DIY repair of cracks in plastic bumpers - methods and technology. Do-it-yourself car bumper repair We close the crack using liquid polymer

In detail: do-it-yourself repair of a hole in the bumper from a real master for the site site.

Having broken a plastic bumper on a VAZ car, the owner can relatively inexpensively purchase and install a new one, painted in a suitable color. Owners of foreign cars are not so lucky, plastic body kits for their cars are much more expensive. The way out is to repair the damaged part by repairing the crack with your own hands in order to save money. It is useful to know about the methods of restoring broken plastic to the owners of Russian cars, not to buy a new element because of small cracks.

Depending on the amount of damage and the type of plastic, the following methods of cracked bumpers are practiced:

cosmetic bonding with acetone and donor plastic;
gluing with modern chemical compounds;
mount on epoxy resin using fiberglass reinforcing mesh;
sealing the crack with a soldering iron reinforced with a metal mesh;
welding with a hot air gun and a plastic rod.

Reference. There is one simple method used by car enthusiasts who are not overly concerned about the look of the car. This is the connection of the edges of the crack with wire or staples from a stapler. This is a simple matter, which means that there is no point in considering this technology, everything is clear.

The use of acetone for bonding, which can dissolve many types of plastics, is a temporary measure used for small cracks that have appeared in the middle of the body kit. Its essence is as follows:

Pieces of plastic, similar in composition to the bumper material, are selected and dissolved in acetone to a thick consistency.
On the back of the bumper, the crack is degreased and also treated with acetone in order to soften the surface.
Liquefied plastic is applied to the damage from the reverse side, and then hardens for several hours. Outside, the defect can be tinted with a corrector tube.

Any single cracks in most plastics can be sealed using thick two-component compounds sold in two tubes. The exception is fiberglass body kits, they are glued together with epoxy resin, and in case of serious damage, reinforcement with fiberglass mesh is used.

With numerous large cracks, breaks and holes in the bumper, bonding methods become ineffective. In such cases, soldering or welding with a hot air gun using a donor polymer material is practiced. After such repairs, the place of the defect is thoroughly cleaned and painted in the color of the car. Finally, a full bumper polish should be done so that the painted area does not stand out against the background of the old coating.

Advice. If you got into an accident or collided with a fixed obstacle and broke the body kit, try to collect all but the smallest pieces that have flown off. This will allow you to use "native" plastic for repairs and not look for something similar.

The preparatory process differs little for various methods of gluing and welding polymer parts, so it should be considered separately. The first question is whether it is really necessary to remove the bumper in order to make repairs. In most cases, dismantling is indispensable, since the plastic must be sealed on both sides. The exception is broken body kits, cracked in many places. They must first be stitched together and then removed. Otherwise, after repair, the part may lose its shape, which is why the attachment points will not converge, and the gaps with adjacent elements will increase.

Reference. Often, the body of the bumper comes off at the attachment points and small pieces of plastic remain on the screws. Before dismantling, such a part is securely welded to the torn mount and only then removed.

To prepare a damaged body kit for repair, you need the following tools and materials:

a set of keys and screwdrivers for removing the element;
electric grinder;
sandpaper of various grain sizes - from P180 to P320;
degreasing liquid - organic solvent or white spirit;
rags.

Note. With the help of a grinding machine, you can perform cleaning better and much faster than by hand. This and other power tools that are needed for painting and polishing can be rented for 2-3 days.

Regardless of whether work is being carried out directly on the car or with the bumper removed, it must be thoroughly washed and dried. Then, with a coarse sandpaper, you need to peel off the paint with an indentation of 3-5 cm from the crack in each direction and sand the area with fine sandpaper. Whichever method of repair you choose, the paint must be removed to the base, otherwise it will interfere with the adhesion of the adhesive or the fusion of polymers during welding. At the end, the area should be degreased.

Advice. The quality of the body kit repair depends on the conditions in which it is made. It is more convenient to repair damage in a garage equipped with a viewing ditch for easy removal of a part and soldering of loose fasteners in place.

To implement this method, you need to purchase the following bumper repair kit from the 3M brand:

2 FPRM components for the preparation of liquid polymer in tubes of 150 ml (price - about 2500 rubles);
special hard tape;
self-adhesive reinforcing mesh made of fiberglass (otherwise - glass canvas) 48 mm wide;
an adhesion initiator in an aerosol can;
2 spatulas - wide and narrow;
stationery knife;
gloves, goggles.

Reference. Similar kits are offered by other manufacturers, but the 3M brand is the most famous and proven in practice.

Liquid resin bonding is suitable for most plastics and can be done either with the body kit removed or on the vehicle. True, the second option is rather inconvenient, plus you will need good lighting in the inspection pit. To cut the crack, you will need an electric drill (not a grinder!) With a mandrel for abrasive wheels. The repair consists of the following technological operations:

Important! After mixing the components, the composition must be used within 6 minutes, which is quite enough for applying to the damage on one side. The curing time of 30 minutes is correct for a room temperature of 21-23 ° C, therefore, when working in a cold room, it is imperative to arrange local heating of the bumper (for example, with an infrared heater).

If irregularities are noticeable on the front side of the element, then before painting, apply a little putty intended for plastic on the drops. After drying, clean it with P1500 sandpaper, degrease and paint with a spray gun, after applying a layer of primer. After 1 day, polish the surface of the body kit.

The technology is used to repair damage to body kits made of fiberglass, since the previous method will not work in this case. What is required for work:

fiberglass for bumper repair;
polyester (epoxy) resin complete with hardener;
soft brush;
utility knife or scissors;
rubber gloves.

Advice. If a bulge or a depression has formed at the place of impact, then immediately after stripping, level it using a construction hair dryer to heat it.

Since fiberglass patches will have to be applied on both sides of the damaged area, it is better to dismantle the bumper from the car. After completing all the preparatory work, including stripping paint and degreasing, proceed in the following sequence:

Using a sander with coarse sandpaper (P80-P120), make a depression in the bumper body from the front side, covering a radius of 3-5 cm from the crack. This is necessary so that the fiberglass overlay does not ultimately protrude beyond the plane of the part.
On the back, sand with a coarse sandpaper, but without a depression. Degrease the area and let dry.
Cut out the fiberglass patches. On the front part, you need to make a neat patch, repeating the shape of the recess, and from the rear you can glue a rectangular overlay.
Mix resin and hardener in the proportions indicated on the package. Apply the composition with a brush to the surface, apply a patch (you can in several layers) and saturate it with resin.
Accurately observe the time specified for the curing of the epoxy compound (written on the container with the resin), then carefully clean the repair area with fine sandpaper. The task is to level the surface by removing the protrusions.

Note. Initially, coarse sandpaper is used in order to create a roughness on the surface of the plastic, which contributes to better adhesion of the polyester adhesive.

This completes the work on the repair of the plastic itself, then cleaning, priming and painting are performed using standard technology. The last operation is bumper polishing, it is necessary to give the element a uniform shine.

Numerous cracks, breaks and torn off bumper elements are repaired using thermal methods, in particular, soldering. This painstaking work requires a small set of tools and materials:

a soldering iron with a power of at least 100 W with a wide sting and a wooden handle;
thin metal mesh specially designed for thermal bonding of plastic parts;
knife, nippers for processing broken off segments;
screw clamp;
fine and coarse sandpaper for cleaning seams.

Note. Soldering of serious defects can take hours. During this time, the plastic handle of the soldering iron will warm up so much that it will become difficult to hold the tool with your hand.

In the process of preparing for soldering, the paint must be removed to the base not only from cracks, but also from torn pieces of the bumper. Moreover, in this case, the body kit from the car is not removed until all the gaps are fastened and fixed by soldering, otherwise the element will lose its exact shape.

Soldering technology is implemented in the following sequence:

Important! When soldering the edges of the plastic, you need to hold it motionless and give time to solidify. If you release the part ahead of time, the seam will come apart.

At the end of the soldering procedure, sand the surface of the element, then degrease and paint in the desired color. During further operation, be more careful, because from a strong impact, the bumper can fly to pieces, breaking in the same places. To hold it together more firmly, it is worth using another method - welding with donor plastic.

This is a more efficient way of joining polymer parts, used not only for repairing bumpers, but also for restoring a variety of plastic products. It allows you to more reliably fasten the elements, spending much less time on work than when soldering. To use this technology, you need to prepare the same tools with materials as for soldering, excluding the metal mesh. In addition, for repairs you will need:

hot air gun with a power of 1600 W with the ability to regulate the temperature of the supplied air from 100 to 700 ° C;
universal welding rods compatible with most plastics.

Advice. If you buy or rent a hot air gun, make sure that it has overheating protection with automatic shutdown.

The welding technology of a broken bumper is very similar to soldering and differs only at the last stage:

After completing the preparatory stage, align the edges of the cracks, secure them with clamps and grab them with a soldering iron, as described in the previous section. Replace the broken pieces in the same way.
Using a soldering iron, cut the crack along its entire length, making a depression where the welding rod will fit.
Take a hair dryer heated to 400-600 ° C (depending on the type of plastic) in one hand, and a welding rod in the other. Attach its end to the beginning of the cut crack and heat with a hair dryer simultaneously with the surface of the bumper, holding the tool at an angle.
When the bar begins to soften, start laying it in the groove without stopping heating. Fill the groove to the end.
For reliability, make several transverse seams, applying the softened bar directly to the inner surface of the body kit.

Note. To cut a crack, instead of a soldering iron, you can use a cutting or abrasive wheel mounted on an electric drill. But such work requires care so that the potholders do not fly off.

If possible, use special welding nozzles for a hair dryer, where a plastic bar is immediately inserted, so that you do not need to hold it with your hands. At the end of the work, the repaired bumper must be repainted and polished.

Advice. If you didn’t manage to get a hot air gun, then you can use a special hot glue gun that welds plastic with thinner rods.

Repairing cracks in a plastic bumper is a painstaking work that requires a serious approach. If you decide to do everything with your own hands, without having the appropriate experience, expect to spend 1-2 days (depending on the damage). If the outcome is successful, you will save a considerable amount, and in case of failure you will always have time to buy a new body kit or go to a car repair shop, so you have nothing to lose.

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The bumper is a vehicle safety element that also has aesthetic functions, improving the appearance. In accidents, in collisions, the part takes on the force of the impact, protecting the body and passengers. Damage also occurs in other situations - when parking, maneuvering.

The cost of subsequent restoration is determined by the degree of damage. But knowing how to repair a plastic bumper yourself, it is easy to cut costs and not leave the car in service.

Work begins with an inspection of the damaged bumper, assessment of defects and the feasibility of restoration. If the damage is accompanied by the loss of pieces, the procedure becomes more complicated - you need to choose the same material to fix the hole or order a new bumper.

The repair technology is determined by the existing defects:

Scratches, chips that have not touched the plastic are removed by sanding, putty and subsequent painting.
Deformations are common damage, often accompanied by cracks. To restore the geometry, the part is heated with a hairdryer; a burner will do. Heating the plastic makes it soft and pliable. Then it is not difficult to give the element the desired shape. The result is recorded until it cools completely. Do not overheat the fragment. This is accompanied by thermal deformation.
Cracks are common damage that requires soldering. Depending on the size of the crack, its location, reinforcement, reinforcement, contraction may be required to prevent further divergence.
Holes are flaws that occur when you hit an obstacle or as a result of a collision with the back of another car. They arise as a result of the effect of the muffler. Self-repair involves soldering, reinforcement. The procedure is possible if there is a missing element. If a selection of material is required, the markings on the inside of the bumper are preliminarily examined.

With the right approach, it is easy to eliminate damage, the main thing is to follow the sequence of stages, technology, and prepare a place for work.

Plastic bumper soldering options

Soldering is an effective method of repairing cracks and holes in a plastic bumper. When thinking about how to solder the bumper yourself, it is better to carry out manipulations from the front side. It is important to solder to the correct depth. Working from the inside, it's easy to make mistakes. Then putty, paint layer will crack soon.

Preparatory steps:

The bumper is being dismantled or the undamaged elements of the car are protected.
A table and a workplace are being prepared. If the part turns over to the front side, the surface is covered with a soft cloth.
At a distance of 1 cm from the edges of the defect, paint is removed.

Bumper soldering options:

The soldering iron heats up, after which notches are made from each edge of the crack. The tool is deepened by half the thickness of the element, held at a 45 degree angle. A comb is obtained at the edges. Further, a soldering iron tip is carried out along the crack, smoothing it. The edges are securely connected.
Using staples from a stapler allows you to get a reliable connection if the material is thin. Staples, in steps of 3-5 mm, are fused into the plastic, the ends are bent from the inside. They shouldn't stick around.
Copper and ordinary wire, as solder, allows you to securely hold the elements together. Skills and experience are required here. Small holes are needed for threading the wire. The further scheme of work does not differ from the use of staples. For minor damage, holes are not made.
The plastic solder helps create a solid surface. It is supposed to be restored by adding plastic in the place of damage. It is important to find the right solder.

Reinforcement of the structure

Brazing is the most effective method. But so that the crack does not reappear, the place of damage is reinforced. Further processing uses fiberglass, epoxy, rubber glue. Over time, materials move away without violating the integrity of the structure. Therefore, they are applied from the inside.

In the area of damage:

- the paint is cleaned;
- the plane is degreased;
- glue is applied;
- mesh, wire is applied;
- alternating a layer of fiberglass and glue, which will be the final one.

Regardless of the choice of soldering and reinforcement method, the process ends with grinding the cooled surface, putty until a flat plane is obtained.

Important points in preparation for painting

Eliminating defects is only part of the job. For a complete restoration, you need to know how to paint a car bumper correctly. The process starts with preparation. If the part is soldered, the work area should be carefully sanded, as if there are scratches.

Putty is carried out in several stages:

a special putty is applied to work on a plastic plane;
such a height is gained so that the putty protrudes a little;
the area is sanded until all irregularities are eliminated, which are checked by touch;

The procedures are repeated until an ideal plane is obtained. When preparing yourself, it is better to choose fine sandpaper. The next step is degreasing. Apply the primer twice, ensuring that each layer dries.

The moment of preparation implies not only the surface treatment of the element.

the place where the work will be carried out must be cleaned, wet cleaned, dust removed;
walls, ceiling, floor covering are cleaned.

it is better to dismantle the bumper, which will ensure a high-quality application of the paint and varnish layer;
if dismantling is excluded, the car is tightened with film.

Selection of paint:

the best option is by VIN-code, then the color match is guaranteed;
computer selection is also effective, but some differences cannot be ruled out.

Paint application, preparation of materials:

the amount of paint, its composition, the method of application determines the quality of coloring, the final shade, consumption;
the spray gun must be properly adjusted, make sure that the pigment supply is normal (if an aerosol is not used).

Secrets of painting technology

Correct painting of a bumper is a simple procedure, provided it is properly prepared. In work you need to use a mask. The amount of materials and the time required for painting is determined by the amount of work.

Types of painting:

Local painting is suitable for inconspicuous areas, lower elements, when damage is minor or scratches on the bumper need to be painted. It is supposed to apply paint to a specific area.
Full bumper painting is used for damage in conspicuous places.

The painting process includes the following stages:

Blowing, degreasing.
Testing paint on parts, applying a small amount.
The first layer is made thin - this is the base. Dries 5 - 10 minutes.
Apply 2 coats of paint with drying intervals of 15–20 minutes.
If dust gets on the part between layers, special interlayer wipes are used to remove dirt.
The final stage is the application of 2 layers of varnish with drying.

With unhurried preparation, careful application of pigment and varnish, irregularities and streaks do not occur. But if defects appear, you need to wait until the element is completely dry, and then grind and polish these places.

Often in the traffic flow you can find a car with a cracked or deformed buffer. What can you do, no one is safe from unsuccessful parking or a minor accident. Nevertheless, this is not a reason to continue driving a car that has lost its "shiny" appearance - there is a practical experience of restoring the original state of this element.

The external plastic components are mainly made of thermoplastic plastics. The technology for restoring such products is based on welding, it is this technology that allows you to get rid of through cracks and even recreate broken fasteners. Actually, the procedure is not much more complicated than preparing and spray paint damaged area of the car body.

Some car enthusiasts assure us that we repair the bumper with our own hands using metal brackets. But an experienced car owner knows that like is treated like this, that is, repair plastic rods are used for soldering. Their composition, color and profile are different; the required core is selected according to the marking on the buffer.

Making the right choice means guaranteeing a high-quality repair, because the mismatch of materials will significantly reduce the life of the automotive element. To find out what the cracked bumper is made of, it is enough to carefully examine the inside of the part. Depending on the marking, the following conclusions are drawn:

PP - polypropylene base.
ABS (GF, PAG 6) are hard plastics.
PUR - polyurethane.

Plastic welding requires high temperatures, for example, 400-450 ° C is suitable for propylene, and 500 ° C is necessary to restore an ABS structure. Many car owners will learn how to repair a bumper with their own hands in a video where craftsmen use an ordinary 100 W soldering iron.

You can also restore a damaged part using pieces from a bumper with a similar marking. They are cut into strips 8 mm wide for PUR, and 4-5 mm for polypropylene.

Almost any breakdowns are treated by welding, even broken parts are reanimated. However, no one canceled the economic feasibility of such work, because the restoration of numerous defects can hardly be called justified. The cost of a complete restoration and staining will be more expensive than a new buffer.

Certain tools are required to complete the repair. These can be both ordinary household appliances and professional tools. The ideal kit includes the following items:

Orbital sander or sanding block.
Grinding wheels of various grain sizes.
Mini drill like Dremel or drill.
Clamps and rubber spatula.
Soldering iron and hair dryer.
Metallic tape.

Of the materials for restoring a cracked buffer, you may need:

Putty and primer.
Brass mesh for crack reinforcement.
A can of paint or a can of paint.
Plastic repair rods of the required configuration and composition.

The damaged part must be dismantled in order to eliminate, firstly, excessive stress in the crack area. Those who have already done such work will say that now we clean the bumper and only then repair it with our own hands.

The cracked parts fit together. For reliability, they are fixed with metal tape from the outside of the part. If the breaks are quite significant, then clamps will be needed to clamp the edges of the cracks. Their number depends on the complexity of the repair.

When restoring PP-based parts, the reinforcing mesh is not used. The process begins with the fact that a nozzle with a nozzle with a diameter of 5-7 mm is installed on the hair dryer. In the future, work is carried out according to the following points:

On the inside of the buffer along the crack joint, use a Dremel mini-drill to make a groove for the plastic rod.
Using a hair dryer, melt and place the repair rod into the prepared groove.
Clean the front part of the bumper with an orbital sander with P240 attachment and repeat the welding procedure similarly to the operation on the inside.
Grind the cooled seam from the outside with a nozzle with the same grit P240, then remove dust from the surface.

Even out irregularities with a special putty for plastic, try to keep the layer as small as possible.
Dilute the primer with solvent 3: 1 and apply two coats to the degreased surface. Drying time for the first layer is 15 minutes.
Apply a developing layer in a contrasting color, followed by sanding with a disc or sandpaper with grit P800 and P1000.
Eliminate the detected defects with a nitro putty followed by sanding with P1000 sandpaper.
Remove dust with a damp cloth and degrease the part, then paint plastic decorative paint with overlapping borders 50-100 mm. Apply the paint in 3-4 coats with intermediate drying cycles.

Anyone who is interested in how to properly repair a bumper in a video with their own hands should take into account an important detail. 30-40 minutes after applying the last layer of paint, the part should be varnished. Thus, we get a flawless appearance of the repaired part. Do not forget to follow a few simple rules:

You should try to apply a minimum layer of putty.
Take a temporary pause for complete hardening of the putty layer.
To process the putty area with a grinding wheel or sandpaper with grit P800, and then - P1000.
It is desirable to apply a developing layer of primer.

In the case of a polyurethane buffer, the preparatory stage in the form of grooving work is excluded. A brass reinforcing mesh is applied to the crack; steel is not recommended for use, because it is prone to corrosion. Alternatively, stapling staples can be used every 10-20 mm. They are recessed into the body of the part across the seam, it is imperative to make sure that the bracket does not go through the part.

Further, the repair technology does not differ from the restoration of a polypropylene part. Wire mesh or staplers should be sunk into the plastic. Only after that, the seam is filled with repair plastic and soldered from the opposite side. Some important points of technology should be taken into account:

It is necessary to solder the mesh or staples carefully so as not to overheat the plastic, otherwise it may deform from the opposite side.
For a complete DIY repair of a polyurethane bumper, the width of the reinforcing mesh should be 15-20 mm.
It is better to press in the mesh or staples with a flat object.
If the legs of the staples pierce the plastic through and through, then they should be shortened using side cutters.
For the convenience of working with metal elements, you can use tweezers.
To prevent the new enamel from peeling off, it is necessary to grind the paint over the entire plane of the part.

Puttying and painting are performed in the same way as described above - according to the traditional scheme. Repair work on the restoration of the buffer can be combined with painting the car , so the consumption of materials will be more rational. It is important to determine in advance the feasibility of carrying out restoration work. If there are significant costs in the future, then it is better to buy a new part.

According to generally accepted safety standards, each vehicle should be equipped not with metal bumpers, but with their plastic counterparts. When hitting a pedestrian, the plastic bumper cushions the force of the impact to a large extent.

Thanks to this, the pedestrian has a chance to stay alive and not get dangerous injuries (of course, provided that the speed of the car was not very high).

In addition, the use of plastic bumpers significantly reduces the overall weight of the vehicle, which has a positive effect on overall agility and dynamics. However, the main disadvantage of a plastic bumper is considered to be its weak shock resistance.

To all of the above, we can add the fact that some car manufacturers are simply trash when making bumpers. They make them out of very thin plastic. Therefore, even a weak blow provokes the appearance of all kinds of cracks and holes.

As a result, the car owner has to do the repairs more often than he would like. All those who have already encountered this nuisance are well aware that such repairs in any car service are not cheap. In some cases, it is easier to buy a new part, but there are amateurs who prefer to do everything with their own hands. This article was written for such beginners Kulibins.

In fact, all actions to restore a problem bumper are not difficult at all, provided that the hands grow as they should :). Therefore, let's look at how to do everything without outside help.

First, let's say that according to statistics, car owners are much more likely to restore the front bumper of their vehicles than the rear one. This is explained by the fact that the front bumper is more often subjected to mechanical damage: collisions on the curb; blows in case of accidents; damage that occurs when stones or other objects hit.

First of all, it must be said that there are several ways to repair a bumper. First of all, the types of repairs are subdivided according to the nature of the damage:

chips, dents, scratches without through damage
cracks
loss of a bumper fragment

If the bumper has retained its integrity, then consider yourself lucky. Repairing chips and scratches is the simplest type of repair, which boils down to cleaning the chip area with sandpaper, filling the damaged area, sanding and painting.

What you should pay attention to when performing these operations, we will consider further when describing other types of repairs, since all these operations will be present in almost all types of bumper repairs.

For the sake of fairness, it should be noted that many motorists do not even repair chips and scratches, but drive with these damages until they decide to sell the car.

But the cracks can no longer be ignored ...

Cracks are the most common problem with plastic bumpers. A timely untreated crack can further cause complete destruction of the bumper. Therefore, try to immediately repair cracks, and not wait for the right moment.

First of all, it should be noted that today there are quite a few ways to repair cracks on the bumper. Special repair kits are sold and the method to choose depends on various factors: on the type of plastic from which the bumper is made; from the tools at hand; from the skill of a motorist in repair; from the time allotted for repairs.

So, for example, in conditions when there is no time for repairs at all, and you need to come up with something very quickly, then you can even fasten the crack with plastic clamps.

For repairs in this case, you will need a drill, a set of plastic, narrow clamps, a drill.

To begin with, the edges of the crack are drilled to prevent its further spread. And then, on both sides of the crack, paired holes are drilled through which a plastic clamp is pulled and tightened from the inside of the bumper.

Such screeds must be made along the entire length of the crack at a distance of 1.5 cm from each other.

Of course, such a repair does not look very aesthetically pleasing and can be used as a temporary way out of the situation before replacing the bumper.

It is, of course, also possible to overhaul the bumper, after which the repaired part will outwardly be indistinguishable from the new one.

There are also several options for this repair, but all of them are united by one principle: first, the crack is eliminated with simultaneous reinforcement, and then the seams are sanded and painted.

The crack can be closed by soldering, gluing, screed with construction staples, special electrodes, metal mesh, etc. A combination of different methods is also possible.

Here we will consider one of the options for repairing a cracked plastic bumper ...

First, it is required to dismantle the damaged bumper from the car. Typically, the bumper is secured with one bolt on the right and left sides in the inner section of the wheel arch (where the bumper connects to the fender) and four bolts in the center (along the top and bottom edge of the bumper).

Next, we begin the procedure for restoring the bumper. First, you need to carefully drill the boundaries of the crack with a small drill so that it does not spread further. Then, to increase the integrity and strength of the structure, a small metal mesh is soldered onto the inner surface of the bumper (on the crack section itself). During this process, it is necessary to solder it as deeply as possible into the plastic, but at the same time not to solder through the bumper itself. This procedure can be done with a 60W soldering iron.

On the outer part of the bumper, we clean the damaged area from the paint, we also solder the crack, but without the mesh. We do this very carefully. Then we clean the seam. We remove dust from the surface. With a construction hairdryer, we burn the villi, which will most likely appear on the plastic after cleaning, and then apply a thin layer of putty. We are waiting for the putty to dry, and then carefully clean it.

Next, we paint the bumper. The bumper should be painted in thin layers with the obligatory drying of each layer within 30 minutes.

A minimum of five coats of paint are required. Then the painted area must be polished so that it acquires the desired shine, and its shade becomes identical to the color of the entire bumper. We advise you to polish first the place that was repaired, and only then the entire bumper. That's all, we can install a bumper on the car.

If holes appear in the bumper or pieces of plastic have fallen off, then take your time to buy a new one. These damages can be easily repaired. In addition, all this can be done by hand.

As in the previous case, remove the damaged bumper. Next, you should clean the damaged area from the remnants of paint. Then, on the inside of the bumper, you need to glue cardboard, which will replace the rear wall and prevent the repair mixture from spreading (when we will make the "build-up" of the bumper).

Next, using epoxy, fill the damaged area with it and let the mixture dry well. After that, we carefully grind and prepare for the application of the putty. Then slowly and very carefully remove the cardboard and putty the problem area from the inside.

As in the first case, after covering with putty, we perform painting and polishing procedures, and then we install the bumper in its rightful place.

A video showing how to repair a plastic car bumper on your own:

Greetings! My name is Petr. From my youth I loved to assemble car models and paragliders, later my hobby grew into something more and for a long time I worked as a foreman in the company “husband for an hour”. For many years of experience, a huge number of different schemes and implementations of repair and do-it-yourself installation of various devices turned out to be in my piggy bank. Not all "recipes" belong to me, but I think that such knowledge should be in the public domain. This was the reason to create this site.

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Not everyone is lucky enough to have their own garage. There are even fewer of those who have electricity supplied to it and it is equipped with a machine park. Therefore, the advice found on the Web, about how, for example, to repair a bumper with your own hands using a soldering iron or a hair dryer, is absolutely useless. In fact, the repair of this car part can be carried out under any unequipped canopy or even without it, achieving an excellent result.

If you inspect your toolbox, much of what is listed below will be in stock.

Screwdriver.
Polishing attachment with felt wheel.
Mechanical riveter and rivet set.
Polyurethane foam, better under the gun, and he himself.
Glue for mice.
Acetone, solvent 647, polyurethane foam cleaner.
Empty disposable lighter.
Acrylic two-component putty.
Narrow spatula.
Tool knife.
Sandpaper.
Nitro-paint of a suitable color. Better in aerosol cans.
Cold two-component welding.

The front bumper repair does not differ, in fact, from the rear part restoration technology. However, on some models it is more difficult to remove. And in some cases it will be necessary to do this. Before starting work, the bumper must be washed and wait until it is completely dry.

Scratches - small and large

The scratch becomes visible due to the fact that it changes the refraction of the light rays. If you look at it at high magnification, you can see crushed fibers, chaotically located bulges of irregular shape and depressions. To make the scratch invisible, all this relief must be smoothed out.

Small scratches on the bumper

A minor scratch is damage that is less than the thickness of the paintwork. Usually it is no more than 70 microns - 0.07 mm. If the main substrate is not visible under the scratch, then it is enough to polish it using a screwdriver with a felt circle nozzle.

A deep scratch damages not only the paintwork, but also the base material. Polishing alone is not enough. The damage is treated with a solvent. It is very convenient to use a polyurethane foam cleaner in an aerosol can for this. After that, break the disposable lighter and fill the pieces of plastic with solvent 647. It will be great if you find a lighter of a similar color.

As a result, you should end up with a fairly thick mass. It is called enamel and is used by aircraft modelers for sealing, filling seams and impregnating sheathing. You fill the crack with the enamel, using a degreased trowel to level it. After half an hour, you can start polishing.

Cracks with and without chips

They can be only internal or continue to the external edge. To stop the crack from growing, you need to drill a hole in the place where it ends.

If the damaged surface is relatively flat, without stiffening ribs and other relief, and its duration is no more than 10 cm, then gluing can be dispensed with. To do this, cut out several plastic plates of the same thickness and elasticity as the main bumper material. They are glued from the inside, so you cannot do without dismantling work.

Soldering the crack with a soldering iron

Mouse glue is the best option for this job. He has great holding power. It does not require special surface treatment and sticks to any material. It is practically not susceptible to drying, its film always remains elastic, withstands vibration loads well.

In the event that the crack is long-lasting, its edges "walk" or it ends at the outer edge, it is additionally fixed with rivets. A mechanical riveter will allow you to do this with good quality and will greatly simplify the work. The rivet itself has a kind of mechanical aesthetics, so using it in reasonable amounts will not spoil the appearance in the least.

The plates that will hold the edges of the crack together are best cut from aluminum or sheet metal with a thickness of 0.5 mm. The fact is that the head on the back of the rivet will turn out to be not very large in diameter. The strength of the plastic may not be sufficient to hold the rivet in it.

The holes for the rivet should be slightly wider than the rivet itself, so that it does not damage the base material during deformation. Outside, they are countersinked, the depth of the countersink should be no more than a third of the thickness of the bumper material.

It is better if the rivet length is one third more than the total thickness of the fastened materials. A long one will create a connection that is too loose. Short - not strong enough due to the small diameter of the cap.

The riveter will also come in handy in case you need to restore the breakaway bumper mounts. They are cut from a metal plate and set on one or two rivets.

Once the edges have been fixed, the crack turns into a deep scratch. It may have chips that increase its width. They will not be covered with enamel. Use a two-component cold seal kit that has good adhesion to any material. While it is in an elastic state, it can be pushed through through large through-holes. Flatten out the excess from the inside, ensuring a secure two-way hook on the edges of the crack. After solidification, cold welding is processed with sandpaper, then the surface is polished and painted.

Holes and massive destruction

Do not rush to throw out the bumper if there are through holes on it and even some of the elements are missing. Of course, renovations get complicated. In addition to repairing scratches and cracks, restoration of the shape will also be required. Polyurethane foam will help you with this.

The bumper is removable. Large fragments, if possible, are fastened with a rivet. The cracks are fixed so that they are not blown apart by the pressure of the expanding polyurethane foam mass. In especially difficult cases, you can create a semblance of a frame from metal plates that remain inside and follow the main contours of the bumper.

Soldering the hole in the bumper

We must try to hook the mass of foam to the internal ebbs, stiffeners and other technological elements. Use a gun - less consumption, more control over the process. Choose low expansion foam to avoid breaking the bumper.

Polyurethane foam is poured into the inner cavity of the bumper in layers of 2-3 centimeters thick with stops for solidification. Your task is to form a volume slightly larger than that of the element being restored.

Start trimming the excess mass of frozen foam one day after pouring. Try to copy the contours of the restored area as accurately as possible. Feel like a sculptor.

The original small fragments are glued to polyurethane foam without much difficulty. The rest of the surface is covered with a two-component acrylic putty in several stages, with thorough drying of each layer. Finally, the surface is formed with scrapers and emery cloth of various degrees of roughness, after which it is processed clean and painted.

A bumper repaired using this technology may not look different from the original one.

Finishing features

If the bumper has a subtle relief or noble roughness, then sanding and polishing will spoil it completely. Such details can only be painted.

Spots of painting can look foreign, even if the color scheme is matched to tone. The reason for this is the microrelief of the repaired site, which has a different refractive index of light. In this case, only multi-layer continuous painting of the entire part will help.

If the differences in tone are caused only by the burnout of the main element, you can try to freshen it up by wiping it with a cloth dipped in acetone.

The bumper does not particularly affect the driving performance of the vehicle. His condition reflects to a greater extent the personality of the owner and his philosophy of life. However, the deterioration of aerodynamics increases fuel consumption, and pieces of plastic flying off on the go can damage surrounding cars. Therefore, even the inveterate "do not care" should think about repairing this body element.

Crack sealing methods

Depending on the amount of damage and the type of plastic, the following methods of cracked bumpers are practiced:

cosmetic bonding with acetone and donor plastic;
gluing with modern chemical compounds;
mount on epoxy resin using fiberglass reinforcing mesh;
sealing the crack with a soldering iron reinforced with a metal mesh;
welding with a hot air gun and a plastic rod.

Reference. There is one simple method used by car enthusiasts who are not overly concerned about the look of the car. This is the connection of the edges of the crack with wire or staples from a stapler. This is a simple matter, which means that there is no point in considering this technology, everything is clear.

The use of acetone for bonding, which can dissolve many types of plastics, is a temporary measure used for small cracks that have appeared in the middle of the body kit. Its essence is as follows:

Pieces of plastic, similar in composition to the bumper material, are selected and dissolved in acetone to a thick consistency.
On the back of the bumper, the crack is degreased and also treated with acetone in order to soften the surface.
Liquefied plastic is applied to the damage from the reverse side, and then hardens for several hours. Outside, the defect can be tinted with a corrector tube.

Advice. If you got into an accident or collided with a fixed obstacle and broke the body kit, try to collect all but the smallest pieces that have flown off. This will allow you to use "native" plastic for repairs and not look for something similar.

Reference. Often, the body of the bumper comes off at the attachment points and small pieces of plastic remain on the screws. Before dismantling, such a part is securely welded to the torn mount and only then removed.

To prepare a damaged body kit for repair, you need the following tools and materials:

a set of keys and screwdrivers for removing the element;
electric grinder;
sandpaper of various grain sizes - from P180 to P320;
degreasing liquid - organic solvent or white spirit;
rags.

Note. With the help of a grinding machine, you can perform cleaning better and much faster than by hand. This and other power tools that are needed for painting and polishing can be rented for 2-3 days.

Advice. The quality of the body kit repair depends on the conditions in which it is made. It is more convenient to repair damage in a garage equipped with a viewing ditch for easy removal of a part and soldering of loose fasteners in place.

Two-component bonding

To implement this method, you need to purchase the following bumper repair kit from the 3M brand:

2 FPRM components for the preparation of liquid polymer in tubes of 150 ml (price - about 2500 rubles);
special hard tape;
self-adhesive reinforcing mesh made of fiberglass (otherwise - glass canvas) 48 mm wide;
an adhesion initiator in an aerosol can;
2 spatulas - wide and narrow;
stationery knife;
gloves, goggles.

Reference. Similar kits are offered by other manufacturers, but the 3M brand is the most famous and proven in practice.

Using a low speed drill and an abrasive wheel, chamfer approximately 30 ° around the edges of the crack on both sides. In cross section, it looks something like this: "><».
Degrease area and allow solvent to evaporate completely. On the front side of the bumper, where the paint was already peeled off in the preparatory stage, glue adhesive tape along the entire crack. It will serve as a kind of formwork when pouring a two-component mortar.
Treat the damaged area on the back of the body kit with an initiator of adhesion from a cylinder, then apply a self-adhesive glass canopy to the split.
Mix the tube components in a 1: 1 ratio using a spatula. Apply liquid resin to the mesh in several thin coats to avoid air pockets. Stack the mixture until it completely hides the glass canopy.
After laying the composition, let it harden for 30 minutes, then remove the tape from the front side and repeat the sealing operation (but without the mesh).
After hardening, treat the area with a grinder, alternately using sandpaper P180, P240 and P400. This completes the repair of the plastic and you can start painting.

Important! After mixing the components, the composition must be used within 6 minutes, which is quite enough for applying to the damage on one side. The curing time of 30 minutes is correct for a room temperature of 21-23 ° C, therefore, when working in a cold room, it is imperative to arrange local heating of the bumper (for example, with an infrared heater).

Covering with liquid polymer - photo

After cutting, manual cleaning of the crack is required The inner side of the body kit also needs to be sanded Cutting the edges of the crack at an angle Adhesive tape is glued from the front side From the inside the glass canal is glued From the end you can see how the tape restricts the outflow of the composition outward when applying 2 component is squeezed out onto the spatula in the same amount Mixing the components with a spatula The composition is rubbed into the gap and the mesh with a spatula After hardening and removing the adhesive tape, the sealed joint is cleaned This is what a sealed crack in plastic looks like

Video instruction on the use of the 3M composition

Fiberglass repair

The technology is used to repair damage to body kits made of fiberglass, since the previous method will not work in this case. What is required for work:

fiberglass for bumper repair;
polyester (epoxy) resin complete with hardener;
soft brush;
utility knife or scissors;
rubber gloves.

Advice. If a bulge or a depression has formed at the place of impact, then immediately after stripping, level it using a construction hair dryer to heat it.

Using a sander with coarse sandpaper (P80-P120), make a depression in the bumper body from the front side, covering a radius of 3-5 cm from the crack. This is necessary so that the fiberglass overlay does not ultimately protrude beyond the plane of the part.
On the back, sand with a coarse sandpaper, but without a depression. Degrease the area and let dry.
Cut out the fiberglass patches. On the front part, you need to make a neat patch, repeating the shape of the recess, and from the rear you can glue a rectangular overlay.
Mix resin and hardener in the proportions indicated on the package. Apply the composition with a brush to the surface, apply a patch (you can in several layers) and saturate it with resin.
Accurately observe the time specified for the curing of the epoxy compound (written on the container with the resin), then carefully clean the repair area with fine sandpaper. The task is to level the surface by removing the protrusions.

Note. Initially, coarse sandpaper is used in order to create a roughness on the surface of the plastic, which contributes to better adhesion of the polyester adhesive.

Fiberglass body kit repair photo

Video about gluing defects with fiberglass

Soldering large damage to the bumper

Numerous cracks, breaks and torn off bumper elements are repaired using thermal methods, in particular, soldering. This painstaking work requires a small set of tools and materials:

a soldering iron with a power of at least 100 W with a wide sting and a wooden handle;
thin metal mesh specially designed for thermal bonding of plastic parts;
knife, nippers for processing broken off segments;
screw clamp;
fine and coarse sandpaper for cleaning seams.

Note. Soldering of serious defects can take hours. During this time, the plastic handle of the soldering iron will warm up so much that it will become difficult to hold the tool with your hand.

Soldering technology is implemented in the following sequence:

After stripping, wipe the area with a degreaser and let it evaporate.
Align the edges of the cracks and, if necessary, fix them in this position with clamps.
Using a heated soldering iron, make tacks along the length of all cracks. For high-quality heating, the sting must be immersed in plastic to a depth equal to half the thickness of the material, and then level the surface of the molten plastic. The distance between the tacks is 1.5-2 cm.
When the potholders are made on all the cracks, the broken piece must be replaced. Try it on to the hole and trim if necessary so that it fits into the hole flush with the surface.
Solder the torn-off segment on the tacks, then repeat the operation from the inside. After that, the bumper can be carefully removed from the car and continue to work in more comfortable conditions, although it is not necessary to do this, as it is convenient for anyone.
Solder all joints on both sides of the body kit. So that the neighboring tacks do not diverge from heating, the seam must be soldered with gaps. That is, first, the first section between the tacks is welded, then the third, fifth, seventh and so on. When finished, go back and solder any remaining sections.
Cut the mesh into 2-4 cm pieces. They need to be soldered across the seam in the most stressful places - along the edges of the cracks, in the middle, at the junction and near the ribs. The technology is simple: a steel mesh is placed on the seam and, heated by a soldering iron, is immersed in the polymer base of the bumper. Finally, smoothen the softened plastic over the mesh.

Important! When soldering the edges of the plastic, you need to hold it motionless and give time to solidify. If you release the part ahead of time, the seam will come apart.

Photo instructions for soldering bumper

All joints are thoroughly cleaned of paint Fastening of cracks with tacks The break is now kept on tacks The broken piece is clearly adjusted to the opening The fragment is also fixed with tacks All seams are fixed at several points Fully soldered joints All soldering operations are repeated from the inside of the bumper

How to properly solder the front body kit - video

Hot air gun welding

If you operate your car almost every day, then one way or another you have to drive through bumps and puddles, and stand in endless traffic jams, which are formed here and there in a big city. In general, whatever one may say, but constantly have to get into situations in which there is a high risk of damaging the plastic bumper. In general, this part of the car is designed to take the first blow in a collision.

Also, he suffers greatly from falling stones from under the wheels of the cars in front. That is, no matter how careful the driver is in driving, the repair of a plastic bumper is something that almost every car owner has to deal with.

1. Damage to plastic bumpers, which most often have to be repaired by car owners

As we said in the introduction, usually our cars are operated in conditions where it is very difficult to protect the plastic bumper from damage. Of course, metal bumpers are more durable and do not require frequent repairs. However, they are expensive for car manufacturers, which is why they replace them with plastic ones. With regard to the most common damage to this part of the machine, experts have created the following classification:

Normal scratches. We are talking about damage to the surface of the part, which is not through and can only touch the paint layer, or only the top layer of the bumper body. The former are referred to by experts as superficial, and the latter as deep. We think you yourself guessed that if the first occurs, the appearance of the bumper can only suffer, while the second can cause more serious damage - cracks.

Dents, cavities. Such damage occurs as a result of collisions or impacts. However, due to the fragility of plastic and low melting points, dents on such parts very often occur under the influence of chemicals or high temperatures.

Cracked bumper body. This type of damage refers to through damage, since it leads to splits of the part into parts. Cracks can be of a wide variety of sizes and configurations. The most unpleasant fact is that if they are not eliminated in time, the cracks can grow significantly under the influence of vibrations. Also, in the presence of cracks, the rigidity and density of the car bumper is significantly reduced.

Breaks. They do not occur very often, but they have the most unpleasant consequences for the protection of the car. We are talking about through holes in the walls of the part, which lead to the chipping off of whole parts from it. As a result, whole holes appear on the bumper.

But no matter how serious each of these damages may have, they all require immediate repair. Simple scratches and dents can be removed with regular sanding followed by sanding, priming and painting. However, more serious damage is eliminated through rather serious technological manipulations. But be that as it may, all this is within the power of any motorist and does not require contacting a specialized service.

2. Preparatory work: processing the bumper and finding the necessary materials

If there is damage to the plastic bumper, you must not delay repairing it and you must immediately begin to prepare for this process. It's about finding the necessary materials and preparing the bumper itself. Indeed, even with constant driving on a fairly flat and completely asphalt road, a lot of dust accumulates on it, which will interfere with the implementation of repair work. However, everything is not limited to ordinary washing, so we will tell you about everything in more detail.

Materials and devices for the repair of a plastic bumper

In order to prepare the bumper and completely get rid of all damage, you will need to immediately prepare and purchase some materials and devices. They are quite common and often used, so it is quite possible that you can simply find all of them in your own garage:

1. Grinding machine. With its help, the bulk of the work will be carried out, both preliminary and basic. You can replace this machine with a conventional electric drill, however, only if you have a set of special attachments for performing such work.

2. Do not forget to purchase a "sandwich" - a special adapter made of foam rubber. It is used for the aforementioned machine and acts as a connecting piece between the abrasive wheel and the sole of the machine.

3. Sandpaper, which may also be needed for sanding. It is best to prepare options with different grain sizes, since you have to work not only with plastic, but also with other materials with which you will correct and repair damage.

4. Soldering iron. Depending on the material from which the bumper is made, and on the complexity of the damage, both ordinary household and super-powerful can be used. In some cases, a construction hairdryer is used instead, for which you will also have to purchase special electrodes.

5. Thinner for removing old paintwork.

6. Putty and primer for leveling already repaired areas.

7. Spatulas, preferably of different sizes (this is necessary for the convenience of work).

8. Paint and varnish to cover the bumper and give it a new look.

During such work, it is very important not to forget about your own safety. Therefore, even before starting work, do not be too lazy to purchase work gloves and safety glasses in a special store. Also, when sanding and painting the bumper, you will definitely need a respirator. Be very careful when using a soldering iron.

Description of mandatory preliminary work

It is clear that in order to carry out a full-fledged, and not emergency, repair, it is necessary to completely remove the bumper from the attachment point. Thanks to this, you will be able to approach even those areas that are closed when the part is installed. Already with the bumper removed, it is necessary to carry out such manipulations as complete cleaning of the part from all contaminants and washing it. Take the time to inspect the bumper in search of additional cracks and damage, which will also need to be repaired. It is equally important for carrying out repair work to find out what kind of material your bumper is made of. You can find out by the corresponding stamps on the inside of the part:

- polypropylene is usually marked with such Latin letters as PP or PPTV;

Polyurethane bumpers can be identified by the letters PUR;

Hard plastics, which have a very high melting point, are marked with combinations of letters and numbers - ABS, GF15, GF30, PAG6;

Even fiberglass is sometimes used for the manufacture of bumpers, but it is not marked.

After clarifying such nuances, proceed to the complete removal of the paintwork from the place of future work. It is important that even within the boundaries of 1-1.5 centimeters, not even traces of paint remain, since it can negatively affect the quality of the work carried out. If there are cracks on the bumper, their ends must be drilled. Otherwise, cracks may continue to grow directly during the repair work.

Even at the preliminary stage, it is important to process the joining surfaces. Directly in the crack itself, using a grinder and sandpaper, small grooves are made in the shape of the letter "V". It is in them in the future that you will have to lay repair composites, which will completely remove the crack and create an integral surface.

As for further work, everything will depend directly on the material from which your bumper is made. For example, if these are thermoactive materials, then their "melting" is carried out using a building hair dryer and using special electrodes. Also, you can work with similar materials with an ordinary household soldering iron, the power of which does not exceed 100W. As for the bumpers, which are made of thermosetting materials, reinforcing material and subsequent gluing are required to restore them.

3. Do-it-yourself plastic bumper repair: get to know the possible options for eliminating damage

And so, we have already mentioned above that plastic bumpers can be made from a variety of materials, which, accordingly, require a special approach. It is for this reason that we will not consider the repair of the bumper in general terms, but we will separately get acquainted with the different options for performing such work.

How to patch holes in the bumper with an electric soldering iron?

This method of repairing cracks and splits in the bumper is quite effective. However, in order to perform work, in addition to a soldering iron, you also need staples from an ordinary furniture stapler. Having all this at hand, he does the following work:

1. Those places of cracks and splits, which we enrolled and cut out V-shaped grooves in them, are combined with each other. It is very important that the plastic is pressed against each other as tightly as possible, otherwise you may have holes after soldering. To avoid this, from the lyceum side of the part, the crack can be fixed with tape and only after that start work from the inside.

2. We start melting the seamy side. Thanks to this, you can practice with a soldering iron and feel how plastic reacts to its temperature. Even if something does not work out for you, then from the outside your "punctures" will not be noticeable. Experienced experts recommend performing very smooth movements with a soldering iron in order to evenly act on the polymer. Extra jerks can cause additional damage.

3. How is the crack closed? To do this, the tip of the soldering iron must be moved along the crack itself, making transverse movements. That is, you kind of have to apply a seam to the crack, which should be even.

4. So that the place where the bumper is “stitched together” does not burst during the further operation of the car, it is recommended to reinforce it. For this we need staples from a construction stapler. They must be soldered across the crack, while holding the bracket itself with ordinary tweezers. Typically, these brackets have long enough tips that they can "stick out" from the front of the bumper. In order to prevent this from happening, they are simply not simply shortened with the help of nippers. Please note that the material from which the staples are made is quite susceptible to corrosion. To prevent this from happening, they must be completely sealed in plastic. For this, the material itself must be pulled from the areas adjacent to the damage.

5. After you succeed in successfully completing all the work from the seamy side, you can safely go to the front. All the same work is done here as on the inside. If the crack is not large, then on the front side it may not even be reinforced.

6. After you have no trace of the crack, you can start leveling the surface of the bumper. It is recommended to carry out such work using an eccentric sander and an abrasive wheel P240. It is very important here not to overdo it with grinding, so as not to thin the material. Therefore, do not try to make the surface perfect. The remaining dimples can be repaired with a plastic filler.

That’s practically all. After working with an abrasive wheel, polymer hairs may remain on the surface of the bumper, which can be disposed of using a regular lighter. Further, the entire "repaired" surface will need to be degreased and putty, and then it will be possible to paint.

Sealing cracks with electrodes

Despite the effectiveness of the above works, today the method of repairing plastic bumpers using special flat electrodes is becoming more and more popular. As we have already mentioned, the role of the welding machine in this case will be played by a construction hair dryer. We only note that when working with electrodes, you need a special nozzle, the size of the nozzle hole of which is 2.4x6.1mm. Such a small nozzle is necessary in order to create the highest possible temperature and achieve the most efficient melting of the electrodes. Note also that it will not be difficult to purchase a flat electrode from you, the main thing is to clarify with the seller its purpose - for polypropylene or for polyurethane.

Please note that electrodes for different materials are not interchangeable and can significantly reduce the rock service of the repaired area, since it makes the connection fragile. Indeed, under the molten patch from the electrode, the same crack will remain, and if this weasel does not fit snugly to the bumper, it will very soon cease to perform the connecting function. If you have flat electrodes lying around in your garage, but you do not know what material they are intended for, this can be determined by simple testing. Weld half of the strip onto the inside of the bumper, let it cool completely and try to pull it off. If you fail, and if you succeed, then with great difficulty, then the electrode is compatible with the material from which the bumper is made. But an even more effective way to seal cracks is to use pieces of plastic from an unnecessary bumper instead of electrodes. The main thing is that this old bumper has exactly the same markings as the one you are going to repair.

As for the work itself, it is important to use such a thermo-gun (as experts call a construction hairdryer), which has the function of smooth temperature control. The importance of this is explained by the fact that different polymers have different melting points, and if the same temperature may not affect the state of one in any way, then it will completely melt the other. To close the crack, you just have to attach an electrode to it and gradually melt it. When it dries, exactly the same manipulations are carried out with the surface of the bumper as after soldering.

Features of the repair of bumpers made of refractory materials

Quite often, hard plastics or fiberglass are used for the manufacture of bumpers. Holes in such a material can be closed using the gluing method. However, there are a lot of features and important points that must be taken into account:

1. Having washed and cleaned the entire surface of the bumper from dirt, it is also necessary to process the edges of the crack. The fact is that after splits appear on the fiberglass bumper, their edges are framed with threads. These threads will prevent you from tightly connecting the torn parts, so they must be removed using a universal grinder - "grinder".

2. We press the fragments of the bumper together and fix them in this position from the front side, using tape or special glue for this.

3. Preparing epoxy for gluing. Instead, you can use a more modern material - polyester resin, although in terms of strength they practically do not differ from each other. When working with resins, follow the directions on the packaging completely.

4. Lubricate the crack on the seamy side with a preparatory compound. Also, it must be applied to the entire area around the split, covering an area of 5 centimeters.

5. Saturate a thin fiberglass mat with the above mixture and apply it to the crack.

6. After the fiberglass, a layer of glue must be applied, then fiberglass, glue, etc. are applied again. The process continues until the thickness of the applied patch reaches the thickness of the bumper in the place where the defect was.

7. Give the fiberglass and glue time to dry and move to the front side.

8. On the front side, with the help of a "grinder", it is necessary to make a V-groove, the edges of which are false to gently approach the patch on the seamy side.

9. The resulting groove is filled with fiberglass, which was previously impregnated with resin. The surface of the part must be leveled until no trace remains of the furrow.

10. After work, all that remains is to grind the sealed surface and paint it.

4. How is the plastic bumper painted?

After all the irregularities are sanded and putty, and the surface of the bumper is completely degreased, you can start painting it. However, don't forget about the primer. It is recommended to use a two-component acrylic primer for this. It is not recommended to apply it in large quantities as it may leak. Multiple coats of primer can be applied. Before applying, it must dry for at least one day. This period can be shortened by using an infrared heater. The primer must also be sanded to keep the surface completely smooth and even.

The painting itself is carried out after another degreasing and blowing air on the bumper surfaces. First, apply the pigment, preferably 2-3 layers, drying each of them for 10-15 minutes. After the pigment, it is also necessary to apply two layers of varnish, not forgetting to dry each of them. This is especially important in cases where the color of the bumper is adjusted to the color of the entire body, since it is the varnish that will prevent its fading. After repair and painting, the bumper is installed in its original place. It is very important to avoid very high pressure washes for the next two or even three weeks. Enjoy the beauty of the updated bumper!