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New Type of Chip

Posted: April 27th, 2015, 6:20 am
by TheGlassMD
I am still fairly new at this but came across something I had never seen nor read about. It was a chip with a crack coming out but there was no surface damage. It seemed that the damage was to the inner pane of glass in the windshield neither of the outside panes had damage. It was however very apparent there was an impact point. Just wondering if anyone else has ever seen this type of damage and any advice on how to handle it.

Re: New Type of Chip

Posted: April 27th, 2015, 9:19 am
by Brent Deines
Can you explain this statement? "It seemed that the damage was to the inner pane of glass in the windshield neither of the outside panes had damage." There is one inner layer of glass and one outer layer of glass with a layer of PVB in the center. The crack has to be in one of the layers of glass.

The crack may be "sub-surface" in which case you would not be able to feel it. This type of damage can still be repaired, however you must be able to determine if it is the inner or outer layer of glass. This can be difficult but using a light and a mirror you should be able to find an angle that will help you make that determination.

How long is the crack?

Does the crack go to the edge of the glass?

What part of the windshield is the damage in?

If the crack is in the outer layer of glass you can likely drill the end, pop a mini-bullseye, and fill as you would any other crack. If the crack goes to the edge of the glass and you are not able to access the edge of the glass because of a molding, etc., you may want to drill and pop another mini-bullseye next to the molding to anchor both ends of the crack.

Many technicians, including me, typically pass on an inverted crack repair (repairing the inside layer of glass from inside the vehicle), however depending on where the damage is located inverted repairs are possible. I did one a couple of weeks ago just to show someone how it can be done and it came out great.

Re: New Type of Chip

Posted: April 27th, 2015, 10:59 am
by TheGlassMD
"Sub-surface" damage must be what I saw. I had never seen this type of damage before. There was a clear impact point with a star break, and then about a 4-5 inch crack extending from the break. However, I used my probe and both the inner and outer layers of glass were completely smooth. There seemed to be no surface damage at all. The chip was located on the bottom part of the windshield (about 6 inches from the bottom) and then the crack ran straight up from the chip. It was not near any of the windshield edges.

Is this a type of repair that you would usually attempt, or is it something that you would typically pass on?

Re: New Type of Chip

Posted: April 28th, 2015, 11:09 am
by Brent Deines
Were you able to determine if the crack is in the outer layer of glass? In my experience most cracks of that length that extend from a star break are on the outer layer of glass but that is not always the case.

If the crack is in the outer layer I is likely repairable. You may be able to get it to fill from the impact point or you may have to fill from your drill point at the opposite end. Either way it should be repairable but you won't be able to run resin along the surface of the crack so you will have to allow additional time for the resin to wick into the crack under pressure. Normally I like to fill cracks from the bottom up so I can control the rate of flow but in this case I would fill from the top down if possible.

If the crack is in the inner layer of glass it will have to be filled from inside the vehicle which means your injector will be upside down. Not impossible but certainly a bit more challenging. Since there is no impact point on the inside of the glass you may have to drill both ends of the crack and you will have to fill from your drill hole(s). If you cannot get clear access to both ends of the crack for drilling and filling due to the proximity of the dashboard I would not recommend repairing from inside the vehicle.

From a money making standpoint I would probably pass on on a crack if I could not tell whether it was on the inside layer or outside layer of glass, but I kind of like a challenge so if it were me I would probably tell the customer that I would be happy to do everything possible to repair the damage but because of the complexity of the damage the only guarantee I could make would be that I would not charge if the result was not to their satisfaction. I would also tell the customer that I may have to drill the glass from inside the vehicle and describe what the drill holes will look like after they have been filled.

If you are not interested in a challenge that may not pay you for your time you may consider passing on this one. No shame in passing on a difficult repair that may not pay in favor of doing an easier repair that will pay for sure. It's just a business decision only you can make.

Re: New Type of Chip

Posted: April 29th, 2015, 11:02 pm
by screenman
You got to know when to say no, is something I try and get across when training guys.

Re: New Type of Chip

Posted: April 30th, 2015, 8:22 am
by TheGlassMD
I don't believe I have conveyed this as well as I should have. The real confusing part of this was not the subsurface crack I have seen those before. But the impact point itself was subsurface there was no damage to either the inside glass nor the outside glass on the impact point. I hope this clears that up. Thanks in advance for any insight to this conundrum, it is greatly appreciated.

Re: New Type of Chip

Posted: April 30th, 2015, 8:53 am
by Clarity Glass
My first thought is if the wiper blades were accidentally dropped on the w/s causing a stress break. I turn these down, next.

Re: New Type of Chip

Posted: April 30th, 2015, 9:22 am
by Brent Deines
TheGlassMD wrote:I don't believe I have conveyed this as well as I should have. The real confusing part of this was not the subsurface crack I have seen those before. But the impact point itself was subsurface there was no damage to either the inside glass nor the outside glass on the impact point. I hope this clears that up. Thanks in advance for any insight to this conundrum, it is greatly appreciated.
Ohhhh, my mistake. From time to time something will hit the glass hard enough to create a crack but not chip the glass at the point of impact. In that case simply drilling into the crack at one end should provide access so you can inject your resin. If the crack is also subsurface you might want to pop a mini-bullseye but if the crack is on the surface I would just use a very small bur and only drill to a depth of about 1mm. Sorry for the misunderstanding.

Re: New Type of Chip

Posted: April 30th, 2015, 10:23 pm
by screenman
Is there any chance of a picture.

Re: New Type of Chip

Posted: May 1st, 2015, 1:25 am
by Glasseye
Do you think it would be a good idea, if we had a permanent picture gallery of various types glass fractures, which could be added to and referenced, as and when variations arose.?