Corrosion with dissimilar metals for watercooling

[ExtreamChaozZ]

I am about to do my first fully water-cooled build, but I'm a little confused. I know about corrosion between dissimilar metals from galvanic corrosion but I quickly wanted to double check with you guys.

Will mixing Acetal Nickel, Copper and Brass be alright together? I know that aluminium is the worst for loops as it corrodes quickly.
As Acetal is just the plastic on top I'm not really worried about it, unless there's something I don't know about it. Also I have seen around that it should be alright to mix these metals I just wanted to ask to be on the safe side.

Here's a list of my parts in case you need/want to know:
CPU Block - EK Supremacy EVO Acetal + Nickel
GPU Block - EK FC970 GTX ACX Acetal + Nickel
Reservoir - XSPC Photon 270 Tube
Radiator - EK CoolStream PE 480 Quad
Pump - Alphacool D5 VPP655 Single Edition
Pump Top - Alphacool HF D5 TOP Black Acetal G1/4 V.2 2 Wahl
Tubing - Mayhem Borosilicate Glass Tubing 16mm OD
Fittings - (Undecided) I will either go for the EK HDC 1/4" 16mm or the Monsoon EV2 1/4" 16mm
Liquid - Distilled water
Dye - Mayhem Deep Red 15ml

I have all the parts except the fittings, liquid and dye, the tubing is on its way.
I would prefer to use distilled water over other liquids as I think its easier to deal with, cheap and I have read that it is the best thing to use as long as you add the inhibitors.

Also what biocides and anti-corrosion inhibitors are the best to get? Also i dont want to use a silver kill coil as being able to see it would bug the hell out of me. Keeping in mind that I'm from the UK and some US stuff is unavailable to me.

Cheers for the help

 

[Eximo]

Acetal is a plastic, not really a problem.

Nickel plated copper, Copper, and Brass are your typical construction materials.

I use a silver kill coil in my loop, and I used the included treatment that my Primoflex tubing came with this time as well. Previous loop I recycled the biocide that my Swiftech came with, diluted it a bit when I increased the loop size. Seemed to do fine.

The kill coil is just a piece of silver you can bend it and reshape it, just has to be in contact with the coolant. So it could be a vertical strip in the back of your reservoir. Or wrapped around the bottom or top near the pump/lid.

Glass tubing on your first go? Going to take a lot of fittings and end up being your most expensive part I would imagine. PETG would probably be safer on your first go. (Or if you really like copper, copper.)

 

[ExtreamChaozZ]

I'm used to working with glass as I've had to deal with it at work, so I know what I'm getting my self into lol. I forgot to mention but I will be getting some PETG tubing so I can plan out the loop first and get the lengths perfect before I cut the glass, like the old saying "measure twice, cut once".

I suppose I could try and hide the kill coil somewhere but I thought it would just be easier to add an anti-corrosive agent along side the biocide. If you know any good brands then please let me know.

Yea there's quite a few fittings considering I'm not bending, I don't trust my self with bending glass nor do I have the tools to bend glass at the moment.

 

[Eximo]

I've never intentionally purchased a biocide, as that was what the kill coil is for. My tubing came with this stuff: www.primochill.com/product/primochill-liquid-utopia/

They also sell all kinds of dyes if you are interested.

I added a little bit to to about 3 cups of distilled water, maybe, lost a bit to getting it to flow through. That damned vertical radiator of mine still has something floating around in there, even after I flushed it, pretty sure it has air pockets too. My latest build is just over a week old, so still a little fine tuning to go. Reservoir level has already dropped a bit the last few days, so I'll probably give it another top off this week. Only regret is not having a larger reservoir, the pump likes to suck the bubbles through.

I was very tempted to do copper hard lines myself, but as I was getting parts together the black/white combo seemed like a good choice. And I might do PETG hard lines in a re-build, perhaps whenever the next appealing GPU comes out. That chunk of thread or whatever in the radiator is a minor concern, doesn't seem like it can get out except through a fitting port.

 

[ExtreamChaozZ]

If your having problems with bubbles i'd be tempted to tap them all out and if theres a big one then i'd get some help and rotate the pc to move it into a position where u can open up the loop and let it escape. Also if you think you have bits in your radiator wouldnt it be better to drain it and give the loop a good clean?
Not that i can give advice for watercooling as i havent even done the build yet lol.

I have looked at primochills dyes not their aditives yet tho, so i will have a look at them. Cheers

 

[Solandri]

The further apart two metals are in electrode potential voltage, the bigger a problem you'll have with galvanic corrosion.

http://www.structx.com/Material_Property_Pictures/001-Galvanic_Series_of_Common_Metals_Scale_of_Nobility_Cathodic_Anodic_Reactance_of_Metals_Corrosion_of_Metals.png
http://www.engineeringtoolbox.com/electrode-potential-d_482.html

Copper and brass are pretty similar, so should produce minimal corrosion.

 

[Eximo]

I believe I have located where the metal is, at the top of the vertical radiator, there may not be a way to remove it as it only has fittings on the other end. It usually settles down into a corner somewhere, and only makes noise usually at start up, when the pump is running at nearly full speed. Even if it blocks one of the channels, still plenty to keep everything cool. Two 280mm radiators is much more than I need to cool an i7 and a 1080.

I am able to rotate the PC while bleeding, just takes a little time to get ALL the bubbles out, and I give it some time between attempts. You get most in the first day or so, but some take a while to work their way out. There is only so much shaking and cajoling you can do. I've found quick spurts of running the pump is the best way. As I said the swiftech H-240X isn't the easiest part to work with.

 

[ExtreamChaozZ]

Thanks for the tables Solandri, and by looking at it I can see that the biggest difference in voltage is 0.16v. As my pc will be in a "controlled" environment I should be ok up till 0.25v right? (Read this source here: http://www.azom.com/article.aspx?ArticleID=11833). This is also assuming that the nickel is nickel silver and not nickel copper.
So by looking at that I should be ok in terms of corrosion, but I think I will still add some anti-corrosion additives just to be on the safe side, I'd rather my liquid degrade over time with more additives in it than my expensive blocks corroding.
Also as I am very limited to anti-corrosive and biocide that is specially made for water cooling in the UK (I can import it from the US, but its very expensive) should I get a pre mixed bottle with everything I need and then add my own colour? for example Mayhems X1 clear? https://mayhems.co.uk/coolants/x1-coolants/x1-concentrate-100ml/x1-clear-100ml/

If you have located the metal I guess you could remove it if you wanted to but that would probably mean draining the system and fiddling around with it for god knows how long; as long as its not causing a problem it should be alright I guess, unless it starts flaking then it could start blocking fins inside your blocks.
I also heard that using some dish soap in your liquid can help reduce air bubbles when filling it up, but I have no idea if that's true or not so I would look it up first before attempting it.

 

[Eximo]

You can use light detergents to clean a loop, not heard of using it for bubble reduction. Others recommend vinegar, but pretty much anything with an acid base will do. (Most soaps are Citric or Phosphoric bases)

I could kind of see that working. A soap without laurel sulfate (the soapy stuff) would reduce the surface tension of bubbles and prevent them from getting stuck in corners. But not my recommendation.

Getting to that metal piece would mean effective destruction of the radiator. With regular maintenance it shouldn't be a big deal.

If you are doing colorants, you might try looking for one that includes an anti-corrosion and biocide. Mixing products might lead to undesirable results.