Originally conceived as a means of protecting the body from deformation in case of collision of the vehicle, the bumper has turned into a part improves aerodynamic and aesthetic properties of the vehicle. To replace the metal bumpers came plastic, the benefit of products from polyvinylchloride polyamides and polycarbonates are lighter, cheaper, does not corrode and is much easier to repair.
Before starting repairs should assess the size and nature of the received bumper damage. The least labor-intensive are scratches and dents — in order to return the bumper as the initial appearance and functionality enough to do the puttying and painting of the damaged area.
In the case of formation of cracks and breaks will need a broader set of reconstruction efforts, which further will be discussed.
Definition of bumper material
Before you start to repair the bumper, for ease of implementation of works it is necessary to dismantle and identify the material from which it is made.
On the inner side by the manufacturer through the stamping or melting is usually a special mark. Letters PPTV or PP will point to the fact that the bumper is made of polypropylene, for marking polyurethane abbreviated as PUR, and on the use of rigid plastics will witness the label ABS, GF15, GF30 or PAG6. The lack of markings on the inner side of the bumper is typical for products made of fiberglass.
First of all removed the bumper should be free of dirt, rinse it after washing. Next you need to remove the primer and paint in the area of repairs at a minimum distance of 15-20 mm around the damaged area. You perform this procedure for both external and internal surfaces.
For stress relief of the material and prevent fraying, the ends of the cracks must be drilled. The edges of the crack or break should be cut off on all sides under an angle of 450. This can be done with a knife or file, but it is preferable to use a grinding machine.
The final stage of preparatory work – degreasing the damaged area and adjacent areas using a solvent, white spirit or special brand of degreaser.
Welding and filling up
The best way to repair bumpers made of polypropylene, having a melting point of 1300 C, a polyurethane with a melting point of 160-2000 and With certain types of thermosetting plastics hard is joining the breakaway fragments and filling up of cracks with the use of a soldering iron or plastic electrodes. Bumpers made of refractory materials should be recovered solely by the method of gluing.
By combining fragments of the bumper and secure them with the front side of the tape, to commence rehabilitation works on the inner side of the bumper. The tip of the heated soldering iron perform movements perpendicular to the direction of the cracks, retreating after each seam is made approximately 3-4 mm along the line of welding. The result should be a band consisting of transverse ribs and grooves.
You can enhance the seam, and melding every 3 cm the metal staple furniture staples. To protect them from corrosion, the coating layer of melted plastic material, taken from the area near the crack.
Similar operations are underway and then on the front side of the bumper, then its all primed and painted.
Another method of thermal bumper repair – plastic welding electrodes. The electrodes are sold in sets of automobile plastic strips width of about 10 mm of a material identical to a material of the bumper. The optimal electrodes – plastic strip cut from an old, beyond repair, the bumper is similar to the model of the car.
As in the embodiment using a soldering iron work better to start from the inner side of the bumper, to study material properties and to choose the desired heating mode without any visible damage to appearance items.
Attaching the electrode to the crack, it direct the flow of hot air from the building dryer so that the material of the electrode vigorously melted, but not bubbling and not boiling. Filling the groove with molten plastic, the hot viscous mass is pressed inside so that it fills the whole cavity, slightly projecting above the surface of the bumper.
Welding is recommended to follow a point, starting with the center of the crack, then running a small seam at each end, then putting the seam between the center of the crack and its ends, and so on.
Bumpers from propylene in the reinforcement do not require that polyurethane is better strengthened by means of metal brackets or reinforcement of the grid.
The repaired item will level up, to putty, to prepare for painting and paint, locally or entirely.
Let you will succeed! Good luck to you!