Corrosion of metal

[JaY_III]

Sorry about me asking some dumb questions but..
its been a while since a chem class for me...

when talking water cooling...
put copper in the mix with aluminum is bad
put stainless steal with aluminum, will that be bad?
stainless steal and copper?

now what if i add brass to the mix?
brass, copper and stainless steal
brass, aluminum and stainless steal

i think i want to use all brass seals
my shower head is made of stainless steal

temp waterblock is made from aluminum (GORB put to good use)
will be getting a copper waterblock(once the setup is, well, setup)

Even with stuff like water wetter (says it stops corrosion), i still want to use metals that will not eat each other away
(if i didnt i would use zinc and salt water :))

Links are great
What you have done is great
Anything you know is great help aswell

[William]

never be afraid to ask a "Stupid Question". Yes, corrosion is going to happen, but just add some polar molecule into the mix such as water wetter or some antifreeze, and you will virtually stop that. Ideally, everything would be the same, but try to find a copper showerhead, its not going to happen. Brass really doesn't react much, and its a mixture of metals anyways. Stainless steel has a Zinc coating, but Zinc is very stable, basiclly, don't worry about it too much, its not a huge issue, just one to avoid where possible.

[Slain]

This type of corrosion is normally associated with different metals in an electrolyte solution.
*BUT*
It requires the metals to be very close to each other *or* to have a conductive electrolyte (e.g. salt water). In a tap water (non conductive) system with widely seperated components this corrosion will occur so slowly as to be ignored. The delta Voltage between Cu, Al, brass and Steel when seperated by an insulator such as tap water is very small. Basically as long as you hav'nt got steel screws in copper fittings or such like you should be fine.

P.S. Fresh *clean* water is such a good insulator that you can actually run a car starter motor underwater !!! (seen it done)

[JaY_III]

cool
thanks for the fast reply...
now if corrosion does come a problem in less than 20 years,
well you know who i am going to blame :)

[Ridenow]

Badger posted a link for an Allied corrosion a while ago. I am not sure I believe all of it, but it was a usefull link. I have lost that URL and do not feel like looking for it right now.

[Badger]

Ridenow (May 30, 2001 10:14 a.m.):
Badger posted a link for an Allied corrosion a while ago. I am not sure I believe all of it, but it was a usefull link. I have lost that URL and do not feel like looking for it right now.

Here's the link:
http://www.alliedcorrosion.com/techinfo.html
Basically what it says is galvanic corrosion can not occur unless the metals are in electrical contact (ie touching each other or connected by a common earth). so most of the talk about galvanic corrosion in PC water cooling syatems is complete BS.
I can't make you believe the Allied info, but they are Specialist professional corrosion engineers and mambers of NACE (National Association of Corrosion Engineers ) they also work on nuclear power stations among other things. So if they have it wrong we are in deep ****.

[JaY_III]

Cool
and thanks

[Ridenow]

Thanks Badger.

The part I have a hard time with is that the coolant does not qualify as the electrolyte and the metallic path. I realize that the coolant has to be saturated for it to have an effect, but it would still happen.

Yes, we would be in trouble if they screwed up.

[Spewn]

As long as you can be sure everything is clean, and you're using distilled water, then it won't happen. However, it's gonna be kinda tough to clean out the inside of the radiator, or the waterblock, but there'll be so little conductivity that it shouldn't matter too much.