Chips into Cracks Part 1
Have you ever put a glass mug of hot water in the freezer? I have, and it’s not fun. But that’s not what we’re interested in; what happens to the glass after it’s one extreme temperature and is exposed to the opposite extreme temperature? It cracks. This is essentially what happens to your windshield.
But why does the strong glass of your windshield, expertly made to handle stuff like this, crack? Because of a built up tension known as thermal stress, or thermal shock. This stress is created when glass rapidly heats and cools unevenly. In other words, it’s not so much the extreme temperatures, though they do play a large role, it’s the speed at which the glass is made hot very quickly, and cooled down equally as quickly, if not faster. Normally, your glass can withstand this flux in temperature; however, if you have a chip or a crack, a weak point is generated in the otherwise very strong glass, which will give in to extreme changes and weaken even further.
Cold temperatures contract everything, from metals, to rubber, to glass. However, each substance contracts to a different degree at a different speed, including the metal frame around your windshield and the glass itself. Your windshield is built in a curve to be able to withstand this, and the sealant the auto glass installer uses is meant to secure the glass to the metal framing tightly, so that when it warps because of the contraction, it’ll hold strong. If the installer incorrectly installed your windshield, it could cause an array of problems that could wreak havoc on your life by putting you in danger of a windshield falling on you or, in the case of a rollover collision, your roof falling into you and squishing everything in the car. Another very common occurrence is the glass busting due to incorrect removal of ice in the winter. If your windshield is frozen over, DO NOT pour hot water on the glass. This will cause the temperatures to become drastically different in a short amount of time, causing it to break.
The best way to avoid these issues is to take your business to a company that you can trust; know your installer. You have the right to choose who services your car. You wouldn’t let just anyone replace your engine, right? How about babysit? Or maybe replace the entire electrical system in your house? Make sure the job is done right the first time by knowing an honest business to install your glass.
Another easy fix is to use a scraper in the winter!
To read about what extreme heat does to your windshield, click here.