Evaporating coolant...?

mike gunnz · 24 Jul 2010 at 13:07

After years of using branded coolants I switched over to deionised water for my latest build out of curiosity and because I got narked when due to a faulty EK res my system sprung a leak and I lost half a tub of expensive Fluid XP+.

Now the water level in my 250ml res is going down at a surprisingly fast rate, I'd estimate I've lost 3" of fluid in the last six weeks. I'm certain there are no leaks so I put this down to evaporation over the extremely warm period we've enjoyed, but cant fathom how it could escape from the loop.

Can someone enlighten me as to whether this is true and does evaporation occur quicker with pure water rather than coolant?

Geckovich · 24 Jul 2010 at 13:18

100% it wasn't an air bubble in your rad or something which has now shifted to the res?

HW91 · 24 Jul 2010 at 13:22

well you can expect a bit of liquid loss because the tubing is slightly porous and does let some liquid through

chances are you have a leak small enough that it isn't immediately obvious (maybe put kitchen towel round the fittings, wait a couple days and see if any of them have water on them) or an air bubble broke down for whatever reason and shifted to your res

Jokester · 24 Jul 2010 at 13:24

What kind of tubing have you got?

I noticed this more when I stopped using thick walled stuff like Tygon.

mike gunnz · 24 Jul 2010 at 13:34

Jokester said:
What kind of tubing have you got?

I noticed this more when I stopped using thick walled stuff like Tygon.

TYGON R3603 7/16" ID 5/8" OD. Wall thickness 3/32" so this is top quality tubing

Yeah I'd expect some to be caused by displaced air bubbles over time but thats a hell of a lot of air. I'll keep checking foe leaks but I havent found any so far.

Puppetmaster · 24 Jul 2010 at 13:54

I have a small leak around the filling cap on my resovoir. Probably not the same for you but worth checking (mine has only recently appeared, it is over 5 years old tho.

PaulyD · 24 Jul 2010 at 14:38

I once had a small leak on a blanking screw for an alphacool pump, it did the same as you, went slowly down over periods of weeks and I could not see any visible leaks, it must have been coming out so slowly that it never left a puddle!

When I found it, it just needed nipping up slightly and that was the end of it.

Do double and triple check every part of the loop just in case as I was sure I didn't have a leak either

Bubo · 24 Jul 2010 at 17:05

It would interest me if you could carefully unscrew whatever blanking plug or fill port you have attached to your 250 res and see if you can detect air being sucked in. This will be with the system shutdown btw. I've always wondered if when water evapourates through tubing does air come the other way into the loop or does the reduction in ater volume effectively leave a vacuum. If air gets sucked in when you loosen the blank it would prove that water lost is not directly replaced by air. The implication of any water-air transfer via evapouration could be that some of this air could get trapped inthe rad rather than getting back to the res.