When drilling into windshield damage, you never want to hit the plastic with the drill bit it will leave a black spot on the laminate making the repair more noticeable. Second you need to use a tool that pulls a perfect vacuum not 20 of inches, you need a vacuum like 30 inches of mercury to get all the air out.Third NEVER use a lighter on on a windshield it will could cause the damage to spread further, also a lighter burns at approx. 2000 degrees fahrenheit any heat over 100 degrees will cause the adhesive properties in the resin to break down leading to an inferior repair.