wood.

The most dangerous mushrooms that destroy the structures of entire buildings are the brownie real, the brownish membrane and the brownie white.

Wood preservation and fire protection.When constructing a house, it is first necessary to take such constructive and operational measures that prevent the appearance and development of rot in wooden structures, for example, arrange insulation between wooden elements and masonry or brickwork, as well as air in the basement to ventilate the underground, eliminate sources of moisture etc. If it is impossible to take these measures (in wooden chairs of the foundation, in the sheathing of partitions for plastering, when installing floors on logs directly on the ground, etc.), chemical measures to combat rotting wood are used - antiseptics.

The main chemicals used in antiseptics, or antiseptics, are sodium fluoride and zinc chloride.

Sodium Fluoride -the main antiseptic used in wooden structures indoors. Its aqueous solution penetrates wood relatively easily. It can be used in combination with other antiseptics.

sodium fluoride - 3.0 kg;

dye - 0.05 kg;

water - 97 l.

Zinc chloridein quality lower than sodium fluoride, it is easily washed out by water. If metal products adhere to wood impregnated with zinc chloride, then they strongly corrode.

The composition of the antiseptic per 100 l of solution:

zinc chloride - 5 kg;

dye - 0.05 kg;

water - 95 l.

The indicated antiseptics are powders readily soluble in water. The surface of the wood is twice sprayed or coated with a solution; re-processing is carried out after 2-4 hours. The flow rate of the solution with this antiseptic is 0.6-0.8 l per 1 m of the treated wood surface.

When antiseptic structures located in the open air or in the soil, the best are the following oily antiseptics, insoluble in water.

Coal Creosote Oil- liquid of dark brown (almost black) color with a specific pungent odor, limiting its use in internal wooden structures. It is used with a solvent (oil, solvent and green oil) in a ratio of 1: 1.

Wood tar(resin) - a thick liquid of a dark color. It is mainly used for lubricating underground structures and places where wood is in contact with masonry or concrete.

Green oil- It is used mainly in the form of an additive to creosote oil, as well as independently.

The method of use of these antiseptics is a brush (preferably heated).

Open wooden structures (rafter system), as well as closed (plaster partitions, floor beams) located in close proximity to heating stoves, chimneys, pipes and performed in violation of fire regulations during construction, can cause a fire or spread it. Therefore, in the first place, it is necessary to strictly adhere to constructive measures that prevent the occurrence of a fire. Fire retardants can only prevent its rapid spread. These products include the following fire retardant paints.

1. Solution for surface treatment (in%):

ammonium phosphate - 20;

ammonium sulfate - 5;

solar contact - 3;

water - 72.

It is applied by spraying or with a brush twice with an interval of 4 to 24 hours. Consumption per 1 m of surface - 1.1 kg of solution.

1. Silicate paint (in g / m):

liquid glass (soda) - 185;

glycerin - 10;

zinc white - 10;

water - 110.

Apply by spraying or brushing twice with a break of at least 12 hours. The normal color is white. Suitable for use within 8 hours after preparation.

1. Superphosphate coating (in g / m):

superphosphate - 1400;

water - 600.

Brushed twice. The normal color is white. Suitable for 6 hours after cooking.

Construction and technological properties of wood.Wood moisturerefers to the ratio of the weight of the water contained in it to the mass of wood dried to a completely dry state, expressed as a percentage.

According to humidity, wood is distinguished as air-dry (with a moisture content of not more than 20%), raw (with a moisture content of 20 to 50%) and freshly cut or alloyed (with a moisture content of more than 50%).

To a given degree of humidity, the wood is dried naturally (for a long time stored in air in stacks protected by a temporary roof) or artificially (in special dryers).

When drying, the wood changes in volume - it dries out, and the wood shrinks unevenly along the trunk cross section.

Cracking of wood occurs due to its uneven drying in different directions, as well as in the outer and inner layers. Cracks form first at the ends, and then along the log or board. With skillful drying of forest materials, minor cracking of wood can be achieved or cracks can be completely avoided.

Warpage of wood occurs when it dries due to uneven drying in different directions. When dried, the boards cut from the raw log are warped in cross section in such a way that the surface farther from the core of the log becomes concave, and closer to the core of the log, it is convex. The board, sawn from the core of the log, becomes thinner at the edges than in the middle of the section.

The swelling of the wood occurs from its saturation with moisture and is accompanied by an uneven increase in the size of the material, similar to a decrease in size during wood drying.

Color is a characteristic feature of wood. By color, you can determine the type of wood, its quality. Healthy wood has a uniform color; spots and stripes indicate the beginning of decay of wood. Natural color, luster from the intersection of core rays, a peculiar arrangement of fibers create the wood texture of this breed. The texture of different types of wood is different: smooth (in boxwood), rough (in oak), slanting, frizzy, etc. The texture of wood is widely used in decorating.

The smell of wood, peculiar to each breed, also serves to recognize the breed and determine good quality.

The calorific value of wood (the amount of heat released by burning 1 kg of wood) at a moisture content of 15% is 3700 kcal, while the calorific value of the best coals of the Donetsk basin does not exceed 7500 kcal.

Wood is a combustible material, therefore, in supporting and enclosing structures it must be protected from fire by impregnation with flame retardants or protective coatings made of non-combustible materials. In the latter case, wooden structures have a significant fire resistance limit, which is characterized by the ability of structures to resist for a certain period of time the effects of fire until loss of strength and stability of the structures or to the formation of through cracks. So, interfloor wooden floors with knurled or hemmed and plastered along the flanks or mesh with a plaster thickness of 20 mm have a fire resistance limit of 0.75 hours; monolithic or prefabricated reinforced concrete floors with a reinforcing layer thickness of 10 mm in slabs, and 20 mm in beams and ribs have a fire resistance limit of 1 hour.

The strength of different types of wood is different. If the tensile, bending, compressing and crushing strength of pine and spruce wood along the fibers is taken as 100%, then the strength of oak, European ash, hornbeam, maple, white acacia will be 130%, larch - 120%, birch, beech, Far Eastern ash - 110%, pine of Yakutia, Caucasian fir, cedar - 90%, fir of the Ural, Siberian and Far Eastern, aspen, poplar - 80%.

The strength of wood also depends on its degree of moisture and age:

- the greater the moisture content of the wood, the less its strength;

- the wood of young trees is less durable.

In construction, lumber is used.

Platesobtained by sawing logs along the axis of the trunk into two parts (Table 1.4).

Table 1.4

Volume of plates, m

The diameter of the plates at the thin end, cm

Quarters- logs sawn along the axis of the trunk into four parts.

Croaker- waste when sawing logs parallel to the axis of the trunk.

Bars— thickness 13 ... 25 cm, width no more than double thickness (Table 1.5).

Table 1.5

Volume 10 m of bars, m

Width mm			Thickness mm

Whetstones- thickness 4 ... 12 cm, width less than double thickness.

Reiki- thickness up to 3.5 cm, width less than 7 cm.

Boards- thickness up to 8 cm, width 8 ... 25 cm (table 5).

Table 1.6

The volume of 100 m of sawn timber with a moisture content of 12%, m

Width mm

Thickness mm

The wide side of the boards and beams is called a sheet, the narrow side is called an edge, and the line of their intersection is called an edge. By the nature of the processing, the boards and beams can be unedged with a pickup (raw edge), half-edged and trimmed.

The standard length of boards and beams is 1 ... 6.5 m with a gradation of 25 cm. Depending on the quality of the wood, lumber is divided into grades: boards and bars are produced in six grades (selected grades C and ordinary grades I, II, III, IV and V) , and bars of five grades.

Semi-finished products from timber are usually made in the form of tongue-and-groove boards, plinths, fillets, handrails, platbands, cornices, rustic, lining, door and window frames, parquet, plywood, etc. (fig. 3). Grooved boards are used to arrange floors, partitions and other structures that require longitudinal communication between the boards.

Clapboard lining the ceilings and walls, platbands frame window and doorways, skirting boards and fillets are used to close the gaps between the floor (ceiling) and the walls.

Plywood is glued and facing. Glued plywood, or dictation, is used in the manufacture of internal doors, base for parquet, light partitions, and facing - from precious wood for furniture.

Glued plywood is usually made with dimensions of 1525 x 1220 and 1525 mm, thickness 2 ... 15 mm with the number of veneers (layers) 3 ... 13. The quality of plywood is made in five grades.

Tools and devices for manual and mechanized work

In the processing and installation of timber, plastic and metal parts and structures, measuring and marking tools and devices are used: folding meter, tape measure, marking compasses, square, malka, bark, level, plumb line, surface gage.

For marking and measuring arcs and circles, a compass is used, and the external diameter of the part is determined by a caliper. Right angles (90 °) are measured with a square, and for marking angles of 45 ° and 135 °, a bark is used. Small can measure and mark angles of various sizes. Level and spirit level are used to check the horizontal and vertical surfaces. A plumb line - a cord with a load in the form of a cone - is used to control the verticality of structures. Thicknessers and spans serve for marking parallel lines.

Hand tools: axes, hammers, saws, plows, chisels and chisels, augers and drills.

Axes for chopping, teeski, splitting wood, cutting tenons and other works have a 49 cm long handle (hatchet) made of birch, maple, elm, ash, hornbeam or beech. After planting the handle, the ax is strengthened with a metal or wooden wedge. Ax angle of the blade ax 30 °. The mass of the ax is 1.1 ... 1.75 kg.

Saws, depending on the purpose, have the corresponding tooth shape:

- for longitudinal sawing - oblique triangle with the direction of the teeth in the direction of cutting,

- for cross cutting - an equilateral triangle,

for universal sawing (along and across) - a right triangle.

So that the saw in the cut does not “jam”, the teeth are bred - after one they are bent in different directions, leaving one or two teeth unexplored to clean the cut from sawdust. The wiring of the teeth is done at 1.3 ... 1.5 thickness of the saw blade, while using special wiring and templates.

One-handed saws: bow (steel saw blade fixed in a wooden machine) and hacksaw (rectangular or trapezoid saw blade with a reinforced handle on the end). There are several types of hacksaws: ordinary - gives a rough cut, not limited by the width of the blade, with a ridge - cut thin, but limited in height, a reward with a permutable blade - cut of a certain depth, narrow - is used for curved cuts in the middle of the board.

Plows consist of a wooden or metal block, a steel cutter (piece of iron) and a wedge; pens are made on the blocks. The plow cutter is placed in a special block nest (letka), the lower part of the block has a slot (span) for the cutter to exit. Cutters should protrude beyond the plane of the sole of the block by 1 ... 3 mm for rough planing and 0.1 ... 0.3 mm for clean planing.

The following planes are used for planing flat surfaces of wood: a bear, a sherbel, planers, a grinder, a jointer, a half jointer, a tsinubel, a cycle.

A bear with a piece of iron (cutter) with a width of 50 ... 60 mm is used for rough planing of logs, beams and boards.

Sherkhebel with a piece of iron 30 ... 40 mm, protruding beyond the plane of the sole by 3 mm, is used for the initial planing of parts before surface treatment with a plane.

A single and double planer (has a second chip breaking piece - a humpback) is used to level the surface planed with a sherbel, and a double planer is also used to cleanse burrs and cut edges.

Shliftik - a shortened double planer with a cutting angle increased up to 60 ° - removes very thin shavings, cleans scuffing, frizzy places and ends.

Jointer - a large double planer (block length 700 ... 900 mm, width 85 mm, height 75 mm) with a piece of iron 50 and 65 mm wide - used for precise machining of large planes to the ruler and aligning the edges of the boards.

The cycle - a plate with a length of 100 ... 150 mm, a width of 60 mm and a thickness of up to 1 mm (made from old hacksaw blades, bow and band saws) - is used to clean hardwood after processing with a double planer.

For figured wood planing, plows with shaped blocks and pieces of iron are used: a zenzubel for sampling quarters, a dowel - dowels, a dredge - ridges, a moulder - on the slats and edges of mulling bars, a humpback - for planing concave and convex surfaces (Fig. 7).

Tsinubel makes the surface to be roughened, which contributes to the strong adhesion of wooden parts, and they also plan out frizzy and very hard wood (elm, beech, ebony). The glands of the planing tool are made with a length of 160 ... 200 mm and sharpened on one chamfer with a taper angle of 30 ... 35%, inserted into the socket pads and wedged at an angle of 45 ... 60 ° and so that they protrude 0.2 ... 0, beyond the plane of the sole of the block 5 mm.

For hollowing out holes and nests, narrow and wide chisels with a cutter blade of 6 ... 25 mm wide and a taper angle of 20 ... 30 ° are used. The hollowed holes are cleaned with flat and semicircular chisels with a width of 4 ... 50 mm and a taper angle of 18 ... 25 ° (Fig. 8).

The mallet - a wooden hammer weighing 1.5 ... 2 kg - is used for mortising and caulking works.

A leopard - a wooden hammer weighing 3 ... 5 kg - serves for upsetting logs when cutting walls, driving piles, etc.

A set of small tools: pliers, a universal sliding key, screwdrivers (large, medium and small), a nail guide for hammering nails below the surface of wood and other materials, files, etc.

The workplace is equipped in the workshop with a permanent workbench (up to 3 m long, 1 m wide and 0.8 m high) and a portable workbench on the construction site (1.5 m long, 0.5 m wide on top and 0.8 m high). The portable workbench (Fig. 14) can be moved directly to the place of work, for example, fitting doors and windows, screwing hinges, etc.

Table 1.7

Technical Specifications of Electrified Woodworking Tools

Tool		Electric motor power, kW	Weight kg	Appointment
Stationary saw, saw blade diameter 200 mm				For sawing wood and cutting parquet boards
Circular saw, saw blade diameter 200 mm				For longitudinal and transverse sawing of wood, as well as artificial wood-fiber building materials
Woodworking machine				For sawing, drilling, planing and milling wood
Manual jig saw				For the device of cuts in wood, dry gypsum plaster boards, aluminum, sheet steel
Planer planing width 100 mm planing width 75 mm planing width 200 mm				For planing wood in the manufacture of elements of wooden structures
Planer				For wood planing in domestic conditions, except for residential premises
Mortar				For selecting holes and nests of rectangular shape, shunt grooves, etc. in the wood.

Carpentry and joinery

Carpentry - the installation of floors, ceilings, partitions, rafters, walls and mantles associated with the processing of wood.

Joinery - the manufacture and installation of window frames and binders, door frames and paintings, clean partitions, furniture manufacturing, artistic parquet floors and other cleaner wood processing.

When performing carpentry and carpentry work, logs, beams, boards are connected in different directions using mates - splicing, building, rallying joints at an angle. Pairings are made by cutting and using nails, dowels, bolts, clamps, staples, glue. Splicing is used for the longitudinal connection of logs, beams, boards to increase their length, and building - to increase their height (Fig. 15).

Combining logs, boards and beams (Fig. 16) is done in the manufacture of large transverse dimensions of wooden structures (flooring, wall cladding, partition walls, etc.).

Connections at an angle of logs and beams (Fig. 17) are performed in the manufacture of window and door frames and paintings or binders, felling of walls and partitions of wooden houses, etc.

When performing carpentry and carpentry, felling, teska, sawing, planing, drilling and chiselling are performed.

Felling and teska of wood with an ax (Fig. 18) is carried out in two directions: first, the fibers are cut across (through 40 ... 50 cm), and then they are chopped obliquely, deepening towards the middle of the timber. Sawing begins with two or three short movements of the saw along the sawing line and after receiving the cut, they begin to work at full swing without a strong pressure on the saw. In order for the cut to be opened and not to clamp the saw, it is necessary to put a lining near the cut.

When sawing several boards at different angles, templates are used that give the direction of the saw - “miter box”.

Planning requires following the sequence: first planed with a rough dagger, after which the surface is leveled with a single and double planer, finally smooth cutting is made by jointer. Solid, uninterrupted shavings are removed by jointer by moving a carpenter-joiner with a jointer along the workpiece. When trimming (cutting edges), in order to avoid chipping off the edge of the workpiece, trimming should be done from the edge to the middle of the part, and then trimming the block from the other edge to the same middle. Chiselling of nests, eyes, etc., is done by marking with notching the edges of the nest - the chisel is placed vertically with a blade across the fibers, chamfered to the nest, leaving a certain supply of wood on the sides of the nest and applying light blows with a hammer. The bit is hammered 3 ... 8 mm deep, then the wood fibers are removed and obliquely chopped. Through nests are hollowed on two sides, and marking is applied on both sides of the part. Through holes first hollow to half the depth of the nest, and then turn the part over and continue hollowing from the other side. For cleaner work, the nests and eyes after peeling are cleaned with chisels.

Drilling of round holes is carried out for setting bolts, pins, spikes according to the marking, template, template-conductor. Templates are made of sheet metal up to 2.5 mm thick, plywood up to 5 mm thick or dry boards. The diameter of the hole should be 1 mm less than the diameter of the bolt, pin or stud.

Rules for connecting elements of wooden structures on pins, bolts and nails:

- the distance between each other of the pins and bolts, as well as their distance from the end edge of the elements, must be at least 5 diameters of oak pins and 7 diameters for steel pins or bolts,

- the length of the nail should exceed the thickness of the element to be nailed 2 ... 3 times,

- the distance between the nails must be at least 15 ... 25 diameters of the nail,

- the distance from the extreme nail to the end of the board or bar is not less than 15 diameters of the nail, do not hammer the nails into the end of the wooden elements in order to avoid cracks,

- do not stitch boards with a thickness of less than 4 nail diameters in order to avoid the possibility of cracking,

- you cannot hammer nails with a diameter of more than 6 mm into coniferous wood, and into hardwood (oak, beech) wood - more than 4 mm,

- if it is necessary to use thicker nails, you must first drill the nests of 0.9 of the diameter of the nail to a depth of 0.4 ... 0.5 of the length of the nail,

- hammering nails into wet and frozen wood is not recommended; if necessary, nailing should be plentifully lubricated with technical oil,

- nails should be driven only with a hammer perpendicular to the surface of the connected elements,

- driving nails so that they do not pull out should be done obliquely in different directions at about an angle of 15 °,

- temporary nailing, if it is planned to pull them out after a certain time, is done so that the caps 5 ... 10 mm protrude above the surface of the nailed element,

- nails bent during driving should be pulled out and replaced with new ones.

The gluing of wooden parts is done mainly in the manufacture of joinery using bone, mezdrovye, casein, resin and special adhesives. The surfaces of the parts to be glued are carefully adjusted to each other and are cut with a zenibel. The wood to be glued must be dry, glue is applied in a thin layer on only one of the surfaces to be glued. The elements to be glued are clamped with clamps or hems. When squeezing, excess glue is squeezed out and only the necessary amount of glue is left between the surfaces for strong bonding.

An adhesive solution of bone and glue glue is prepared for 1 ... 2 days of work, can be stored at a temperature of 5 ... 10 ° C for 5 ... 7 days, without losing its properties.

Preservation of basic qualities in casein solutions - 4 ... 5 hours, resin - 2 ... 4 hours, special adhesives - according to the instructions.

1. ORGANIZATION AND TECHNOLOGY OF PERFORMANCE OF WORKS.

SURFACE PREPARATION FOR PAINTING.

Preparation of wooden surfaces

Scope of work.Cleaning the surface of the spray solution. Cutting out knots, removing tanning marks, recessing nail heads, splitting holes.

Manufacturing jobs.Quality requirements. Wooden products prepared for coloring should not have defects in carpentry (cracked panels, chopped boards, dropped knots, etc.).

The prepared surfaces should not have traces of woodworking machines, putrid places. The knots found during the inspection are cut down, the resins are cut to a depth of 2 ... 3 mm, small defects of the joinery (uncircumcised fibers at the interface, burrs, spalls) are removed and cleaned with a sanding cloth.

In wooden floors, boards should be well-knit and nailed to the lags, nail caps should be sunk to a depth of 3 ... 4 mm.

The slots formed at the junction of the boards or in the direction of the fibers must be expanded for the convenience of their subsequent termination.

Wooden products and structures to be painted should be dry (humidity should not exceed 12%), cleaned of spray mortar, dust.

Technology work.Prior to the preparation of surfaces for painting, it is necessary to check the rigidity and strength of embossment of dropped knots, cracked panels, etc. Major defects in carpentry should be fixed before painting, and not be corrected with grease, since it subsequently falls out.

Pre-clean the surface of the spray solution.

New wooden floors are cleaned, but not washed, as slow drying of the surface will delay the execution of subsequent processes. Small areas are cleaned with metal spatulas or brushes, as well as steel scrapers on an elongated handle, dust is removed with hair brushes or rags; for large volumes of work, parquet grinding machines are used. Machines not only clean the surface, but also collect dust using a vacuum cleaner installed on them or a fan with a dust collector.

Despite the fact that carpentry (window frames, door leafs) is more often prepared for painting in the factory, defects can be formed when the wood dries and must be removed before painting.

The protruding knots and pins (wooden nails) are cut with a chisel (Fig. 20). First, a chisel marks the border of the removal of wood, then a knot or a nagging is made with a small diameter on both sides, with a large diameter from three to four. A knot is cut to annual layers, to a depth of 5 mm, and a piece of wood of the same breed is inserted in its place. The inserted piece is fixed to the adhesive so that the direction of the fibers in it matches the direction of the fibers of the main product.

Pitches that can form on structures and products made of coniferous wood (pine, spruce) are cut with a chisel to a depth of 2 ... 3 mm (to healthy wood).

Small defects - protruding fibers, burrs - with slight movements, the chisels cut along the fibers without affecting the healthy part of the wood.

When cutting knots, pins, pitches, etc. the chisel should be kept at an angle of 35 ... 40 ° to the surface.

As a result of wood drying, cracks and cracks also form, both at the junctions of individual boards and in the direction of the fibers. In order to more conveniently and more firmly seal cracks and crevices, it is necessary to expand them somewhat with a chisel. This operation is called cutting or stitching cracks.

If after installing the carpentry in the building under construction, plastering was performed, then window and door blocks, as well as molded products, door trim, baseboards, the edges of the door and window block boxes built into the walling with the formation of slopes, must be cleaned of spray mortar. Painting without cleaning the surface of the solution leads to marriage (the colorful film that has fallen on the solution quickly peels off). Properly clean wooden surfaces with a metal spatula, brush or scraper.

Drying of wood occurs unevenly. Thus, shrinkage in the radial direction is 5%, and shrinkage tangential to the annual rings is greatest and reaches 10%. In this direction, the logs are sawn into boards, as a result of which knots can fall out, and in the places where the joinery is fastened with nails - ledges can form. The paint compositions on the ledges do not hold well.

For cutting knots and pitches, use a semicircular chisel with a blade width of 12 ... 15 mm and a hammer.

When cutting knots, it is necessary to pay attention to the position of the chisel during operation - at an angle of 35 ... 40 ° to the surface, as well as the cutting technique. Incorrect cutting will result in wood breaking and damage to the product. When trimming burrs, punctures and other defects, trimming should be done with light movements of the chisel along the fiber, cutting off the defective places, but without affecting the healthy part of the wood.

Preparation of a wooden surface is the most important stage in the preparatory work before applying the varnish, without which it is extremely difficult to achieve a high-quality result. Varnish gives the product an additional charm, which is achieved due to the glossy shine. In addition, after applying the paintwork, the service life of the wood increases, the material acquires additional strength and good water-repellent properties, the structure becomes more attractive and has a special shade.

Where does the preparation of wooden surfaces begin

Each type of wood has its own unique pattern that needs to be emphasized. This is best done with a special wood varnish. But before you start applying it, the surface should be well prepared.

The preparation process depends on what composition of the varnish will be used transparent or opaque. The preparatory process is also affected by the chosen method of painting, its complexity and volume. It will not be superfluous to mention the properties of the materials to be used. The time spent on the organization of work will directly depend on their quality.

Opaque coating

With an opaque coating, it does not matter how a flat, smooth surface is achieved, anyway it will then be painted over. The sequence of work is as follows:

1. Previously, the surface is protected by a grinding plane, then, if necessary, it is cycled and ground with a fine emery cloth.
2. After this, the surface must be primed. It is not worth paying attention to any cracks, chips and other pits, the main thing is that there should be no bulges.

For primers, drying oil, varnish or paint (enamel) is usually used, from which the surface will subsequently be painted.

Thinner (white spirit, etc.) is added to drying oil, varnish, and paint until 10 — 15% by volume. This is done so that the liquid primer penetrates deeper into the pores of the wood and dries faster.

Important! It is not necessary to allow the final drying of the primer. There should be an adherence that provides the greatest adhesion (adhesion) of putty to the surface.

Putty on wood

It is not difficult to make putty with your own hands; it is enough to knead any fine-grained powder on the primer: chalk, talc, flour, starch, small (from under the file) wood sawdust, etc. The powder is mixed with the primer to the consistency of a thick dough and rubbed with a spatula into cracks and other notches.

It should be remembered that the putty shrinks when dried, so it must be applied with a slight excess. If necessary, the resulting mixture is applied several times.

Then the surface is sandpaper. To achieve a flat and smooth surface, the skin should be attached to a wooden block. After thorough preparation of the surface, it is painted one or two times, depending on the opacity of the paint or enamel.

Transparent coating

Transparent finish does not cover the wood texture and consists of the following steps:

1. Wood surface preparation;
2. Wood surface coating with stain (stain);
3. Varnishing or polishing the surface.

Preliminary preparation of the surface is done in the same way, but more thoroughly.

In most cases, grinding is carried out in two stages: first, smooth the surface with a sandpaper, and then moisten it with a wet rag or foam rubber to raise the smoothed villi. After the surface dries, it is again ground with a fine sandpaper.

Existing minor defects must be lubricated with a putty selected in color, while the filler must be smoothed out raw. High-quality training also involves the use of special grinding machines.

DIY bog oak

Existing pores in oak wood must be wiped. Grated pumice is best suited for this. It is kneaded on the varnish in the form of slurry, and the excess is removed immediately after application. After drying, the surface is ground.

If an ordinary oak tree needs to be imitated as stained (black), you need to take black nitro paint (SC) and dilute it one to one with the solvent. The resulting liquid paint is gently applied to the surface with a flute. It easily penetrates into all pores of the oak, preserving them, and gives the oak a dim shine. Such an oak practically does not differ from a real moraine.

After that, it is not necessary to cover it. During operation (after 2 to 3 years), such a surface must be re-coated.

Application of varnish to the surface

Varnishing is the most common way to decorate a wooden surface. The best quality can only be achieved with oil varnishes, which are applied with soft fillets. The width of the flutes is selected depending on the area of \u200b\u200bcoverage.

It should be remembered that the varnish lays down better if its layer is thinner. Varnishing a wooden surface at a time will not succeed. In some places it will remain on the surface, and in some places it will be absorbed into the wood, and dull spots will form.

After the first layer has dried (it is better to varnish overnight and at the same time to ensure that there is no dust), sand the resulting tubercles with a fine sandpaper, wipe the surface with a damp cloth that does not leave a lint, and cover the surface a second time.

After the second layer has dried, a decision is made to apply the third layer. In the process of varnishing, determine what surface you can cover in one dipping brush. Having dipped a brush in a jar of varnish, you remove excess varnish on the edge of the can, and apply the rest to the surface with spots or short strokes.

Then the surface is shaded first across, and then along - in the direction of the incident natural (window) light or in the direction of the view.

It should be remembered that the glossy, shiny surface is not always elegant. All irregularities reflect light unevenly and are especially noticeable on a glossy surface. The lacquered plywood sheet will definitely glare.

If the room is lined with plywood, it is advisable to make the surface matte. To do this, add solvent to the oil varnish 15 — 20% from the volume of varnish and cover the plywood. The entire texture of the tree is manifested, it will not change its color under the influence of light rays and will not get dirty, like pure plywood.

Walls lined with such plywood will have a smooth matte surface of straw color. If the ceiling in the room is white, the fenders at the joints of plywood sheets can also be painted white. The room will be very elegant.

Nitro-lacquers are applied only with a spray. The coating should not have spots, roughness and other defects. The gloss of the coating can be increased by polishing it with polishing paste (for example, GOI). Such a surface imitates natural polishing well.

All photos from the article

The purpose of the painting is to decorate building structures and increase their operational and hygienic properties. The technology of painting wooden surfaces provides for their preparation in accordance with the requirements of SNiP 3.04.01-87.

Strong and durable coating ensures the safety of the elements. It protects from warping, cracking and damage to wood by insects and fungi.

Painting work can be done with your own hands without the involvement of masters of a specialized specialty. Instructions for painting surfaces made of wood are given below. To perform such an operation, it is necessary to prepare the building structure, tools and materials. Application of coatings is allowed with a moisture content of the base not exceeding 12%, respectively, it must first dry out.

Preparation of wooden surfaces for painting

Repair of building structures should begin with their cleaning and leveling. The question arises: how to remove paint from a wooden surface?

Currently, several methods are used to perform this operation, described in a special section below. The surface cleaned from old coatings must be leveled with putties, carefully primed and degreased. After the base has dried, you can proceed directly to the application of paint.

Methods for cleaning wooden surfaces from old coatings

There are several technologies for removing previously applied layers of paintwork, based on the use of different principles.

Removing paint from wooden surfaces is carried out in the following ways:

1. Mechanical Work is carried out using sandblasting equipment or rotating wire brushes. In relatively small areas manually.
2. Thermal. Provides for the use of industrial hair dryers or blowtorches. Under the influence of high temperature, the coating swells, after which it is easily removed with a spatula.
3. Chemical. It implies the use of special compounds applied to wood. They partially dissolve the paint and ensure its peeling.

Choosing a way to remove paint from a wooden surface, you need to take care of protective equipment. Goggles, respirators or masks and protective gloves will be required, and safety measures should be observed during work. At the end of the operation, the wooden structure is cleaned of dust and debris by hand with a brush or by blowing it with compressed air.

Degreasing surfaces

The base from which the old coating is removed usually has contamination of a very different nature. They reduce the adhesion of putties, primers and paints to the surface; cleaning from them is required. How to degrease a wooden surface before painting and preparation? To carry out this operation, solvents based on mineral spirits or formulations specially developed for this purpose can be used.

Tip: It is not recommended to apply a degreasing agent with a brush for two reasons. Firstly, it increases material consumption.
Secondly, the brush does not remove dirt from the base.
It is best to use rags or napkins.

There are other degreasing technologies: immersion in special ultrasonic baths, treatment with solvent vapor or dry ice. This technique involves the use of special equipment, and are used at specialized enterprises.

Old window frame

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Before painting a wooden surface, you need to carefully process it in order to ultimately get an aesthetic and high-quality coating. In this article, we have collected some recommendations that help to properly prepare the surface.

First you need to evaluate the wooden surface - to identify roughness, chips and bumps, pay attention to knots, spots of resin and protruding nails. All these defects must be repaired or repaired. The protrusions, tubercles and burrs can be removed with a loop or chisel. To prevent nails from interfering, their hats are driven a few millimeters deep. The protruding knots must be replaced with corks of similar wood using a cork. The inserted corks are fixed with PVA glue or wood glue. It is necessary to arrange the plugs so that the arrangement of their fibers coincides with the direction of the fibers of the base.

See also: Primers on wood: recommendations for selection and technique of use General purpose wood primers form the largest group of wood primers and perform the main task of preparing the base for topcoat application

There is another way of surface treatment with knots, it consists in sealing holes with a dense mass of sawdust and casein glue. If there are spots of resin, they should be smoothed out 2-3 mm deep and cover the formed depressions with a mixture of casein or wood glue and sawdust. Use cleaned kerosene, gasoline or acetone to remove oil stains. After these steps, sand the wooden surface with sandpaper.

Defects in the form of cracks and potholes are masked using a water-based putty specially designed for wood. After the putty has dried, it must be wiped. It is not recommended to apply a continuous layer of putty on the wooden base, since in this case the surface will lose its unique fibrous texture.

Now the final stage of preparation is the application of a primer on the base. It is necessary to ensure the temperature in the room within + 18 ... + 28 degrees and clean the wooden surface from dusty particles.

The primer must be suitable for the type of surface (choose a composition suitable for wood), as well as the paint applied. After applying the primer, blend it with a fleitz (flat brush), and after the composition dries, lightly sand the surface with fine-grained abrasive paper. After finishing grinding, you can start painting the base.

Almost all wooden surfaces and interior items need to be painted. On the one hand, this helps protect them from harmful external influences, and on the other hand, creates the necessary decorative effect. At first glance, it may seem that there is nothing complicated in this process, and anyone can cope with the task. But do not forget that not only the appearance, but also the service life of these items depends on how well the painting of wooden products is done. That is why, long before the start of work, it is necessary to study all the nuances and subtleties of the procedure, determine the choice of coating and consider the technology of staining wood. In this article, we will analyze in detail each step, from the choice of a tool to the application of paint.

Characteristics of wood paints

There are three types of paint for woodwork: oil, alkyd and acrylic. Choosing the appropriate option, it is necessary to take into account the species of covered wood, the conditions, as well as the climate in which the product will be operated.

For example, acrylic paint can be used on all types of wood except varieties with a high resin content. Water acts as the basis, due to which the composition does not emit an unpleasant odor, dries quickly and is considered an environmentally friendly finishing material. does not clog the pores of the tree, allowing it to preserve its natural breathing properties. The coating is very easy to apply, resistant to moisture and low temperature, and also able to maintain saturated color for a long time.

Painting wooden products with alkyd compounds can reliably protect wood from the harmful effects of moisture. This paintwork is characterized by excellent frost resistance and affordable cost. The components contained in the material form a protective film that repels water. But alkyd paints are not able to penetrate deeply into the structure of wood, which is why the coating is very short-lived.

Oil compositions are made on the basis of drying oil, therefore they have a pungent smell and are quite toxic. Such paints are distinguished by increased wear resistance, color saturation and the ability to withstand sudden changes in temperature. It is quite difficult to work with this material, as streaks often form on the surface. Nevertheless, the painting of wooden products made of resinous wood is most often carried out by this means.

Enamel

The composition of this material is characterized by an increased content of film-forming components that perform protective functions. This allows the use of enamel even for outdoor use. It should be noted that this coating is exclusively white. If necessary, concentrated dyes are used, which are already added to the enamel itself. The white base does not allow you to get bright shades, so the resulting colors are much paler than the tones indicated in the dye palette. Unlike water-based paints, enamels have a strong unpleasant odor and require regular ventilation of painted rooms.

You should also take into account the fact that white paint for wood is not able to hide the structure of the base, therefore, can only be used on flat surfaces that do not have dark defects. In some cases, flaws have to be smoothed out using putty.

What else will you need for painting wood

The list of necessary tools and accessories includes:

Tool for painting (brushes, roller, spray gun);

Putty knife;

Gloves;

Respirator;

Putty;

Primer;

Depending on the type of surface to be painted, this list may be supplemented.

Brush selection

In order for the painted surface to look beautiful and neat, due attention should be paid to the choice of painting supplies. Properly selected will help to apply the most even and thick coating layer, which will contribute to the long-term preservation of wood.

For surface treatment with varnish, oil composition or antiseptic, it is better to use brushes with bristles made of natural materials. For works with a water-based paint coating, it is recommended to purchase paint brushes with artificial bristles, because, unlike natural, it does not absorb water and does not lose elasticity.

Also do not forget about the size of the tool. For painting surfaces of large area, a brush with a width of 150 mm is acquired; for narrow, 12 mm is sufficient. For painting corners and wooden frames, brushes with a width of 25 mm are optimal, and for work in hard-to-reach places it is better to use wedge-shaped ones.

Before starting work, the tool is soaked for an hour in water so that the bristle hairs swell, increase in volume and become more elastic.

Preparation of wooden facades for painting

The choice of paint depends on what the owner wants to get: completely paint over the structure of the tree or leave it visible. In the first version, acrylic or oil products are used, in the second - colored antiseptics, which are coated with varnish after drying.

Painting a wooden house outside begins with surface preparation. If the facade is not painted for the first time, remove all previous layers of paint, putty and primer. To do this, use a small machine, a special wash or a building hair dryer.

If the old paint adheres well and does not peel off, a new coating can be applied on top of it, but in this case the same composition should be used as previously applied. To determine how the wooden house was painted (outside or inside - it doesn’t matter), you can cut off a small piece of the old coating: acrylic paint will immediately roll into a roll, and oil will quickly wash off.

Fresh wood must be well cleaned of dust. If we are talking about a rounded log, then you need to eliminate all the bumps and smooth the knots. A grinding machine can easily cope with this task. Further, the walls are treated with an antiseptic primer, focusing on the lower part of the house, which is most exposed to the negative effects of the environment.

Facade painting technology

When the primer is completely dry (after a couple of days from the moment of processing), you can proceed to painting the facade.

For work, it is best to use a brush. The coating is applied in the longitudinal direction, trying to avoid excessively thick layers. Staining begins from the very top of the wall to prevent droplets from falling onto the already covered area. In the process, the paint must be periodically mixed. This allows you to achieve the most even color across the surface. Particular attention must be paid to the ends of the boards and logs, as they most need reliable protection.

It should also be borne in mind that the quality of work performed is highly dependent on weather conditions. Covering the facade with paints and varnishes should be carried out at an air temperature of at least +5 degrees. At the same time, the scorching sun will contribute to the drying of the paint too quickly, and the increased humidity will not allow to apply the composition at all.

Floor painting

It should immediately focus on the fact that not all coloring compounds are suitable for the floor. This area uses paint specially designed for this purpose. The floorboard undergoes rapid wear, so the paintwork should be characterized by maximum strength and resistance to wiping. The resistance to moisture and ultraviolet radiation is also very important.

The technology of painting floors is for the most part similar to the process of painting the facade. Here it is also important to properly prepare the surface: clean the wood from dust, cover cracks and defects with putty, and eliminate unevenness.

Work begins with the edges of the room. So that during the painting of skirting boards not to stain the walls, their edges are covered with masking tape. Further, paint is applied over the entire area using a roller or a wide brush. The floor surface is covered with a uniform layer so that the wood does not shine through and dark areas are not formed. After the paint dries, it is recommended to re-brush the entire floor.

This will help consolidate the result and make the surface more uniform. So that the coating lasts longer, it can be opened with a layer of protective varnish.

Coloring of furniture, doors and other decorative elements

Painting of wooden products inside the house is carried out using absolutely any coloring compounds. Wooden elements are well polished, if necessary they are putty, degreased and covered with paint. If we are talking about doors and furniture, then all glass and mirror surfaces are removed or sealed.

Very often for homework use spray paints in spray cans. This method is convenient when painting small and inaccessible places. The paint is sprayed evenly at a distance of 25-30 cm. Particular attention is required to the surface on which white paint for wood will be applied. It strongly displays the structure of wood, therefore, in order to achieve a uniform glossy effect, it is necessary to apply an even and thick layer of putty along the entire length of the product.

Use of a spray gun

To simplify and speed up the staining process will help special equipment for painting wooden products - spray gun. Pneumatic spraying allows you to create the highest quality coating. However, using this technology, it is very difficult to apply the paint evenly. Even the most experienced specialists cannot guarantee the absence of sagging, especially in the places where the boards are joined, where excess solution is almost always collected.

For this reason, the spray gun is not used when applying transparent compositions that make such defects very noticeable.

Helmet spray technology

The surface to be painted is conventionally divided into zones A, B, C, where sector A is considered the most important area. Lastly, they start painting it, when the master gets used to working with the spraying tool.

The gun trigger is pulled exclusively at the edge of the zone, moving in the direction of the wood fibers. It is very important to maintain the same distance between the sprayer and the surface, to prevent the tool from tilting and to move it at the same speed. The trigger is released only when the torch approaches the edge of the area to be painted. Inspect the work in bright light, in case of detection of defects paint over them already at a higher speed.

How to calculate the required amount of paint

Before starting repairs, it is very important to correctly calculate the right amount of paint. When finishing wooden surfaces, it is necessary to take into account such a property of the material as the ability to absorb liquid, therefore it is necessary to cover it in 2-3 layers. Manufacturers of coloring compounds indicate on the packaging their approximate consumption per 1 m 2, so all that a consumer needs is to correctly calculate the surface area that will be painted. On average, 1 square meter requires 0.05 liters of funds. Thus, for three-time staining of 10 m 2 you will need 1.5 liters of paint.

When undertaking work on painting wooden surfaces, one should heed the recommendations set forth in this article. This will help to avoid unwanted mistakes and make a quality coating that will have a beautiful appearance and extend the life of the product itself.