It is bitter cold and snowy across much of the United States today, and sure as frozen fingers and salty floor mats, some brilliant individual out there is going to put hot water on their ice-coated windshield.
Look, I get it. I spent 14 miserable Midwest winters as a car owner without a garage. Snow and ice removal sucks! Sometimes, with tedious tasks, you can get away with short cuts, but when it comes to cold cars meeting hot water, you’re better off doing things the long, and right, way.
This video below is old, but it is also a perfect example of What Not To Do. The owner of this Dodge Neon says he’s testing out how hot water effects his cold car for Fargo Cruising, a car enthusiast group out of Fargo, ND. Occasionally, this trick will work, but why risk it?
The answer is don’t.
Maybe he just wasn’t aware of how thermodynamics work? If that’s the case, he sure is now. You can practically hear the moment he realized physics made a sucker out of him.
Here’s your middle school science lesson for the day: When hot water hits cold glass, the glass expands rapidly. It doesn’t expand evenly however, especially since glass is a crappy conductor of heat. Where the still cold glass meets the now hot glass there’s bound to be a breaking point, causing cracks in windshields and windows.
So, what are you supposed to do then? Let an old salt at winter driving tell you how it is done. First, if you can get into the car, you should properly warm it up with the vents blasting on defrost which is actually a really good idea. If your car is frozen shut and none of the doors will open, you can slowly pour warm (not boiling) water to loosen them up. You can even use a hairdryer, if you don’t have any legit de-icing agents laying around.
Don’t use anything to pry open the doors, as the pressure can also destroy frozen windows and wrenching on the car door handle could cause the handle to rip loose. Chipping ice away is acceptable, as long as you are very careful to not hit the windows.
As in all things, there’s no replacing simple preparation. Drop some coin on a top-of-the-line ice scrapper, you’ll be glad you did. You can prevent your car from freezing shut by rubbing simple cooking spray along the edge of your doors.