3 ms·

The Pitting PowerBook (2005)

10 points by Lammy 3y ago

542458 3y ago
I have a milder version of this body chemistry. Old Apple laptops seemed more vulnerable - my 2014 MBP shows only very mild pitting, but my 2009(?) had significantly worse pitting in half the time. I still haven’t upgraded off my 2014, so I can’t speak to anything newer than that.
- turnsout 3y ago
  I saw a mild version of this on my 12" Powerbook G4. FWIW, I have never had any issues with the surface of my unibody MacBooks, other than some smoothing of high-touch areas.
acherion 3y ago
I had this occur with my 2004 PowerBook back in the day, it was pretty bad. At the time I had found a company that made adhesive transparent stickers that you could place on either side of the trackpad that would protect the aluminium from being eaten away by the sweat on your palms. I bought this when I upgraded from my PB to my Core 2 Duo MBP in 2007, fearing that this newer machine would suffer the same fate as my PowerBook, but all is well and that machine didn't experience pitting. Having said that, the pictures in the link are pretty bad, I've never seen pitting that bad before, that looks horrendous!
wkat4242 3y ago
Perhaps this might also have something to do with the way a ln aluminium Apple laptop is always electrically charged while plugged in and not connected to a grounded socket. It's a bit annoying to me because I feel this, it causes the surface to feel rougher to me. But it could also cause chemical effects.
- rwl4 3y ago
  Whoa! I remember experiencing this and just assuming it must be my imagination! I also remember that same laptop getting those pits. No where as dramatic as the pictures in the linked page, but still pronounced. Crazy. It's never happened to my more recent MBPs.
  - wkat4242 3y ago
    All my more recent alu macbook did the same. I can feel the roughness as soon as it's plugged in. If you rub over it with a hand you feel this 'friction'. It's hard to explain. You can also measure it by the way. It's significant voltage but can't sustain any current of any kind. My hypothesis was that it's some minor induction from the PSU transformer being picked up by the shielding and transferred to the laptop through the ground wire. But the pitting, no. But I never got that back in the day with my 15" PowerBook either. I mustn't have the right chemistry. I'm just saying that if you have the pitting, using a grounded socket might make the chemistry different in a way that it causes this less. Putting an electric charge on metal is used to prevent corrosion in underground fuel tanks for example, but it can do the opposite too. Ships do it too but they usually use 'sacrificial metals' to transfer the corrosion to. PS: I don't know the correct English terminology for the above because when I did chemistry it was a long time ago and in Dutch.
jacknews 3y ago
Same thing for me, though slightly less severe on 2013 macbook pro and 2016 macbook pro. What's more concerning than the cosmetic damage to the laptops, is where the (presumably dissolved) aluminium is ending up.

10 points by Lammy 3y ago

I have a milder version of this body chemistry. Old Apple laptops seemed more vulnerable - my 2014 MBP shows only very mild pitting, but my 2009(?) had significantly worse pitting in half the time. I still haven’t upgraded off my 2014, so I can’t speak to anything newer than that.

turnsout 3y ago
I saw a mild version of this on my 12" Powerbook G4. FWIW, I have never had any issues with the surface of my unibody MacBooks, other than some smoothing of high-touch areas.

acherion 3y ago

I had this occur with my 2004 PowerBook back in the day, it was pretty bad. At the time I had found a company that made adhesive transparent stickers that you could place on either side of the trackpad that would protect the aluminium from being eaten away by the sweat on your palms. I bought this when I upgraded from my PB to my Core 2 Duo MBP in 2007, fearing that this newer machine would suffer the same fate as my PowerBook, but all is well and that machine didn't experience pitting. Having said that, the pictures in the link are pretty bad, I've never seen pitting that bad before, that looks horrendous!

wkat4242 3y ago

Perhaps this might also have something to do with the way a ln aluminium Apple laptop is always electrically charged while plugged in and not connected to a grounded socket. It's a bit annoying to me because I feel this, it causes the surface to feel rougher to me. But it could also cause chemical effects.

rwl4 3y ago
Whoa! I remember experiencing this and just assuming it must be my imagination! I also remember that same laptop getting those pits. No where as dramatic as the pictures in the linked page, but still pronounced. Crazy. It's never happened to my more recent MBPs.
- wkat4242 3y ago
  All my more recent alu macbook did the same. I can feel the roughness as soon as it's plugged in. If you rub over it with a hand you feel this 'friction'. It's hard to explain. You can also measure it by the way. It's significant voltage but can't sustain any current of any kind. My hypothesis was that it's some minor induction from the PSU transformer being picked up by the shielding and transferred to the laptop through the ground wire. But the pitting, no. But I never got that back in the day with my 15" PowerBook either. I mustn't have the right chemistry. I'm just saying that if you have the pitting, using a grounded socket might make the chemistry different in a way that it causes this less. Putting an electric charge on metal is used to prevent corrosion in underground fuel tanks for example, but it can do the opposite too. Ships do it too but they usually use 'sacrificial metals' to transfer the corrosion to. PS: I don't know the correct English terminology for the above because when I did chemistry it was a long time ago and in Dutch.

jacknews 3y ago

Same thing for me, though slightly less severe on 2013 macbook pro and 2016 macbook pro. What's more concerning than the cosmetic damage to the laptops, is where the (presumably dissolved) aluminium is ending up.