A car came in recently for minor auto body repair and the customer asked that while it was here they also wanted their cracked windshield replaced. When our windshield vendor came out to replace the windshield they couldn't replace it because of corrosion (rust).
We have used J & M Glass exclusively for the last decade because of their high quality workmanship. Mark, the owner is a walking encyclopedia on anything related to auto glass so we went to him to find out more.
Here's what we found out... 
When windshield glass is removed the installer uses a knife or special metal tool to cut through the adhesive to release the old glass. The area the windshield sits on is about a half inch wide.
We replace our windshield more often in Colorado due to the sand and gravel so it's important each time glass replacement is performed it's done correctly. If there's a small amount of corrosion a good installer will grind the area, acid etch and prime it to slow down any rust.
Using a controlled environment to replace glass is superior to a mobile service.
If a mobile technician runs into an issue in your driveway or at your workplace and needs a part(s) or finds corrosion he may not be prepared to perform the installation properly. Mobile technicians have a schedule of 8-10 windshield replacements a day. J & M Glass installers bring clip kits for every windshield and set aside 1 to 1 1/2 hours for replacement.During a mobile installation watch for these things:
We recommend that you add glass coverage to your auto policy and be sure the deductible is low enough that it doesn't exceed the replacement cost of the windshield. An insurance company will either have no glass deductible or a small deductible. A good question to ask your agent.
- If you see the technician installing the windshield with the wiper blades in an upright position he is "stuffing" the windshield into the cowl area and it has a high risk of leaking allowing the frame to rust.
- Make sure that the technician uses a primer to cover all bare metal scratches prior to putting the bead of urethane down to secure the glass.
We recommend that you add glass coverage to your auto policy and be sure the deductible is low enough that it doesn't exceed the replacement cost of the windshield. An insurance company will either have no glass deductible or a small deductible. A good question to ask your agent.
