DIY bumper repair with a soldering iron

In detail: do-it-yourself bumper repair with a soldering iron from a real master for the site my.housecope.com.

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 the 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, appropriate conclusions are drawn:

  1. PP - polypropylene base.
  2. ABS (GF, PAG 6) are hard plastics.
  3. 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.

Video (click to play).

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.
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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.

Many car owners have probably noticed that one of the weak points of a car is plastic bumpers. No matter how carefully we try to drive the car, bumper damage sometimes occurs due to carelessness.
This can be a run over a pipe, rubbing against a curb, or a minor accident.

In the civilized world, broken plastic bumpers are usually thrown away, the same attitude is observed in us in most cases to bumpers from VAZs (fortunately, a painted part is usually no more than 3,000 rubles).
But if the cost of a bumper begins to exceed $ 200-300, which is beyond the means of most motorists, and sometimes it is costly to buy a new bumper for an old car.

Meanwhile, in most cases, plastic bumpers can be repaired and restored to their original appearance. The most important thing is to collect and not lose all the cracked bumper parts. Well, this article will discuss how to solder, spit, prime and paint your damaged bumper.

To carry out repairs, the bumper must be removed from the car, this will make it easy to position the bumper in a position convenient for repair - soldering and painting.

The bumper must be washed and cleaned from dirt. For soldering the plastic of the bumper, an electric soldering iron or heated by a blowtorch can be used. Using burners will require more skill and skill, since plastic under the influence of temperatures can "lead", if you do not have experience in this matter, then your option is still a soldering iron

- To prevent further cracks from continuing, a hole must be drilled at the end of the crack.

- It would be convenient to first fix the bumper before soldering with a clamp.

- We begin to solder the bumper parts from the inside, this will allow us to understand what properties the material has without significant damage to the appearance.

- Solder in 2 steps.

First, grab the edges of the damaged area in order to fix the relative position of the fragments and correct a slight deformation, just here it is convenient to use clamps. Soldering the tack is carried out after about 10-15 cm.

Only after tacking can you begin to fully solder the bumper along the entire length of the seam.

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:

  1. Pieces of plastic, similar in composition to the bumper material, are selected and dissolved in acetone to a thick consistency.
  2. On the back of the bumper, the crack is degreased and also treated with acetone in order to soften the surface.
  3. 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.

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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 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 produced. 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: ">Image - DIY bumper repair with a soldering iron 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:

  1. 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.
  2. On the back, sand it with a coarse sandpaper, but without a depression. Degrease the area and let dry.
  3. 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.
  4. 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.
  5. 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.