by Nick Somoski

Created on: December 19, 2010   Last Updated: December 27, 2010

A crack in a plastic car bumper can be a burden, but there's no reason why it can't be fixed. Bumper cracks can appear even if the car hasn't been in an accident, and as long as the crack is of reasonable size, replacing the bumper isn't necessary.

Once the bumper has been removed from the car, there are two ways to go about repairing the crack.

The first is by using a soldering iron. A soldering iron is a commonly-used hand tool that melts the solder to flow into the juncture between two workpieces. In this case, it'll be used to melt the two sides of the cracked bumper together.

Thoroughly clean the bumper to make it easy to work with. Plug in the soldering iron and give it time to heat up. The point of the iron is to melt the two sides of the crack together. Learn how to use a soldering iron before you work with it. When using it, press deeply into the bumper in order to pull plastic from either side into the aperture. A flat tip should be used on the soldering iron.

Once the crack has been filled, let it cool for several minutes, and then use fine sandpaper to smooth and polish the bumper.

If the crack is slightly larger, or a soldering iron isn't available to use, a more commonly used method is to fill it with a plastic filler compound. Again the bumper will need to be cleaned thoroughly before working with it. Place a piece of aluminum tape on the backside of the crack. Before filling it, with fine sandpaper (about 80-grit), smooth around the edges until an even surface is reached.

Any filler material, such as epoxy, Bond-O, adhesion promoter, or a repair adhesive and hardener mixture, will work to fill the crack. Spread it across and into the crack, on the front side of the bumper. The tape will keep the filler material from escaping out the back. Something like a spackling knife or squeegee can be used to evenly spread the filler. Allow it to dry for at least 20 minutes.

Turn the bumper over and remove the tape. Do the same on the back side. Spread the filler evenly and allow it to sit out and dry completely for at least an hour. Once dry, sand the front side with a sanding wheel or 200-grit sandpaper. Apply a small amount of plastic finishing putty and smooth once more, this time with an 80-grit sandpaper.

Once the crack has been repaired, painting the bumper will be necessary. It's best to paint at least a day after repairing, just in case a problem occurs and the crack doesn't stay sealed. A crack or hole in a car bumper isn't as problematic as it may appear. It's actually quite simple to fix, and as long as the proper tools are available, the crack will disappear with ease.

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