Maintenance (TO) of the car body. Car body repair of any complexity Elimination of minor scratches on the body

One of the important issues of car body repair is painting, which should be carried out in accordance with the repair technology and with the help of properly selected materials: fillers, primers, paints and varnishes. The main task of repair painting is to restore the factory paintwork while maintaining the main functional characteristics (mechanical strength, corrosion protection, etc.), as well as achieving maximum compliance of the repaired area in color and structure with the original body paintwork. The repair must be invisible.

Consider the main technological stages of body repair: washing and degreasing, cleaning the surface, puttying, applying primers and finishing coatings.

With the help of a wide range of professional body repair products, you can carry out high-quality preparation for painting and do-it-yourself car painting. If the technology is followed, the result will be impressive. And the acquired skills will help you quickly and without extra cash costs to paint the entire car or only damaged parts.

The materials included in the repair system must meet the following requirements:

good adhesion
corrosion protection
leveling (filling) ability
color for discreet repairs
appropriate gloss level

Obviously, all these factors are closely related. In order to select the optimal repair system, a good knowledge of body repair products and their characteristics is essential.

What materials are needed for a standard repair with painting?

As a rule, self-painting of some parts of the car may be required if, for example, scratches or scuffs appear on the bumper, as well as doors, due to careless parking. It is not always necessary to immediately contact the service station, sometimes the situation can be corrected on their own. It will be enough to correctly estimate the scale necessary repairs and choose high-quality materials for preparing the surface for painting and painting the car itself. If the damage is minor, you can limit yourself to a set of simple standard repair operations:

Putty
Ground Leveler
Finish: synthetic, acrylic or polyurethane enamels
Finishing coat: base paints under varnish

What is included in the full cycle repair with car painting?

If you had to deal with serious damage, which, moreover, was not repaired in a timely manner, most likely you will have to carry out a full cycle repair with subsequent painting. This process will take longer (especially if rust needs to be removed) and requires the following materials:

Epoxy primer
Putty
Corrosion protective primer
Ground Leveler
Finishing coating - enamels
Finishing coat - base paints under varnish

Do not forget that the selection of products for preparing the car surface for painting also depends on the material from which the repaired part is made (steel, galvanized steel, aluminum or plastic) and on the type of old paintwork (hard or soft).

Currently, many manufacturers make their car bodies from galvanized steel and aluminum. This provides higher corrosion resistance and durability, but at the same time requires the use of special repair materials. There are a number of products suitable for application to galvanized steel and aluminium.

Any type of body repair requires careful and correct execution certain sequence of operations. A missed or incorrectly performed operation can lead to various defects in the paintwork.

Proper preparation of a car for painting: step by step instructions

Washing

We clean the place for painting

Degreasing

Putty application

grinding

Degreasing.

Ground camouflage.

Degreasing

Application of etching soil

Application of primer-filler

Drying

Removing the disguise.

grinding

Degreasing

Camouflage for paint

Degreasing

Applying paint / varnish

Drying

Removing the disguise

Assembly

Polishing

Washing

Dust, dirt, road salt, grease, etc. are the main enemies of any paint system. Therefore, in any type of body repair, the first operation is a wash.

Stage number 1. Washing

Why do we need washing and degreasing a car when preparing a surface for painting:

to remove various salt compounds, dirt, grease, etc. (due to unwashed salt, a defect such as “bubble” may occur);
for optimal adhesion of the repair coating (dirt that is not washed off clogs into scratches when stripping);
to save materials, time and money (due to the dirt that has got on it, the abrasive material quickly clogs and fails - grinding time increases);
to exclude the possibility of craters (the dirt remaining in the risks after stripping may contain fats or silicones);
to exclude low gloss (due to the grinding product remaining in the risks).

Stage number 2. We apply masking and clean the surface for painting

When the car is washed, you can safely proceed to the preparation of the surface for painting. To do this, we designate the place where the painting work will be carried out. If we paint a separate part, its borders must be pasted over with masking tape and thick paper. Then you need to clean up the defects (chips, scratches) with sandpaper (grain size P150-P280). This will remove layers of old paintwork and smooth out the edges.

Stage number 3. Degreasing

Always use two clean wipes when degreasing - the first wets the surface, the second (dry) removes the contaminants dissolved in the degreaser;
Degrease in small areas (approximately 50x50 cm) in order to have time to wipe with a dry cloth until the degreaser evaporates;
Carry out degreasing immediately before applying the material;
During degreasing, the surface cools, so you need to allow time for the temperature to equalize (condensation may occur);
It is necessary to degrease in personal protective equipment: rubber gloves, a respirator, goggles.

Degreasing is a mandatory step in the process of surface preparation for painting, and it must be carried out before applying each subsequent layer.

Stage number 4. Puttying

If the car has chips or deep scratches, before painting the car, you will have to use putty to level the surface. The putty is the thickest layer in the system, so it is the putty that influences the final shape of the car body. When puttying, special attention must be paid to the choice of polyester putty and to the preparation of the surface for puttying.

Surface preparation for putty

Sanding before applying putty	Grind to metal - P120 circles, then smooth out the boundary edges P220
Shaping putty	Sheets P120-P180 on grinding with dust extraction
Preparation for primer leveler	Wheels P220 - P280 - machined
Preparing a new panel for wet-on-wet ground	P320 wheels - machined
Sanding before applying paint	Waterproof sanding paper P1000 - hand sanding Dry sanding paper P320 - P500 - machined

Improper preparation of the surface for putty can subsequently lead to such a defect in the paintwork as contouring. You can avoid this by following the following technology:

Clean the degreased surface down to metal ;
Smooth out the edges of the stain of the repair area by thinner .

The choice of putty

When choosing a putty, you should pay attention to the nature of the damage (the size and depth of the dents, a hole in the body panel, etc.) and the type of surface (steel, galvanized steel or aluminum).

Basic rules for applying putty

Apply putty only to bare metal or epoxy primer.
Follow the correct proportions when mixing with the hardener (maximum 3% hardener) - otherwise, with an excess of hardener, molecules will remain that have not reacted with the putty.
Mix very thoroughly with the hardener.
Never sand the putty "wet", as it is hygroscopic.
Soil application.

Hardeners

The hardener affects primarily the speed of hardening of the product. Therefore, the drying time of the product will be a decisive factor when choosing a hardener. Hardeners are mainly of three types - slow, standard and fast. It is very important to observe the correct proportions when mixing any paint product with a hardener:

With a lack of hardener, curing (polymerization) will not occur completely.
With an excess of curing agent, the curing agent molecules may react with another substrate. For example, with water (moisture), causing loss of gloss of the paintwork. Remember that hardeners are the most sensitive of all products to humidity and low temperatures. Therefore, never leave a can of hardener open and observe the temperature conditions for storing and transporting hardeners.

Stage number 5. grinding

Before painting a car, any paint and varnish coating should be applied to a well-degreased and sanded surface. With the help of grinding, we make the surface "rough". The many thousands of small scratches resulting from sanding increase the surface and this ensures optimal adhesion of the coating to the substrate.

The time spent on surface grinding takes more than 50% of the total repair time. For this reason, this part of the work should be as efficient as possible.

When carrying out grinding work, pay attention to the following points:

Choice of type of grinding: dry or wet, manual or mechanical.
Selecting the appropriate sander for the type of work being done: orbital, eccentric or surface sander.
Choice of abrasive material and grinding steps.

Is it possible to do without sanding a car before painting?

We have already said that the sanding process, performed in good faith, guarantees half the success of all paint jobs. During grinding, all irregularities are removed and a risk is created for better adhesion of each new layer of material with the previous one. We list the main points on which the grinding stage should never be skipped and why it is needed:

To improve surface adhesion with subsequent applied materials
To create the desired shape and surface
To remove old coating

Dry or wet sanding

Dry grinding is the most advanced and promising and has a number of advantages compared to wet grinding:

Time saving
Material saving
Elimination of the possibility of corrosion
Exclusion of absorption and saturation of processed materials with water
No need to wait for the water to completely evaporate
Less harmful to health (in the version with dust extraction)
More diverse range of equipment for mechanical dry grinding
Significantly wider range of abrasives for dry grinding
For high-quality repair, the use of high-quality abrasive materials is necessary.

Choice of grinding steps

Do not sand polyester materials (fillers) with water. Grinding of this type is allowed only at the stage of processing the leveling soil.
When grinding, it is necessary to follow the correct steps in reducing the grain size of abrasive materials (each step in reducing the grain size should not exceed 100 units).
The abrasive material must be with the sign of the international standard, which indicates the quality and uniformity of the grain.
Border zones should overlap.

Stage number 6. Padding

Primers provide corrosion protection, level the surface and create good adhesion between the substrate and the finish coat. They are etching and acrylic primers.

Purpose of primary soils:

Corrosion protection.
Ensuring adhesion of the surface and the basis of the subsequent coating.

Appointment of primers-fillers:

Filling scratches from abrasive material, irregularities, leveling the surface.
Base for subsequent paint application.

How to work with soil?

Use a measuring ruler when mixing.
Thoroughly mix the soil before dilution.
If the primer is tinted, then paint is first added, and then a hardener and solvent are added to the resulting volume in the appropriate proportion.
Do not attempt to extend the pot life of the product by adding a solvent.
Apply layers correctly - inside the stain to avoid overspray.
Observe the correct drying intervals between coats and do not speed up the drying time between coats by blowing - the solvent is blocked by a film and “boiling” occurs.
Use either dry or aerosol developer before sanding.
Never use primers beyond the specified pot-life after mixing.
Do not paste too close to the priming area.
Make sure that the primer is completely hardened (risk of deep scratches during sanding and settling).

Stage number 7. Base/enamel application

When the preparation of the surface for painting is completed, you can proceed directly to painting the car. In fact, this step will take you much less time than those described above.

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Introduction

Under the influence of natural, climatic and anthropogenic factors, as well as the human factor, the integrity of the body is violated: damage as a result of traffic accidents, corrosion, warping. To restore the car to the original or close to the original body repair is carried out. The main task of body repair is the restoration or replacement of body parts. But before doing repairs, it is necessary to design the site on which this repair will be carried out.

Technological design is a very time-consuming process, the operation of this site, the profit of the enterprise where it is located, entirely depends on it. It systematizes a large and diverse range of organizational, technological and economic issues. Their study will help the young mechanical engineer road transport it is enough to present and master almost all the questions.

The purpose of the course project: development technological process TR of car bodies.

To this end, it is necessary to solve the following tasks:

1. Develop a technological process for TRing car bodies.

2. Perform technological calculation of a specialized section according to TR of car bodies.

3. Select equipment for a specialized area according to TR for car bodies.

1. Development of technological process TR of car bodies

The body is a part of a car or other vehicle designed to accommodate passengers and cargo.

Body repair in its current state, in terms of technological complexity and cost of equipment, it is not inferior to such serious areas as the repair of engines or electrical equipment. In addition, over time, the complexity of the geometry of hulls increases, new color effects of finishing coatings appear, and the requirements for corrosion resistance of coatings increase. All this requires the improvement of repair technology.

Nowadays, dozens of pieces of equipment can be used by bodyshops, from a hammer to a draft stand, and each tool can be selected from a variety of representatives of its class. There are about ten painting systems that have worldwide distribution, each of which has its own pros and cons. In addition, there is a large selection of auxiliary materials and devices that facilitate certain operations. The right choice of workshop equipment, as well as the painting system, determine the future success of the enterprise, and right choice technological chain in each specific case - saving the client's time and reducing the cost of the enterprise.

In figure 1 you can see the basis of the body of a modern passenger car mobile. Reinforcing elements are visible in the cab floor, in the engine and front suspension mounting area, as well as in the trunk area and rear suspension. In addition, it becomes clear which body parts are included in the base and which are mounted: there are no mounted ones in the figure.

Figure 1 - The base of the car body

1.2 Malfunctions of body elements

The main malfunctions of the car body are its mechanical (dents, holes, cracks) and corrosion damage, destruction of the paintwork and anticorrosion coating.

Mechanical damage occurs in traffic accidents and when driving at high speeds on rough roads. The most destructive damage to the body is in frontal collisions and collisions with the front part of the body at an angle of 40 ... 45 ° or from the side. Such collisions usually occur between two moving vehicles whose speeds add up. In this case, the car body is destroyed, especially its front part, and the large loads acting in this case in the longitudinal, transverse and vertical directions are transferred to all closely spaced parts of the body frame, especially its power elements.

Up to 6% of the country's car park are annually involved in traffic accidents of varying complexity. Some of the collisions are minor and do not cause significant damage to body parts. But the bulk of damaged bodies requires the involvement of qualified specialists with the necessary skills and experience in body repair, special tools and equipment to perform restoration work.

The most devastating damage to the body occurs in collisions with the front of the car. Such collisions occur, as a rule, between two vehicles moving towards each other, the speeds of which are added upon impact. The amount of energy released on impact is enormous. This energy is absorbed by the deformation of the car in tenths of a second. In such collisions, the body of the car is destroyed, especially its front end. The large loads acting in this case are transferred to all adjacent parts of the body frame, and through them to the front parts of the entire body. The energy released during the impact is absorbed during the deformation of the spars, mudguards, thresholds and the floor tunnel. The gaps in the openings of the front doors, which are pressed by the front pillars, are reduced. The front doors through the hinges and locks press on the central pillars and so on until the impact energy is completely absorbed. Corrugations are formed on the thresholds, the floor tunnel, the roof panels. There is a general distortion of the base and body frame. The attachment points of the transmission and engine assemblies change their location. The absorption of impact energy cannot cause shrinkage and thickening of thin metal such as a sheet, so large folds are formed in the impact zone or the metal is pulled out when dents are formed. The degree of damage to the body and the amount of subsequent repair vary significantly, with seemingly equal collision conditions. Slight changes in speed or angle of impact, vehicle weight or force application, vehicle design or road conditions, vehicle age, etc. significantly different volumes of repair are obtained.

Damage to the body in an accident is light, medium and severe. Depending on the degree of damage, the straightening method and tool are selected. Classic car body straightening is not a very complex science, but requires certain skills for medium and severe damage.

Light damage - the consequences of inattention when maneuvering or parking, carried out at low speed. Removing minor damage, as a rule, takes no more than a few hours. The work consists in preparing the damaged surface for painting, followed by painting.

Light damage to the body, in most cases, can be removed with improvised means, such as: rubber and metal hammers, levers, mandrels. Light damage to the metal, with a whole paintwork, can be eliminated with a minilifter. This is a dent removal tool. body repair technological calculation

The tool base for removing dents without painting has a number of specific tools, which are divided into several groups.

Figure 2 - Tools for removing dents without painting

The first group includes hooks or levers, this is the main tool that allows you to carry out repairs in hard-to-reach places.

The use of one or another hook is determined by the location of the defect, in each case the master chooses one or another hook for high-quality dent removal.

Hooks or levers are made of high-alloy steel, have a different diameter and bend of the rod, the handle is made of high-strength plastic.

Figure 3 - Hooks or levers

The second group includes knives for removing sealant in hard-to-reach places. With the help of a knife, the body sealant is removed, which interferes with the implementation of high-quality repairs. Also indispensable devices is a lamp with a vacuum clamp for quality control of the repair surface.

Figure 4 - Sealant removal knives

Figure 5 - Lamp with vacuum lock

The third group of tools includes a mini-lifter with a set of pistons and special adhesives for external pulling out of dents, to which there is no internal access.

Figure 6 - Minilifter

Thanks to this tool, minor irregularities are quickly leveled. As a rule, it takes no more than an hour.

Before proceeding with the repair, it is necessary to assess the degree of damage, determine the ways and steps for further action. To gain access to hard-to-reach places, you will have to dismantle decorative panels, lights, handles, sidelights, seals. Next, you need to install the lamp at a convenient angle to observe the behavior of the defect. The technology is based on the principle of impact with inside, to restore the geometry of the body part. As we know from physics, a metal sheet has a molecular memory, which allows us to ultimately achieve a perfectly smooth surface.

To remove a deep dent, glue the plastic caps included in the minilifter kit.

Figure 7 - Plastic caps

Figure 8 - Reverse hammer

Figure 9 - Extraction with a reverse hammer

Figure 10 - Extraction with a reverse hammer

It should be noted that it is impossible for minilifters to completely restore the surface, so you will have to use hooks and levers to control the behavior of the dent with a suction cup lamp.

Figure 11 - Dent behavior control

Regular straightening a car takes much more time, as a different technology is used, which requires a different approach to business.

Medium damage - collisions at low speeds, when the body part can be restored by straightening. Such damages include: a broken wing arch, creases on the roof, hood, and so on. Probably, the damaged element will have to be dismantled for further restoration of geometry, preparation for painting, painting and installation of the restored element in its rightful place. Elimination of medium damage to the body takes from one to several days. In this course project, I will give an example of using a spotter.

Spotter (from the English spot - “point”) is a one-sided spot welding device, which has found its application precisely in the repair of car body panels. Spotters with electronic control welding modes are usually called digital.

The most relevant is the use of a spotter when repairing bulky body parts that are difficult to get close to from the back (doors, thresholds, etc.). The spotter allows you to weld a fastener to a damaged surface, for which you can really pull out a dent, without wasting time on disassembly and assembly. Also, with the help of a number of spotters, you can heat the metal, which, with some minor damage, makes it possible to do without stretching at all - the metal itself takes on its previous shape.

Figure 12 - Spotter

Figure 13 - Spotter kit

1. To start work, you need to clean the work surface. All places of contact between the washer and metal must be thoroughly cleaned of paint and other materials.

Figure 14 - Cleaning the work surface

Figure 15 - Cleaned work surface

2. The repair part must be attached to the ground, if the part is not removed from the car, must be disconnected battery to avoid shorting the electronics.

3. With the help of a “spot gun”, we weld fasteners in the right places, for which we will “pull” the metal. (It can be washers, studs, "snake", triangles, etc.)

4. With the help of a reverse hammer, we pull out the necessary places. Other tools can also be used, for example: hydraulics, cables, chains, slipway.

5. Washers and rings that have acted as a "hook" can be easily removed with a twisting motion.

6. In the end, all that remains is to clean up the place of welding and start filling the car.

The most difficult blows are side and frontal. Usually in such cases, the geometry of the car body is greatly distorted. It is possible to perform such work qualitatively only with the availability of special equipment. In such situations, the slipway is used.

Stapel - equipment for restoring the frame and geometry of the car body, a device that allows you to straighten the body to the standard parameters by applying multidirectional efforts. A car is fixed on it in order to check the condition of its bottom and perform the necessary work on inspection and replacement of parts. The second name that a professional slipway has received is a body stand or straightening stand, which gives a complete picture of the area of use of this type of equipment. It is extremely difficult to do without it - it allows not only to establish the cause and nature of the malfunction, but also to outline a repair plan and control its quality, both in the process and after completion of all necessary operations.

The scope of the slipway is quite wide: it is used both for fixing minor breakdowns, and for more serious and lengthy work - restoring a car after an accident or rollover, guaranteeing the car owner an attentive attitude to the problem and a wide range of basic and additional services. The slipway allows you to significantly reduce the time spent on car repairs, provide access to parts and mechanisms located both near the bottom and inside the body, which are extremely difficult to reach under normal conditions and is possible only if the car is partially disassembled, which slows down the repair process and automatically increases its value. And after all repair work completed, the slipway provides the ability to monitor the vehicle's performance, if necessary, correct it.

The slipway has a relatively small size and minimal weight, it will easily fit even into the limited space of the service center. But at the same time, he is able to easily lift passenger cars into the air, the mass of which significantly exceeds his own mass. Strong fixation of the car and its protection against falling is provided by a special fastening system that has undergone rigorous testing for strength and reliability. At the same time, the slipway design eliminates damage to the car body or violations of its geometry both in the process of fixing and during repair work. In addition, it allows the use of sophisticated measuring technology during the repair process in order to establish the existing body geometry parameters with high accuracy and restore them to the required values.

Another important advantage of the slipway is the ability to create conditions for a more affordable repair of spare parts and car body, while in the absence of the necessary equipment, it is necessary to change a non-working part, which entails large expenses. The presence of a body stand in a car repair shop is a guarantee of reasonable prices for car repairs and maintenance.

The use of a slipway with special control stands guarantees the correct position of the base points of the body, and this significantly improves the quality of repairs and labor productivity. The slipway consists of a base, a device for straightening a car body, a set of supports and a set of tools.

Fastening of the car body at the control points is provided by installing a set of interchangeable stands located on the transverse beams. Interchangeable supports provide the possibility of replacing body parts and are used in this case as base elements for determining the main overall dimensions of the body elements. This also allows the slipway to be used as a conductor for welding. For more reliable fastening, two clips are used for flanging the bottom of the body. Beam 2 for editing is fixed anywhere along the periphery of the support frame with wedge grips. The lever is connected to the beam at two points by means of a hinge, and through a hydraulic cylinder, and the lever is rotatable in the horizontal and vertical planes. The pressure in the hydraulic cylinder is generated by a pump.

Figure 16 - Building berth

Figure 17 - Building berth

Figure 18 - Slip for bodies

The body to be repaired is placed on appropriate supports and secured to them using locating pins and screws. One of the tools of the set is fixed on the damaged area and connected by chain 6 to lever 1. The pump drives the hydraulic cylinder rod and lever 1, which pulls the crumpled parts of the body through the chain in the right direction to the right size. For the final editing of individual elements, hand tools are used. If it is impossible to stretch and straighten some parts, then these parts are completely replaced by installing the replaceable elements at the control points of the slipway and their subsequent welding. The slipway is smaller overall dimensions in comparison with the R-620 stand, compactness and mobility in the production of work. In addition, it allows you to restore bodies with large violations of geometric dimensions, which were previously considered unsuitable for restoration.

The service stations use special tools and devices to increase labor productivity and improve the quality of repair work. To remove sections of panels and replace body plumage elements that have significant mechanical damage and corrosion damage, a pneumatic hammer with a set of special cutters is used (Fig. 6). Providing high productivity when cutting metal, the pneumatic hammer allows you to get edges good quality with a slight deviation from the applied markup. During the operation of the body, gas, electric arc, electric contact welding and in a shielding gas environment are used.

A characteristic feature of body assembly during repair is that the installation of parts on the body (wings, panels, inserts, etc.) is associated with their fitting in place. Using a set of special clamps for fast fastening and detachment of parts can significantly reduce the auxiliary time when installing parts. Shown in fig. 7 Clamps are available in four different gripping jaws. Clamp a is used to fasten parts of various configurations together, 9 for example, a sheet and a round bar, a round bar and a hexagon, etc. The clamp is designed to fasten large panels in case of a risk of warping during welding. The clamp is used practically for fastening all elements of the body plumage. Clamp g allows you to capture parts in hard-to-reach places hidden by large flanges. For the final dressing of individual body elements, a manual dressing tool is used. Body repair using special equipment makes it possible not only to increase labor productivity and production culture, but also to expand the list of services provided by service stations to car owners.

Figure 19 - Pneumatic hammer and a set of cutters

Figure 20 - Clamp for fastening body parts

Wrinkled areas on body door panels are repaired different ways depending on the location of the damage and its size. To straighten small dents on the outer door panel, use holes and mounting hatches in the inner door panel or pierce a special hole with a beard. Insert a support, screwdriver or appropriate spoon into the existing or obtained hole and squeeze out the dent until the surface of the outer panel is leveled. If necessary, the dent is finally leveled with solder or plastic and cleaned flush with the base metal of the panel.

When repairing the outer panel of a door that has large dents, metal deflection with tension, deflection with sharp transitions or the presence of cracks and breaks, it is partially replaced. To do this, using a hacksaw, a slotted grinding wheel, a chisel or a gas burner, cut out the outer lining and remove the damaged panel. Then the door frame is corrected, gaps and cracks are welded, and if necessary, these places are strengthened. According to the existing template, a blank of a new panel is cut out and installed in place. Attach the outer panel in several places to the frame and to the remaining part of the panel by welding. Then they are adjusted and checked along the doorway of the body. After that, finally welded new part panels with a gas burner. The resulting welds on the outer surfaces are treated with abrasive wheels, and then finally leveled with solder or plastic. Stands are used to fix doors during repairs.

Wrinkled areas on the wings, hood, trunk lid, mudguards and other body parts are corrected by punching and straightening, filling irregularities with solder or plastic, and heavily dented and rusted areas are replaced with new elements.

The process of preliminary alignment of dents is performed in the following sequence. The part is laid on the plate with a surface having a dent, and with the blows of a straightening hammer it is knocked out to the level of the undamaged part of the part. Then, with a wooden or rubber mallet, trim the surface. After preliminary leveling for the final finishing of the panel and giving it smooth surface apply straightening. Parts are straightened manually, using machine tools and pneumatic hammers.

For manual straightening, straightening hammers, supports, stands with supports corresponding to the profile of the concave surfaces of the repaired parts are used. Working on a stand with a fixed support greatly facilitates the work of a tinsmith, since there is no need to hold the support and it becomes possible to easily move the straightened part along the support surface. For straightening, straightening and stripping the body, use a set of hand tools. In cases where the metal is stretched, local heating of the part is used to simplify the correction of dents.

Before proceeding with the elimination of body skew, its value is determined by comparing the damaged area with the same undamaged one, or a template is applied, made according to the shape of the opening in the body, for example, under the wind or rear glass. Distortions of the front spring brackets in relation to the rear and to the axle of the body are checked with templates.

Distortions are corrected mainly in a cold state with the help of mobile mechanical or hydraulic stretch marks. Mechanical is a pipe, at the ends of which threaded bushings are welded - one with a left-handed, the other with a right-handed thread. On the free ends of the screws screwed into these nuts, they put on and fix the heads with the help of conical pins. The heads are shaped to match the profile of the stretchable surfaces. In the middle of the pipe there is a through hole into which a rod is inserted to rotate it; while the screws respectively converge or diverge.

Stretching with a hydraulic device for correcting body distortions consists of a hydraulic cylinder, on one side of which an extension tube is screwed, and on the other, an additional lever with a rubber head. The plunger, on the outer end of which a rubber head is mounted, is driven by hydraulic pressure generated by a hand pump. A hydraulic device with a hand pump can generate a force of up to 10 tf.

Ties differ from extensions only in their mandrels, the working part of which is made according to the profile of the parts to be tightened. When installing stretch marks in the body, one head should rest against a fairly rigid base, and the other will allow you to correct the skew.

Some types of curvature on the doors, the roof of the trunk are corrected with screw clamps with appropriate linings. Cracks and breakages existing or formed as a result of stretching are welded, the welding spots are cleaned, after which the parts are finally straightened. To increase strength in places of body cracks, linings are welded, made of sheet steel with a thickness of 1-2 mm and fitted in place of the body from the non-front side.

The entire process of repairing and assembling a car body before painting is divided into separate operations. The sequence of body assembly operations depends on the design and occurs in the reverse order of disassembly. Initially, repaired metal parts or new spare parts are installed, then the body is painted, an anti-corrosion coating is performed inside and out. The final operations for the installation of units, electrical equipment, upholstery and fittings are performed after painting the body, mainly at the same work stations where disassembly operations were carried out.

Another factor in the failure of bodies in operation is corrosion - the destruction of metal when interacting with the environment. Corrosion develops especially strongly in places that are difficult to access for inspection and cleaning. These are closed cavities. load-bearing body, structural pockets, sinuses, flanging, hemming, welds, etc., where moisture, dust, salt solutions periodically get in and remain there for a long time, gradually and inevitably converting the metal into rust. Atmospheric pollution by emissions from industrial enterprises, vehicle exhaust gases and saline solutions from roads greatly accelerate corrosion processes.

Corrosion of a car is the destruction of metal parts of a car (bodywork, etc.) under the influence of an aggressive environment, due to irrational design and careless handling.

The car can be subjected to both chemical corrosion and electrochemical. A striking example of chemical corrosion is the destruction of the exhaust tract of the engine under the influence of exhaust gases. Also, gas chemical corrosion of a car can be observed in its fuel system if impurities of hydrogen sulfide, mercaptans, elemental sulfur, etc. are present in fuel liquids. This corrodes the metal bearing shells.

But in most cases, the car is still susceptible to electrochemical corrosion, which affects more of the constituent parts of the car and takes place only in cases where an electrolyte is present on the metal surface. Studies have shown that under atmospheric conditions, a film of moisture is always present on the surface of any metal. Its thickness depends on temperature, air humidity and other indicators.

Any metal surface of a car is electrochemically inhomogeneous (some areas have a difference in electrode potentials). The surface with a lower value of the electrode potential (in contact with the electrolyte) becomes anodic, and with a large value - cathodic. Each pair of heterogeneous sections forms a short-circuited galvanic cell. There are a lot of such working galvanic cells on the surface of the car. In this case, only the anode sections are destroyed. The potential difference can occur for many reasons, which can be read in articles about external and internal factors of electrochemical corrosion.

If the metal surface is not protected, then there are always conditions for the occurrence of corrosion processes. The car can be subjected to local (spotting, pitting, filiform, through, intergranular, pitting, subsurface) corrosion damage.

Corrosion damage occurs due to the spontaneous destruction of metals as a result of their chemical or electromechanical interaction with the external environment, as a result of which they pass into an oxidized state and their physicochemical properties change. According to the mechanism of formation and course of the corrosion process, electrochemical and chemical corrosion are distinguished.

Electrochemical corrosion occurs when two different metals form a galvanic cell in the connection. Such corrosion can also occur when there is no contact between different metals with each other. The steel from which the body is made corrodes with water and oxygen. On the surface of the body there are areas with different electrode potentials, which is associated with local deviations in the chemical composition of the metal, leading to the formation of galvanic microelements. The rate of the process of electrochemical corrosion increases in the presence of pollutants, salts and acids in the environment.

Chemical corrosion occurs as a result of the oxidation of metals under the influence of atmospheric oxygen, salts, sulfur compounds.

Figure 21 - Corrosion of the car body

2. Technological calculation of the body shop for the repair of cars

2.1 Initial data

The initial data for the technological calculation of the project are taken on the basis of the results of the marketing research, i.e. for 2015; part of the data is selected from the statistical information. Initial data are given in Table 2.1.1

Table 2.1.1 - Initial data for technological calculation

Name	Designation	Meaning
Brand of serviced vehicles	cars
The number of arrivals of one car per year at the service station
Average annual mileage of serviced vehicles, km
Number of serviced vehicles per year, pcs.
The number of potential customers whose cars need to be carried out body work, PCS
Average labor intensity of light body repair, person h
Average labor intensity of repairing a medium-damaged body, people h
Average labor intensity of a complex body repair, people h

2.2 Mode of operation of the body shop

The mode of operation is characterized by the number of working days per year, the duration of the shift and the number of shifts. At the same time, the mode of operation should be selected based on the most complete satisfaction of the needs of the population in services with minimal production costs. The values of the listed characteristics for the reconstructed service station are given in Table 2.2.1

Table 2.2.1 - Service station operation mode

Based on the data in the table, we are able to determine the fasting time fund, h:

D work.G T CM S, (2.2.1)

255 1.5 8=3060h.

2.3 Calculation of the annual volume of work of the body shop and the number of vehicles serviced

According to statistics, 70% of body repairs are light repairs, 23% - to eliminate distortions of medium complexity, and 7% of work - to eliminate complex and especially complex damage to the body.

Thus, taking into account the data obtained and the data in Table 1, we determine the number of cars that can be serviced on the projected site.

The calculation data are presented in Table 2.3.1.

Table 2.3.1 - Distribution of the scope of work by type of repair and forecast of the number of serviced vehicles

Let's determine the number of work posts for the reconstructed area:

Where?? - coefficient of non-uniformity of cars entering the body section;

The average number of workers simultaneously working at the post, people;

The coefficient of use of the working time of the post;

b - share of guard work;

Annual volume of body work.

We accept: ??=1; ; ??=1; b=1.

Let's take the number of working posts = 1.

The annual volume of acceptance and delivery of vehicles, man-hours, is determined by the formula:

where is the one-time labor intensity of work on the acceptance and delivery of cars, man-hours. Accept =0.5

By formula (3) we find:

Find the annual volume of auxiliary work, which is determined by the formula:

where b VSP is the share of auxiliary work, we accept 10%.

2.4 Distribution of annual volumes of work on the site

The annual volume of work of the TR section of passenger car bodies is distributed in accordance with the formula (5):

Table 2.4.1 - Distribution of the scope of work by type and place of their release

completion

Type of work	Scope of work
		At posts


Reinforcing

Harvesting and washing works are carried out before TR; they can be considered as an independent type of service, at the rate of 1 car arrival per 800 - 1000 km of run.

The annual volume of cleaning and washing work of city service stations, man-hours, is determined by the formula:

One-time labor intensity t U.M. (accepted according to Appendix A, Table A.1); for cars of an especially small class, we accept t U.M. = 0.15 man-hours

Table 2.4.2 - Distribution of auxiliary work

2.5 Calculation of the number of employees on the site

The technologically necessary number of workers at the body post, man-hour, is determined by the formula:

where T G - the annual volume of the type of work at the post.

F T is the time fund of a technologically necessary worker, equal to 2024 hours.

To determine the regular number of workers at posts, the time fund of a full-time worker is first established:

1832 hours for washers, cleaners, maintenance and repair mechanics, motorists, electricians, tire fitters, machine operators, carpenters, upholsterers, fitters, tinsmiths;

The number of workers at a post or in a workshop is determined by the formula:

The calculation results are entered in table 2.5.1.

Table 2.5.1 - Number of workers at posts

Type of work	At posts
			R ShP calculated, pers.	R ShPP accepted, pers.	T C man-h.	R ShTs estimated, pers.	R ShPC accepted, pers.
Body and aggregate (tin, copper, welding)
Reinforcing
Cleaning and washing
Total number of workers	At the posts? R ShPP = 2	In workshops? P ShPC = 0

Table 2.5.2 - Number of auxiliary workers

Type of work	T VSP i person-h.	R W calculated, pers.	R ShP accepted, pers.
Repair and maintenance of technological equipment
Acceptance, storage and issuance of material assets
Cleaning industrial premises and territories
Car driving
Acceptance and delivery of cars
Total number of support workers?R GSP

2.6 Calculation of the number of posts and car-waiting places

The number of working posts for the i-th type of work is determined by the formula:

Body and assembly (tin, copper, welding) works:

Reinforcing works:

where T P i - the labor intensity of guard work of the i-th type, person-h;

P CP - the average number of employees at the post.

To determine the number of cleaning and washing posts, the daily number of car arrivals is first calculated using the formula:

The number of cleaning and washing posts during their mechanization is determined by the formula:

where c U.M. - coefficient of non-uniformity of the arrival of cars at the site of cleaning and washing works (for a site with up to 10 working posts u U.M = 1.3-1.5);

T U.M. - working hours of the cleaning and washing works area;

N U.M. - the productivity of the washing plant (accepted according to its

passport);

h - the coefficient of use of the working time of the post, equal to

The calculation results are entered in table 2.6.1.

Table 2.6.1 - Number of working posts


Body and aggregate (tin, copper, welding)
Reinforcing
Cleaning and washing
The total number of work posts? Х Рп i

The number of auxiliary posts is determined by the formula:

The number of auxiliary posts also includes receiving and issuing posts, the number of which is determined by the formula:

where all parameters are taken in relation to the points of acceptance and issuance.

The number of car-waiting places (places for cars waiting to be placed at work or auxiliary posts) is determined by the formula:

The number of car-places of storage (accepted for repair and ready for delivery) is determined at the rate of three car-places per one working post according to the formula:

The number of car-storage places of a road service station is determined by the formula:

Number of car storage spaces per open parking store is determined by the formula:

where D 3 - the number of days of car stock in the store; usually take

d WORK.M - the number of days the store is open.

The number of car spaces for staff and clients in an open parking lot (located outside the station) is determined by the formula:

3. Equipment selection

The requirements for two-post lifts are best met by the following:

- Two-column lift Stankoimport PGN2-4.0(B);

- Two-column lift Peak 208;

- Two-column lift LAUNCH TLT235SB;

- Lift Peak 212.

We will choose a specific model of the lift by determining the value of the compliance of a piece of equipment with the requirements,% according to the formula:

, (3.1)

where - the value of satisfaction of a piece of equipment according to the k-th indicator;

- weight of the k-th indicator, %.

The main technical characteristics of two-post lifts, as well as the values of the quantities included in the formula (3.1) are given in table (3.1).

Table - 3.1- Technical characteristics of two-column lifts

k-value	Weight, bk, %	Two-column lift Stankoimport PGN2	Two-column lift Peak 208
		Indicator value	Ac satisfaction value	Indicator value	Ac satisfaction value
Load capacity, kg
Power, kWt
Distance between racks, mm
Lifting height, mm
Mass of the device assembled, kg
k-value	Weight, bk, %	Two post lift LAUNCH TLT235SB	Lift Peak 212
		Indicator value	Ac satisfaction value	Indicator value	Ac satisfaction value
Load capacity, kg
Power, kWt
Distance between racks, mm
Lifting height, mm
Mass of the device assembled, kg

Based on the data in table (3.1) according to the formula(3.1) we have the opportunity to determine the value of the compliance value of a piece of equipment with the requirements.

So, for the lift Stankoimport PGN2 we get:

50 1+10 1+15 1+10 1+15 0,9=98,5

for lift Peak 208 we get:

50 0,9+10 1+15 1+10 0,9+15 1=94

for lift LAUNCH TLT235SB we get:

50 0,9+10 1+15 0,8+10 0,9+15 1=91

for lift Peak 212 we get:

50 1+10 0,9+15 1+10 1+15 0,8=96.

Table 3.2 - Compliance values for two-post lifts with the requirements

Stankoimport PGN2

From the analysis of Table 3.2 it follows that the requirements for two-post lifts are more consistent with the two-post lift Stankoimport PGN2.

Equipment used in this area for the repair of car bodies.

Figure 20 - Two-column lift Stankoimport PGN2

A car lift is a special equipment for facilitating the repair and maintenance of vehicles, designed to lift cars and hold them in a raised position at a certain height, can be used in conjunction with other equipment and tools, as well as to save space in car workshops and garages.

Table 3.3 - Specifications lift Stankoimport PGN2

Figure 21 - Stand for straightening car bodies PROFESSIONAL KS-105 P-10 SIVIK

Stapel - equipment for restoring the frame and geometry of the car body, a device that allows you to straighten the body to the standard parameters by applying multidirectional efforts.

Table 3.4 - Technical characteristics of the stand for straightening car bodies PROFESSIONAL KS-105 P-10 SIVIK

Figure 22 - Spotter VS-6

A spotter is a contact welding device. In fact, the spotter is a welding machine, the principle of which is based on the emission of a significant amount of thermal energy at the point of contact of the materials to be welded during the passage of current.

Table 3.5 - Specifications of Spotter VS-6

power, kWt
Welding current, A
Voltage, V

Figure 23 - FORCE 905M4 Body Vacuum Reverse Hammer

Its purpose is to correct small dents on the pillars, sills, arches, i.e., in areas where there is no access from inside the body.

Table 3.6 - Specifications of FORCE 905M4 bodywork vacuum breaker

Figure 24 - Rubber spinning hammer MATRIX 10986

Steel balls and fine lead shot inside the case dampen rebound after impact.

Table 3.7 - Specifications of the MATRIX 10986 rubber freewheel hammer

Figure 26 - Clamp for straightening the body FORCE F62502

Table3.9 - Specifications of FORCE F62502 body straightening clamp

Figure 27 - OMAS TRK1205 hydraulic reverse action coupler

Table 3.10 - Technical characteristics of the OMAS TRK1205 hydraulic reverse action tie

Figure 28 - Hydraulic stretcher TORIN TRK0210A

Table 3.11 - Technical characteristics of hydraulic stretching TORIN TRK0210A

Figure 29 - Measuring system for body repair TROMMELBERG EMS-1-A-Light electronic

Table 3.12 - Specifications of the measuring system for body repair TROMMELBERG EMS-1-A-Light

Figure 30 - J-T16 Pneumatic Random Orbital Sander

Angle grinder with small circle diameters (115, 125, 150 mm) is designed for grinding and other similar work, and with large circle diameters (180, 230 mm) for cutting.

Table 3.13 - Specifications of J-T16 Pneumatic Random Orbital Sander

Figure 31 - Clamp for straightening the body FORCE F9M1604 with a loop

A clamp is installed at the repair site to carry out repair work.

Table 3.14 - Specifications of FORCE F9M1604 body straightening clamp with loop

Figure 32 - Professional hydraulic pump MATRIX 51325

It is intended for creation of pressure in systems with a hydraulic drive.

Table 3.15 - Technical characteristics of the professional hydraulic pump MATRIX 51325

Figure 33 - Straightening hammer FORCE 9M1501

Designed to repair dents and other defects on metal surfaces and to clean up corrosion.

Figure 34 - Leveling support FORCE F68354

Designed to support a sheet of metal from the inside during straightening.

Figure 35 - Leveling canvas

Designed for sheet metal work. Also for filing soft materials where high material removal rates and good surface finish are required.

Figure 36 - Professional figured hole punch

The puncher is intended for a punching of openings manually.

Figure 37 - JONNESWAY AB010002 047652 windshield removal kit

Figure 38 - A set of mandrels and a blade ...

Where to start body repair?

It is possible to start work on restoring the integrity of the body and paintwork only after the entire surface has been thoroughly washed and dried, and a visual inspection of the damage has been carried out. This will allow you to assess the degree of damage, the depth of damage and choose the most appropriate type of repair.

Repair is an expensive procedure that takes a lot of time and effort. The cost of work will increase if the vehicle has a long service life, and repair work has not previously been carried out at all.

Local body repair of the car will eliminate such defects:

Minor scratches and all sorts of chips on the paintwork of the car.
Small dents.
The centers of corrosion processes developing on the metal.

For various reasons, body repairs can be performed poorly. The master may not be qualified enough to carry out such work, the body was improperly prepared, or materials of dubious quality were used in the process. In addition to additional financial costs, such repairs will have other consequences:

Poorly executed straightening can cause incorrect visual perception of the car.
Body hood, which was carried out in garage conditions, can lead to a violation of the overall geometry of the body. This, in turn, will provoke a decrease in the life of car tires and various deviations in the chassis.

You can do a local body repair with your own hands, but only if the damage is minor. Otherwise it's better to trust vehicle hands of service station professionals.

When is Body Repair Necessary?

Body repair is of two types: local and full. The choice of method for eliminating a defect depends on how deep and extensive it is. There are several types of damage:

Mechanical damage that occurs as a result of an accident, various impacts, improper parking, etc.
Violation of the integrity of the paintwork of the car (scratches of different depths and all kinds of chips).
The appearance of rust due to developing corrosion processes.

Often, car owners are not very attentive and do not notice various damage to the car's paintwork. Untimely elimination of such flaws leads to the fact that moisture accumulates under the damaged paint and corrosion processes begin to develop.

Therefore, you need to remember that even a small scratch can greatly harm the paint and spoil the layer of the applied coating. Timely repair will avoid serious financial and time costs.

To detect a defect, it is necessary to inspect the machine regularly. It is better to do this in daylight, choosing a sunny day. Due to visual inspection, various damages can be detected and immediately repaired. LCP defects can be divided into several groups:

Scratches, touching only a layer of varnish. They do not damage the paint layer, and they can be removed by regular polishing with special products or polishing paste.
Deep scratches when a layer of soil or metal is visible. You can remove the defect by carrying out minor body repairs.
Deep scratches that touch the layer of metal from which the body is made. Such damage is considered serious enough that it will be necessary to completely restore the body geometry before restoring the paintwork. It is better to entrust such work to specialists.

When the flaw has a small area and the paintwork is not damaged, repairs can be done without painting. If more than 50% of the body is damaged, the part will need to be repainted again.

Removing dents without painting the part

After washing and drying the car on its bumper and fenders, you can see slight damage in the form of scratches, which are caused by the attack of pebbles from pavement. Damage of this kind can be avoided by regularly polishing the car and covering it with a layer of special polish that protects the paint and varnish layer on the body. Thus, the paintwork will last longer and re-painting is not necessary.

The layer of paint in most cases remains untouched, so there is no need to paint the part. Repair of car bodies in this case is limited to careful polishing and application special means masking scratches.

If a slight deformation of the body has occurred, but the applied paint layer has not cracked, you can level the dents without painting. There is a special set of professional tools with which you can carry out the necessary operations.

It includes various suction cups, hooks and hammers for pulling and removing various kinds of dents that could remain on the car body after exposure to hail or various mechanical damage. There are several ways in which you can return the body to its original shape.

Local repair without painting became possible due to the fact that the metal has the ability to remember the original shape that was given to it at the time of manufacture. And since modern paints incorporate special polymer compounds that give them additional flexibility, the paintwork at the site of the defect will not crack during the work.

Repair of a car body using the method of contrast temperature exposure is popular in cases where small but numerous dents need to be removed. Its essence lies in the fact that the dent is first exposed to hot air from a building hair dryer, and then the cooled air of their aerosol can is sprayed onto the damage site.

Under the influence of a sharp temperature drop, the metal straightens. The place of the defect will need to be further polished, and the repair is over.

You can eliminate small defects by tapping with a special hammer or using a coin, which is soldered to the place of damage, and then the dent is pulled out. Minor car body repairs using this technology can be done with your own hands, because this does not require special skills.

Advantages of local repair:

It is possible to keep the paint applied at the factory.
You don't have to worry about possible color differences as the part will not be repainted.
Almost always, work can be carried out without dismantling the part, which means that the integrity of the factory assembly is not violated.
Low cost and time of all works.

How to repair a car body if painting is needed

For such a repair, you need to prepare everything in advance necessary tools and materials. In the process, you will need skins of various grain sizes, automotive putty for leveling the surface, a primer, a degreaser and paints and varnishes, you also need to remember about personal protective equipment. To paint the entire body, you will definitely need an airbrush and a compressor for better application of paint and varnish.

Minor body repairs and painting can only be carried out with quality if the surface of the car has been properly prepared. The old paintwork must be thoroughly cleaned, remove all dirt and rust from it.

Cleaning can be done with sandpaper, gradually reducing its grain size or using a special machine. In the process of work, it is necessary to process an area slightly larger than the defect itself, so that subsequently the place of repair is not allocated.

All foci of corrosion must be removed, because if the surface is not cleaned, rust will appear under the applied paintwork and the paintwork will soon become unusable. Then the surface is cleaned of accumulated dust and degreased. If there are damages and defects on the body, they must be eliminated with putty. Apply it in an even layer and be sure to let it dry before applying the next layer.

After drying, the place is polished with sandpaper and degreased again. Car body repair should be done in stages, without violating technology. After priming the surface, you can start painting. Parts that will not be stained should be covered with polyethylene using masking tape.

If the area to be painted is large, it makes sense to dismantle the part and carry out all work in a special paint box. In this way, possible ingress of dust can be avoided and various defects will not appear on the surface of the body after painting.

The paint must be trimmed very carefully, because there is a possibility that the selected shade may differ from the existing one. Therefore, you can contact the service station specialists who will tint using special equipment. This procedure is expensive, but it guarantees 100% matching of the paint tone.

Small scratches can be painted over with a special pencil, which is made on the basis of wax or Teflon. At the same time, it must be remembered that such a tool is short-lived and sooner or later you still have to repair the paintwork.

Defects that have a large area must be painted with automotive paint, which can be purchased at specialized stores. To avoid incidents, before starting work, you can paint an unnecessary body part to check the quality of the paint and its color.

Work is best done indoors, protected from dust and drafts. Paint the part with an aerosol can, moving from the bottom up to avoid smudges. Each coat of paint must be given enough time to dry before applying a new one.

This must be done until the part acquires the desired saturated shade. After completing the work, the car should dry out and now you can start polishing. This is done with a special polishing machine using polishing paste or manually. As a result, you can get a perfect surface with a mirror finish, and the repair site will not stand out at all.

In the overall design of the car, the most expensive and at the same time vulnerable is the body. In case of traffic accidents, even minor ones, its individual parts and details are most often affected. The simplest damage to the painting of exterior surfaces can occur when driving through the forest or due to poor workmanship at the factory. At the same time, the body repair technology is so well developed that it can be done not only with the help of specialists in service stations, but also in a private garage.

The design of such a part of a modern passenger car as a body, on cars of different classes is similar in its main elements, however, there are some differences that primarily affect the rigidity of the car body. SUVs mostly have a frame body, crossovers and some cars equipped with subframes, most cars have a rigid load-bearing body.

These features are important when it comes to repairing the car body. The main elements of the body structure are:

roof;
the base, which is the floor of the machine;
front, middle and rear racks;
front shield separating the engine compartment from the passenger compartment;
mudguard;
trunk panel;
central tunnel;
wings - front and rear;
doors.

The power frame of the body includes:

front and rear spars;
fixed thresholds;
front and radiator crossbars;
transverse beam under the engine supports;
cross bars under the front and rear seats;
window sill;
front and rear roof beams.

Some features of body repair

Do-it-yourself car body repair can be done if the damage to stamped surfaces or load-bearing structures is not severe and special technological equipment is not required for troubleshooting.

These works can be attributed to minor repairs, if only local body repairs are needed. That is, it is required to eliminate scratches or chips in the paint. You can also do it by hand complex repair when there are dents with paint damage, deformation of the body or subframe.

With any degree of damage, the first step is to diagnose the object of the forthcoming work to determine the required amount of materials, the required tool and the estimated amount of labor. This should always be done - when scratches and corrosion are detected, if repairs are needed on the body chips or serious straightening is needed, as well as painting parts or the entire body.

dents

Deformation of stamped elements of the body structure can be repaired independently by the driver or the owner of the car. For these works, you need a workbench or a special table, a set of straightening tools, anvils and hoods. Before proceeding with straightening the damaged area, it is necessary to determine whether this can be done without subsequent painting, or whether additional costs will be required for this. Read about the technology in a separate article.

Difficult repair of the car body, when the geometry of the structure is broken or a serious deformation of the structural element of the frame, such as a spar, has occurred, it is better to entrust it to specialists.

If straightening cannot be done without painting, then after straightening the metal, it is necessary to level the straightened surface with putty. Putty should be applied with a soft spatula. A primer is applied over the leveled part. This is a prerequisite for preventing corrosion and eliminating scratches when the putty is applied carelessly. The last step is painting the repaired part or the entire body.

Corrosion

Local body repair includes, among other things, the elimination of corrosion on individual elements. Thresholds are most susceptible to this due to scratches that form when stones hit while the car is moving and the lower parts of the wings, where water and dirt constantly get.

Before removing metal areas affected by corrosion, the entire part must be thoroughly cleaned of dirt. Determine the degree of rust damage to the metal and decide how to eliminate corrosion. With slight rust, it is enough to treat it with an anti-corrosion compound that contains phosphoric acid. Then rinse the surface, degrease and apply primer.

Painting the part completes the process. If the rust damage is significant, then you need to cut out the damaged area and put a patch of quality metal.

Chips and scratches

During the operation of the machine, especially on Russian roads, scratches of different depths and other damage to the paintwork cannot be avoided. - this is the most simple views body work. In order to remove these minor damages, it is often enough to polish the damaged area.

To eliminate deeper scratches, it is necessary to thoroughly rinse the desired area, then wipe it with white spirit and treat it with a special automotive putty.

The final step will be priming and painting the desired surface. In cases where the number and depth of scratches in a separate area are large enough, grinding this surface with a special machine is required.

Further processing of this area also begins with putty and primer.

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