Auto repair shops that practice body repair always have a special set of tools and special equipment for repairing dents without straightening and painting the metal. And although the damage is serious, and even located on large area without the use of powerful stands, the stocks cannot be corrected, pulled out small areas dents with difficult access are quite possible. To do this, you just need to use a special small-sized auto tool called a reverse hammer.
Using a reverse hammer
Reverse hammer can be called one of the best tools for car body repairs. It is also often used to repair arches, sills or pillars where access from the inside of the part is impossible. The device is very simple, and operation does not require great skills.
Exist the following types hammers - pneumatic reverse tools and reverse hammer spotters. There are also hammers with two and three weights, thanks to which you can adjust the force of impact. Besides standard version There is vacuum equipment that also removes dents. The advantage of this reverse hammer is that it has a suction cup. It acts as a grip on equipment and does not disrupt paintwork body
Carrying out straightening involves a number of tools, in addition to the basic ones - a straightening hammer, a file, a machine tool, a saw, a stand and spacers, an electric reverse hammer, a reverse hammer. Often a reverse hammer is used in conjunction with other tools to resistance welding. As a rule, the back hammer is included in the straightening kit, which is usually included with the welding machine.
A back hammer is often included in bearing removal kits. They are intended for use in automotive workshops for the purpose of removing various parts by gripping their internal location using a reverse hammer. Grips of a special design fit tightly to the bearings, allowing you to remove the bearings without damage and evenly, as well as turning the handle clockwise. Thus, the purpose of the hammer may differ, but the price of the reverse hammer remains the same.
Reverse hammer design
The design of this tool is very simple - it has a steel rod with a diameter of 20 millimeters and a length of 500 millimeters (base) and weights mounted on it that are loosely mounted on it, as well as a hook and a washer. On the base there is a weight or several weights, which may differ in weight. On one side of the rod there is a hook, and on the other there is a washer, which does not allow the weight to fly out and transfers the force of the impact of the reverse hammer to the rod.
A modern tool is equipped with several types of grips, which allow it to be used for leveling damaged areas, in particular dents, on various areas body At successful combination There is quite a lot of weight and length that can be knocked out - from the crumpled sills to the crumpled double metal that is in the rear fender. During repairs, reverse hammers are often used in conjunction with a spotter.
Working with a reverse hammer
Before you start working with this tool, you need to become familiar with the damaged area of the car body (or other object). Places that are subject to pulling should be thoroughly cleaned down to the metal, degreased, and a primer and subsequent painting should be applied to them. Next, you need to drill a small hole and weld special repair washers. Often, such reverse hammers, no matter how much you would like to carry out painting work later, are the only solution for body repair. After these steps, a hammer is attached to the damaged area.
Use the hook of the tool to hook onto the washer and pull out the dent with gentle, light blows. This action should be repeated until the dent is completely leveled and removed. After a series of procedures, part of the body is subject to mandatory painting. To remove long dents and edges, you should weld several washers and insert a metal rod through the holes.
It is very important to remember that a standard hammer cannot be used to repair areas that are too large, such as the center of the roof, hood and trunk lid. In these places, the metal can be pulled out too much by welding washers, so the part will simply have to be thrown away.
The use of a reverse hammer requires the creation of a paint coating on the surface. But there are hammers that are equipped with pneumatic suction cups, for the use of which there is no need to make holes in the metal and thereby save the machine from unnecessary painting work. This option is recommended for repairs large plots. To create pneumatic fixation to the surface, it is necessary to apply compressed air, therefore during operation vacuum hammer connects to a special compressor.
Making a reverse hammer with your own hands
The technology for creating a reverse hammer at home is quite simple. Before you start, you need to be well prepared. You must carefully plan and think through your work in advance. You should prepare a steel or stainless steel rod, the diameter of which is 20 millimeters and the length is 500 millimeters. You will also need a steel weight and a hook. A standard reverse hammer is very quick to make - you will only spend thirty minutes creating it.
Let's look at a drawing of a reverse hammer, where you can use available tools. Let's say you have a very thick pipe, e.g. ski pole and a weight with a hole in the middle for attaching to this pipe. At one end of the pipe you need to make a limiting area for the load that will knock on it, and attach a hook or another version of the hook to the other side.
Instead of a hook, you can use a hairpin that has a long thread. In this case, the pin must be pulled into the hole in the body, and with reverse side Screw the temporary fixing nut through the washer.
Many people have a question: how to attach replaceable attachments? The answer is very simple. The pipe should only end with a threaded rod. Likewise, the nozzle should have the same pin at the end. To connect them, you can screw about 10 nuts onto one stud and weld them together.
When the hook catches on the metal of the body, you should use the weight of the load on the pipe, that is, you must accelerate the load in your direction. It will hit the limiting area, which can be a large washer welded to the pipe. A strong shock will appear, which will be transmitted to the pulled metal. Builders recommend using a load weighing at least three kilograms.
You can make a hook from sheet metal, the thickness of which is about four millimeters. If you want to make a vacuum reverse hammer with your own hands, you should use a suction cup from a plunger instead of a hook. The beauty of vacuum check hammers is that they do not disrupt external painting car.
When creating a reverse hammer, experts advise processing each part with a file. It is also necessary to remove all nicks and burrs. Remember that the reverse hammer is hand tools, so try to make it as comfortable and pleasant for your hands as possible.
Body straightening at home
A car with smooth and even shapes involuntarily attracts the gaze of passersby. Nobody wants to drive with dents on the body and asymmetry. Motorists know that damaging the body is easy. This is caused by branches, fencing, small traffic accidents, accidentally fallen objects, etc. To restore the car to its former beauty, it is necessary to carry out straightening, which will return your car to its original attractive appearance.
Straightening involves restoring the deformed shape and individual body parts. You can fix this problem at home yourself, so as not to overpay for the services of specialists. A homemade reverse hammer is ideal for these purposes.
So, you need to extend or straighten the concave areas. If a car part is severely damaged, it is better to simply replace it with a new one and not waste extra time on repairs that may not give the desired result. Before starting work, the paint is removed and putty and grout are performed. Some experts heat the metal to a reddish hue before tapping, but it is important not to overheat or melt it.
After this, the straightening process is carried out. To tighten metal you need to have blowtorch or a burner. When the bulge warms up, the borders should be covered with a wet rag. The metal will contract due to temperature changes. Carefully inspect all dents, be sure to evaluate their complexity and size. The large dent is aligned along the edges, and the small one in the middle.
Along with dents, cracks may also appear on the car, so you need to get a welding machine. For quality work You'll probably need a spotter, a sharp-faced hammer, and a scoring block. Perhaps you should acquire some more tools that are necessary only for your case.
Many people prefer vacuum body straightening at home, which can remove dents without painting, and in a matter of seconds. It works using special vacuum suction cups and can be used even on large, flat dents. The disadvantage of vacuum straightening is that it cannot completely get rid of the defect. Additionally, if the damaged surface has cracks, vacuum straightening can further damage it.
Therefore, you should carefully consider the method of straightening and the choice of tools. After using the reverse hammer, it is necessary to fill the holes or weld them. Then the repaired part should be rubbed down and paint applied to it. Deep and small dents that have strong stretching, in addition to standard work by pulling and tapping, require pulling off excess metal.
In some cases, it is necessary to cut off stretched areas and apply patches using a spotter (welding machine). Tapping is done using a reverse hammer. Usually the deformed body element is removed, but if this is not possible, the dent can be squeezed out with a special spoon. This technique is often used if it is possible to get close to the concavity through the skin. But if this option is no longer available, you have to drill holes on the damaged part and select through them, using special tools.
The reverse hammer is one of the essential tools for body repairs. In cases where access from inside absent - it is simply irreplaceable. Any craftsman knows how to make a reverse hammer at home in about an hour. If you carefully select parts and strictly follow all stages of assembly, you will be able to make reliable tool, which will complement your home collection.
Correcting car body defects is not complete without the use of special tools. In particular, a vacuum return hammer or modifications thereof are required. The types are different, some models are created. What it is and how to make a tool with your own hands is described in this article.
What is a straightening hammer and what is it used for?
Not all parts of the body can be repaired with outside. For sills, pillars and arches, a reverse hammer for a spotter - a welding machine - will come in handy. The device is a pistol-shaped design with a retractable electrode and an impact blank. Automation operates without the participation of the master’s hands, only operating the keys of the device.
A typical hand straightening hammer consists of a steel rod with a hook on one side and a steel washer on the other. The operating principle is simple:
- The handle and weight - steel washer - are the moving elements of the hammer.
- The place for straightening and repair is initially prepared for the procedure. The hook at the end of the hammer is firmly installed in the defect areas on auxiliary washers.
- By sharply moving the weight towards the handle of the hammer and making strong blows, the dent is straightened.
Using hammer models, they not only straighten dents, but also use them as a puller. For example, if you have to separate lapped parts, a return hammer for bearings is indispensable.
Any body work requires detailed consideration, otherwise using a hammer will do a disservice by creating new dents. They use the tool independently only when they have the appropriate skill.
Types of straightening hammer
The locksmith industry offers several tool options. For example:
- Reverse hammer with pneumatics. The mechanism increases the impact force, making the result satisfactory without long work.
- . As described above, this welding machine, necessary for cauterizing the metal and relieving stress from it. A reverse action hammer with it makes the job complete.
- A set of 2–3 weights. A large number of weighting agents, contributes to the accuracy and force of impact. Dignity in . The straightening hammer is created according to this principle and is being improved.
- Vacuum. A hammer is the most gentle on a car's paintwork - it does not need to be removed from damaged areas. It is a reverse hammer with a suction cup. Straightens out dents with strong air compression.
Accordingly, models and prices. It is easy to assume that the last option is the most expensive.
How to make a hammer model yourself
Simple kettlebell model available for self-assembly. It is quite possible to make a more modern reverse hammer for body repair with your own hands if you purchase components. Let's consider one of the options, which will require the following materials:
- Steel rod. With a cross-section of at least 2 cm. If you do not take this into account, the thin rod will not last long - enough for one straightening.
- Rubber handle. It is specially machined from whole piece or use a nozzle for something.
- Steel hook. A thread is cut at its end for screwing into the pin. It is needed not only for pulling the surface by the brackets, but also as a reverse hammer for removing injectors - it is convenient for them to pick up obsolete parts that need to be replaced.
- Welding machine. For home needs.
- Steel washers - 2 pieces. Diameter – 3 cm.
- Weight. Use a regular headstock from a store scale, without corners or protrusions. Otherwise it is inconvenient to use. Section up to 6 cm and length up to 15 cm.
To make it more convenient to assemble a makeshift model, it is better to have a drawing of a reverse hammer with standard dimensions on hand. This will certainly increase the build speed. It is made as follows:
- The rod is brought into proper condition - soaked in an anti-corrosion solution, ground and degreased. It is important that the pin for the homemade reverse hammer remains level - either it is selected according to this, or it is straightened at the initial stage.
- One of the washers is welded onto the end of the rod so that when struck, the weight does not fly off the rod and touch the surface of the car body. Immediately equip the reverse hammer with a grip with your own hands - weld or screw a hook to the end of the rod.
- The weight is drilled into lathe all the way through so that movement along the steel pin becomes unhindered. Check this immediately by putting on the weighting material from the other end. If he walks slowly, then increase the diameter of the internal hole.
- After putting on the weight, a second washer is fixed at the other end to prevent the heavy headstock from breaking the handle.
- All you have to do is put on the rubber nozzle and the reverse hammer for the spotter is ready. The makeshift model is tested in action on an old, unnecessary piece of iron and the shortcomings are eliminated, otherwise additional defects will appear on the car body.
Rubber attachment on the end of a body repair tool To make a reverse hammer with a vacuum suction cup, you will need the same components, only instead of a hook you use a plunger - a new one, the old one will be of no use. First, they “suck” the nozzle onto the iron and then begin work. The advantage is that you don’t have to weld additional brackets to the body and then remove them, thereby spoiling the already ugly surface.
The model, which is a reverse electric hammer, is a version of a straightening tool equipped with a motor. There is practically no effort required to straighten dents - the power of the engine allows you to pull out and strike the iron with a greater amplitude than a person can do.
Straightening technology
It’s not enough to make a reverse hammer with your own hands - it’s important to know how to work with it in order to get a decent result or, at least, not do the worst. There are several options for straightening the body, depending on the problem:
Removing large dents
Typically, a reverse hammer is used to remove dents. It starts in a spiral - from the edges to the center. If you do the opposite, then only the center will shift, and the sides will remain concave, which will make the defect even more complex and rigid, and cannot be straightened in the usual way. Therefore, the work requires skill.
When the body profile is restored, the work cannot be considered finished - the view is not conducive. Next, direct forging occurs with the same tool, but with a smoothing attachment in the form of a spatula and a counter support. To carry out the work you will need a reverse hammer with a set of attachments - so the work will pass the best way and even minor defects will be eliminated.
Eliminating bulges on the body
Dents do not have the opposite effect - bulges appear on the surface of the car. Their elimination is possible. For this purpose it is used thermal effect by welding to relieve the stress of the metal in the middle, thereby making the defect ready to be smoothed out. The work is carried out from the edge of the red-hot swelling to its center - it is felt by hand, where the spring is greatest. When the contours of the body are marked, the straightening area is shed cold water, which will further promote the retraction of metal.
The second way to fix bulges. It consists of cold straightening the metal to its contours using a support and a shovel-shaped attachment that is placed on a reverse hammer for body repair. And then the finished place is heated to smooth out the contours of the installation. After which the defect is spilled with cold water. However, this method has a significant drawback - if the metal is thin, then the temperature difference will lead to rupture and cracks.
Correcting dents with a pulling hammer
This is the standard procedure described above. Let's take a closer look: the defect site is thoroughly cleaned of paint and varnish material over a larger area than necessary and the areas are carefully sanded. Auxiliary rings are welded to the dent, onto which the reverse hammer for straightening clings. They are then beaten off. Then, by hitting the load on the limiter on the handle, the force is transferred along the rod to the dent, and thus the tool will gradually pull out the defect.
A pull-out reverse hammer is needed for vertical surfaces of a car - it is not suitable for the roof and bottom; a regular mallet or a standard iron tool will do the job.
Electropulling
It is better to pull out small dents special tool, since a kickback hammer can cause large defects. Externally, the device resembles a short drill, where an electrode is inserted instead of a drill. As a result of the work, metal deposits are obtained in the center of the dent, which are then pulled out by pressing the reverse button of the device. A nuance - you cannot burn through the metal, so welding takes no more than 0.3 seconds, using point movements. If you have the skill to make a reverse hammer for a spotter with your own hands, it is possible, but not without difficulties, using a welding machine and a drill body with a retractable mechanism.
The complexity of the work lies in the diagram - the drawing of the reverse hammer for the spotter is not its most important part. The main element of such a tool is the electrical filling, which includes a transformer, stabilizer, thyristor and capacitor. If these words mean anything to a home-grown master, then he can safely get to work - the diagram is attached.
Fine body straightening
After the principle of operation of the reverse hammer has been mastered in practice and the surface of the body has reached a usable condition, it is brought to its logical conclusion. This procedure is considered to be treating the damage with files after eliminating a major problem. Fine grinding will not do the job, so they select coarse ones, but there is a nuance in the work - they deform the surface if there is no skill.
Final processing of the body
After straightening, it is not possible to immediately apply a primer or paint coating - the defects will become visible in all their glory. The body needs to be finally put in order. It consists of grinding the treated body with six or heptagonal discs that do not leave steps or small defects on the surface. A specialist consultant at the relevant store will help you choose the correct grain size of the wheel or the number of revolutions of the machine.
WATCH VIDEO INSTRUCTIONS
In conclusion, it is important to say that making a reverse hammer for your own needs and thereby restoring your own car is not difficult.
It is important to collect the available information and isolate the worthwhile nuances from it - then working with the tool will not become a burden, and the result will exceed expectations.
Any type of body work is expensive and requires special skills and tools. However, you can save on buying some by building them yourself. For example, you can make a reverse hammer with your own hands in an hour. This will allow you to independently carry out and control the process of leveling dents on the body in hard-to-reach places.
There are several options for the reverse hammer structure:
- vacuum;
- with pneumatic pulling mechanism;
- devices with multiple weights;
- models with an adhesive base or replaceable nozzles.
The first of the presented types has unique advantage before similar devices. The vacuum suction cup allows you to carry out repair work without damaging the paintwork. Depending on the power of the vacuum reverse hammer, it is possible to pull out small and medium-sized damage onto various parts body However, when working, it is necessary to follow a special technology: pulling should be done from the edge of the damage to its center. Otherwise, a dangerous stress for the metal arises, which can lead to fracture or unpredictable deformation.
Pneumatic reverse hammers are convenient because they require reduced effort when performing work. Another area where this tool is indispensable is work under the hood, including removing stuck parts.
A homemade reverse hammer can be built from the simplest components:
- metal rod suitable thickness and about half a meter long;
- steel washers of the appropriate diameter for installing stops;
- weights to increase impact force;
- rubber handle (can be replaced with any other convenient material);
- a hook or a metal plate with a holder - depending on the design of the intended hammer.
The condition of all components determines whether grinding and cleaning of metal parts will be necessary. To do this, you can use sandpaper or a metal grinding disc, and may also come in handy special compounds. The design features will determine whether a welding machine is needed or only a thread cutting device is required. However, most often it is impossible to do without welding, since it is better to secure the lock washers to the rod of the reverse hammer using a reliable seam.
You need to select an iron rod that will be 3-4 cm thicker than the base of the reverse hammer and saw off a part 5-7 cm long. A hole is drilled inside to suit the thickness of the rod. The thread is cut inside at a right angle so that the plate welded further is strictly perpendicular to the working handle. This area should be well sanded and cleaned, and outside a ribbed texture is artificially created so that the sticky base interacts better with it.
Homemade Velcro sealant for a reverse hammer can be made from various materials. The adhesive composition must meet several characteristics:
- it should not leave marks on the car’s paintwork;
- its degree of interaction with the surface must ensure reliable adhesion;
- the composition must be sufficiently elastic.
For this purpose, you can choose any household composition. For example, scraping it off the parts from which they are made plastic windows or use resin, which can be purchased at a hardware store.
It’s also easy to make a sliding hammer with additional attachments yourself. To make it you just need to apply a thread to the base. At the same time, future nozzles of the reverse hammer will need to be made with a diameter larger than the rod, several centimeters - this will ensure reliability during operation. If you already have attachments and they are all designed for different rods, you can make an adapter for the reverse hammer with your own hands or purchase a ready-made one at any automotive store.
The use of a reverse hammer in dent pulling work has proven effective when working on arches and sills where available inner space not much. It can also be used for minor damage to the doors and body if the stiffener is not affected. Making your own reverse hammer will save you a significant amount.
Many drivers, when faced with the concept of “reverse hammer,” do not understand what it is. Although, if you have never had to do body repair yourself, there is a high probability that you have never seen such a tool. But if you still have to repair the body, you cannot do without a reverse hammer. In this regard, the purpose of the article below is to tell not only what a reverse hammer is, but also how to make a reverse hammer for body repair with your own hands.
What is a reverse hammer for body repair?
In the process of working with a car body, the hardest and most important part is straightening, that is, leveling the surface of the body. To perform this task, even specialists need to have professional equipment on hand, which includes a reverse hammer.
IN classic version a reverse hammer is a pin made of metal and 50 centimeters long.
The diameter of this pin is only 2 centimeters. There are only two elements on the pin: on one side there is a rubber bushing, and on the other there is a small metal washer. The task of the latter is to hold the bushing and prevent vibrations from impacts from transferring to the hammer body.
In addition to this, many reverse hammers also have hooks, with which the device can grab staples welded to the body, and thereby be securely held on it during straightening.
Purpose and types of reverse hammers Often a reverse hammer is used to remove small dents on metal parts car body, which either cannot be accessed directly or must be aligned from the reverse side.
Using a reverse hammer is very convenient for working with car sills, wheel arches and pillars.Important!
A reverse hammer is designed to work on small areas, so it is not suitable for straightening large dents on the roof or trunk. This is due to both the operating technology that is used when using the reverse hammer and its size.
There is a classification of reverse hammers for body repair, which includes:
Vacuum hammers.
Spotters. With weights
(two and three are used).
Reverse hammers operating thanks to a pneumatic mechanism. The specificity of straightening work depends on the type of reverse hammer. To level the surface of the body of a new car, it is better to use a vacuum return hammer, since only it allows such difficult work without first removing the paintwork. In the same case, if you are going to use one of the remaining types of hammers, the part of the body where the dent is located will first need to be thoroughly cleaned using sandpaper
. Otherwise, the paintwork will still be damaged by the reverse hammer.
How to use a reverse hammer
1. The entire process of straightening dents on a car body using a reverse hammer should be performed in the following order:
2. Rinse the entire work surface with water to remove all contaminants, and be sure to treat the entire surface with a degreaser. If necessary, remove from work surface
3. Weld round repair washers to the area with the dent.
4. Attach a special hook to the reverse end of the hammer, which should come with the tool.
5. Hook the hook onto the washer.
6. While holding the tool by the handle with one hand, grab the weight with the other hand and point it towards the handle. In this case, your movement should be as sharp as possible.
Due to the fact that the reverse hammer is tightly coupled to the body surface, with each of your movements with the weight, the reverse dent is leveled. At the same time, the harder you hit the weights, the faster the process of straightening the car body will go.
Attention! It is necessary to work with a reverse hammer very carefully, since using it in the middle of the body can achieve the opposite effect. The point is that very often, when aligning one dent, new defects can form. Therefore, in such areas of the body it is more rational to use more professional equipment.
You must be extremely careful when working with a reverse hammer. Do not rush under any circumstances and after each impact evaluate how the dent has changed. This will help you avoid creating new dents at the edge of an existing defect. But if you work slowly and follow all the instructions correctly, you can remove a small dent in just a few minutes.
It is often impossible to repair a car body without a reverse hammer, although each time it is necessary to soberly assess the situation, and if the work area is too large, resort to using other tools. As for the reverse hammer, fortunately, such a tool for body work can be made with your own hands.
We manufacture our own reverse hammer
Today, reverse hammers can be purchased at any auto store. It is worth noting that they can be sold either as a separate unit or as part of a set of tools specifically designed for body repair. But since there are no complex mechanisms, it can be done at home.
To make your own body repair tool, you will need to prepare some materials:
The pin is made of durable steel, 50 cm long and 2 cm in diameter.
Using a reverse hammer is very convenient for working with car sills, wheel arches and pillars. To make a reverse hammer, you can use a pin of a smaller diameter, however, its service life will be significantly reduced, since under the influence of constant impacts the thin base will rapidly collapse.
A handle or attachment that can be placed on a steel pin. The handle should be made of ebonite or rubber.
Welding machine and protective devices to him (gloves, mask).
Steel hook no more than 0.5 mm thick.
A 16cm weight is about 6cm thick.
Steel washers in the amount of 2 pieces (a diameter of 2.5-3 mm is suitable).
We recommend doing all other work on making a reverse hammer for body repair with your own hands in the following sequence:
1. Clean if necessary metal pin from rust by grinding and treat the perfectly flat surface with any degreaser.
2. A hook must be attached to one end of the pin. If the hook has a thread on one side, it can also be threaded on the pin, creating a removable connection. Otherwise, you will have to use welding to attach the hook.
3. It is necessary to place a washer at the base of the hook, which will prevent the weight from moving to the working surface and accidentally damaging it.
4. To put a weight on a metal pin, you need to make a hole in it, the diameter of which should be 1 millimeter larger than the diameter of the pin. Thanks to this, the weight will be able to move freely, and you will be able to give it any possible acceleration.
5. The weight is put on the pin, and on top of it are attached steel sheets, which will allow you to grab it as securely as possible to strike the body. It is also worth putting and welding another washer on top of it so that the weight does not hit the handle.
6. Proceed to fix the handle. Please note that it should sit on the pin as securely as possible, so if possible it should be welded to the base of the pin.
This completes the process of making a reverse hammer. As you can see, if you prepare materials and tools in advance, all work will take no more than 40 minutes. With your own hands, you can even make a reverse hammer with a vacuum suction cup, which will greatly simplify the execution. repair work on the body. To do this, instead of a hook with which the tool is attached to the working surface, it is necessary to use special suction cups that can provide the same reliability of fastening.