Straightening repair operations are included in the range of the most common car service services. This is due to the fact that the car body suffers as often as the internal filling wears out. At the same time, the restoration of metal structures presents certain difficulties for the contractor. Self-straightening of a car body is justified as a way to save money, but requires the owner to have the appropriate skills. However, using a suitable modern tool, some types of such work can be easily mastered by a non-professional.
General principles and technology of straightening
The need for straightening measures arises in cases where the car, for one reason or another, receives external damage to the body. In this case, we are not talking about light scratches of the paintwork, although its restoration is expected as part of a complex of similar works. The main task is to correct the metal body or its individual parts that have been deformed. Using hydraulic installations, pneumatic equipment and hand tools, effective do-it-yourself body straightening is carried out. The technology involves mechanical impact on the problem area so that the body geometry takes its original shape. Depending on the nature of the damage, you should select the appropriate angle of impact on the dent and the initial area of restoration.
General provisions
Straightening of the railway track is assigned based on the results of the inspection - either full-scale or with a measuring car. But it should always be done only after all the work on raising the track has been completed. In addition, before starting to resolve the issue, it is necessary to inspect the joint gaps and adjust them (when necessary), but if more than three of them are merged in a row on a link line, it is permissible to only replace the grating.
Attention, the shift is carried out precisely along the outer rail side - this is relevant both for curves and for straight double-track or right-hand single-track sections.
The following general rules apply:
- It is better to carry out work either early in the morning or on cloudy days - when there are no temperature changes that cause heating of the VSP elements.
- According to the route plan, it is worth starting from the point where you need to perform the most serious movement.
- If the ballast is compacted, it is necessary to loosen it first - at the ends of the sleepers.
- In the winter season, it is not recommended to solve the problem, but if the direction has gone astray in the most serious way, it is permissible to change the track.
- The distance between the axes of adjacent blades should be controlled at each link.
Technologically, straightening curved sections of track can be carried out in two ways:
- By eye - it is possible only in those places where deviations from the norm are small, in “corners”, and short in length (up to 30 m).
- Combined - at reference points (one from the other - at a distance of 10 m) shifts are carried out strictly according to calculation, and between them - by smoothing, if a machine is used, or approximately, with manual labor.
In all situations and for any method, the need to move the grid is determined based on an analysis of the degree of deflection.
Necessary equipment
Unlike most repair work, which is carried out by car owners themselves, it is advisable to carry out straightening on the site of a special stand - a slipway. Thanks to this equipment in the garage, you can even cope with the restoration of a hood folded like an accordion. This effect is achieved thanks to the power drive of the stand, which can be represented by hydraulics or pneumohydraulics. For private needs, the first option is quite sufficient, in which you can count on providing a force of several tons. The pneumohydraulic force itself is more difficult to organize technically, although the working effect provides a much higher one. In any case, straightening the body on a stand will be a significant advantage for the garage technician, regardless of the nature of the operations performed. However, slipways are not cheap and, of course, require a special place in the room.
Straightening tool
Still, most of the straightening operations will be carried out on the scale of small repairs. But even cosmetic body correction requires the use of a special tool. In this case, it will be a set of hammers, differing in functional attachments. In particular, on the market you can purchase branded cases from auto tool manufacturers, which contain hammers with flat, sharp and convex strikers. In addition, the kits include hammer-smoothers and tools with notches. All this equipment will assist in the repair process. Of course, using hammers alone is rarely enough to straighten a body. The master must also be armed with special files, a spotter for spot welding, anvils and bench hooks. Each of the listed tools has its own task, the implementation of which facilitates the overall process of restoring the structure of a car body.
What a straightener should be able to do
Of course, first of all, in such an area it is necessary to have sharp vision and good coordination of movements. If a straightener works on cars, he must be resilient and strong.
Among other qualities of the profession, one can answer:
- accuracy;
- responsibility;
- diligence;
- hard work;
- perseverance;
- communication skills;
- skill to work in team.
The straightening profession is not suitable for persons who have chronic diseases, as well as nervous and mental disorders.
Vacuum straightening without applying paint
There are often situations when a change in the geometry of the surface of the metal base of the body entails the need to damage the paintwork. But with the help of a vacuum pneumatic tool, it became possible to straighten the body without painting using special suction cups. The device is applied to the damaged surface, fixed with suction cups, and then smoothly restores the structure line.
But this method has two significant drawbacks. Firstly, it only works in cases of minor damage. Secondly, it does not provide complete smoothing, but only minimizes the depth of the formed dent. It is also worth noting that an alternative option is mechanical straightening, during which painting of the body will be inevitable. In this case, the first stage involves physical leveling with hand tools, after which the area is sanded, primed and coated with paint.
Levels of the straightening profession according to ETKS
Since there are two areas of activity in the profession, each of them has its own skill levels of specialists.
Leveler of needle-platinum products, 1st category
Works with simple needlework as well as fish hooks.
Leveler of needle-platinum products, 2nd category
He uses special machines in his work and smelts products of more complex configurations.
Leveler of needle-platinum products, 3rd category
It can work both manually and using semi-automatic and automatic machines.
Body straightener 3rd category
Engaged in straightening parts of trucks and cars.
Body straightener 4th category
In her work she uses a straightening tool, as well as mastics, pastes, and putties.
Body straightener 5th category
Works with high-end cars, as well as showroom models.
Dent pulling technique
This is another way to fix dents, which is based on the principle of minimal contact of the working tool with the surface. In this case, a hook is used that pulls out the dented area, fixing it at one point. For gripping, a special hole is made into which the hardware is integrated. Subsequently, the operation is performed using an inertial hammer. Such body straightening may seem inconvenient and time-consuming, but in practice it is more effective than other methods in dealing with large areas of dents. Moreover, even the creation of a technical hole for a hook is justified. After leveling, the hole is sanded and puttied with special solutions.
Correction of defects by tapping
In terms of the quality of the result, this is one of the most effective ways to restore a body. Moreover, this same operation is final in relation to the above-mentioned procedures that correct large defects. Tapping is done on the back side of the metal sheet, which was previously removed from the body. Most often, such straightening of a car body with your own hands is done with hammers with different attachments. In this process, the delicacy of the impact on the material and attention to detail are especially important. The fact is that the slightest deviation from the original geometric line may in the future result in problems in the process of installing the problematic piece in place. Then the dismantled area is welded and covered with paint and varnish material.
Reviews about performing self-straightening
In most cases, straightening in your own garage lives up to your expectations. Of course, home craftsmen are not always able to achieve quality at the level of a professional workshop, but there is some success provided they use the right tool. But it is not without mistakes. Thus, there are often reviews about the improper use of heating metal to make it more pliable. Experienced craftsmen emphasize that straightening a body with heating requires special skill from the performer, since soft metal is easier to control in terms of molding. Many car enthusiasts also have difficulty operating heavy straightening equipment. This applies not only to stands, but also to winch mechanisms, as well as cables and supporting devices. Experts recommend that beginners in the business of automobile repair avoid using such equipment.
Main types of straightening
Many car owners are sensitive to body damage resulting from:
- random collisions;
- collisions with obstacles;
- throwing stones from under the wheels of passing and oncoming cars;
- a number of other reasons.
Dents can be corrected in various ways. The process of restoring the surface of deformed body parts is called straightening. With its help, you can return the appearance of the car to its original shape. Straightening refers to the final stage of body restoration work and requires a careful, careful, professional attitude.
With minimal plumbing skills, many damages to body parts can be repaired yourself. The straightening technology should be selected taking into account the make and year of manufacture of the car. The bodies of Soviet Volgas, Moskviches, Zaporozhets, etc. were made of durable tin, which was very difficult to restore to its original form. Gas welding work was often required, a skill that not all drivers possessed. In modern cars, thin plastic steel sheet is used for body parts, which is easily restored by extrusion, tapping, vacuum and other methods. Therefore, most car owners can handle simple body work on their own. The following types of manual straightening are distinguished:
- Removing dents. This is the most common type of straightening. Various technologies are used to eliminate dents.
- Elimination of bulges. Bulges are formed as a result of body parts bending during impacts and collisions. They are eliminated by frequent and gentle blows of a hammer through the substrate. In difficult cases, a gas burner is used. Heating is carried out in a spiral from the center to the edges of the convexity.
Irregularities in the form of bulges are eliminated by hammer blows through the substrate
- Local straightening. The original shape of the part is restored without dismantling it. However, it is often necessary to remove handles, trim, lights and other elements that interfere with the work from a damaged door, fender or hood.
Work order
The general technology of track straightening involves three stages:
- preparatory,
- basic,
- final (final).
Before considering each of them in detail, we note that in a normal situation the problem is solved by a team of 7 people, which, in particularly complex or urgent cases, as well as when using optics, can be expanded to 8-10 fitters of the 4th category.
The initial stage of preparation comes down to the study of deflection arrows - the curvature is measured along a chord 20 m long - and to calculations based on the data obtained, carried out using the Pashkarpov method.
Having received the necessary numbers, in accordance with them you need to drive in temporary reference points - so that after alignment they are located at the same and constant distance from the outer side of the sole. For this, wooden pegs with a cross section of 3-4 cm in the wide part, 25 cm long, with a hewn edge, which should be placed in the direction opposite to the track vector, are best suited. They should be placed strictly opposite the division points, and in such a way that the distance from their tip to the rail support is equal to the template with a tolerance up or down exactly by the amount of shift.
Body straightening technology
Before starting work, you should decide on the straightening technology. All the numerous methods for restoring body parts can be attributed to one of four technologies.
Classic or regular straightening
Classic straightening is performed using special hammers, jacks, spoons, mandrels, levers and other devices. Sometimes resistance welding machines are required. This technology is usually used to correct local body defects. It assumes:
There is no need to waste time, money and effort on restoring a badly damaged wing, door, hood, or trim. The best option is to replace with a new part.
Vacuum straightening of dents
Vacuum straightening is used to remove dents that do not have sharp corners and have not damaged the paintwork. These may be marks from elbows and knees due to unsuccessful leaning against the body of a car. Such defects with smooth rounded edges are corrected using special vacuum suction cups. In a garage, you can use improvised means. These can be suction cups for attaching a rear view mirror, sun shade, organizer, etc. to the windshield. The straightening technology is very simple. A suction cup is installed on the degreased and water-moistened dent and fixed with strong pressure or special devices.
The universal vacuum suction cup is easy to use and does not require special skills
When working with suction cups, it is important to find the place where the metal stress is greatest. This is usually the perimeter of the dent. It is the ability to accurately find points with maximum tension that determines the qualifications of the master.
This method is especially effective in removing smooth, shallow dents with a diameter greater than 12–20 cm. The suction cup is fixed and then sharply pulled towards itself. Sometimes a strong cord tied to the suction cup rod is used for this. The main advantages of the vacuum method:
- there is no need to dismantle the damaged part, since the work is carried out on its outer surface;
- the paintwork is not damaged;
- does not require a lot of time.
Hot straightening
If body defects cannot be eliminated using conventional methods, hot straightening technology is used. A gas burner is usually used for this. However, in inexperienced hands it will do more harm than good. You can heat parts made of thin sheet steel using a hair dryer with an air stream temperature of several hundred degrees. This will prevent damage to the paintwork. In addition, a hair dryer is not as dangerous as a gas torch.
Straightening by contact welding
Lately, straightening using a spotter has become popular. Fastening elements are welded to the deformed area by contact welding, with the help of which the surface is leveled. This method is not cheap - not every car owner can afford to buy a spotter. For these purposes, many craftsmen convert portable welding machines, microwave ovens, or assemble a device from scrap materials. Resistance welding technology has a number of undeniable advantages:
- the heating time is 0.3 seconds, and the metal does not have time to burn out;
- no slag, scale, or sparks are formed at the welding site;
- fasteners are designed for repeated use;
- the fasteners are securely welded and can be easily removed from the surface;
- straightening is highly accurate and does not take much time;
- the work is carried out from the outside, so there is no need to dismantle the damaged part and provide access to its inside.
When straightening by contact welding, a spotter is used
Algorithm for self-straightening of the body
When straightening yourself, failure to comply with the technology can lead to dire consequences. The appearance of the car can be damaged, and restoring it in a car service center will require a significant investment of time and money. Therefore, before starting work, it is very important to objectively assess your capabilities.
The main disadvantage of straightening in a garage is the lack of special equipment and devices. Therefore, it is recommended to independently remove only small dents, abrasions and shallow grooves. For ease of operation, removable body elements should be dismantled. With a set of wrenches and sockets available, removing the front fenders, doors, trim, hood and trunk lid is quite simple.
You should only repair minor damage to the body yourself.
Determining the feasibility of self-straightening
Before starting straightening yourself, it is advisable to test your capabilities on old parts that can be damaged. The easiest way to straighten parts is with one outer and one inner surface. These are the front (usually removable) and rear fenders, the roof, the front trim and the rear trunk. To get to the inner surface of the door trim, you need to remove the handles, trim, window lifting mechanism and the windows themselves. The most difficult parts to straighten are hoods, pillars, and sills - the frame of these elements is a complex double structure. To bring them to their original form, you will need stocks, special tools and certain skills. Experienced car owners can easily assess which damages they can fix themselves and which they will entrust to professionals.
Preparation for straightening
Before starting work, you should first prepare the tool. For straightening you will need different types of hammers:
- flat for straightening straight sections;
- convex for straightening relief areas;
- a hammer with notches for straightening long narrow dents.
For straightening you will need a set of hammers, spoons, pads, brass anvils, and smoothers
In addition, you need to take care of purchasing:
- shaped plates (trowels) for smoothing the surface;
- rasps (files with a large notch) for leveling small irregularities;
- brass anvils to support the deformed area during straightening;
- steel hooks, spoons, clubs for squeezing out dents from the inside.
Spotter technology
To correct severe deformation of a part, you will need a spotter. The principle of its operation is quite simple. First, using contact welding, a fastening element in the form of a washer is firmly welded to the dent. Then the washer is grabbed by a special gun, and by connecting the retractor coil, the deformed surface is leveled.
How to straighten or straighten a hood
In order not to overpay at a car service center, it is important to know how to straighten the hood of a car yourself. To complete this work, you will need to do the following:
- Carefully inspect the damaged area, determine the severity and nature of the damage.
- If the damage is a dent with metal bends and deep depressions, use a straightening hammer and anvil.
- Deep defects are corrected by stretching the metal and then removing excess parts.
- If the hood is severely damaged, then the worn-out piece of metal is removed and a new one is welded in its place. Subsequently, the weld is ground, the irregularities are covered with putty, primed and painted.
- In some cases, it is not possible to remove the damaged body element. In this case, use a special spoon to straighten the dent.
3 Straightening with hand tools - sequence of actions
Damage of irregular shape, with sharp creases, damaged paint layer is leveled in the traditional way, using impact tools. If the body element is removable, we dismantle it, remove the trim and everything that interferes with easy access. We lay the removed part on a flat base and outline the border of the damaged area.
We begin leveling out large dents on the car body from the edges, which is where the metal is subject to the greatest stress. Lightly tap with a hammer, gradually moving in a circle towards the center. The diameter gradually decreases. On the other hand, we will definitely use support. The work requires patience and gradualism. Sometimes inexperienced drivers are in a hurry and start hitting hard, deforming the metal. You should do it slowly and little by little, then the dent will definitely take almost its original shape.
If using a hammer is not possible, use a hook. We drill a hole in the center and insert a hook into it. We lean on the stiffening rib located nearby and pull, at the same time turning the hook so that with its bend it levels the metal from the inside. A similar technology using hooks. We screw in the screw and pull it. You can spot weld the washers, which we then pull.
To work with hooks, hooks, and washers, it is recommended to use a special tool - a reverse hammer, which allows you to control shifts in the metal.
A simple dent without severe deformation can be squeezed out with the palm of your hand. It happens that it is impossible to approach the damaged area, then a hairdryer will come to the rescue. The main thing is not to overdo it, so as not to damage the paintwork. We heat no higher than 100°. If a minor dent is accessible from the back, such as a door panel, it can be easily repaired. We make a gasket from hard rubber and lightly tap it with a hammer.
Straightening small smooth damage is also possible from the outside using PDR technology. If the painting remains intact, pulling is performed without disturbing it. We use a suction cup, glue it in the center of the dent, and pull it towards ourselves. It will not be possible to level it completely; then we use pistons selected according to size. Pull it out using a reverse hammer. An alternative is a mini-lifter, which is sold in a set with pistons and glue.
Practical advice
In fact, there are a huge number of tools, methods and methods with which you can straighten the damage on the hood. You should start straightening dents with your hands and only then apply more drastic methods in practice.
The body of many cars consists of such thin metal that it easily responds to manual straightening and does not require the use of additional tools. It happens that the dent itself is not serious and can easily be squeezed out with your hands, but it is difficult to get to it. In this case, you can use a heat gun, which will heat the dent from the inside. You should be careful here, since if the temperature conditions are not observed, you can observe swelling of the paintwork. The paint should not heat above 110 degrees.
When leveling out serious dents, it will not be possible to avoid damage to the paintwork, which will have to be restored. There are such complex damages that to correct it is necessary to make holes in the hood, insert hooks into them and pull them. You can weld washers to the metal on the outside, by which the metal will be pulled or twitched. With this straightening method, each shift of the metal can be controlled, achieving high precision in the work.
It is rare that straightening does not require the application of putty. Lumps and various irregularities remain on the straightened part, which have to be painstakingly worked on. The former dent on the hood needs careful degreasing and application of automotive putty. This material quickly becomes hard, tightly adheres to the metal, can be sanded and promotes even painting. If all this work is done efficiently, then it is impossible to see the difference with the naked eye.
4 Correcting dents - instructions for individual elements
Quite complex damage occurs to the door. When hit hard, it sometimes jams. The most important point is to determine where the blow landed. If you find that the creases come from there, then this is where you should start. This is the key to success: to create anti-pressure at the point where the initial impact occurred. Often the edge is the first to suffer, so that’s where we start.
We clean the place to the base, spot weld the rings, placing them nearby. We thread a rod through them, hook them to the winch and begin to slowly pull. We pull until the first clap of metal. Holding it taut, use a wooden stand to tap the protruding irregularities with a hammer, helping the metal to level out. Again we tighten it a little, repeating the operations.
This method is used if it is impossible to get to the damaged area from the inside. It is more convenient to work by removing the door and trim from it. We lay it on a bedding made of soft material, such as felt. We level it using the available tools. It happens that the metal does not give in, then we heat it. If you have a spotter, you can use it to warm it up without fear of damaging the metal. If the panel and frame have collapsed, separate them using a hook or straightening spoon.
It is convenient to straighten the hood because it can be easily removed. We start with reinforcements, folds, kinks. We strike often with little effort. On the reverse side there must be support that corresponds to the geometry of the defect. To fix the wing, it is better to dismantle it, if possible. This is not available on some models where the fenders are welded on. The roof is also leveled without dismantling. The jack is widely used. We lay a wide board on the floor and install a jack. We transmit the force through a piece of timber with a nailed piece of board. We remove the upholstery before work.
It is possible to do straightening in the garage, using the opportunities that are available. It is impossible to give any one universal advice. Assess the damage and take advice. Use techniques that are appropriate for a particular case.
How to straighten or straighten a hood
In order not to overpay at a car service center, it is important to know how to straighten the hood of a car yourself. To complete this work, you will need to do the following:
