Getting Clear on Windshield Repair Kits

Is that rock chip in your windshield really starting to annoy? If you're not ready to spring for a new windshield, you might be able to fix that small chip yourself. And even if you can't make it perfect again, a windshield repair kit can often prevent the damage from spreading further.

We had stars in the windshields of two of our cars and wanted to see how well a do-it-yourself kit sold in auto parts stores worked. While it didn't make the damage completely disappear, it reduced the visibility of the crack and can ensure the break doesn't grow any larger. Since these kits are inexpensive Band-Aids rather than a complete repair, keep your expectations in check. The damage is unlikely to become invisible, but the small investment can buy some time before you need a new windshield.

Consider Your Options

Replacing a windshield can easily run $200-$500, and you can also hire a glass expert to come and fix cracks, bull's-eyes and stars for about $75. However, their method is only slightly better than what you can do yourself. The professional may use a diamond-tipped drill, and have a better "bridge" -- the guide that attaches to your windshield with suction to force resin into the crack.

There are a number of windshield repair kits on the market, including the highly rated Fix-A-Windshield, which contains a plastic bridge similar to those used by professionals. We tried the popular Permatex kit ($11.99) which uses a syringe to suck air out of the break and then inject resin into the area to seal the glass.

Tools and Repair Time

The kits come with almost everything you need for the repair, which will take about an hour to perform. In addition, we recommend that you wear latex gloves to keep the resin from contacting your hands, get a towel to protect your car's finish and put a roll of paper towels under the windshield wipers. Also, bring a bottle of glass cleaner for post-repair cleanup.

The first steps should not be done in direct sunlight and the windshield should not be hot to the touch. For the final steps of the repair, you will move the car to direct sunlight so you might want to pick a spot that has both sun and shade nearby.

Repair Steps

You should always follow the specific instructions of the kit's manufacturer, but here's a general overview of the process.

1. Clean the area around the break with an alcohol pad.
2. Using a push pin, dig out any loose chips of glass, making sure not to let the sharp particles come in contact with your hands. A professional glass repair worker would drill a small hole through the top layer of the windshield glass to allow the resin to better penetrate the break. Clean the area again with the alcohol pad.
3. Peel off one side of the backing of the doughnut-shaped adhesive and press it on the windshield so that it completely surrounds the center of the break. Firmly press the adhesive onto the glass.
4. Peel off the other side of the backing and press the "pedestal" onto the adhesive so that it angles straight up.
5. Snap or cut the tip off the tube of resin and empty about three-fourths of the tube into the pedestal. This is hard to do because you have no idea how much is in the tube. Just don't squeeze it too strongly. Put the cap back on the resin and set it aside. Resin will now be flowing into the broken glass area.
6. With the plunger pushed all the way in, put the syringe into the pedestal and push it into place so it forms an airtight seal. Draw the plunger back to the indent near the tip of the plunger and then twist it so it locks in this position. This will draw air bubbles out of the broken glass area. Leave the syringe in this position for 10 minutes.
7. Remove the syringe to break the vacuum and allow air into the pedestal. Now, reinsert the syringe so that it is airtight again. Holding the syringe in place with one hand, press down on the plunger with the other hand and lock it in the lower setting. In this step, you are using the sealed space, and the airtight plunger, to force the resin down into the break. Leave the assembly in this position for at least 20 minutes.
8. Remove the syringe and use a safety razor (included in the kit) to cut the adhesive doughnut and pedestal from the windshield. Some resin will flow down and be absorbed by the paper towels under the windshield wipers.
9. Move the car into direct sunlight. Put several drops of the resin into the center of the break. Place the plastic square over the resin and smooth out any air bubbles with the edge of the razor so that the resin evenly coats the area. Let it stand for 15 minutes (or an hour on a cloudy day). The ultraviolet rays of the sun will harden the resin.
10. Remove the plastic strip using the razor and scrape the resin from the glass. Spray the area with glass cleaner and wipe it down.

Repair Tips

Here are a few additional tips not generally found in your kit's instructions: