Fixing a Long-Cracked Windshield Is an Intermediate-Level Repair for Most DIYers. Here’s Everything You Need to Know to Fix a Long Windshield Crack at Home.
- DIY Difficulty Level: Intermediate
- Time Required: 15 to 30 minutes, plus 30 minutes to two hours for the resin to cure
- Tools & Materials: Windshield repair kit
What Is a Long-Cracked Windshield?
A “long-cracked windshield” is one that has a large crack running across its length or width. Other types of cracks include star breaks, chips, bulls-eye cracks, and half-moon cracks. Some cracks are combination cracks with more than one type of damage. What sets long cracks apart from the others is that they present a long fracture along a single line, while the others are more circular and localized.
The simplest way to repair a long windshield crack is with a windshield repair kit, such as the Rain-X 600001 Windshield Repair Kit available on Amazon. You can also find windshield repair kits at your local hardware or auto parts store. Be sure to get a kit that is designed for long cracks. Some kits will only work for bulls-eye cracks or other small cracks.
Is It Safe to Drive With a Long-Cracked Windshield?
You can drive with a cracked windshield. However, your car’s windshield is a key piece of safety equipment. It absorbs some of the impacts of a collision and protects the passengers from outside debris. It also helps maintain the integrity of the vehicle in the event of a rollover. A cracked windshield may not be sturdy enough to stand up to these stressors, so it’s best to avoid driving your vehicle until the windshield has been repaired.
You can buy a windshield repair kit for less than $20. Hiring a professional could cost anywhere from $20 to $70. Expect to pay a little more if the technician has to come to you. Taking these numbers into account, attempting a DIY repair may be a good option if you’re on a tight budget and are confident in your skills. However, paying extra for a professional job could be worth it for your peace of mind. A professional can also take the guesswork out of deciding whether a repair or replacement is the best option.
When Should You Replace Your Windshield or Repair It?
Not all window cracks can be safely repaired, and in some cases, replacing the windshield just makes more sense. Consider replacing the windshield if any of the following are true:
- You have comprehensive insurance. Most comprehensive insurance policies cover glass replacement at no cost to you. You usually won’t even need to pay a deductible.
- State safety inspections won’t allow it. In states that perform safety inspections, any cracks in the windshield at all may fail.
- The crack crosses the driver’s line of sight. You may find the crack distracting even after it’s repaired, especially if you go the DIY route.
- The crack is longer than 3 inches. A professional may be able to repair a longer crack, but most will advise you to replace the windshield instead.
- The crack is wider than an inch. If the crack is wide as well as long, your windshield will be too weak to keep you safe.
- The crack isn’t brand new. The longer you take to repair a windshield crack, the more likely your windshield will need to be replaced. Cracks that are not addressed right away can spread or become irreparable.
- The crack is deeper than surface-level. Windshields are comprised of three layers: a sheet of polyvinyl butyral (PVB) sandwiched between two layers of glass. Only cracks in the outermost layer of glass are repairable. Deeper cracks can compromise the integrity of the windshield, making it more vulnerable to shattering.
- There are more than two cracks. If your windshield has multiple cracks, it is usually better to replace it. A professional may be able to repair up to three cracks, but they may also recommend replacement.
Keep in Mind
Remember to follow any recommendations in your vehicle’s owner manual regarding windshield care, repair, and replacement. In some cases, your insurance may cover the repair or replacement.
How to Fix a Long-Cracked Windshield
Most repair kits use a resin that must be cured with ultraviolet rays, so plan to perform the repair on a bright sunny day or have a UV lamp on hand. You’ll want to keep the car in a shaded spot while applying the resin, though.
Step 1: Prepare the area
The first step of any repair will be to clean the area to remove any debris that might be inside the crack. You can use a dust blower or a little acetone to remove any dust. Then dry the area thoroughly with a blow dryer if necessary.
If the crack ends in a semicircular or circular indentation, you’re good to go. Otherwise, you will need to bore a small hole at the end of the crack to help funnel the resin into the crack. You can tap a hole with a bulls-eye tapper, a sturdy needle, or a 1/16-inch drill bit. This must be done very carefully to avoid making the hole too deep or damaging the windshield further.
Step 2: Prepare the applicator
When preparing the applicator, read the instructions of your repair kit carefully. Some kits have a bridge-style applicator, while others have a simple syringe. You will need to load the applicator with the resin. If your kit has two types of resin, use the one that’s designed for cracks rather than chips. Position the applicator as the instructions direct.
Step 3: Apply the resin
Use the resin to fill the crack, starting at the end of the crack. Once you are sure the resin is entering the crack properly, you should be able to move the applicator along the remaining length of the crack in one smooth motion.
Step 4: Remove the applicator and cover with curing tape
Once the crack has been completely filled, you can remove the applicator. Then, cover the area with special curing tape. It could take 30 minutes to two hours for the resin to cure completely.
Step 5: Remove the excess
Once the resin has cured, use a razor blade to remove any excess and smooth out the area.
Still Need Help?
Want an expert mechanic on speed dial who can walk you through DIY repairs and answer any questions? Join FIXD Mechanic Hotline for unlimited access to our Master Mechanics Monday through Friday, 8 a.m. to 8 p.m.
At FIXD, our mission is to make car ownership as simple, easy, and affordable as possible. Our research team utilizes the latest automotive data and insights to create tools and resources that help drivers get peace of mind and save money over the life of their car.