Rock Chip Repairs on Vertical Windshields

Question:

My question centers on repairs to vertical windshields like on RVs. I use a “side-port” injector for these repairs. I carefully use a diamond drill to ensure the crack is free of loose material. The problem I have is that sometimes the auto glass resin (MagniBond) will not fully penetrate the entire length of the crack on these vertical windshields. Is there any way to attack these rogue cracks once the resin has set?

Answer:

If the resin has already cured, the only thing you can do is drill the crack again, either from the end opposite the original injection point or from where the resin stopped flowing into the crack, then continue filling from that point. There is no reason that MagniBond will not fill a crack completely on a vertical windshield, so I would look to the injection design or amount of resin being used to solve the problem, or perhaps a combination of the two. Keep in mind that many RV, bus, and truck windshields are thicker than car windshields, so they will require slightly more resin and a bit more time for the resin to penetrate.