Windshield ding

By any chance is your Dino Silver?
Nick at motoclassic told me of a doc near him that just restored a 246 in a big way...is that you?

 

I have used that stuff from auto parts stores..........it comes in a "syringe type thing" and costs about 10 dollars.............follow the directions EXACTLY and I repaired a chip about 2 years ago.......after the repair it is almost completely invisable, and it has spread AT ALL..........my advice is to try this, it worked great for me.....also DO NOT drive the car at all until you get it fixed.........that chip can spider web across the whole windshield in minutes of driving then you're hosed......in fact, if those cracks get anymore than 1 inch long, it will make the repair nearly impossible...................

 

i had one of the large window ding shops do my 308GT4 a year or so ago, and they just wanted to be relieved from responsibility when the crack enlarged exponentially.
they did a great job - i asked to send their BEST person, who repaired a large run from when i bought the car. the stuff you do yourself does not (INHO) do as good as they use better equipmnt, pressure and powerful vacuums to push/pull the epoxy into the hole, depending on the application and nature of the hole/crack.

i was happy with them, they just didnt want to have to replace the glass if the worst case happened. think i signed a disclaimer. i figured that THEY had less of a chance of screwing up than i did, with all my experience at doing it, and all. HA! saved me having to replace the 2k window, anyway......

 

I used to have a window crack repair business. Most windshield glass, is two 1/8" pieces of glass with laminate inbetween. When the top part of the glass gets a crack in it the bottoom part is still fine. When you look at the crack, and see it kind of sparkle, what you are seeing is the air that is in the crack refracting the light. There are different kinds of cracks. The most common are bullseyes, and stars. Then there is the combination, a bullseye with a star. The bullseye is just a round crack with no other cracks (called legs or runners) coming off of it. A star has two or more cracks that start at the center, ususally the point of impact, and go outward. The combination is a bullseye with crack/s coming out of it. Depending on were the crack is located on the windshileld and what kind it is, determines how fast it will spread and if it will spread at all. Temperature and pressure are also factors in this.

If a crack is a pure bullseye, no legs coming off of it, they normally do not spread. They are just an eye sore. The reason a bullseye doesn't normally spread is that the crack is round and has no place to go. What makes a bullseye is when, an object hits the windshield, ususally a rock kicked up from a tire, causing a piece of the glass to break of in the shape of a cone. The tip of the cone is the point of impact and the base of the cone is the laminate inbetween the two pieaces of gass. So all you have is a little cone sitting under the glass, refracting the light from the air that is around it.

Star cracks and combinations are the ones you really have to get fixxed right away. The star crack is made the same way as a bullseye, but instead of breaking off a cone under the glass, it makes a vertical crack/s in the glass. The crack is from the top of the glass to the laminate. You also see the sparkle in this crack from the air that is inbetween the two sides of the crack. The crack/s starts and the point of impact and then go outward, giving it the look of a star. These are the ones that will spread.

When a crack is low on a windshield it has a greater tendancy to spread. When you are driving, the pressure from the air going over the car is greater at the bottom of the window. Also the faster you drive the greater the air pressure becomes. So if a leg, of a star crack or combo, is put under pressure it will start to crack more. Then this legs becomes what is called a runner. Because it continues to run (crack) until it comes to the edge of the windshield or another crack. This is why you shouldn't drive your car until it gets fixxed.

Temperature is another factor. When glass gets heated and cooled, it expands and contracts. This expanding and contracting will result in the crack running. Outside air temperature can cause this. Air conditioning can also result in a crack running. When you are running the a/c on a hot day, the a/c has the inside of the car cool, while the outside temerature is hot. So this difference in temperature can cause the crack to run. Same thing for the heater on a cold night. But the fast change occurs when you wash the car. If the windshield is hot, and then you use cold water to get the car wet, the cold water hitting the glass will cause it to contract rappidly resulting in the crack running. So until you get the crack fixxed don't wash the car.

To fix the crack what is used is an acrylic resin. It is kind of a mix between super glue, and the stuff used for fake finger nails. The difference being that the resin cures with ultrviolet light, and not air. What you are doing when fixxing the crack is 1) glueing the side of the crack together, and 2) removing the air from inside the glass. If you have a bullseye crack you want to get all of the air out of the crack as possible. You want to find a windshield repair kit that can extract the air from the bullseye.

So here is what I used to do to fix a bullseye. Put the car in a shaded area were no light will get on the place to be repaired. With a clean towel and rubbing alcohol clean off the area to be fixxed. Take the injector and put in the right amount of resin needed to fix the crack. Put the tip of the injector on the crack so that it covers the entire point of impact. You don't want any air getting in. Now put pressure on the injector to draw OUT the air that is in the crack. If you go inside the car you will be able to see little air bubbles going up into the resin. You want to wait until the air bubbles stop. If you have ever sucked on a coke bottle and your lip went into it, the same type of thing is happening to the air inside the bullseye. You want to make sure you get as much air out of the crack as possible. Once the air bubbles have stopped then you can reverse the pressure to inject the resin. When you start to inject you will see the resin filling in the bullseye. Be careful not to put too much pressure, because if you do you will break the seal that the tip has made over the little hole, loosing the pressure need to fill the bullseye. So just use light pressure to inject at first. As you see the resin slowing down or stopping you can increase the pressure to inject more resin until the crack is completely filled. The more complete the crack is filled, the the less of a chance it will spread, and the better it will look when it is done. Leaving the crack under injection pressure. Pull it out into the sunlight so that the ultraviolet light can cure the resin. Let it cure for about 15 to 20 minutes. You wanna make sure that all of the resin gets cured before you release the pressure. You can also use a little mirror to get the places the the sunlight can't hit. After the resin has cured release the pressure and remove the injector. Now with a brand new razor, holding it straight up and down, not at an angle, using a fast side to side motion, scrape off the excess hardend resin. Then if they gave you some in the kit, apply the glass polish and buff out the crack. Then clean up your windshield and drive down the road.

Keep in mind that the window is cracked and you will see the crack. It will look like a little scratch, instead of a big crack. It just will not be as evident because the resin is not refracting the light. In some cases, noramlly small bullseyes, the crack will almost completely dissappear.

Happy fixxing.

 

I agree with Fanatic1. I've done two repairs so far on windshields and had good success. Thank goodness the 328 winshield hasn't been hit....

 

Most insurance companies will send somebody out to repair a windshield for free. I had my M5 windshield so repaired in my office parking lot by Allstate a few months ago.

 

ernie,

Very informative. Thank you for posting that.

Barry

 

Ernie: Great write-up.

I've worked with windshield repairers for decades, and they will tell you that on RARE occasion, a windshield will severely crack while undergoing the repair. That's why many places won't touch an exotic.

 

Solly did you remember to use a MIRROR to get the parts that the sun couldn't get to. Try it one more time, but this time get a makeup mirror, and when you leave it in the sun put the mirror on the inside of the car, so that you are reflecting the light on to the underside of the crack. The ultraviolet light has to hit all of the parts of the crack that are filled with the resin. The part that the injector was covering didn't alow the light to get to the resin that is why it didn't cure. So try it one more time using a mirror to make the light hit the crack from underneath.