Coolant types...
 

First off let me tell you that I'm new to the whole liquid cooling scene and just have a few quesitons to ask, and if they have been asked repeatedly before...BAH!

Is it possible to use alcohol (rubbing alcohol to be exact) as a coolant? And if it is possible, is it a good idea (as in maybe it would eat away at the metal or the tubing or destory your pump).

And I forgot what the other question was...so...thats all you get from me.

Rubbing alcohol is possible, but it's not the best for a couple of reasons.

1) Isopropyl alcohol (what is in your rubbing alcohol) doesn't carry as much heat as water.
2) It can eat up some types of seals, leading to leaks.
3) It evaporates easily.
4) It may not prevent galvanic corrosion (dissimilar metals actually causing each other to corrode).

The best bet seems to be distilled water with water wetter added to it. Do NOT use tap water because the dissolved stuff will precipitate out and clog up your system.

Do a search on alcohol and water. There have been some good posts.

Good luck!

Distilled water and Hyperlube Supercoolant. The latter can be bought at most auto parts stores

i second that

Here, here. Don't use alcohol of any form unless you are specifically planning on going far below 0C. Distilled water + (water wetter || hyperlube || purple ice || goo of choice) = a good idea. If you don't want to spend the dough on an additive, THEN use a tablespoon or two of isopropanol per L of water. Even then, there will be no protection from galvanic corrosion.

Speaking of galvanic corrosion, just make sure that all parts of you WC system are of similar metals. That is the easiest way to limit/prevent it. All additives only work so much. It is easier to prevent the program before than after the fact. May I recommend all copper to you?

The problem with trying to go with a single type of metal is that it is much more difficult. The cheap heatercores are made of aluminum, brass, tin and lead (the tin and lead from the solder). Right off the bat, you are in trouble!

Of course, the best solution would be to use a copper waterblock, a copper radiator/heatercore, and plastic (usually nylon) barbed fittings. It's a pain to do it though.

There is an easy solution. You can get radiators designed for computer use online that have copper channels for well under $30-40 if you look around. They aren't the greatest in the world, but they work. Similarly, you could just go with a BIX and save yourself some hassle. Really, keeping to similar metals is NOT a difficult thing. It just costs a little more. Yeah, you could gripe that you want to do this on the cheap, but in the long run, if your equipment fails because of substandard parts, you end up spending a hell of a lot more than if you just put it together right in the first place. A high end fully copper system would cost less than $200 USD if you looked around. You could probably do it for significantly less if you bought WC parts used from other WC guys who are upgrading.

The difficulty lies in the eye of the beholder, true!

To me, not difficult means I can go to the Home Depot and/or Autozone on my way home to pick up parts. Plus, you mention $200 for your copper system. I spent:

Heatercore: $20
Barbs: $6
Epoxy: $2
Aluminum home-made Xjinn block: $0
Vinyl tubing: $3
Distilled water: $1
Water wetter: $5
Eheim pump (used 1250): $50 (I think)
2 120mm fans: $4
Fan control circuit (discrete parts and solder): $10

Total: $101

That doesn't include all the crud that I bought because I didn't know what I was doing, nor does it include the costs of the tools that I bought. I got lucky by getting chunks of aluminum stock that I could drill and put onto the CNC at work, too.

Also, I'd buy better stuff if I knew better. Replace the vinyl tubing with tygon. Replace the aluminum block with copper. Etc...

With regular maintenance such as system flushes, my system will do just fine. It just doesn't happen to be as good as possible.

For someone interested in buying rather than fabricating it, yeah, go with a copper radiator. I just couldn't pass up the opportunity to save thirty or so US dollars. That money went towards tools, books and other misc parts (e.g. I spent over $250 on electronics books, tools and parts when doing my PWM fan control circuit). Cheap education/expensive system cost.

Many are the paths that we take, and it really depends upon your available resources and intended goals.

Its not hard to find a heatercore with all copper tubes. Remember corrosion is still a concern to car companies as well.