How to identify stress crack?

[scratchy]

I have seen a couple of cracks that nothing will stop, drilling cleanly down to the laminate or perfect mini bulls eye. It seems as if there is some kind of invisible pull on the glass which was provoked when the chip occured. Any opinions?

[StarQuest]

Scratchy,

A stress crack would be described as a crack starting from the very edge of the windshield going outward. Is this what your talking about? If it is there's not much you can do to stop it. Stress cracks can be caused by vehicles that have had been in prior accidents where frame structure has been altered or compromised. This may also occur when a new windshield may have been installed incorrectly.

If it's something different than that please explain futher.

[Lee]

I have seen many cases where the crack extends beyond the visible separation of the break. It seems that the pressure on the glass from just being in the vehicle will close the break. This is good reason for a disclaimer because you never can be sure where it ends.

[Mikedoby]

I too have ran into the phantom cracks that suddenly appear for no known reason. My insurance agent told me about one of his customers that had her windshield replaced two times and was working on the third replacement before the glass shop found out that the car had been wrecked which left the window frame slightly warped. These are things that I guess will happen to all of us over the years

[scratchy]

Yes that is what I have seen. Chips hitting roughly 1 inch from the edge and a crack running briskly toward center. Vertical or horizontal, it doesn't matter which. It seems like you can place a mini bulls eye or a clean hole right off the end, just where it normally should be, put the injector on it lightly and after filling it with resin, it has passed the stop and kept on going. Try it again, and it passes right on by again! I think I have seen 2 of these in 6 months. I give a refund if it doesn't hold but I would like to have not even dealt with it in the first place.

[chip-gone]

I had one of these (impact about 1 in from edge w/ 8 inch "L" shaped crack) on my own vehicle. Drilled the end & the crack ran another 2 inches instantly. Filled it to near invisibility, but the crack STILL ran another 1/2 inch AFTER curing. It seems to have stabilized, so I have decided not to mess with it any more.

[johnnyone]

Dont really know how to identify a stress crack but after working on them they will let you know. After a few corrective repairs they continue and I usally let them go and call it quits unless I want to chase the crack all over the wind shield.

[WIN-1]

Stress cracks blow me outta the water.
I've had more problems when it begins from the bottom of the drivers side on late model pickups. They start the "Energizer Bunny March" across the windshield.
I wake up in cold sweats from nightmares from the blasted things!
Jeff indicated my scribe was dull, so I started with a big sewing needle.
The verdict is still out, I put on the guy's truck who will be my Flight Examiner for the next rating on my pilot's license.
?:~(
Ken

[screenman]

Only come across about ten cracks that would not stop where I wanted them to. Most of the time this is due to having the screen to hot.
I agree that there is such a thing as a badly fitted screen but drilling and popping correctly should stop almost everthing. Stop getting so stressed all of you and enjoy the job its a piece of cake if you have been trained properly and kept on practising. Clear the bad jobs out of your head and concentrate on the good ones.