Has anyone ever had this problem

[bearbait]

The way thieves used to break into cars was by throwing a piece of spark plug ceramic at the tempered side windows.

The only reason laminated glass is used in the windshield of cars and trucks is to keep those with no seat belt on inside the car. The other windows are tempered. The tempered glass is much stronger so a branch or similar wont damage it.

Closing the cab door is not going to do it. I have hit some tempered glass with a 12 lb sedge hammer and it bounced off.

There are glass breaking and seat belt cutting tools for those who want to rescue someone after an accident.

The glass breaking tool's important detail is a very hard, very pointed tip.

Make certain nothing like your roof work lights mounting bolt can touch the edge of the glass. Something has created a pressure point.

Perhaps something in the cab structure has allowed the windshield area to rack and thus press against the edge of the glass. An improper install can do this but this is very rare.

Dave

Well Dave all I can tell you is what happened to me and I have no reason to lie about it, the windshield was being covered by insurance whether my fault or not. I know there were no dings in the windshield because I cleaned all the glass inside and out not so long ago. There was nothing touching the glass inside or out. The only thing different are the new lights put on the first week in January using the same factory mounts, using the same bolts the only difference being I had to use an extension so the lights would clear the roof, that's it. As for closing the door not being able to break the glass well that's exactly what happened. As for why I really don't know, I'm no expert. Also as I said the glass place here was not surprised at all and said mine was not the first one they have replaced along with cars and trucks that the back window blows out of them. All I can tell you is I'll be glad to have it back today. Thanks for your reply and giving me your take on it.

All the best, Donnie

 

[OrangeJoe]

Tempered Glass is funny that way. Some times the glass fails, perhaps because of stress due to how it is mounted, perhaps because of a manufacturing defect. There is currently a large (and growing) recall on several car brands for failures of the Tempered Glass in their Sun Roofs.

 

[Dave_eng]

Well Dave all I can tell you is what happened to me and I have no reason to lie about it, the windshield was being covered by insurance whether my fault or not. I know there were no dings in the windshield because I cleaned all the glass inside and out not so long ago. There was nothing touching the glass inside or out. The only thing different are the new lights put on the first week in January using the same factory mounts, using the same bolts the only difference being I had to use an extension so the lights would clear the roof, that's it. As for closing the door not being able to break the glass well that's exactly what happened. As for why I really don't know, I'm no expert. Also as I said the glass place here was not surprised at all and said mine was not the first one they have replaced along with cars and trucks that the back window blows out of them. All I can tell you is I'll be glad to have it back today. Thanks for your reply and giving me your take on it.

All the best, Donnie

Please realize I completely accept your explanation of what happened.
There would have been no dings or chips in the glass. You are absolutely correct about that.

I think it is a mistake to try and out think the Kubota designers and switch to a laminated glass and you have not done that..

You could set up a jig to open and slam closed the side door a million times and your experience would not re occur. That is what would happen in the engineering labs at Kubota to proof test the design.

Often, if you look closely at a piece of tempered glass, you will notice two small dimples along one edge. The glass is hung by two tiny clamps as it undergoes the tempering.

Do you ever watch the TV series Forged in Fire? Contestants fabricate knives and swords from scrap pieces of steel. At the end of their work the critical step of quenching takes place where their weapon, red hot, is thrust quickly into a vat of cool oil. Success of failure after days of work all hinge on this critical step.

The clamping, heating and final air quenching parts of the manufacturing process, can, if the process does not go perfectly, bring the piece of tempered to the edge of failure where it sits until some tiny event pushes it into failure.

The outer surfaces are undergoing the strengthening from the flame treatment and the air quenching of the inner and outer surfaces. If there is lack of uniformity in the temp each side of the glass sees, this creates the stresses which can lead to your type of sudden failure

In your case, the closing of the door combined with certain temperature changes pushed the glass over the edge.

The odd of this happening again are extremely remote.

You may find reading the material below explaining the manufacturing process informative.

Dave

Mark Ford, fabrication development manager at AFG Industries, Inc., explains:
Tempered glass is about four times stronger than "ordinary," or annealed, glass. And unlike annealed glass, which can shatter into jagged shards when broken, tempered glass fractures into small, relatively harmless pieces. As a result, tempered glass is used in those environments where human safety is an issue. Applications include side and rear windows in vehicles, entrance doors, shower and tub enclosures, racquetball courts, patio furniture, microwave ovens and skylights.
To prepare glass for the tempering process, it must first be cut to the desired size. (Strength reductions or product failure can occur if any fabrication operations, such as etching or edging, take place after heat treatment.) The glass is then examined for imperfections that could cause breakage at any step during tempering. An abrasive such as sandpaper takes sharp edges off the glass, which is subsequently washed.
Next, the glass begins a heat treatment process in which it travels through a tempering oven, either in a batch or continuous feed. The oven heats the glass to a temperature of more than 600 degrees Celsius. (The industry standard is 620 degrees Celsius.) The glass then undergoes a high-pressure cooling procedure called "quenching." During this process, which lasts just seconds, high-pressure air blasts the surface of the glass from an array of nozzles in varying positions. Quenching cools the outer surfaces of the glass much more quickly than the center. As the center of the glass cools, it tries to pull back from the outer surfaces. As a result, the center remains in tension, and the outer surfaces go into compression, which gives tempered glass its strength.


GLASS INSPECTOR examines a sheet of tempered glass, looking for bubbles, stones, scratches or any other flaws that could potentially weaken it.
Glass in tension breaks about five times more easily than it does in compression. Annealed glass will break at 6,000 pounds per square inch (psi). Tempered glass, according to federal specifications, must have a surface compression of 10,000 psi or more; it generally breaks at approximately 24,000 psi.

 

[bearbait]

Please realize I completely accept your explanation of what happened.
There would have been no dings or chips in the glass. You are absolutely correct about that.

I think it is a mistake to try and out think the Kubota designers and switch to a laminated glass and you have not done that..

You could set up a jig to open and slam closed the side door a million times and your experience would not re occur. That is what would happen in the engineering labs at Kubota to proof test the design.

Often, if you look closely at a piece of tempered glass, you will notice two small dimples along one edge. The glass is hung by two tiny clamps as it undergoes the tempering.



Do you ever watch the TV series Forged in Fire? Contestants fabricate knives and swords from scrap pieces of steel. At the end of their work the critical step of quenching takes place where their weapon, red hot, is thrust quickly into a vat of cool oil. Success of failure after days of work all hinge on this critical step.

The clamping, heating and final air quenching parts of the manufacturing process, can, if the process does not go perfectly, bring the piece of tempered to the edge of failure where it sits until some tiny event pushes it into failure.

The outer surfaces are undergoing the strengthening from the flame treatment and the air quenching of the inner and outer surfaces. If there is lack of uniformity in the temp each side of the glass sees, this creates the stresses which can lead to your type of sudden failure

In your case, the closing of the door combined with certain temperature changes pushed the glass over the edge.

The odd of this happening again are extremely remote.

You may find reading the material below explaining the manufacturing process informative.

Dave

Mark Ford, fabrication development manager at AFG Industries, Inc., explains:
Tempered glass is about four times stronger than "ordinary," or annealed, glass. And unlike annealed glass, which can shatter into jagged shards when broken, tempered glass fractures into small, relatively harmless pieces. As a result, tempered glass is used in those environments where human safety is an issue. Applications include side and rear windows in vehicles, entrance doors, shower and tub enclosures, racquetball courts, patio furniture, microwave ovens and skylights.
To prepare glass for the tempering process, it must first be cut to the desired size. (Strength reductions or product failure can occur if any fabrication operations, such as etching or edging, take place after heat treatment.) The glass is then examined for imperfections that could cause breakage at any step during tempering. An abrasive such as sandpaper takes sharp edges off the glass, which is subsequently washed.
Next, the glass begins a heat treatment process in which it travels through a tempering oven, either in a batch or continuous feed. The oven heats the glass to a temperature of more than 600 degrees Celsius. (The industry standard is 620 degrees Celsius.) The glass then undergoes a high-pressure cooling procedure called "quenching." During this process, which lasts just seconds, high-pressure air blasts the surface of the glass from an array of nozzles in varying positions. Quenching cools the outer surfaces of the glass much more quickly than the center. As the center of the glass cools, it tries to pull back from the outer surfaces. As a result, the center remains in tension, and the outer surfaces go into compression, which gives tempered glass its strength.


GLASS INSPECTOR examines a sheet of tempered glass, looking for bubbles, stones, scratches or any other flaws that could potentially weaken it.
Glass in tension breaks about five times more easily than it does in compression. Annealed glass will break at 6,000 pounds per square inch (psi). Tempered glass, according to federal specifications, must have a surface compression of 10,000 psi or more; it generally breaks at approximately 24,000 psi.

Great write up Dave thanks. Yes I understand completely what you are saying and you'll have argument from me. Basically it's pretty much the same thing my glass guy said and I sure hope your right about it may never happen again. As for forged in fire I wish they would make some new shows so I don't have to keep watching the reruns.

Thanks again, Donnie