One problem that plagues windshield repair technicians is the use of various hydrophobic coatings that cause water to bead up and roll off of windshields. The problem they pose for repair technicians is that these coatings prevent repair resins from fully bonding to the glass which may cause the cured pit resin to pop out when scraping a repair flush.
Rain-X® and Aquapel® are probably the most commonly used coating products and it’s always a good idea to test the windshield to see if a coating has been applied before starting the repair. To do this, cover the area to be repaired with a Chip Saver patch to prevent liquid from infiltrating the break and spray it with water or glass cleaner. The water will bead up on the glass if the windshield has been treated.
The good news is that windshield coatings are typically applied with an applicator or soft cloth, so the liquid does not penetrate deeply into the damage, but remains mostly on the surface. This makes removal relatively easy one of the two methods recommended by Delta Kits.
First, every Delta Kits car windshield repair kit includes 4-O steel wool expressly for the purpose of removing hydrophobic coatings. You simply take the steel wool and rub it vigorously over the area to be repaired until the coating is removed.
A second option utilizes the moisture evaporator which is normally used to remove water from a break. The heat of the moisture evaporator will burn away any coating in a matter of seconds. Be sure to slowly cool the glass back down before you continue with the repair.
While it is easy to forget to check for these coatings because you can’t see them, they can have a visible impact on the quality of your windshield repairs. A simple spray test lets you know what you’re working with and keep your repairs from being “the pits”.