There are plenty of innovative ways to clean off your windshield during the winter season when it’s coated in ice. But dumping hot water on it is the wrong way, as one North Dakota man discovered.
In the video (which kind of seems like it might be fake), the driver walks outside and dumps hot water on his windshield. Moments later, the windshield cracks and he eloquently responds to the situation by crying “son of a bitch — my window broke.”
The video is a few years old and most of the commentators on YouTube have declared it to be fake. After watching the clip a few times, it’s pretty easy to come to the conclusion that the video is fake; mostly because the acting is terrible. Also, the unwise driver has a pretty strong Canadian accent, suggesting that he’s from the northern part of North Dakota, which borders Canada. And if he’s that far north, it’s just about impossible for him not to be aware of the effects of hot water on a frozen windshield.
But now for the real question that we’re all asking — why does hot water make cold glass crack? While it’s a lot of complicated physics and numbers, Jalopnik explained it simply: basically, when you pour hot water on cold glass, the class “expands rapidly.” Too rapidly, in fact, and the result is a split in your windshield. It doesn’t help that glass is a poor conductor, which means that it expands unevenly. At some point the cold glass meets the hot glass and the result is a split. An ugly one.
If you’re looking for a way to get the ice of your windshield, we’d suggest an ice scraper. If you don’t have one of those, a credit card or your driver’s license can work. If you have a few minutes, you can even get in your car and defrost it.