Windshield wipers that skip or rub across the glass can be annoying -- and dangerous. There are various causes for skipping wipers. The rubber may be dried out or corroded from salt or sun. They also could be bent in a way that prohibits correct movement across the windshield. Another cause could be your windshield if it has amassed a film from tree sap or gathered acidity from rain. Take several steps to troubleshoot and remedy the problem.
Clean your windshield. This is the cheapest way to begin troubleshooting and fixing the problem.
Check the angle of your blade. If a good cleaning doesn't work, check to see that your blade is angled correctly. If it looks badly shaped, replace the arms.
Apply windshield wiper lubricant. If your windshield is clean, and the wiper angle is fine, the rubber may be dry. Using directions on package, apply the lubricant to the rubber.
Check the windshield for contamination, if the wipers check out. At times, windshield glass can become contaminated. After cleaning, put your hand inside a plastic bag and run it over the glass. If the texture is pebbly, it is contaminated.
Apply clay to the windshield. If the glass is contaminated, you can "clay" it. Usually, claying is to remove a pebbly texture on car paint, but it works on the windshield as well. Buy a clay bar and clay lubricant, available at auto stores. Directions are on the package.
Buy new wiper blades if the problem persists.