Quote Originally Posted by serialk11r View Post
I have no clue why they used aluminum. I don't see any reason why aluminum should be used. That's one of the questions yet to be answered...
Looks, pure and simple. They wanted to make it look like Edelbrock valve covers and I think it does look good. I love the bling what can I say.

But that does not justify bringing Aluminum in contact with our loops. Now if they would have just put the aluminum on top and not have it contacting the water (like have a copper top and then just screw the aluminum on top of that as eye candy)... then I would be ok with it. I would even pay a little more for it. But as it stands I will never own this block because of the potential hazard it poses (which saddens me cause I really do like the looks of this block and would have purchased based on that over the D-Tek). Yes if the plating is good it should not corrode but guess what? Manufacturing processes are not perfect and defects can, no, will occur. To say they wont or to say none will make it past QC is a lie to the entire manufacturing community.

Quote Originally Posted by Fossil View Post
Zinc plating can help reduce significant corrosion of alu even when the plating is scratched or penetrated - the zinc and alu are still in electrical contact and the zinc will still oxidize preferentially. I'm reasonably convinced that Swiftech's top poses no real risk of a corrosion disaster in the working life of a real block. Nevertheless, a copper top seems a more obvious choice.

It's possible that the alu+cu risks are somewhat overstated: if your water is de-ionized, and your alu has some sort of protective coating, the corrosion problem should be ... tractable. The life of a block is rarely more than a year or two. You have to look very carefully at the horror stories, question all the details and see how the problem arose.

Maybe if somebody were heating up tap-water in their loop they'd quickly see serious problems. Maybe they bought deionized water that wasn't, maybe there was a residual substance (such as flux) that contaminated their water...

What we do know is that there is a very small number of verified cases of mixed metal disaster in water-cooling loops but those few cases are 'sensational' enough to make an impact on everyone - despite the fact that more people probably lost kit to cracked Tt perspex blocks, o-rings damaged in mis-assembly, dodgy quick-fit connectors, and dead Mag2 pumps.

I'm not saying don't worry about mixed metals, just that in the case of this block the reaction is a little extreme. Swiftech did the best thing they could to protect the Alu, it's just not obvious why they chose to use it in the first place.
Re-read Marci's post and reconsider your stand.