Removing Dents From Chrome Bumpers

Things to Know About Chrome Bumpers

Chrome bumper is a somewhat misleading term. A chrome bumper has a core made from a mixture of iron and copper, over which is a thin layer of buffed nickel. Atop this is a layer of elementary chromium. This layer is so thin that it's transparent, having been applied at a molecular level by a process similar to electrolysis. The purpose of the chrome is to add a certain sheen to the nickel beneath which is that element's hallmark. When a chrome bumper is dented, the layer of chrome around the dent is shattered and most of it flakes off. That's why, even when the dent has been fixed, it never quite looks the same. There are two ways to fix a chrome bumper: cheaply or correctly.

Simple Method

The simple and cheapest method to fixing a chrome bumper is to remove it from the vehicle and flip it over so the hollow backing is placed on a sturdy surface. A rubber mat, such as a thick floor mat, is pressed inside the bumper against the protruding part of the dent. A rubber mallet is then used to push the dent back into its proper place. The bumper is then reattached to the car and shined up as much as possible in the hopes that the slight difference in shine between the dent and the surrounding bumper isn't noticeable.

Best Method

The best method is expensive to the degree that it's often cheaper to just buy a new bumper, but that may not be an option for those whose cars are irreplaceable collectors items. The entire bumper must be taken to an auto-body shop that specializes in working with chrome. They remove the chrome on the bumper by dipping it into an acid bath. They then remove the nickel beneath the chrome by soaking it in a solution of cyanide. A brazing rod, which is a rod made from solder with a high silver content, which makes it harder and more easily worked with, is heated with a blowtorch. The softened solder is pressed into the dent in layers and shaped to match the surrounding metal. It's then sanded and buffed smooth. The bumper is then recoated in a bath of molten nickel. Once it's dry, the chrome is added by a process known as electroplating. During this process, the bumper is placed in a metallic electrolyte solution into which an electrode providing a positive charge has been inserted. The bumper is connected to another electrode carrying a negative electrical charge. Less than an ounce of molten chrome is poured into the solution. By dint of its natural positive charge, the chrome will be attracted to and distribute itself across the bumper in a molecule thin shell. The bumper is removed from the solution, rinsed off and buffed until it shines like new.