coolant mixture

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yazz4210

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Dec 24, 2010
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hey guys, can anyone help me with the coolant mixture,I've read so much about it that i'm confused.On a low buget I was hoping for some home remedies.I know distilled water is involved but thats as far as I got .there are a couple of things I should mention. I have two alluminum waterblocks. The ZW-GS8800GTS on two asus 8800gts in sli and a swiftech copper block on the cpu,I've heard that it isn't recomended to mix metals in the same loop,but my buget didn't think so.Now i need a solution.just so you can get an idea its a EVGA 680i MB,two gigs OZC pc8500 1066MGz,intel quadcore Q6600 2.66 MGz,zalman xfinity 650watts powersupply,500gb western digital caviar green,and two asus 8800gts in sli.in a lian li pc-V1100plus.a 360 radiator mounted vertically at the back of the case.a swiftech pump and res.and home depot 's special black tubing.Thanks.
 
With mixed metals, you're going to require a more aggressive coolant solution.

I would say a 15% concentration of regular strength (aka not the 50/50 diluted stuff) car antifreeze in distilled water should do the trick. I mixed an aluminum radiator with copper blocks using that concentration and had little to no corrosion over a full year and a half service life. Your temperatures will suffer a degree or two due to the high amount of antifreeze, but it's better than ruining your parts.
 
I use distilled water, 15% Prestone extended life, about 5 drops of some spa algaecide crap, and a couple capfulls of water-wetter.
 
see,now I'm comfused again.could someone explain what is the difference between all these combinations of mixture.and please explain the purpose of each component to be able to decide. thanks again forum.
 
-Distilled water is free of stuff that is in drinking water that might cause corrosion over time on metals.
-The straight coolant (NOT 50/50 pre-mixed stuff) is just coolant and I'd recommend staying away from GM Dexcool and just using something like Prestone or Texaco.
-Don't know about algaecide but might be a good idea.
-Water-wetter is an additive that helps vehicles run cooler.
 
It's not complicated. In mixed metal loops with copper and aluminum you need an additive to reduce the conductivity of the coolant, otherwise galvanic corrosion will eat the aluminum. You can use 15% car antifreeze or just buy one of the various "non-conductive" PC coolant mixes.

In all-copper loops it's best to use pure distilled water, additives don't improve heat transfer.

A piece of silver (like a silver kill coil) or PT Nuke are common biocides to keep algae and microorganisms from growing in any loop.
 
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With my current build I tried to do 25% Prestone (pure) and 75% distilled water. was likely less than 25% Prestone because I had to drain the loop and I didn't add nearly as much the 2nd time.

My system is 100% copper, I read that it helps with lubing the pump but I am not sure.

I know with cars you need to run anti-freeze for two reasons, keep it from freezing and to lubricate the water pump. figured it couldn't hurt here.

I looked into the silver coils but really couldn't find enough on them to pull the trigger, but sure it works, Prestone is still cheaper, and I have it laying around for the cars anyways ;)
 
I ran 10 parts distilled water to 1 part water-wetter.....its the red stuff. Had great temps and no corrosion or life form growth. With copper and aluminum parts.
 
i ran an experiment a few years ago for an automotive forum which tested the conductivity of different antifreezes-

prestone cheapo green stuff is the most conductive and corrosive fluid you can use. when brand new, it is 3-4 times more conductive than dexcool, and 6 times more conductive than G12. when contaminated it gets even worse. prestone starts out about 1.5x more conductive than distilled water. if your goal is to reduce conductivity of the fluid, using prestone is the opposite way to do it.

distilled water, for the most part, is non conductive. deionized water is even better. if you are really that concerned about galvanic corrosion, you can run a small ground wire and electrically connect each piece of metal in the loop (although the computer case and most large metal components are already electrically grounded on the same ground plane, so most likely this is unnecessary). FWIW- a lot of radiators are aluminum, almost all blocks are copper. people have been using dissimilar metals in cooling loops for a long time without noticing any problems.

your cars engine block is usually iron, the head is aluminum, radiators are brass or aluminum. why doesnt your car die after 10 years of running a super conductive fluid like dirty prestone that you havnt flushed in years? because all the metal parts are electrically connected to chasis ground.

galvanic corrosion is a small concern in some situations, but it really seems to be blown way out of proportion around here.

using 'non-conductive' fluids is up to you, but consider this- if you spill pure distilled water on your motherboard, all you have to do is let it air dry. if you spill non-conductive fluid, you need to disassemble everything, clean off all the fluid which does not dry or evaporate and will leave a sticky film all over, and then put it all back together. if you leave it there, it will absorb dust and become conductive quickly. this stuff is also almost impossible to get out from under SMD components and will corrode copper traces and pads if left for long periods of time. i learned this with my P5W-DH Delux mobo, may it rest in peace.
 
is galvanic corrosion the same as distilled water simply causing a reaction with the metals? I thought that was the main reason to add antifreeze or similar additives.
 
JustinsBuilds said:
is galvanic corrosion the same as distilled water simply causing a reaction with the metals? I thought that was the main reason to add antifreeze or similar additives.
Click to expand...

If i recall it correctly, its the transfer of electrons from aluminum to copper via a water medium.
 
JustinsBuilds said:
is galvanic corrosion the same as distilled water simply causing a reaction with the metals? I thought that was the main reason to add antifreeze or similar additives.
Click to expand...

no its an entirely different process from a simple chemical reaction. fluid flowing over a surface (or thru a tube) creates an electric charge the same way that rubbing your socks over carpet creates static electricity. the theory is that this current builds up in the water blocks in a loop. when one block has a different electrical potential (different voltage) than another, electrons migrate from one block to the other.

this can only occur in the presence of an electrolyte (tap water has a good amount of mineral salts in it, like saltwater, it is a decent electrolyte) . distilled or deionized water which which has had these mineral salts removed, is a very weak electrolyte and does not easily alow electron migration.

in the end though, we are talking about a few µV-DC and maybe 1mA at most. a piece of equipment we use at work has a water bath that runs thru a copper pipe and over some metal pieces. there is a difference in electrical potential of ~600mv DC, 12mA between the water source and the test equipment. over 5 years of daily use, there is a slight aluminum buildup (discoloration) on the wastewater drain made from the aluminum test block the water flows over. even at that elevated current level, it would be decades before it ate thru enough metal to be noticable.
 
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