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NBAasDOGG

Suspended
May 27, 2017
644
1,534
Netherlands
Black PVD coating on cheap watches use to shrink when exposed to bright sun light.
Same thing probably happened to your phone. I guess it was standing in the sunlights for a long time, so the black surface of the PVD got hot and resulted in a slight shrink.
 

Motionblurrr

macrumors 65816
Jul 1, 2008
1,303
1,623
Yes I have the exact problem of this kind of "burn mark" after few month on my iPhone XS MAX, Apple been replace my iPhone twice and its the same, and I notice that many users that faced this kind of problems have Apple case on it. Hmmm

Hm, this is unrelated since it's not about the XS Max but my old Space Gray iPhone 6 Plus has a discoloration just like that on the dark apple logo. It kind of looked like an oil spill type of effect.

I don't have the phone anymore but I suggest everyone who sees anything like that to take it in.
 

44267547

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Jul 12, 2016
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Black PVD coating on cheap watches use to shrink when exposed to bright sun light.
Same thing probably happened to your phone. I guess it was standing in the sunlights for a long time, so the black surface of the PVD got hot and resulted in a slight shrink.

I doubt the sunlight had anything to do with that discoloration on the bottom of the grill. If you look at that picture closely, that’s the combination of heat, which may have been produced from the charging process where the the stainless on the bands became warm enough with the heat caused a reaction to cause a rainbow/burnt hue affect on the bands.
 

chonghao

macrumors newbie
May 3, 2019
4
1
Looking at your picture, something either came into contact with the bottom of the iPhone grill area or it’s heat that’s being produced from your charger, which is discoloring the metal like that. That’s *exactly* what stainless looks like when it’s under a higher temperature, it starts to form a rainbow-like color. Are you using an Apple certified OEM charger? This isn’t anomaly, there’s something happening to cause that type of reaction on the bottom of the iPhone like that.
[doublepost=1557073333][/doublepost]
Looking at your picture, something either came into contact with the bottom of the iPhone grill area or it’s heat that’s being produced from your charger, which is discoloring the metal like that. That’s *exactly* what stainless looks like when it’s under a higher temperature, it starts to form a rainbow-like color. Are you using an Apple certified OEM charger? This isn’t anomaly, there’s something happening to cause that type of reaction on the bottom of the iPhone like that.
I am using Apple original charger all the time to charges my phone, and also my phone didn't heat up like crazy. It just a normal temperature tho. From what i observed, this matter happen mostly for many space grey iphone x above users with apple case. We need an answer!
[doublepost=1557073476][/doublepost]
A new pic with better lightning. Under most lighting conditions is barely noticeable, but this represents more accurately how it looks most of the time.
Hi bro, is that silicon or leather apple case? And did the problems solved by now ?
 

44267547

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Jul 12, 2016
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I am using Apple original charger all the time to charges my phone, and also my phone didn't heat up like crazy. It just a normal temperature tho. From what i observed, this matter happen mostly for many space grey iphone x above users with apple case. We need an answer!

Like I said, something must’ve caused an interaction with the stainless bands to cause a discoloration/tarnish with the bands or it’s heat transfer. But the fact that it’s on the bottom of the iPhone, near the speaker grill/charging port indicates to me that that’s where the heat is transferred from the charger, which when stainless exceeds higher temperatures, it starts to show a burnt form or rainbow color pattern. The thing is, your case and the OP of this thread have the same general location of where the discoloration is, and not on the rest of the bands surrounding the iPhone. If there was somebody that specializes in Metallurgy, I’d be willing to believe they would have some feedback as to what would cause that type of discoloration.

[Keep in mind, it may be a reaction with the PVD coating that’s on the space gray caused from the unknown factor, as the regular stainless iPhone does not have a PVD coating either.]

It definitely is a rare issue, because I’ve only read this thread that others are experiencing this.
[doublepost=1557077129][/doublepost]
We need an answer

....Which you won’t find on here in all liklieness. Also, it seems the OP agree’s heat may have been a contributing factor if you read the beginning of this thread.
 
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JCCL

macrumors 68000
Original poster
Apr 3, 2010
1,925
4,330
[doublepost=1557073333][/doublepost]
I am using Apple original charger all the time to charges my phone, and also my phone didn't heat up like crazy. It just a normal temperature tho. From what i observed, this matter happen mostly for many space grey iphone x above users with apple case. We need an answer!
[doublepost=1557073476][/doublepost]
Hi bro, is that silicon or leather apple case? And did the problems solved by now ?

It was Leather Case, I actually sold that iPhone in September, so wouldn't know.
 

Dirtydutch

macrumors 6502a
Sep 19, 2015
685
571
Jerseyyy
Honestly, it's possible since that's where your finger sits when you're supporting the bottom of the phone that the PVD coating may have rubbed off/discolored because of wear...Especially since while using the Apple official cases there is no coverage on the bottom...We've seen this scenario with the SG color, only the silver seems to be impervious to discoloration.
 
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ActionableMango

macrumors G3
Sep 21, 2010
9,612
6,907
If it takes 450C/840F degrees to make stainless tarnish with dark purple (according to post #21), wouldn't the cable or charging mat have extremely obvious heat damage?
 

44267547

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Jul 12, 2016
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Honestly, it's possible since that's where your finger sits when you're supporting the bottom of the phone that the PVD coating may have rubbed off/discolored because of wear...Especially since while using the Apple official cases there is no coverage on the bottom...We've seen this scenario with the SG color, only the silver seems to be impervious to discoloration.

I think this is a fair post and logical. It’s possible others might be experiencing through corrosion through sweat, and as you said, might have a reaction with the PVD coating.
 
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JCCL

macrumors 68000
Original poster
Apr 3, 2010
1,925
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Maybe I missed something, but what ended up happening with your phone? Last time you commented you were taking it to be looked at.

They inspected it, made some tests, determined it was normal and refused to do any exchange. Luckily the buyer didn’t care much about that stain.
 

DevinNj

macrumors 68000
Apr 27, 2016
1,722
1,740
New Jersey
They inspected it, made some tests, determined it was normal and refused to do any exchange. Luckily the buyer didn’t care much about that stain.

Wow, I'm no expert or anything, just a keyboard warrior, but that doesn't seem normal to me. Sounds like you ended up making out alright in the end, that's good.
 

44267547

Cancelled
Jul 12, 2016
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They inspected it, made some tests, determined it was normal and refused to do any exchange. Luckily the buyer didn’t care much about that stain.

Not sure where you’re based out of, but I wouldn’t accept that for an answer if they told you that was ‘normal use’. That certainly is _not_ normal, I would’ve escalated that case if that was me.
 

Radu_k

macrumors newbie
Jul 7, 2019
3
4
Hi. I have .... had exactly the same problem. I might have a good news for you. If it’s just discolouring it’s not the heat, unless you purposely heat it with something! It’s most probably just stain from your fingers ( sweat, that can be on some surfaces quite aggressive) Just use a silver polish and you’ll have your phone as new. I just did it and only signed up to this forum to share my experience. Sorry didn’t take pictures before but here is the polish i use SILVO ( it’s wadding not liquid!!!) And after i cleaned it. Just use tiny amount, i just used cotton bud saturated in the wadding. Hope this helps.
 

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chonghao

macrumors newbie
May 3, 2019
4
1
Hi. I have .... had exactly the same problem. I might have a good news for you. If it’s just discolouring it’s not the heat, unless you purposely heat it with something! It’s most probably just stain from your fingers ( sweat, that can be on some surfaces quite aggressive) Just use a silver polish and you’ll have your phone as new. I just did it and only signed up to this forum to share my experience. Sorry didn’t take pictures before but here is the polish i use SILVO ( it’s wadding not liquid!!!) And after i cleaned it. Just use tiny amount, i just used cotton bud saturated in the wadding. Hope this helps.
Hey bro , do you have the pic before you use the polish stuff ? Cause I still having the same issue after get my phone replaced.
 

Radu_k

macrumors newbie
Jul 7, 2019
3
4
Hey bro , do you have the pic before you use the polish stuff ? Cause I still having the same issue after get my phone replaced.

Hey. Unfortunately no. Colour of my spot was the same as the original post but bit smaller along 3 speaker holes. It’s exactly where I rest my little finger when holding phone. Just noticed it today and started panicking. I’m sorry i didn’t take a picture before i did think of it. Jus try the polish. If you can’t get the brand i used , it that pink cotton saturated in some cleaning solution. Stuff you use for polishing gold and silver jewellery.
 

44267547

Cancelled
Jul 12, 2016
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Hey bro , do you have the pic before you use the polish stuff ? Cause I still having the same issue after get my phone replaced.

Your sweat is causing a reaction with the stainless, especially since this is your second phone experiencing this. If you think about it, if the discoloration is at the bottom of the iPhone, it’s where your finger is resting, then somehow contact from your hands is causing a reaction. There’s no other explanation.
 

Tofupunch

macrumors 6502
Dec 4, 2014
387
557
No way I would put up with that if in "fact" it is from normal use.

This it's another reason I don't like the oxidized versions of the iPhone. Too many instances of foolishness like this.

IPhone Xs Max Silver FTW!!!
So does that mean the regular stainless steel without the space grey coloring has better longevity? What about the gold?
 

44267547

Cancelled
Jul 12, 2016
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So does that mean the regular stainless steel without the space grey coloring has better longevity?

The space gray uses a PVD {Physical vapor deposition} coating, all that is a protective layer against scratches/scuffs to protect the aesthetics of a darker color. Raw surgical stainless steel in its original form will hide scratches better, but they can also be removed with a polishing cloth. As far as ‘longevity’ is concerned, that would depend how the device is managed/treated.

What about the gold?

Gold also uses a PVD coating, which there again, is to protect against scuffs/scratches.
 
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Radu_k

macrumors newbie
Jul 7, 2019
3
4
So does that mean the regular stainless steel without the space grey coloring has better longevity? What about the gold?

Sort of does. Stainless steel is bit unique steel as it doesn’t rust. Welding is done differently from other steel and when polished it lasts. That makes tricky to give it additional finish such as paint or electroplating. I would say much harder than aluminium. I haven’t looked into it but they might do it chemically that’s why it stains easily. So i’m guessing to achieve the space grey finish it has to be quite elaborate process and as we can see it’s not without flaws. The staining is not in the steel it’s the thin layer of coating. As i said i polished my stain off with silver ware wadding and it’s gone for now. The bottom line is we pay very premium price for not very premium quality. Even the crystal glass on camera isn’t real crystal glass you find on high quality watches.
 
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heit0r

macrumors newbie
Aug 23, 2019
3
0
Hi. I have .... had exactly the same problem. I might have a good news for you. If it’s just discolouring it’s not the heat, unless you purposely heat it with something! It’s most probably just stain from your fingers ( sweat, that can be on some surfaces quite aggressive) Just use a silver polish and you’ll have your phone as new. I just did it and only signed up to this forum to share my experience. Sorry didn’t take pictures before but here is the polish i use SILVO ( it’s wadding not liquid!!!) And after i cleaned it. Just use tiny amount, i just used cotton bud saturated in the wadding. Hope this helps.
Hey, dude. Just signed up to this forum to thank your for spending your time bringing us your feedback about this situation. I even had set an appointment at an Apple Authorized Service Center (since there's no Apple Store in my city), but your feedback has saved me some time. Thought I wouldn't able to find Silvo in my country (I'm out of US), but I easily got it and it worked absolutely fine in my case. My iPhone XS Space Gray is now shiny as new. Thank you once again.
 

alpi123

macrumors 68020
Jun 18, 2014
2,023
3,376
Hi. I have .... had exactly the same problem. I might have a good news for you. If it’s just discolouring it’s not the heat, unless you purposely heat it with something! It’s most probably just stain from your fingers ( sweat, that can be on some surfaces quite aggressive) Just use a silver polish and you’ll have your phone as new. I just did it and only signed up to this forum to share my experience. Sorry didn’t take pictures before but here is the polish i use SILVO ( it’s wadding not liquid!!!) And after i cleaned it. Just use tiny amount, i just used cotton bud saturated in the wadding. Hope this helps.
You polished a space gray iPhone and didn't have the coating come off?
 

44267547

Cancelled
Jul 12, 2016
37,642
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You polished a space gray iPhone and didn't have the coating come off?

Yeah, I was wondering the same thing. I would like to see pictures of the [before and after] before I would even attempt that. Keep in mind, there’s abrasives that’s built into the Cape Cod cloth that will strip/remove coatings.
 

alpi123

macrumors 68020
Jun 18, 2014
2,023
3,376
Yeah, I was wondering the same thing. I would like to see pictures of the [before and after] before I would even attempt that. Keep in mind, there’s abrasives that’s built into the Cape Cod cloth that will strip/remove coatings.
Really weird why whenever someone says they had polished space gray/gold iPhone Xs, and I ask them if the coating has came off, they go silence. I've asked several people and nobody has said a thing.

I just want to know if the coating is thin enough for you to be able to take it off with one wipe or the first few times wont harm the coating.
 
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