How to repair the car’s plastic bumper

Repairing the car’s bumper is not a particularly complex operation when dealing with localized damage and very often its replacement  is not necessary. Car bumpers are practically all made of a composite plastic material and are generally painted in the same colour as the body, but there are also many unpainted versions and the classic dark grey colour. It is common for this part of the car to come into contact with foreign objects, during parking or when travelling.

The damage that can ensue are varied: from a small scratch to deformation, up to the compound breakage of the surface. In less serious cases it is possible to carry out a repair on your own obtaining excellent results, leaving the repair of more serious situations to the body-shop, especially if they also involve parts of the bodywork. For small repairs it is not necessary to have a particular set of tools and materials, while for more demanding repairs some special tools are required.

Things you will need

Step 1

REPAIR THE BUMPER FROM SMALL SCRATCHES

The simplest situation in repairing the bumper is represented by the presence of slight scratches, usually caused during parking or manoeuvring operations. If the scratches are not deep and do not affect the body of the bumper in a particular way we can eliminate them quite quickly. If the bumper is not painted, proceed with a thorough cleaning of the damaged part with the WD-40 universal cleaner applied with a sponge and dried well with a microfibre cloth.

Then the special abrasive paste is applied to the affected part working patiently and repeatedly with circular movements until the part is smoothed and the scratches disappear. If the scratches are a little deeper, you can use very fine abrasive paper (over No. 400) without pressing too hard. If the bumper is painted, we work in the same way with the abrasive paste, but we do not use abrasive paper especially if the paint is metallic, as its action removes the transparent lacquered finish. If the scratches do not disappear, you have to act differently.

Step 2

DEEP SCRATCHES ON PAINTED BUMPER

You have to make a decision before repairing the bumper in this situation: handle the paint touch-up yourself, with probable visible results of the touch-up, or contact a body-shop. If you decide to do it yourself, after cleaning and treatment with the abrasive paste, a light layer of filler for plastic materials, which remains more flexible than that for bodywork, must be applied to the damaged part and then after further sanding, restore the coloured paint and the transparent lacquered finish that blends it to the rest of the surface. The job is then completed with a polishing pad.

Step 3

DEFORMED BUMPER: REMOVAL

In the presence of deformation – typically a dent – it is best to remove the bumper to be able to work more easily. Disassembly is carried out by loosening the various screws that secure the bumper to the bodywork, remove any internal fender guard, and disconnect the cables that power any headlights. This is a job that can be complicated and care must be taken not to break the contours that are used for fixing and interlocking. For this purpose it is useful to use, in order to loosen the screws more easily, WD-40 Fast Release Penetrant that frees the pieces with remarkable effectiveness. Its formula is also suitable in difficult cases of oxidation.

Step 4

DEFORMED BUMPER: RESTORE THE SHAPE

A deformation resulting from an impact can be addressed by using a heat gun that produces a blast of air of at least 500° C. With the gun, carefully heat the edges first and then the central area of the dented part. When it is sufficiently softened, pushing from the opposite side easily returns it to its original shape. However, since the precise shape is not perfectly obtained, it is always necessary to carry out sanding initially with a higher-grit abrasive and then with a fine-grit one to smooth and even out the profile. Then filling is performed, followed by further sanding and final painting. The painting can be performed by a body-shop.

Step 5

REPAIR THE BUMPER FROM BREAKAGES

If there are cracks, it is necessary to act on the inside of the bumper. A special tool is used that heats the plastic and applies staples that, when the part has cooled, remain firmly affixed in the material. In this way the torn parts are firmly repositioned according to the shape of the bumper. Then follows the filling and painting procedure examined previously.

Step 6

REASSEMBLY OF THE BUMPER

After the bumper has been repaired and repainted it must then be put back in place. In order to avoid problems, you need to thoroughly clean the screw seats, the screws themselves and any joints in the profiles and the internal stone guards. These parts, washed and brushed, can be treated before assembly with WD-40 Multi-use.

CONCLUSION

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The uses shown and described for WD-40 Multi-Use Product were provided to WD-40 Company by the users themselves. These uses haven’t been tested by WD-40 Company and do not constitute a recommendation of suggestion for use by WD-40 Company. Common sense should be exercised whenever using WD-40 Company products. Always follow the instructions and take heed of any warnings printed on the packaging.