I agree

from my system:

Very reassuring.

Yet in this case it won't be submerged in a liquid. It will be in a warm, moist, oxygen-rich environment. Recipe for tarnish.

So the bottom of this cap will grow scuz and eventually cloud the water, and it will react with any copper/brass in the system...

but in a good way. Galvanic corrosion, sacrificial.

"When contact with a dissimilar metal is made, however, the self corrosion rates will change:

-corrosion of the anode will accelerate

-corrosion of the cathode will decelerate or even stop."

Any copper in the system reacting with the aluminum cap will actually tarnish more slowly than without the cap. The copper (cathode) "eats" the aluminum (anode). It's not just a plug, it's an anti-corrosion pill for water-cooled rigs!

Um, except it will coat the copper with Al, clogging the system.

Mixed metals is never a good thing, in this case it's not as bad as some others, but I'd still avoid it.

That got me googling to learn if "coat" can actually mean "plate", in this case. Apparently not - aluminum doesn't plate well to copper. So what's wrong with a bit of Al suspended in the coolant?

***

But if they'd bonded the outside terminal of that battery to the waterblock... with a resistor...

ever see a cascade's "middle plate"

will clog rather quickly

Depends on how big the particals are does it not?

yes, but I've seen corrosion in some pretty big pieces, enough to cover several holes of a cascade

I'd think it'd be even bigger on a t-lne cap, as material would corrode until it falls off, as pposed to corroding a little and being washed away....not an experyt hre by any means

point is, nickel plate for 25cents and be done with it

i'll see about nickel plating, who does it around here and what they charge and minimum quantity..

thanks, man

You haven't seen the MCW6002 yet have you?

No offense to Swiftech, the block performs very well from what I've been reading.

guys, nickel plating aluminum is not gonna happen. nickel + aluminum is not a good combo..

will just have to stick with anodized

You can plate aluminum with nickel - in fact, if you want to copper plate nickel, you need to nickel plate it first. In order to Nickel plate, you need to zincate the aluminum, but any place that does plating should be able to do that.

Too much effort and cost. Maybe powder coat it?

I was under the impression that it was only a matter of cleaning the part and giving it a short (1 min or so) dip in the zincate solution, then nickel plating as usual.

you can actually plate directly from aluminum to copper with the zincate solution, but I dont see why you would really want to. I would either anodized them or use brass, and guys, get your heads out of your butt, how often will the water touch this and something copper or brass. The corosion happens when theres a voltage differential right? if theres no connection theres no problem, yes I realize the condensation thing but I dont think it will conduct enough or if at all to cause corosion.


Jon

I have an aluminum cap I was using to cap my t-line until I could find a nylon or brass one but I never found one locally. Well when I removed the system recently I noticed the cap had quite a bit of corrosion on the inside and outside. Water in the system never touched the cap but it still corroded all over. I tried taking a picture but it just wont come out well.

That corrosion in the cap is a good thing. It's sacrificial - so the copper/brass corrodes less (e.g. stays shinier) than without the aluminum anode. This is a selling point. We do the same for vehicles and steel structures, why not waterblocks. Give it a copper wire tail to hang in the coolant.

Aluminum does pit when it corrodes. So chunks can fall off.

Still, I think people might buy these as expendable anti-corrosion anode plugs. Replace every 6 months...

Or, you could just use 10% glycol, and avoid the problem all together? :shrug: Why mix metals when you dont HAVE to?

try google
you are wrong

jfetting, thank you.

i've been doing some tests with aluminum and brass and copper in water together.. and i haven't been able to get the aluminum to corrode badly enough that chunks start falling off it.

that's gotta take YEARS

But if its caused by condenstion, the condensation will be pure water and the glycol will have no effect.

geek and SMan
the 2 of you are congratulating each other on how equally ignorant you both are about the same subject

BTW SMan - why Aluminium anyway, can't you just machine some brass caps instead and solve the whole issue?

put them in a closed system with a reasonable flow rate, and watch galvanic corrosion take place.

look through dansdata to see this is action with a aluminum WB, and copper radiator.

i can't be bothered to explain simple chemistry.

all fine and good until said chunks clog your loop

not just water evaporates, guys....think puddle of gasoline/mineral spirits/acetone/alcohol.

cathar said nickel plating is possible for 25 cents each....and is there a problem with machining out of brass?

if you wanted a sacrificial metal, just stick zinc in your system. and i don't think comparing the use of sacrifical metals, in oxygen rich environments applies to water cooling. where the whole point of sacrifical metals, is that they are more reactive to oxygen, and therefore stop the steel from rusting.

Aluminum is a poor sacrifical metal, because its expensive, and also a aluminium oxide layer protects the rest of the aluminium form oxidisation. thatis until a bit falls off, in the case of a water cooling system.

guys, if the aluminum is anodized, nothing is going to react, corrode, fall off, blah blah f-in BLAH..

why the hell can't any of you understand that?

i've been advised to never nickel plate aluminum, and i have been shown what nickel plated aluminum can look like when finished. very interesting and nothing you want to do with.

and bill, who the hell are you talking too? who is "geek" and who's congratulating who?

Geek is Jfettig. Nickel plating AL certainly is not uncommon. Example: http://www.enetshoponline.com/niplcoramsif.html

or

http://www.bakerprecision.com/aqp5c.htm

or

http://www.pfonline.com/articles/pfd0318.html

Corsair and Silver Prop Used Nickel plated AL on ther water blocks aswell

Not saying you should do it thought. Type 2 anodozing would be fine IMO. Should be able to get all 50 done at the same time for not much $$$. Unless you wanted different colors... Looks like great machine work.

If you did nickel plate them, and a customer asked about corrosion, then you could say any copper in the system must decay until it falls off before the cap loses its shine. Nickel, paired with copper, eats.

You are right anodising will pretty well stop reaction with copper. And how often do we see any computer components older than a decade anyway?

As I said before, any doubts about adding aluminum to a copper system you may answer with the good news that your aluminum plug actually helps protect any copper it electrically connects with.

So you can guarantee a perfect anodize on every part?