The importance of air bubbles

[bldegle2]

Well, this AM was a corker, fired up unit, wouldn't quite boot all the way, reboot, hmm...shut down and check water block, it is piping hot!!!! phuckinaye....it got so hot the inlet Tygon tubing had started to deform at the block inlet nozzle from the heat....thought for sure another CPU was toast....a quick bios cruise had the cpu temps @79*c....whoa!

disconnected PS from MB, then took the water system apart, checked pump first, works great, WTF, so I purge the whole system with air, then water, then air, then a complete refill of 50/50 fluids, this time using an external PS hooked to the pump ONLY....spent about 30 minutes getting all the air bubbles out, tilting, wiggling, tapping, topping after each sequence to get ALL the AIR out....

Apparently, since my new waterblock is so enormous, and if the system is not COMPLETELY bled for a long period of time, air bubbles are hiding here and there, and if there is enough air, eventually it all collects in the PUMP when shut down and resting over night (I have my pump mounted as high up as possible, the refill plug is on the side of the pump,)....i thought that I had gotten all of them previously, but I did not spend that much time bleeding the setup as I did this time.....

Air bubbles suck....

CPU is okay....

Wasted 2 hours this AM fixing it...all is good again....

The trails and tribulations of phucking around with a rig....LOL

Laterzzzzz..........

[M_S]

Most pumps have the nasty habit of accumulating air-bubbles inside at the center of the impeller because water is heavier and, therefore, is more affected by centrifugal forces. In the case of positive displacement pumps this is not that much of a problem but it'll still come into play. The other location where I have always found air-bubbles is in the water blocks themselves, depending on the position of the intake - outlet.

In addition, if the temperature goes beyond boiling at the CPU (hopefully not) then this can really screw up things (in the old Intel CPUs) because it creates vapor inside the block that block the fluid flow.

[Mr Bill]

There are impellers with slices on the blades intended to inject air into the fluid stream, used in salt aquariums for skimmers. Seems to me one of those impellers would be an improvement at getting those bubbles out. On another note, when doing high pressure liquid chromatography its used to be a good idea to sparge the eluent water with helium. Helium is very insoluble in water compared to other gases. So, the excess of helium drives out all other gasses and then the helium left is negligable. Might be a good way to degas coolent. However, be aware that only lab grade helium would work. Consumer grade has air added in a misguided attempt to keep people from asphyxiating while trying to imitate Alvin and the chipmunks.