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First indication that galvanic corrosion is a potential problem

J

JayLenochiniMac

macrumors G5
Original poster
Nov 7, 2007
12,819
2,390
New Sanfrakota
Many here are planning to get the aluminum Sport model and one of the bands from the stainless steel collection to wear to nicer occasions. However, all the non-Sport bands (except the Leather Loop) house stainless steel connectors, and we know that aluminum and stainless steel together poses a bi-metallic corrosion risk, also known as galvanic corrosion, especially in the presence of sweat (from working out or just from wearing the watch on a hot day).

Newly released training material contains the following disclaimer:

"Bands work with all collections but may not match the finish or be optimal for use with that specific collection."

The bold part seems to indicate that galvanic corrosion is a potential problem, especially when the anodized coating inside the aluminum connectors get worn down and you wear it with the stainless steel bands while working out or on a hot day.
 
If corrosion does become a problem that's gonna suck and be a huge disappointment to many people. I wonder if Apple plans to mention this to customers when they buy a metal band. It is on the training material which has me thinking they will.
 
Wow good find. I actually had this happen with some tire caps on my car believe it or not. Makes me feel better about SS
 
Can attest that this can be a problem when I got the original Nike fuel band with aluminum screws on the inside of the band ... corroded to the point that the casing opened. Complained to Nike and got a free SE version of the fuel band.
 
Not if it is Anodizing Aluminium as in the Apple Watch case (similar with unibody iPhone, Macbook, iMac).

This is interesting read: http://www.engineerguy.com/elements/videos/video-anodizing.htm

Anodizing aluminium starts out much like titanium. Using aluminum as the positive electrode, engineers first pass enough current to grow a thin "barrier" layer - similar to that which forms naturally. Then, as the anodizing proceeds, the current "pushes" this barrier deep down into the aluminum converting the aluminum above into a very porous oxide layer. It isn't a layer being put on top, but instead the reaction consumes and converts the aluminum; this is one of the reasons it's so effective at preventing corrosion. The pores in this layer give the aluminum a unique characteristic important for a consumer device: The ability to be colored. The pores formed on the surface have a honeycomb pattern. Inside these layers one can place dye of any color. Once the pores are filled engineers seal the layer by boiling the aluminum in hot water. This closes the pores, locking the color in forever, you cannot scrape it off without removing the aluminum. The toughness comes from the oxide being structurally similar to tough gemstones. Sapphire is an aluminum oxide - with trace amounts of iron and titanium to give it a blue color; it's also the basis of ruby, the same crystal structure with chromium that absorbs yellow-green. Both materials are very hard: Nine on the Mohs scale.
 
JayLenochiniMac said:
Newly released training material contains the following disclaimer:

"Bands work with all collections but may not match the finish or be optimal for use with that specific collection."

The bold part seems to indicate that galvanic corrosion is a potential problem, especially when the anodized coating inside the aluminum connectors get worn down and you wear it with the stainless steel bands while working out or on a hot day.
Click to expand...

Not to discount what you're saying, but I think you're reading an awful lot into a fairly innocuous statement. I would hope that if this is really a concern that they would have a more carefully-worded warning about corrosion than something as incredibly vague as what you quoted.
 
I don't think this will be an issue at all. The iPhone 6 and Plus have an anodized aluminum case with a stainless steel Apple in the center, and they don't corrode.
 
Yeah, I'd say that statement is more of a first indication that a stainless steel link band isn't an optimal accessory to a watch designed for more active use.
 
ZombiePete said:
Not to discount what you're saying, but I think you're reading an awful lot into a fairly innocuous statement. I would hope that if this is really a concern that they would have a more carefully-worded warning about corrosion than something as incredibly vague as what you quoted.
Click to expand...

I agree. I think the statement is more about clashing looks than it is about corrosion.
 
ksuyen said:
Not if it is Anodizing Aluminium as in the Apple Watch case (similar with unibody iPhone, Macbook, iMac).
Click to expand...

You do know that the anodized coating is prone to wearing off, as we've seen numerous times especially with the black and slate iPhone 5. It's going to get even worse inside the aluminum connectors from repeatedly sliding the hinges in and out when swapping bands.

ZombiePete said:
Not to discount what you're saying, but I think you're reading an awful lot into a fairly innocuous statement. I would hope that if this is really a concern that they would have a more carefully-worded warning about corrosion than something as incredibly vague as what you quoted.
Click to expand...

I didn't say it is direct evidence, only an indication that it's a potential problem. Who knows what else is inside the training materials as we don't have access to them?
 
JayLenochiniMac said:
Many here are planning to get the aluminum Sport model and one of the bands from the stainless steel collection to wear to nicer occasions. However, all the non-Sport bands (except the Leather Loop) house stainless steel connectors, and we know that aluminum and stainless steel together poses a bi-metallic corrosion risk, also known as galvanic corrosion, especially in the presence of sweat (from working out or just from wearing the watch on a hot day).

Newly released training material contains the following disclaimer:

"Bands work with all collections but may not match the finish or be optimal for use with that specific collection."

The bold part seems to indicate that galvanic corrosion is a potential problem, especially when the anodized coating inside the aluminum connectors get worn down and you wear it with the stainless steel bands while working out or on a hot day.
Click to expand...

Only an insane person would buy a Sport and a SS band that costs more than the watch. Therefore, most people won't experience this problem.
 
Defender2010 said:
I think you are reading too much into it. They most likely mean "cosmetically".
Click to expand...

"May not match the finish" is what they mean cosmetically. What do you think "or be optimal for use with" means?

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dacreativeguy said:
Only an insane person would buy a Sport and a SS band that costs more than the watch. Therefore, most people won't experience this problem.
Click to expand...

It's only $149 for the SS bands except the link bracelet.
 
JayLenochiniMac said:
I didn't say it is direct evidence, only an indication that it's a potential problem. Who knows what else is inside the training materials as we don't have access to them?
Click to expand...

It's only an indication that corrosion might be a problem if you're already expecting it might be. No one who isn't already concerned about it would even begin to think that's what that statement was indicating, IMO.

Again, I'm not saying you're wrong, I just think you're jumping to conclusions.
 
ZombiePete said:
It's only an indication that corrosion might be a problem if you're already expecting it might be. No one who isn't already concerned about it would even begin to think that's what that statement was indicating, IMO.

Again, I'm not saying you're wrong, I just think you're jumping to conclusions.
Click to expand...

Maybe, but we do know that aluminum and stainless steel together poses a bi-metallic corrosion risk so it's reasonable to expect that, especially in the presence of sweat.
 
dacreativeguy said:
Only an insane person would buy a Sport and a SS band that costs more than the watch. Therefore, most people won't experience this problem.
Click to expand...

First of all, the leather classic and modern buckle bands and the Milanese loop band don't cost more than the Sports watch.

Second, never presume what most people will do. Yes, some people might stop and think about how much the band costs in proportion to the watch, but others might just think about the cost of the entire package. After all, it's a matter of looks and feel (how it feels when worn on the wrist). People are willing to pay a lot for something they wear, because they want to look and feel good.

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JayLenochiniMac said:
Maybe, but we do know that aluminum and stainless steel together poses a bi-metallic corrosion risk so it's reasonable to expect that, especially in the presence of sweat.
Click to expand...

If this is a real concern, I would expect Apple to put a much stronger warning -- even make it so that the steel bands can't physically fit the aluminum case. Otherwise, they are looking at a massive "corrosion-gate."
 
JayLenochiniMac said:
"May not match the finish" is what they mean cosmetically. What do you think "or be optimal for use with" means?

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It's only $149 for the SS bands except the link bracelet.
Click to expand...

It means apart from the metal finish "may not look good together or fashionable or practical for various situations eg. A classic buckle whilst canoeing as the water may damage the strap".
 
Defender2010 said:
It means apart from the metal finish "may not look good together or fashionable or practical for various situations eg. A classic buckle whilst canoeing as the water may damage the strap".
Click to expand...

I agree, that makes more sense. Apple did mention this, but never mentioned about the corrosion from metal band and sweat.
 
This all may be moot. The Sport bands appear to slide into the C-shaped notch in the case. Other models appear to have a bar structure that either fits into the notch or is built into the case.

If so, then a bar adaptor will be needed for Sport compatibility with bands other than the standard fluoroelastomer Sport bands. Those can be made of any compatible material, ideally a dielectric.
 
Timeframe?

What's the timeframe on this type of corrosion??
If it's greater than two years, I honestly couldn't care less.
 
While I'm not going to pretend that I have a great in-depth knowledge about this subject (more of an organic chemist myself), I highly doubt it will be an issue. Apple really won't want something like this (which, if it did corrode, would make great fodder for the media due to the immediate cosmetic issue) to become the Apple Watch's "-gate". I'm sure they've tested it, especially after the LG G Watch had an issue with galvanic corrosion.

I'm not even sure how much of the band touches the case - it looks like there are a couple of rubber bits on the band to keep them separated - never mind being enough to scrape away the metal to reveal the non-anodised aluminium.

Reading a bit too much into it I think.

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sjinsjca said:
This all may be moot. The Sport bands appear to slide into the C-shaped notch in the case. Other models appear to have a bar structure that either fits into the notch or is built into the case.

If so, then a bar adaptor will be needed for Sport compatibility with bands other than the standard fluoroelastomer Sport bands. Those can be made of any compatible material, ideally a dielectric.
Click to expand...

I'm not sure what you mean. All bands are technically compatible with every Apple Watch, no adapters are needed.
 
Galvanic corrosion isn't something to worry about or obsess over.

Apple's pretty good about building lasting hardware. If you are concerned the solution is very easy, just put forth a little extra effort to keep the watch clean and you'll be fine.

I'd bet the primary and perhaps only reason it's talked about in the training materials is at the suggestion of Apple's attorneys.
 
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sjinsjca said:
This all may be moot. The Sport bands appear to slide into the C-shaped notch in the case. Other models appear to have a bar structure that either fits into the notch or is built into the case.

If so, then a bar adaptor will be needed for Sport compatibility with bands other than the standard fluoroelastomer Sport bands. Those can be made of any compatible material, ideally a dielectric.
Click to expand...

That's inconsistent with "Bands work with all collections," not to mention that the SS models also come with black or white Sport bands.
 
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