Windshield Danger Zone?

[ChipKing007]

Just saw this and wondered if it seemed strange to anyone else. I've never heard of a danger zone on a windsheild before or an insurance company that would not pay for a second chip. Even if the insurance company won't pay for the second chip it's my job to look for and point out all chips found on a windsheild. The bullseye in the picture should have been easy to see and easy to fix. http://www.krgv.com/news/local-news/Roc ... k/33558462

[screenman]

Sounds like somebody making things up in that article.

Modern windscreen glass has a black ceramic or enamel band (sometimes called the frit) around the periphery which is baked onto the internal surface of the glass. The band has an etched surface to enable special windscreen adhesives to bond to the glass as well as acting as UV light protection for the adhesive preventing it from deteriorating over time. This black band includes a border of dots. Some windscreens also use the dots as a third sun visor to block the sun behind the rear view mirror where most visors don't reach.

[Windshield911]

I've never heard it called the danger zone. Now the edge area chips do seem to crack out easier. I have done the same thing as in the video myself. A few months ago repaired a chip for a guy in the driver side lower corner of a big jacked up truck. He called me about 2 weeks later saying there was a 8 inch crack coming down from top of passenger side but towards the middle. It started in the frit and the truck being so high up I just never noticed it. I was able to repair the crack. Customer had no idea it was there either till it cracked out.

I should add that it wasn't cracked out when I did the first chip repair or I would have seen it. It cracked out a couple weeks later and customer called me back.

[Mr Bill]

When parked in the sun, on a warm day, the frit will get hotter than the rest of the windshield because it is black.
This difference in temps on the windshield can create thermal stress.
If there is a chip near the frit, a crackout could help relieve that stress.

[Brent Deines]

I've never heard it called the danger zone either. I've been repairing chips in the frit band since they started setting windshields with urethane and adding the frit band to help protect the urethane from UV and the only difficulty I have ever had is 1) identifying the chips and cracks in that area and 2) determining if the resin has reached the ends of cracks in that area. These are challenges to be sure but certainly not something to be overly concerned with in my opinion. Just inspect a little more closely to find the damage prior to repairing and a little more closely during the repair (from the inside and the outside) to make sure you have it filled completely before curing.

As for thermal stress, the rapid heating and cooling of glass is far more likely to cause enough thermal stress or thermal shock to make an existing crack run than the difference in temperature between glass in the frit band area and glass outside the frit band area. Use your IR thermometer to check the temperature in both areas and you will find that difference is not all that drastic in direct sunlight and pretty much non-existent if the windshield is shaded, as it should be, when you are repairing on a hot sunny day. I know, I know, we all read the AGRR article on thermal stress and saw the photo of the windshield that was cracked completely in two because of thermal stress, but if you believe that you have never worked in a glass shop. You can lay a cracked windshield in the sun all day in 100+ degree temperatures and at the end of the day it will still be in one piece. If you pour a little alcohol down the crack to melt the PVB it will separate into two pieces but that has nothing to do with thermal stress.

A properly performed repair made in the frit band can handle the natural expansion and contraction of the glass just fine, or at least that has been my experience.

[Dempsterglass]

25 yrs in the business and this is First time I've heard of "The Danger Zone".
One more reason to thoroughly explain process and what to expect and not expect. Have it written on your invoice and a spot for customer to initial they understand process and risks.
I personally inspect entire windshield for previous repairs as well.
I have a diagram of windshield on invoice that I use to mark where I did repairs as well as list any previous repairs so if there is ever a warranty claim I know what was and wasn't done be me or new breaks

[Dr.Chipster]

The windshield repair company could have saved himself from an embarrassing news report and bad publicity with an "I am sorry we missed that, what can I do to make you a satisfied customer?" The guy was looking for an apology which I am sure he didn't get before the expose. We all make mistakes from time to time, but I believe when we treat people like we would want to be treated we win.

[Brent Deines]

Amen to that!