Can Hot Water Fix Car Dents?

It's hard to believe anything you see on social media these days, and that's especially true of video content. For example, when you see a video of someone fixing a car dent using fire, it's best to research the claim to find out if it's even possible. The same goes for using hot water to fix dents, though the science behind it might seem logical. The key is that while it can work under the right conditions, there's no guarantee it will work all the time.

The idea is to take boiling hot water and pour it onto a dented car bumper to make the plastic more pliable. While the bumper is in this condition, use a plunger to form a strong seal like a suction cup and gently pull while also pushing from the backside of the bumper. The actual method can be a two-person job depending on the size and location of the dent.

The problem is that to actually do this, the dent's shape and location have to be right. Plus, if you don't have help pushing the bumper out, or you can't access the area behind it, you may not be able to make it work. If the plunger can't properly adhere to the dented plastic, then you may be done before you even start. There's also no guarantee that the plunger trick will work on metal, which means a dented metal panel may not be fixable using the hot water method.

Family Handyman put the hot water and plunger method to the test on a dented bumper and was unable to fix it. DingGo, an Australian auto body repair service, recommended against using hot water to repair a vehicle dent. Other companies, including Arizona-based A Better Repair, warn that hot water and plungers won't repair dents in metal body panels. In fact, attempting to do so could make the damage much worse than it already is.

Using a plunger on the dent can potentially cause the affected part to crack. While the amount of pressure needed to actually do that can vary, it's still a risk that exists when you use a plunger. It can also harm the paint job, and just using hot water alone can cause even more damage. If you decide to go the extra mile with the repair and physically remove the bumper to access the back of the dent, you could also harm the bumper's internal components in the process.

Other heat-related DIY repairs involve using a hair dryer on the dent, then pushing the dent out from behind the part. But this can also potentially damage the paint, and you could accidentally compromise the affected area, just like with the hot water method. So if your vehicle does have a dent that needs to be fixed, you may be better off contacting a service professional in your area before trying to fix it yourself.