LG Nexus 4 Experiencing Cracking Problems Due to Glass Backing

[sidamos]

Isn't it possible that those N4, that cracked without real interference by the user, are probably badly assembled? Maybe with stress on the glass?

 

[Kevin OQuinn]

Isn't it possible that those N4, that cracked without real interference by the user, are probably badly assembled? Maybe with stress on the glass?

Very possible. The bigger question is how Google/LG handle it. My guess? "It's physical damage and won't be covered" But company's have been known to do the unexpected before.

 

[yfan]

Did you read the scientific research that I provided? Goes into pretty good detail about the temp difference required for glass to crack with no external force.

And then when I point out even more variables that we can't possibly know you ignore that. Smh

Sent from my HTC One X using Tapatalk 2

Lol, okay, keep shaking your head. Yes, I read the paper. It isn't about glass breaking without external force. Since when is fire not considered an external force???? And the article is talking about how hot glass has to get in order to break just from the heat (or the top and bottom temperature differences on a window glass), vs. breaking or cracking due to temperature differentials between surfaces and something drawing heat far more quickly from one surface than the other. These are two different things. The primary reason a whole surface is different is because there is a lot bigger surface area (hence the term) to cause the conflict.

Addressing the paper, one more time, air is NOT granite. The temperature difference required to crack glass with AIR on each side would be MUCH bigger than required if one side was granite and the other side air. Please look up a comparison of specific heat between air and granite. I will guarantee you that if a room was on fire, and the window glass was covered on the outside by stone cold granite, it would crack WAY faster than if it was just air outside, as is usually the case. It ISN'T just about temperature differences. It is also about how fast heat is drawn/transferred to this thing on surface. This is a critical difference you ignore, and seem to think that all temperature differences, regardless of material in contact, are created equal. They are not.

 

[yfan]

My question is what is so different between the N4 glass and the glass on an Apple?

Not sure why this matters. The glass back on Apple's iPhone 4/4S cracked too. There was just as many complaints about it - especially in communities where it is intensely followed, and the truth again was that it didn't just spontaneously crack. I have two close friends who own iPhone 4S's. They don't use cases, just take care of their phones. They haven't cracked their front or back.

 

[Kevin OQuinn]

Lol, okay, keep shaking your head. Yes, I read the paper. It isn't about glass breaking without external force. Since when is fire not considered an external force???? And the article is talking about how hot glass has to get in order to break just from the heat (or the top and bottom temperature differences on a window glass), vs. breaking or cracking due to temperature differentials between surfaces and something drawing heat far more quickly from one surface than the other. These are two different things. The primary reason a whole surface is different is because there is a lot bigger surface area (hence the term) to cause the conflict.

Addressing the paper, one more time, air is NOT granite. The temperature difference required to crack glass with AIR on each side would be MUCH bigger than required if one side was granite and the other side air. Please look up a comparison of specific heat between air and granite. I will guarantee you that if a room was on fire, and the window glass was covered on the outside by stone cold granite, it would crack WAY faster than if it was just air outside, as is usually the case. It ISN'T just about temperature differences. It is also about how fast heat is drawn/transferred to this thing on surface. This is a critical difference you ignore, and seem to think that all temperature differences, regardless of material in contact, are created equal. They are not.

I figured you would say that. Temperature difference is exactly what we're talking about. Explain how the speed of the temp change matters. If they difference is only ~40-50 degrees then why would it matters if it takes 1 second or 10 seconds to get there? In the case of fire heating it up, it's staying at that temperature difference for a long, drawn out period of time and NOT cracking. How is maintaining a temperature difference for an extended period of time not more stressful than changing temps quickly? You're still talking about a GREATER TEMPERATURE DIFFERENCE with the fire, with different temps on each side of the glass, being maintained for an extended period of time. In your granite example the temp will reach parity in a much shorter period of time than with fire. It's not the act of the temp changing that would cause it to crack. It's the actual temp difference. THAT was the point of the article. To take external force out of the equation. If you're going to allow external force, then we're back to something else is happening and it has nothing to do with temp difference.

 

[Blendercloud]

This thread makes me wish the back of the N4 was a solar panel and not glass.

Even a cracked N4 back isn't as ugly as the Evo 4G LTE.

 

[yfan]

I figured you would say that. Temperature difference is exactly what we're talking about. Explain how the speed of the temp change matters. If they difference is only ~40-50 degrees then why would it matters if it takes 1 second or 10 seconds to get there?

This is why I asked you to look up specific heat. Speed of temperature change matters because that is what determines how fast each surface of the glass expands or contracts. With cold granite, heat moves off of the surface faster than glass' conduction ability can compensate in spreading the heat from the other side. Granite simply robs the surface in contact of the heat too fast, making that side of the glass contract much faster than air would (which is presumably on the other side). Try it. Heat up a piece of glass in the microwave. Wave it in the air. Nothing is going to happen. Now put that on a stone cold granite counter top. Watch it crack.

Here's another easy way to understand why specific heat matters. Freeze some butter and water in your freezer (ice) - each enough to fill a container of the same size. Same temperature. Take them out. Stick one hand into the ice bucket, and the other into the butter bucket (cube up the butter if you want). You will notice that the hand in the ice bucket "feels" much colder than the one in the butter bucket. Why? Both are the same temperature, and your body temperature is the same! So why would it feel different? Because water/ice has a higher specific heat and drawing heat from your hand much faster.

 

[donm527#IM]

i have my 4s next to my n4 (waiting on my n4 case before I swap sims and use it full time)... the construction of metal and glass together on the 4s just feels so much more solid imo than the n4... nice design on the n4 and feels well built. but it doesnt feel as solid. again, imo. back of the glass on the 4s... could be just how its assembled so well... but feels like a much more thicker piece of glass and i have no reservations carrying it without a case and worried about pressing against the front or back glass. the n4 feels fragile and we'll see over time if i get over that. waiting on my case though.

Not sure why this matters. The glass back on Apple's iPhone 4/4S cracked too. There was just as many complaints about it - especially in communities where it is intensely followed, and the truth again was that it didn't just spontaneously crack. I have two close friends who own iPhone 4S's. They don't use cases, just take care of their phones. They haven't cracked their front or back.

 

[Kevin OQuinn]

This is why I asked you to look up specific heat. Speed of temperature change matters because that is what determines how fast each surface of the glass expands or contracts. With cold granite, heat moves off of the surface faster than glass' conduction ability can compensate in spreading the heat from the other side. Granite simply robs the surface in contact of the heat too fast, making that side of the glass contract much faster than air would (which is presumably on the other side). Try it. Heat up a piece of glass in the microwave. Wave it in the air. Nothing is going to happen. Now put that on a stone cold granite counter top. Watch it crack.

Here's another easy way to understand why specific heat matters. Freeze some butter and water in your freezer (ice) - each enough to fill a container of the same size. Same temperature. Take them out. Stick one hand into the ice bucket, and the other into the butter bucket (cube up the butter if you want). You will notice that the hand in the ice bucket "feels" much colder than the one in the butter bucket. Why? Both are the same temperature, and your body temperature is the same! So why would it feel different? Because water/ice has a higher specific heat and drawing heat from your hand much faster.

Here's a pretty good breakdown on glass and how "strong" it is. Note that gorilla glass uses ion-exchange to create it's compressive layer.

Using concrete like I did is actually very close to granite as evidenced by THIS table. THIS article states that thermal stress fractures always start from an already existing imperfection. THIS article (specifically on page 725 second full paragraph down) explains what types of glass are susceptible to thermal shock. It specifically mentions standard soda-lime glass (easily susceptible to thermal shock), and borosilicate (better known as Pyrex). Borosilicate is commonly used in baking, and is highly resistant to thermal shock. Slide 16 in THIS table contains a chart listing of different types of glass and their coefficient of thermal expansion. Please note the difference between soda-lime and borosilicate, and the fact that aluminosilicate (better known as Gorilla Glass) falls in the same range as borosilicate. If you would like, I can also link to plenty of articles from granite counter top makers that recommend Pyrex for use as baking dishes specifically because they WON'T shatter due to thermal shock of being set on a cool granite surface.

I think we can agree that baking at 350 degrees is far above the temps our phones will ever see, and putting Pyrex on a MUCH cooler granite counter-top won't shatter it. Therefor our phones glass won't shatter either (assuming it's Gorilla Glass). Also to make a note, the only difference between GG and GG2 that's been stated by Corning is thickness, with all else being the same.


Of course, none of this REALLY matters since no one will say what material the back actually is. LG went out of their way to NOT mention it when Phil was in Korea talking to them, and you won't find anywhere that states that LG or Google has said the back glass is actually Gorilla Glass 2. Anywhere that says that is just making an educated guess. Of course, it may very well be GG2 and they just don't want to say so because of the fact that it will scratch and they don't want the reputation of GG to be damaged because of it.

Bottom line, GG and GG2 aren't going to suffer from thermal shock due to being put on a cold granite surface. Sorry my reply took so long, I had to find places that stated this in plain language (i'm not a scientist and can't understand all the formulas and such).

 

[yfan]

Bottom line, GG and GG2 aren't going to suffer from thermal shock due to being put on a cold granite surface. Sorry my reply took so long, I had to find places that stated this in plain language (i'm not a scientist and can't understand all the formulas and such).

They are resistant, not immune to thermal pressure. There's a difference. Unless you know a granite counter top maker that will guarantee that your Borosilicate won't break when placed on it, and if it does, they will replace the top free of charge.

But be that as it may, I am trying to get what your point is - that it is *impossible* (as opposed to simply unlikely) for this phone's back to crack due to thermal pressure? And if so, the people who are reporting that the glass cracked without them dropping it ... are they (you suspect) lying/didn't notice something happening/what? I am not saying that any of that isn't happening. It's entirely possible that someone hit their phone against something and didn't notice anything, but later when they noticed it, it became a "spontaneous" crack. I think we have discussed the thermal science (and I *do* understand the equations in scientific articles), but why did we just argue about this? Are you under the impression that I think Nexus 4's are cracking left and right because of thermal pressure? If it is, that's not a correct impression. I'm simply stating it's possible, not that it's commonplace or likely.

 

[XChrisX]

It sounds to me like there's a lot of people out there dropping their phones. The laws of physiques support the claim that when the phone is dropped it is likely to crack. Even the iPhone 4/S was prone to cracking but I don't recall any random out of the blue occurrences where phones would just crack for no reason.

 

[Kevin OQuinn]

you are still talking about glass, but try this with glass with some tension from frame and it will crack. same happened in my car with front window...

I just don't understand why some of you trying to prove that we are wrong... we know what happened with our phones, not you...

They are resistant, not immune to thermal pressure. There's a difference. Unless you know a granite counter top maker that will guarantee that your Borosilicate won't break when placed on it, and if it does, they will replace the top free of charge.

But be that as it may, I am trying to get what your point is - that it is *impossible* (as opposed to simply unlikely) for this phone's back to crack due to thermal pressure? And if so, the people who are reporting that the glass cracked without them dropping it ... are they (you suspect) lying/didn't notice something happening/what? I am not saying that any of that isn't happening. It's entirely possible that someone hit their phone against something and didn't notice anything, but later when they noticed it, it became a "spontaneous" crack. I think we have discussed the thermal science (and I *do* understand the equations in scientific articles), but why did we just argue about this? Are you under the impression that I think Nexus 4's are cracking left and right because of thermal pressure? If it is, that's not a correct impression. I'm simply stating it's possible, not that it's commonplace or likely.

I'm saying that based on all that research that I did (that you suggested, thanks ), that it seems highly unlikely that GG or GG2 (because again, we're not really sure what the back is) will be susceptible to thermal shock. I think what is most likely happening is that there is already a small imperfection somewhere on the glass, most likely on the edge, that is "focusing" the stress (whatever may be causing it) and causing the cracks. Or that stuff is just happening that people aren't realizing or noticing. I have ever so slight sleeks on my One X that I have no idea how they got there, but that doesn't change the fact that they're there, and that I did something to cause them.

And personally I enjoy a thorough conversation like the one we just had. Hopefully both people involved learn something, and the people reading/following the thread learned something. But yeah, somewhere, somehow I did get the impression that you were trying to place the blame squarely on thermal shock, or at least give it more credit than it's due. Can't really explain where exactly I got that impression, though, sorry. :/

 

[sonicresidue]

Is it possible that the cracking is caused by the pressure from squeezing the device when pushing the power or volume buttons?


Sent from my Nexus 4 using Tapatalk 2

 

[Kevin OQuinn]

Is it possible that the cracking is caused by the pressure from squeezing the device when pushing the power or volume buttons?


Sent from my Nexus 4 using Tapatalk 2

Yes, but I think it would take a lot of pressure and would maybe be more widespread.

Sent from my HTC One X using Tapatalk 2

 

[thawk333]

Mine cracked very badly on the back. I'm not really sure what happened, but it's pretty much shattered. The only thing holding it together is the screen protector film I have had on it since day 1. Google and LG do NOT cover this under warranty. Google says it's not their problem, it's LG's problem. LG basically told me that I could mail it to them for repair which would cost an estimated $100 and would take 2-4 weeks to complete. I said that seems too expensive and too long to wait, and they told me that I could go f myself if I didn't like it (I'm paraphrasing of course.) I ordered a hard cover from Amazon and I'm hoping that keeps the glass from falling out and embedding itself in my leg.

In the meantime I'm using my old LG Thrill which never had a case on it and never had any durability problems in over a year of use.

Hopefully some 3rd party company comes out with a replacement back made out of aluminum or something. I'm not interested in sending my phone back to LG to get another fragile glass back. You guys can argue all you want about what causes the glass back to break, but you better believe that it DOES break.

 

[Citizen Coyote]

You guys can argue all you want about what causes the glass back to break, but you better believe that it DOES break.

Well of course it can, it's glass. No one ever said it was indestructible.

 

[accesschristopher]

Mine is cracked also. Never dropped

 

[tomjdavies]

Anyone else think that the supply issue may be down to a manufacturing problem?

The glass on my Nexus 4 hasn't broken but I dropped it from maybe 50-60cm whilst sitting (was a bit merry) with the bumper on and since then its... creaked?

 

[Derek Courson]

Literally dropped mine from about 1 foot above the tile floor in my classroom (I'm a school teacher) and it broke. It started off as a small crack but of course grew. At first I did not think it would have cracked because it landed flat... meaning that it did not land on an edge or whatnot, just flat on its back. But it broke. I work overseas and have had some problems finding a case for it. I love the phone, but I'm not sure how bad the crack is going to be. If it keep growing I suppose it could destroy the back of the phone leading to other bad things happening.

I don't think the back is made from the same stuff as the front. The front seems a lot tougher. The back reminds me of sheets of safety glass from the 1960s.... anybody else remember that stuff?

This phone is cool, but not nearly tough enough for real world use.


It ain't "high school teacher" tough anyway..... maybe it's fine for elementary...