Can You Drill a Hole in Glass Windshield? [Comprehensive Guide]

Can’t you stop trying new things with your automobile? Then, you probably consider drilling a hole in your glass windshield to mount your phone holder or something else. Yes, most people try to drill glass windshields, but it is extremely risky; there is no need to even mention it! In today’s guide, we will provide you with essential considerations you should pay attention to before drilling a hole in your glass windshield. We will reveal to you the correct procedure to drill your glass windshield safely, too.

Why Are Glass Windshields Drilled? 

Glass windshields are drilled primarily for two reasons. It is possible to mount accessories and/or stop cracking with precise drilling.

1. Stopping Crack Propagation: In certain cases, a small hole drilled at the end of a crack in a windshield can help prevent the crack from spreading further. This technique, often employed by professional windshield repair technicians, involves drilling a tiny hole at the end of the crack and then filling it with a special resin. The resin fills the crack and the hole, stabilizing the glass and preventing further damage. However, this is a delicate procedure that requires expertise because incorrect drilling can worsen the crack or lead to further damage.
2. Mounting Accessories: Drilling holes also help mount accessories like GPS devices, dashcams, antennas, or phone holders. This is less common with modern vehicles, as there are usually alternative mounting methods available that don’t require drilling, such as suction cups or adhesive mounts. Drilling for accessory mounting is generally not recommended. The reason why, it can weaken the structural integrity of the windshield and potentially lead to cracks or shattering, especially under stress or impact.

Can You Drill a Hole in the Glass Windshield?

Yes, you can drill a hole in a glass windshield, but it is a risky task and should be approached with utmost caution due to the potential for damage and safety issues. The windshield is a critical safety component of a vehicle, contributing to its structural integrity and the safety of its occupants. Altering it in any way, such as by drilling, can compromise its strength and safety features. Therefore, it is generally not recommended to drill a glass windshield without professional involvement.

These are the major factors to consider before drilling a hole in a glass windshield.

• Safety First Approach – We always recommend exploring safer alternatives for drilling. For mounting accessories, suction cups or adhesive pads are often a better choice, as they avoid damaging the windshield. If you’re trying to stop a crack from spreading, professional windshield repair is usually the safest and most effective method.
• Should You Need to Drill– In cases where drilling is the only option, consulting with windshield specialists is crucial. They can provide advice on whether it’s safe to drill in your specific case. Using the right tools, like diamond drill bits designed for glass, and applying controlled, gentle pressure can reduce the risk of damage. It’s also important to choose the drilling location carefully, avoiding any critical structural points or areas that might obstruct the driver’s view. And remember, drilling into a windshield can void warranties.

How to Drill a Hole in a Glass Windshield? 

Drilling a hole in a glass windshield is a very delicate process that requires professional knowledge and the right tools. Here’s a complete guide on how to do it, but please be aware that this process is risky and can easily damage the windshield or compromise its structural integrity. Thus, it’s often best left to professionals.

• Gather the Right Tools: You’ll need a variable speed drill, a small diamond drill bit (specifically designed for glass), masking tape, and safety equipment like gloves and eye protection. Using inappropriate drill bits can damage your windshield.
• Prepare the Windshield: Next, clean the area where you will be drilling thoroughly. Apply a piece of masking tape over the spot where you want to drill. The tape helps prevent the drill bit from slipping and the glass from chipping.
• Mark the Drill Point: Use a marker to make a small dot on the tape where you want to drill the hole.

• Start Drilling at a Low Speed: Now, fit the diamond drill bit into your drill. Make sure to begin drilling at the lowest speed to create a small indent in the glass. Apply very light pressure — let the drill bit do the work.
• Increase Speed Gradually: Once the initial indent is made, you can gradually increase the speed of the drill. Maintain steady, light pressure. Do not rush this process, as applying too much pressure or speed can crack the glass.
• Keep the Area Cool: Periodically, you may need to lubricate the drill bit with water to keep it cool and prevent glass dust because overheating can cause the glass to crack.
• Complete the Hole: Continue drilling until you break through to the other side. Be extra cautious as you near the end to avoid chipping the exit point.
• Clean and Inspect: After drilling, remove the tape, clean the area, and inspect the hole for any cracks or rough edges.

Important Notes:

• Consider the location carefully. Avoid areas near the edges or where the glass experiences high stress.
• If the windshield is part of a vehicle’s safety system (like those with advanced driver assistance systems), drilling could interfere with these systems.