My progress
Chris Katko


Homemade water cooling reservoir second attempt once I bought a drillbit set.

Edgar Reynaldo

At first glance I thought you had created your own IV :


Chris Katko

I have.


Eric Johnson

That's pretty cool. You should fill it with the oil from a lava lamp. 8-)

Chris Katko

I was actually thinking of measuring how effective Mountain Dew is at cooling a CPU.


I was actually thinking of measuring how effective Mountain Dew is at cooling a CPU.

It would probably be pretty good for a while, but since it would be nearly impossible to not expose it to oxygen at some point, it'll get start to get sticky, I'd imagine.

Chris Katko


The price of running a l33t haxor battlestation is, a weekly flush of fresh Mountain Dew!


What are you currently using, PG?

Chris Katko


I'm using automotive 50/50 coolant/water mix. =D I've always got coolant lying around from all my crappy cars so it seemed a logical choice.

And since my actual degree (as opposed to what I get paid for!) is in mechanical engineering, if I couldn't solve a system of pump/radiator/etc selection, as well as lubricant compatibility with seals, basically, I never should have graduated. :)

I could/should probably run less than 50/50 mix since water is a much better heat transfer medium, and there's tons less metal to react with through electrolysis in a CPU cooling setup than a full engine. So I really don't "need" all those additives, nor is my computer ever going to hit -30 F.

Though, I did run it outside once over the winter and had it at ~20 F! The cheap PVC tubing actually goes from flexible, to super stiff (that I dare not bend lest it burst), as it gets that cold. It also had a light layer of frost around it.

I was going to use this full size Toyota radiator:


But the fittings to go from 1.5" down to 3/8" cost more than the radiator alone and it's so bulky (and my space so limited in my place right now) that I figured I'd reduce the complexity of the project a bit to ensure completion. And I can "upgrade" or build a second one with it later on. Also, the other big issue is that car radiators are super fragile and expect to be protected by the surrounding car. Having one in the open is a recipe for disaster. So when I move up to it, I'll have to build a protective grill/box for it. The "CPU" grade radiators are a little more durable because they know people are stupid and bump into things.


PG = propylene glycol

It can be used as a cheap replacement for coolant fluid.

It's also used (in food grade quality) extensively in bars and restaurants in post-mix systems to keep the syrups from separating from the carbonated water. Another use is in e-fluid for the same purpose. Most E-fluid is either 1 50/50 or 30/70 mix of PG and VG (vegetable glycerin).

Chris Katko

I'm running ethylene-glycol. So far, no problems with any of the seals being eaten.

(Bottle also mentions diethylene glycol and potassium 2-ethylenhexandate)


Specifically, a mixture of 60% ethylene glycol and 40% water freezes at −45 °C (−49 °F).[3]

That's actually neat. The freezing point of a certain mix, ends up lower than the freezing points of BOTH individually. I can't remember if we covered that in Chem class (10+ years ago!)

And of course, 50% distilled water.

Basically, I picked up a bottle of generic "all car" 50/50 mix, and dumped it in. Ran it for a few weeks out of the system to see if it'd eat any seals, and then installed it.

I don't recommend touching it with your hands (no gloves) though. I'm sure it's toxic, and very sticky... like a sugary (non-diet) soft-drink.

Though the material safety literature/etc shows it's not super dangerous unless you actually drink it:

[edit annoyingly long URL]
[/edit annoyingly long URL]



[when touching] the rate of penetration is so slow that excretion and metabolism
pathways are not overwhelmed. Metabolites do not accumulate, therefore, and toxicity does not occur.

I couldn't find any material details on the seals used from random Chinese fitting sellers. But "meh, !@$! it" happened so I winged it. If I was actually experienced in engineering (as opposed to degree), I'd probably be smart enough to tell the material of an o-ring by feeling it, smelling it, etc.

Oh, and PVC should definitely be rated for EG:

Although, with the bends from gravity/etc, I really could have sprung for the "reinforced PVC" so the tubes wouldn't easily collapse on themselves for future projects. I thought "it's not under vacuum or high pressure so = go cheap" but I didn't think about the small 3/8" tubing collapsing so easily.


Yeah, the toxicity of other alternatives is also a reason why some people use PG. It's completely harmless (we consume amounts of it everyday in processed foods).

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