tiny rust spot on Unibody MBP

[sn0warmy]

The day I bought my Unibody MBP I bought/installed the "Power Support Protection Pack":

http://store.apple.com/us/product/TV054LL/A?mco=NTAwMjgzNw

it was great, but I decided to start using this RadTech screen protector instead:

http://www.radtech.us/Products/NotebookScreensavRz.aspx

After removing the Power support piece surrounding the keyboard, I immediately noticed two tiny rust spots on the computer :

These pictures don't do it justice at all. The spot was noticeable to all 3 people who immediately looked at my computer and said "what's that brownish red spot?"

I understand that aluminum does not rust. But it does show rust stains. Has anyone else had this problem? And does anyone know of a nice safe way to remove a rust stain from this kind of aluminum?

thanks,
Kevin

 

[GGJstudios]

Aluminum doesn't rust.

 

[drewsof07]

Aluminum doesn't rust.

Though it does oxidize. But I'm thinking Aluminum Oxide is white Anyone know how the anodizing process could cause this? I've seen alu powerbooks that have a similar "cavity" where the anodized portion is missing and left with bits of brown that look like rust.

Perhaps a friction based scrubber, such as the "magic eraser" could work. I've used those on iBooks and MacBooks before, but not on aluminum. Use it cautiously of course

 

[GGJstudios]

Though it does oxidize. But I'm thinking Aluminum Oxide is white Anyone know how the anodizing process could cause this? I've seen alu powerbooks that have a similar "cavity" where the anodized portion is missing and left with bits of brown that look like rust.

Reddish-brown rust only occurs with ferrous metals and never occurs with any form of aluminum. My guess is the spots are something else that can be cleaned off. There's no way it's the aluminum, anodized or not, since aluminum oxide is whitish, as you said.

 

[kastenbrust]

This isn't rust this is dirt, thats why people buy these:

http://www.moshimonde.com/palmguard.htm

A) Aluminium cant rust, it can oxidize but thats white

B) It cant be burned because the computer would have to be running at 660C to do that

If you want to get rid of it, try using a gentle aluminium cleaner, theres no protective layer on the aluminium so you dont have to worry about anything like that.

 

[Kronie]

It could be the anodizing scraping off.
I have a teeny tiny spot on the corner lid that looks like the rust. I think its the anodizing coming away.

 

[mikes70mustang]

seriously? take it to a genius, better get a new one, looks ruined

 

[shoulin333]

Aluminum doesn't rust.

iron oxide = rust = red/orange

iron oxide = doesnt exist on Aluminum

This is why our street signs don't rust

 

[GGJstudios]

It could be the anodizing scraping off.
I have a teeny tiny spot on the corner lid that looks like the rust. I think its the anodizing coming away.

That's not possible. Even if the anodizing were not there, the aluminum underneath is silver colored... whitish if oxidized, so there's nothing reddish-brown anywhere on a Mac enclosure.

iron oxide = rust = red/orange
iron oxide = doesnt exist on Aluminum
This is why our street signs don't rust

Yes, I already said that. Try reading the whole thread.

 

[miles01110]

Macbook Pros aren't anodized, they're powder-coated. Not that this fact changes anything related to your dirt problem.

 

[GGJstudios]

Macbook Pros aren't anodized, they're powder-coated. Not that this fact changes anything related to your dirt problem.

I've been searching, but can't find anything that says the MBP is powder-coated. On Apple's site, I do find the fact that the Apple Wireless Keyboard, the iMac, the Mac Pro, Apple Cinema Displays, etc. are anodized, so I'm interested to know where it says the MBPs are different. Have a link?

 

[Kronie]

Even if the anodizing were not there, the aluminum underneath is silver colored...

Well mine still has this corrosion, whatever it is:

Granted its tiny but the anodizing is doing something and there seems to be some brownish, rough, something underneath. It looks like rust. I know its not rust and I also know I didn't bump or scrape the lid on anything.

My wife is an art teacher and she gave me this:

What I found out is that this silver metallic paint when painted on a UMBP looks just like the original finish. I didn't paint the corner yet because I'm waiting to see if my spot gets bigger. If it grows more I'm going to have apple take a look at it.

 

[TheMonarch]

That spot is corrosion from something rubbing or impacting on the anodized aluminum. I have two spots on mine [Unibody], one of which is exactly where Kronie has his. My G5 also has a couple of spots on the handles.

I can tell you from experience, its not going to go away . But if its any consolation, its not going to get worse either. I highly doubt Apple will do anything about it, as the affected piece is probably the most expensive part of the entire computer. It couldn't hurt to try though.

 

[mikes70mustang]

But really, its a freaking speck. Thats not going to affect resell. And oxidation on Aluminum is white. Not brown or what ever. Unless you got a steel metal flake on there in a humid room...i reallly doubt its a rust spot. Just a stain, you didnt effectively clean the palm area b4 putting the protector on and it got mashed down and it stained it. If it wont wipe off with iklear or mild soap then stick a palmguard on it and move on.

 

[miles01110]

I've been searching, but can't find anything that says the MBP is powder-coated. On Apple's site, I do find the fact that the Apple Wireless Keyboard, the iMac, the Mac Pro, Apple Cinema Displays, etc. are anodized, so I'm interested to know where it says the MBPs are different. Have a link?

They say they're anodized, but anodized surfaces have a different texture than the surface of those items (anodized surfaces are much smoother and harder). Anodized surfaces do not wear down like this. In fact without blunt pressure they don't wear down virtually at all.

So yeah, unfortunately I can't provide any hard evidence other than my experience with anodized surfaces used in electronic assemblies.

 

[war eagle]

Stop sitting your smokes on your MBP.

 

[GGJstudios]

They say they're anodized, but anodized surfaces have a different texture than the surface of those items (anodized surfaces are much smoother and harder). Anodized surfaces do not wear down like this. In fact without blunt pressure they don't wear down virtually at all.

So yeah, unfortunately I can't provide any hard evidence other than my experience with anodized surfaces used in electronic assemblies.

Anodizing makes aluminum oxidation-resistant, but you can't tell anodized from non-anodized by touch; only by oxidation. From all the evidence I can find, Apple ONLY uses anodized aluminum:

The thinness of MacBook Air is stirring. But perhaps more impressive, there’s a full-size notebook encased in the 0.16 to 0.76 inch of sleek, sturdy anodized aluminum.

http://www.apple.com/macbookair/design.html

Your Apple display matches the sculpted aluminum enclosures of the new Mac Pro and the 17-inch MacBook Pro. ... because this strong, anodized aluminum allows for an exceptionally narrow bezel ....

http://www.apple.com/lae/displays/cinema/design.html

With its elegant anodized aluminum enclosure, the Apple Keyboard looks equally at home in your living room or on your desk.

http://www.apple.com/keyboard/

From any view, iMac is impressive. But little compares to sitting in front of the glossy widescreen display framed in amazingly slim anodized aluminum.

http://www.apple.com/imac/design.html

Mac mini is made from sleek, anodized aluminum with refined, rounded corners and a pearly white cover.

http://www.apple.com/macmini/design.html

 

[miles01110]

Marketing dictates that "anodized" aluminum is advertised instead of "powder-coated" aluminum. As an analogy, Apple also reports drive space in decimal capacity, which isn't technically correct either, especially since the simple reality of computers demands that the operating system reports capacity in binary. Is it "wrong" in the absolute sense? No. But it's not 100% accurate.

It could be argued that powder coating is a specialized form of anodization, but in reality they have significant physical differences in the final product.

 

[Kronie]

I always thought these were some kind of powder paint and not truly anodized. Powder paint makes more sense because its way stronger and wont come off as easily.

 

[GGJstudios]

Marketing dictates that "anodized" aluminum is advertised instead of "powder-coated" aluminum.

It's not a matter of marketing. The two are different processes. If Apple powder coated, they would say so. If they say anodized, then it's anodized. The two are not interchangeable terms.

As an analogy, Apple also reports drive space in decimal capacity, which isn't technically correct either, especially since the simple reality of computers demands that the operating system reports capacity in binary.

Most computer and hard drive manufacturers do the same and, like Apple, they usually clarify their terminology, to avoid confusion:

1GB=1 billion bytes; actual formatted capacity less.

It could be argued that powder coating is a specialized form of anodization, but in reality they have significant physical differences in the final product.

Anything can be argued, but that doesn't make it true. Powder coating is not a form of anodization. If you take the time to learn what they are, you'd know they're completely different.

I always thought these were some kind of powder paint and not truly anodized. Powder paint makes more sense because its way stronger and wont come off as easily.

Actually, powder coating comes off easier than anodization.

 

[Gonzo3333]

Try gently rubbing a Scotch Brite pad on the mark, I think that would take care of the problem.

 

[JBazz]

Well mine still has this corrosion, whatever it is:

Granted its tiny but the anodizing is doing something and there seems to be some brownish, rough, something underneath. It looks like rust. I know its not rust and I also know I didn't bump or scrape the lid on anything.

That is not corrosion. It appears to be where the finish has chipped off. As has been posted here already, aluminum corrosion is white and powdery in the beginning. When it spreads deeper, the metal will appear swollen and flaky. I am well versed in corrosion and corrosion prevention.

If it were corrosion, the correct thing to do would be to remove it so it doesnt spread. But it is not, it is surface finish damage and scotch brighting it will only do further damage. Touch up painting is acceptable only because it is not corrosion.

 

[Kronie]

Actually, powder coating comes off easier than anodization.

I disagree. I have worked with metals for years as a metal fabricator and powder coating is much much tougher than anodized aluminum. I don't think you CAN powder paint aluminum though, only steel. It wont stick on aluminum the right way. That's why if you want to color aluminum you anodize it.

I also don't think whatever process apple uses to finish there Macbook line is just anodizing either. There is something else done to it. I have seen lots and lots of anodized parts and nothing ever looked like a Macbook pro finish.

 

[miles01110]

It's not a matter of marketing. The two are different processes. If Apple powder coated, they would say so. If they say anodized, then it's anodized. The two are not interchangeable terms.

Two different processes that use more or less the same physical principle to adhere a coating to a metal surface. Like I said, they're "different", but it doesn't take a major stretch of imagination to consider one a subset of the other. And I never said they're interchangeable, just that Apple is using the wrong term. It's clearly not anodized.

Most computer and hard drive manufacturers do the same and, like Apple, they usually clarify their terminology, to avoid confusion:

So because "most computer and hard drive manufacturers do the same", it makes it true? This is funny, considering what you say below...

Anything can be argued, but that doesn't make it true.

Right, like powder coating vs. anodization, and binary vs. decimal representation of capacity. I know you're a huge fanboy and take everything Apple says as gospel, but you need to face reality in some situations (like this one) that your beloved company is not telling you the full story.

 

[PeterQC]

I also don't think whatever process apple uses to finish there Macbook line is just anodizing either. There is something else done to it. I have seen lots and lots of anodized parts and nothing ever looked like a Macbook pro finish.

They probably sandblast the body before anodizing it.