For someone that repairs windshields water is an enemy. When water gets in a windshield chip it can create problems if it isn't removed before resin is injected and the windshield repair process is completed. Ideally you want a chip completely dry. Any water that is in the damage being repaired will mix with the resin causing the resin to discolor. It also weakens the resin so the repair is prone to fail. That's why you should repair a chip as soon as possible when it's dry.
Over the last several years I have been watching the weather reports and the dewpoint. The dewpoint in simplest terms is an indicator of how much water is in the air. As the air temperature and dewpoint temperature become the same fog is formed. I've found that once the dewpoint temperature and air temperature come within 5 degrees the quality of the repair goes down. Particularly true if it has been raining, as the ability to dry out a windshield chip becomes less possible.
So how bad can it be when trying to dry out a chip? Well here in Oklahoma City, this last Wednesday was a classic example of how the dewpoint comes into play. Monday and Tuesday it rained all day; Wednesday morning was cloudy with a dewpoint that was 4 degrees below the temperature. There was a very slight haze in areas of the Oklahoma City. One of my fleet accounts had an auto with 2 chips on the windshield. The night before they had pulled the car inside where it remained until I got there in the morning. Everything looked dry so I did the repairs and not to brag but they looked great. When I went to clean the windshield after finishing the repairs I found the glass cleaner left a haze on the windshield for several minutes. Even though it has alcohol in it, the glass cleaner didn't readily dry. Now think how hard it would be to dry out a chip. Even if you pull a vacuum in the chip which lowers the water's boiling point and warm the windshield, trying to get 100% of the water out is most likely impossible.
So if your auto's windshield gets a chip your best bet is to get it repaired as soon as possible if it is dry outside. Waiting for a rainy day to get your windshield repaired is not a wise move.
