Generally a chrome bumper doesn't dent easily, but if it does, replacement is the likely option. The biggest reason for this is that the dent causes the metal to stretch and warp and, hence, is very difficult to bring it back to shape. Also, the chrome can crack while trying to do so which leads to replacement as the only option. However, if you want to save money and are fine with slight imperfections, you can fix the dent yourself by following the steps described below.
Step 1 – Set the Emergency Brake
You need to make sure that the car will not move while you do the repairs, so it is best to set the emergency break before starting anything else.
Step 2 – Suck Out the Dent
In case the dent is small or you can’t reach behind it properly, it is better to suck out the dent using a plunger. Center the plunger over the dent and push it in, exactly the way you do with a clogged toilet. This may not work in the first attempt, so give it some tries.
Step 3 – Use Dry Ice
If a plunger doesn’t solve the problem, try dry ice. Put on protective gloves, as prolonged skin exposure to dry ice can cause injuries similar to burns, and then place a block of the dry ice over the dent. If you are fortunate, ice will be able to pull it out, but you might need to repeat the process a time or two to get it to work.
Step 4 – Banging Out the Dent
If either of the above methods doesn’t work, banging out the dent is one last option. Place yourself behind the dent properly; if required, remove the bumper or drive onto jack stands. It is advised that you get someone to brace the dent from the other side so that it doesn’t pop out the other way. You’ll need them to cover the dent with a silicone cutting mat.
As a dent stretches the metal, it is best to soften the metal before you use the hammer. Otherwise, the dented area will never return to normal and some marks/warps will be left. Heat the chrome surface using either an acetylene torch or the inexpensive propane torch. Take care not to heat the metal too much and that you don’t touch the hot metal.
Place a wood block over the dent next to ensure that the force of the blows will get diffused and the chrome will not crack. Then, start tapping the wood block with a mallet, lightly to start and then with a gradually increasing force. Keep checking the dent regularly to see if the surface appears smooth or not. When it is smoothed out, remove the silicone mat.
Step 5 – Repeat the Process
As mentioned earlier, some waving is expected to remain in the chrome. Repeat the process until the dent is smoothed out to your satisfaction.