Crack

February 11, 2022

It is appropriate after I posted on sand this week that I encountered sand on the road.  The ice and snow we received last week had been countered by a variety of treatments, and one of them was sanding the roads.  I am always careful after the roads are sanded as there is an increased likelihood that the small particles of rock will be kicked up by tires and sent crashing into my windshield.  The threat is intensified as the outside air temperature is cold and the windshield is warmed by my defroster, making it easier to crack.  I thought I had made it safely as I got off the interstate and headed down the last stretch of divided highway toward home.  I was following a pickup truck as I cautiously moved along side one of the semi-trailers that frequent the highway when I heard a crack.  I slowed to avoid further debris thrown from the pickup and did a quick survey of my windshield.  I did not see a crack.

When I looked online, I found the Arkansas Department of Transportation (ARDOT) uses several treatments to prepare for an upcoming ice storm.  This usually means preparing the roads with salt brine, or a mixture of water and salt.  Since rain was predicted prior to the ice, ARDOT was worried the rain would wash the brine away, so they used rock salt instead.   Once the ice and snow arrive, the snowplows traversed the roads to remove as much of the accumulation as possible.  A mixture of salt and sand is scattered on the road to help with the melting process (salt) as well as to provide traction (sand).  After the ice dissipates the sand is often still on the road.  Vehicles traveling at high rates of speed can throw the rock pebbles, causing windshields to crack.

Cracks in vehicle windshields may be the result of several different conditions.  Extreme temperatures and sudden fluctuations from hot to cold can cause stress to the glass, causing the windshield to crack.  Temperature changes may result from fluctuations in the outside air or from the defroster used to defog the windshield.  Sunlight can have a similar effect as the heat causes the outer edges of your auto glass to expand faster than the center of the glass.  A stress crack can occur when the air pressure fluctuates.  This damage can be caused by travelling at high speeds or from objects pushing against the windshield.  Finally, you can be traveling a road and have a rock thrown into your windshield causing it to crack.  If a crack occurs in your windshield it will continue to grow until it is repaired.

Thoughts:  While I did not see a crack in my windshield on impact, the damage had been done.  When I drove the following day, I noticed a crack that was about 3 inches (8.5 cm) long in the lower left of the glass.  I assume this had happened overnight as the temperature dropped and then warmed again.  As I continued to drive my eyes were again diverted to the small crack, which had now grown to 4 inches (11 cm) and had taken off at an angle.  By the next day, the crack had expanded to almost 7 inches (17.5 cm) and I knew it was time to get the crack fixed.  Actually, I knew it was time to get the crack fixed when I first noticed it.  The crack was too large to be repaired and the glass would need to be replaced, causing me an inconvenience (time and money), so I put it off.  Many have treated our response to the virus in the same manner.  It is an inconvenience to get a vaccine, isolate, or wear a mask.  As a result, the crack has continued to grow.  Follow the science.  Change is coming and it starts with you.