In detail: do-it-yourself bumper repair mesh from a real master for the site my.housecope.com.
The car bumper is the first damping element at the moment of contact of the front or rear of the car with an obstacle. In some cases, the bumper can even be considered a consumable. Unfortunately, domestic realities are such that the cost of plastic elements forces drivers to do bumper repairs with their own hands.
The type and extent of restoration work largely depends on the nature of the damage. The most common are:
chips and scratches paintwork. In this case, only cosmetic repairs will be required. Minor scratches can be repaired. Only repainting the damaged area or the entire element as a whole will help to eliminate more significant defects;
the presence of cracks, breaks. For repairs, you will need a special tool (depending on the choice of technology: hair dryer or soldering iron, mesh, glue, electrodes);
missing fasteners or individual parts of the case;
dents without tearing paintwork. If the bumper is made of a soft plastic alloy, such a defect can be corrected by heating the surface and applying force from the back side;
curvature of geometry. At home, you will need a hair dryer to repair the damage.
The do-it-yourself plastic bumper repair we are considering will help you get rid of the most difficult types of damage: cracks, tears, and lack of fastening. Let's talk about what a soldering station is and how to solder a bumper with electrodes at home. Consider whether a mesh or fiberglass glue is suitable for repairs.
Video (click to play).
If we are talking about this type of restoration work, like soldering the bumper, then a few words should be said about the composition of the plastic from which they are made. In our work, we will use either a construction hair dryer, to which a special nozzle is attached, or a hair dryer, which comes with a soldering station. Elimination of cracks in this way is carried out by heating the repair zone. Each type of plastic has a temperature boundary value, violation of which leads to the loss of plastic elasticity and strength. It is also important to know the type of plastic because the electrodes used to solder cracks or weld fasteners must be made of the same material. In this way, the maximum degree of structural strength is achieved.
The main types of thermosetting (that is, those that lend themselves to reheating and melting) include:
polypropylene (PP, PP / EPDM, TEO, PP);
copolymer of acrylonitrile, butadiene and styrene (ABS, ASA, ABC);
polyethylene (PE, PE-LD, PE-LLD, PE, etc.).
You can find the corresponding designations on the back of the plastic product.
For repairs you will need:
soldering station, which will include both a soldering iron and a hot air gun. If you do not want to overpay, then the hot air gun can be purchased separately. The volume of work assigned to the hot air gun can also be handled by an ordinary building hair dryer. But keep in mind that the nozzle of the nozzle for soldering cracks or fastening must be narrow enough in diameter;
electrodes that the device will melt;
stripping burr.
Serious repair of plastic bumpers always starts with cleaning the damaged area. Attach the burr to the screwdriver and clean the damaged area. The crack should be deepened a little. A few centimeters around the repair area should be without paintwork or remnants of old putty.Before using the device (hair dryer), degrease and dry the surface.
In the process of soldering, the electrodes should lie down from the edge of the cracks. You should direct the hot air gun in such a way that during the uniform lowering of the rod, the air flow is always directed to the place of the electrode joint and the damaged zone. The essence of the process is that the apparatus, which produces a hot air stream, will melt the lower part of the welded rod and the upper layer of the bumper surface. If you have positioned and adjusted the device correctly, then a ball of molten plastic should "run" in front of the falling twig. Thus, there is a strong adhesion of the materials.
It is necessary to remove a small chamfer from the edges of the places that were torn off "live" and require a new fastening. Then, with a soldering iron, "grab" the parts so that they are held without outside help and correspond to the geometry of the bumper shape. Then take the apparatus (hair dryer) and fill the seam with electrodes as described above. The same procedure should be done on the back of the bumper.
It is possible to qualitatively restore the missing headlight mountings or the bumper itself only in this way. In this case, the glue gun will not be able to provide the required degree of strength.
The thermoplastic adhesive that heats up the gun does not adhere well to the bumper plastic. Such a device costs little money, but it is worth considering that it is not worth using a glue gun to repair vibration-loaded elements. If there is no way out, and you decide to make repairs in this way, mat (walk with sanding paper at the joints and around the edges) the surface before applying the repair compound. Run the glue through the gun until it is hot enough. Then do not just lay down the glue that will feed the gun, but press the tip to the surface of the bumper, slowly moving along the repair area. These two tricks will help improve adhesion.
Bumpers made of a material that cannot be welded or soldered (for example, fiberglass) require a special technique for restoration work. Of course, reinforcing mesh, hot air gun and electrode repair are inappropriate here. How does the repair of cracks with fiberglass take place?
We clean the paintwork and chamfer the edges of the cracks (we make them wider in order to subsequently fill with fiberglass cloth). For such work, a sander is perfect (grinder, orbital sander);
holes must be made around the perimeter of the damage. In this way, we will improve the adhesion of the two layers;
we fill the risk with sandpaper (grain p80), and then degrease the surface;
apply glue (epoxy resin diluted with a hardener) and apply pre-prepared pieces of fiberglass (the size should be several centimeters larger than the break point). With a brush moistened with glue, smooth the fiber so that there is no air left at the place of contact. We carry out the procedure on both sides of the damaged element;
after drying, the repair area must be sanded.
The metal mesh, which is soldered into the bumper with a soldering iron, is still used by many craftsmen. It is worth considering that combining two materials with different reactions to temperature changes and the degree of elasticity is not a good idea. If you will be using this technology, use brass mesh or stainless steel mesh. The method is convenient because you do not need the following tools: a hot air gun or a building hair dryer, glue and fiberglass.
Before starting work, it is necessary to scrape off the top layer of plastic from the welding rods, making the surface rough;
heating the plastic leads to harmful fumes. Use a respirator during repairs.
It is quite difficult to imagine a vehicle that does not have such a necessary element as a bumper. The main purpose of the part is to protect the body from damage and deformation. When a difficult situation arises, he takes on all the shock and damaging factors. It is for this reason that the question of how to repair a plastic bumper with your own hands is one of the most relevant.
It is easy to guess that the bumper with a high degree of probability can be damaged if the car is used quite intensively and even with very careful operation. The bumper can be damaged not only due to lack of driving experience, but for reasons such as:
actions of other sloppy and inexperienced drivers;
the departure of small stones from the movement of other vehicles.
Regardless of the cause and nature of the damage, the appearance of the vehicle after a bumper breakage deteriorates significantly. The car owner automatically wants to solve a similar problem by doing a bumper repair with his own hands.
Ways to eliminate the problem and mechanical damage directly depend on what kind of plan the defect was applied to the car part. Among the most basic types of damage are:
Scratches, which can be superficial and deep, that is, reaching the ground or to the base layer of the part. This damage must be repaired immediately, as later cracks may appear at the scratch site.
Cracks - this is a more serious damage to a car part, which belongs to the category of dangerous. Without removing it, it is not recommended to operate the machine.
Dents - are formed by a strong mechanical effect on the bumper. These injuries are very often accompanied by other adverse manifestations. Scratches and cracks almost always appear next to dents.
Chips and breakouts... This is a special through damage that has a fairly large area. They appear most often at the edges of the bumper after a collision of the car with a certain obstacle.
Of course, you can contact any service center, but in this case, the cost of restoring the bumper, even with minor damage, becomes much higher than the cost. Of all the options listed above, it is self-repair that will become the optimal and affordable method for restoring the bumper.
Directly depending on the degree of damage, repair work aimed at restoring the bumper can be divided into local and complex ones. Scratches and small chips of various types on the surface of the paintwork can be eliminated without preliminary dismantling of the part.
It is necessary to work with this element so that access to the outer and inner surfaces of the element is provided. The installation of the part in its original place is carried out after the implementation of the required repair and restoration work.
When carrying out a process such as self-repairing a plastic bumper, you will need to prepare special tools and materials. Among the most important of them are:
Competently thought-out protection will comprehensively protect the respiratory organs, eyes and hands from the effects. This is an automatic guarantee that the body will not be harmed by the spraying of harmful substances in the air and by high temperatures.
Along with the acquisition of the necessary materials and tools, in the preparation process, you need to carry out certain work with the bumper itself. Among the most important points are:
Removing the bumper from the car body.
Thorough cleaning of the part from dirt and dust. The surface must be dry and clean.
Determination of the material from which the bumper is made.
In areas where restoration work will be carried out on the bumper, it is imperative to remove the applied paint.It is necessary to thoroughly clean and degrease not only the damaged area itself, but also the adjacent space.
The crack must be drilled with small through holes at the ends before repairing. This will avoid the subsequent spread of damage, its increase in size.
Any crack has special joint edges. Therefore, before repairing the crack, it will need to be filled at the joints with a special composite.
After completing all the above processes and manipulations, you can start repairing the bumper with your own hands.
The scheme according to which the repair of plastic bumpers will be carried out depends directly on the degree and level of damage. The following recovery techniques may be applicable:
Gluing - it is used for parts produced by the cold forming method. A special polyurethane-based adhesive is used here.
Heat sealing - Suitable for bumpers that have been hot formed. The bumper fragments are connected using special welding equipment.
Lamination - the method is suitable for restoring lost fragments similar. It uses a special reinforcing mesh and putty.
Using flat electrodes... The technique is based on the use of a special construction hair dryer, which melts the electrodes and effectively repairs cracks.
Soldering - the best option for repairing a bumper in normal home conditions. You will need to use a soldering iron, sandpaper and paint.
Brazing with reinforcement - suitable for the elimination of large cracks. The process is based on the use of double-sided soldering and simultaneous reinforcement with special staples or metal mesh.
Pasting - crack elimination is carried out with fiberglass and epoxy glue. The restoration material is applied to the glue and strictly on both sides of the bumper.
Below is a description of the most common and labor-intensive methods of restoring a car bumper, depending on the damage caused.
The previously prepared putty must be prepared according to all the rules of the instructions, add a special hardener there. After that, the resulting mass is applied to the area of the bumper where the damage is located. You need to wait about 10 minutes, take sandpaper No. 80 and grout the composition with special circular movements. The result becomes visible after several manipulations.
Priming work is carried out just as easily. It is required to take a prepared rag and rinse the bumper very well. Once the surface is dry, the entire bumper should be inspected for correct shapes. If there are no dents, you can start priming. This process is carried out according to the following rules:
Apply the primer in a circular motion towards the left or right side of the element.
The composition must be allowed to dry completely.
After that, sandpaper No. 800 is taken and everything is thoroughly overwritten.
Using a regular water bottle, you need to wash the bumper. In this case, it does not matter where the crack or other damage has formed, the bumper must be washed out completely. As soon as one layer is completely dry, the plastic automatically takes on a matte shade. The top soil is then completely washed off.
Only then can the second layer of the primer be applied.
Once all the applied layers are dry, a thorough inspection of the part will need to be performed using a lamp. The layers should be perfectly even and make up one piece together.
If, after examining the part, it becomes clear that all coatings are applied as efficiently and evenly as possible, you can proceed to such a process as painting.The room must be prepared, all surfaces that need to be protected from the paint used are closed. The pigment is applied strictly in two to three layers. Drying should take 5 to 10 minutes between each layer.
After applying the required paint coating, the bumper is coated with two layers of varnish. Intermediate drying is also important here. At the end of the painting work, you need to check the quality of the applied compounds again; if smudges are found, light sanding and thoroughly polishing the surface are required.
In the process of restoring the integrity and appearance of the bumper, the upcoming work will depend on the type of damage found. This is an important point, since one option is used for scratches and chips, a completely different method is required to remove a dent.
If you need to carry out repairs with your own hands, or the insurance does not work, or there is no money and desire to contact the service center, you will need to carefully study the nature of the damage. If the driver realizes that the bumper is very badly damaged, you should not try to restore the part on your own, but it is better to purchase a new one. If relatively small chips or dents are found, the problem can be completely eliminated on your own, knowing how to act in this or that case. So, how can scratches, dents and cracks be repaired quickly and effectively.
Elimination of this problem can be carried out by using sandpaper. Material No. 50 is taken and grouting is carried out. In this case, it is necessary to carefully eliminate all irregularities, acting until the surface becomes completely correct in shape. In the course of this process, the damage may become slightly larger in size, but their depth will become much smaller. Do not be afraid of this, after thorough cleaning all the irregularities will be filled with putty.
If there is a desire and certain skills, then instead of putty, you can use a special liquid plastic, which fully corresponds to the type of material from which the plastic is made. After applying this composition, after it has completely dried, it will also be necessary to clean the surface and carefully sand it, sanding it to the most even surface.
To repair a minor dent that did not damage the paintwork, you simply need to heat the deformed part of the bumper. The concave part of the plastic must be heated with a previously prepared thermal or technical hair dryer until the material becomes soft enough. After that, the dent is manually straightened, at the same time giving the damaged section of the bumper the correct geometric shape.
If cracks appear on the surface of the bumper, it will be necessary to use a pre-prepared metal mesh and a soldering iron. The sequence of actions in this case will be as follows:
The edges of the damage must be brought together and soldered to one side of the mesh. It is advisable to drown it as deeply as possible in the plastic, but you cannot overdo it, as a hole may form.
The end of the mesh is covered with melted plastic.
Similarly, you need to walk along the entire crack.
If the damage to the bumper is minor, special construction brackets can be used instead of the mesh. In the process of soldering them, it is recommended to use tweezers, which will prevent burns of the brushes. Bonding actions should be spaced 2 cm apart and along the entire length of the crack.
To prevent the mesh and metal staples from rusting after a while, the items must be covered with special liquid plastic. At the end of all the work that is carried out on the inner surface of the bumper, its front side immediately takes on its original appearance.
The question of how to restore and repair a car bumper with your own hands is relevant for all modern motorists without exception. If you follow the instructions and tips provided in the article, you can repair damage to the bumper with minimal money and time.
Posted by admin in Auto repair and tuning 09.05.2018 0 17 Views
The car bumper is the first damping element at the moment of contact of the front or rear of the car with an obstacle. In some cases, the bumper can even be considered a consumable. Unfortunately, domestic realities are such that the cost of plastic elements forces drivers to do bumper repairs with their own hands.
The type and amount of restoration work largely depends on the nature of the damage. The most common are:
chips and scratches paintwork. In this case, only cosmetic repairs will be required. Minor scratches can be repaired. Only repainting the damaged area or the entire element as a whole will help to eliminate more significant defects;
the presence of cracks, breaks. For repairs, you will need a special tool (depending on the choice of technology: hair dryer or soldering iron, mesh, glue, electrodes);
missing fasteners or individual parts of the case;
dents without tearing paintwork. If the bumper is made of a soft plastic alloy, such a defect can be corrected by heating the surface and applying force from the back side;
curvature of geometry. At home, you will need a hair dryer to repair the damage.
The do-it-yourself plastic bumper repair we are considering will help you get rid of the most difficult types of damage: cracks, tears, and lack of fastening. Let's talk about what a soldering station is and how to solder a bumper with electrodes at home. Consider whether a mesh or fiberglass glue is suitable for repairs.
If we are talking about this type of restoration work, like soldering the bumper, then a few words should be said about the composition of the plastic from which they are made. In our work, we will use either a construction hair dryer, to which a special nozzle is attached, or a hair dryer, which comes with a soldering station. Elimination of cracks in this way is carried out by heating the repair zone. Each type of plastic has a temperature boundary value, violation of which leads to the loss of plastic elasticity and strength. It is also important to know the type of plastic because the electrodes used to solder cracks or weld fasteners must be made of the same material. In this way, the maximum degree of structural strength is achieved.
The main types of thermosetting (that is, those that lend themselves to reheating and melting) include:
polypropylene (PP, PP / EPDM, TEO, PP);
copolymer of acrylonitrile, butadiene and styrene (ABS, ASA, ABC);
polyethylene (PE, PE-LD, PE-LLD, PE, etc.).
You can find the corresponding designations on the back of the plastic product.
For repairs you will need:
soldering station, which will include both a soldering iron and a hot air gun. If you do not want to overpay, then the hot air gun can be purchased separately. The volume of work assigned to the hot air gun can also be handled by an ordinary building hair dryer. But keep in mind that the nozzle of the nozzle for soldering cracks or fastening must be narrow enough in diameter;
electrodes that the device will melt;
stripping burr.
Serious repair of plastic bumpers always starts with cleaning the damaged area. Attach the burr to the screwdriver and clean the damaged area. The crack should be deepened a little. A few centimeters around the repair area should be without paintwork or remnants of old putty.Before using the device (hair dryer), degrease and dry the surface.
In the process of soldering, the electrodes should lie down from the edge of the cracks. You should direct the hot air gun in such a way that during the uniform lowering of the rod, the air flow is always directed to the place of the electrode joint and the damaged zone. The essence of the process is that the apparatus, which produces a hot air stream, will melt the lower part of the welded rod and the upper layer of the bumper surface. If you have positioned and adjusted the device correctly, then a ball of molten plastic should "run" in front of the falling twig. Thus, there is a strong adhesion of the materials.
It is necessary to remove a small chamfer from the edges of the places that were torn off "live" and require a new fastening. Then, with a soldering iron, "grab" the parts so that they are held without outside help and correspond to the geometry of the bumper shape. Then take the apparatus (hair dryer) and fill the seam with electrodes as described above. The same procedure should be done on the back of the bumper.
It is possible to qualitatively restore the missing headlight mountings or the bumper itself only in this way. In this case, the glue gun will not be able to provide the required degree of strength.
The thermoplastic adhesive that heats up the gun does not adhere well to the bumper plastic. Such a device costs little money, but it is worth considering that it is not worth using a glue gun to repair vibration-loaded elements. If there is no way out, and you decide to make repairs in this way, mat (walk with sanding paper at the joints and around the edges) the surface before applying the repair compound. Run the glue through the gun until it is hot enough. Then do not just lay down the glue that will feed the gun, but press the tip to the surface of the bumper, slowly moving along the repair area. These two tricks will help improve adhesion.
Bumpers made of a material that cannot be welded or soldered (for example, fiberglass) require a special technique for restoration work. Of course, reinforcing mesh, hot air gun and electrode repair are inappropriate here. How does the repair of cracks with fiberglass take place?
We clean the paintwork and chamfer the edges of the cracks (we make them wider in order to subsequently fill with fiberglass cloth). For such work, a sander is perfect (grinder, orbital sander);
holes must be made around the perimeter of the damage. In this way, we will improve the adhesion of the two layers;
we fill the risk with sandpaper (grain p80), and then degrease the surface;
apply glue (epoxy resin diluted with a hardener) and apply pre-prepared pieces of fiberglass (the size should be several centimeters larger than the break point). With a brush moistened with glue, smooth the fiber so that there is no air left at the place of contact. The procedure is performed on both sides of the damaged element;
after drying, the repair area must be sanded.
The metal mesh, which is soldered into the bumper with a soldering iron, is still used by many craftsmen. It is worth considering that combining two materials with different reactions to temperature changes and the degree of elasticity is not a good idea. If you will be using this technology, use brass mesh or stainless steel mesh. The method is convenient because you do not need the following tools: a hot air gun or a building hair dryer, glue and fiberglass.
Before starting work, it is necessary to scrape off the top layer of plastic from the welding rods, making the surface rough;
heating the plastic leads to harmful fumes. Use a respirator during repairs.
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;
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 indent of 3-5 cm from the crack in each direction and grind 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:
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: "> Before painting, irregularities need to be putty
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. A 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;
latex 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 a 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 is not removed from the car 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 in one hand a hair dryer heated to 400-600 ° C (depending on the type of plastic), and in the other - a welding rod. 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.
Video (click to play).
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.