When a repair is made on your windshield, a variety of tools are employed to make the work is done correctly. First, a drill is used to smooth surface and interior of the crack or chip. Next, a tool called a “bridge” is used to inject an acrylic-based resin into the damaged area. Once the resin has taken the place of any air inside the crack, a special UV light is used to cure the resin and help it to bond to the glass. Usually, the bridge is still used to help “cure under pressure,” a process that forces the resin to stay where it is while it hardens under the UV light.