Fixing a windshield chip yourself


If you are unlucky enough to get a chip in your windshield resulting from a random pebble launched by the tires of some truck in front of you, and mechanical stress hasn’t caused cracks to immediately spread outwards, hopefully you can reverse that bad luck, avoiding a windshield replacement, by fixing the chip yourself with a repair kit, prior to cracks eventually spreading across the windshield.  Usually the cause of the crack(s) happening after the fact, is additional thermal stress, such as:

  • the defrost heater hitting the very cold windshield
  • the AC defogger hitting a very hot windshield, etc.

A rock of some sort hit my windshield a couple of weeks ago while driving in Michigan (on my other vehicle – not my 124 Spider), and after watching this YouTube video, I ordered the Blue-star Windshield Repair Kit from Amazon (under $8.00), although there are plenty of other alternatives out there, including companies that will repair the chip, likely at no cost to you if submitted to your insurance company.

windshield repair kit

Windshields are laminated using glass and plastic, so that when glass is shattered, the shards are held in place by the plastic film within (hence it’s called “safety” glass).  The principle behind this repair kit (and many others), involves creating a vacuum, sucking all the air out of the little voids within the shattered glass (that make up the visible chip), and then pressure injecting clear epoxy resin to fill those voids.  I imagine that some of the voids on the backside of the plastic film (closest to the vehicle’s interior), as well as the deformed plastic film itself (at the point of impact), won’t be fixable with resin, which may result in the slight reveal, some report seeing after their chip has been repaired.

Today, I’m happy to report that my chip did not spread, and it was a simple half-hour procedure for me to fill the chip in with the epoxy resin formula that cured in 15 minutes (as the sun was shining brightly), using the UV radiating from the sun.  My experience was even better than the typical repair results, shown in the top photo.  The entire chip is gone!

If this had been my 124 Spider, I wouldn’t hesitate to try this solution, especially if it appears that you will successfully mitigate unsightly stress cracks from emanating outwards from the chip.  The worst that can happen, is that cracks do occur afterwards (highly unlikely if the resin is bonded to the glass thoroughly), and you end up calling up your insurance company to initiate a windshield replacement, which I might add, after learning that it may take a week or two to obtain the glass and windshield surround trim pieces, the replacement job itself can be a very tedious and expensive endeavor, as you can read more about here.

Instructions (from a similar kit)

Perform repair in shaded area (not in direct sunlight) with the windshield temperature between 50°F and 75°F (10°C to 25°C). Do not allow the resin to come into contact with car’s finish or painted surfaces as this may cause damage. The Windshield Repair Kit repairs damages not exceeding 1 1/4 inch in diameter.

  1. Clean windshield around the damaged area with the alcohol towelette. Clean loose pieces of glass from the damaged area with the pushpin. Suggested: Place a cloth near the bottom of the windshield, below the damage. This will stop any resin that might flow from the repair area.
  2. Take the adhesive disc and peel the backing off ONE side of the adhesive disc. With tab pointing upward, line up the hole in the disc with the center of the damage. Make sure tab points upward. Press the adhesive disc onto the glass. Ensure that the whole adhesive disc is in contact with the windshield. Look at the disc from the inside of the vehicle to make sure there are no air bubbles.
  3. Peel off the OTHER side of the adhesive disc. Line up the pedestal with the adhesive disc making sure that the tab again points upward and matches the tab on the adhesive disc. FIRMLY press the pedestal against the disc again making sure that there are no air bubbles in the adhesive.
  4. Remove the cap from the resin tube. Away from painted surfaces and your face, carefully cut tip off (approximately 1/8 inches) to open resin tube. Place resin tube stem 1/4 inch into the pedestal opening and carefully squeeze tube to load resin into pedestal. Once tube is squeezed, remove resin tube from pedestal. Wipe off any residual resin from tip. Replace cap on resin tube and save any remaining resin for use in step 9.
  5. Make sure that the plunger is pushed all the way into syringe prior to use. Carefully and firmly twist the tip of the syringe into the pedestal. The fit between syringe and pedestal should be tight.
  6. Hold the syringe with one hand and gently pull plunger upward with the other hand. LOCK IN PLUNGER AT LOWEST INDENT SETTING by turning plunger indent into clip. Spring clip system will secure plunger in place. Allow entire assembly to sit as is for 10 MINUTES.
  7. Once step 6 is completed, temporarily remove the syringe from the pedestal. This will allow air into syringe. With plunger still locked in lowest indent setting, carefully replace syringe by twisting the tip of the syringe into the pedestal. Hold the syringe with one hand and gently push plunger down with the other hand. LOCK IN PLUNGER AT UPPER MOST INDENT SETTING by turning plunger indent into clip. Allow entire assembly to sit as is for at least 20 MINUTES.
  8. Once step 7 is completed, remove the syringe. Using the safety razor, slowly remove the pedestal and the adhesive disc from the glass. Wipe off any residual resin from glass.
  9. Remove cap from resin tube. While holding resin tube in one hand and curing strip in the other hand, carefully squeeze a bead of any remaining resin into the hole of the damaged area. Place curing strip over damaged area to hold in resin.
  10. Remove any air bubbles by using safety razor to lightly smooth over curing strip. Move the vehicle to sunlight area and let sit in direct sunlight for 15 minutes. Resin will cure with natural UV Sunlight (at least 1 hour is required on cloudy days). Once resin has cured, carefully remove curing strip by peeling it away from windshield.

Finishing tips: If the surface of the glass is uneven, safety razor may be used to remove any excess cured resin from windshield. Clean windshield again with alcohol towelette.



4 thoughts on “Fixing a windshield chip yourself

  1. That’s a much more economically attractive solution than what I use. About 8 years ago, I purchased a kit from Glass Star America for around $500 USD. It’s pretty much what you see the folks use that set up the tents in parking lots to do chip repair work. I’m able to fix pretty much anything except long cracks, and it came with enough supplies to do 100 repairs. My theory was, I was paying around $40 a pop to have a chip fixed in my windshield, and my family has three vehicles. Calgary is infamous for it’s love of using coarse aggregate sifted on the roads for winter ice management, and it takes a heavy toll… both on the glass and the body paint. But, the kit has paid itself off over time, and when I was working, my colleagues loved me because if I had time, I might do a quick chip repair for them in the underground staff packing over lunch-hour. Friendship has it’s benefits. lol Here’s the link to the kit I purchased. They make others, and I’m sure there are other manufacturers of kits as well. For people with several vehicles and that live in areas with gravel roads,etc., it might be worth consideration.


    • That was my first stone chip on my 15-year old vehicle, so i’m not buying my kits in bulk. 😉 Hoping my 124 Spider windshield never intercepts any rocks, although I’ve seen evidence of same on my painted parts.


  2. When my Classica was nearly new and returning from its first trip to San Diego, the windshield caught a rock in a Santa Barbara construction zone. My wife googled up the nearest Autozone store. Bought a kit and applied it right in the parking lot and 90 minutes later we were back on the road. Glass saved – though if you know exactly where to look it can be seen depending on available light.

    Liked by 1 person

    • Windshields are laminated, and although the resin can fill in the voids of the shattered glass within, I imagine that the deformed plastic sheet(s) in between the layers of glass can’t be fixed by resin, which might be the slight reveal you are detecting. Pressurizing the resin into the chip really does do a superb job though!


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