How many bubbles...

[miniyazz]

... can there be hiding in a loop

My pump appears to be churning them out at a rate of knots (microbubbles, not big ones) although there's none going into the loop, I've got the intake covered!
I'm aiming to make this one a completely sealed loop - the quick disconnects have been put to rest, and I'm currently leaktesting (with the mobo+cpu on, 'cause I tightened those fittings real good, and I can't be bothered to fiddle with the power connector )

Anyway, stupid bubbles this may take a while.

On a side note, imbibing mouthfuls of month-old water contaminated with biocide while refilling the loop is decidedly not fun

 

[miniyazz]

makes your knobs drop off too

*drinks charcoal and vomits*

 

[miniyazz]

Righty, I'm off to bed now. Any tips on how to get air out of waterblocks/pump? Hopefully it'll have sorted itself out by morning (yes I am about to leave my computer on and unattended for hours with an open water-cooling loop while technically still leak-testing )

 

[miniyazz]

Just musing...

Say you have a reservoir, there's a space at the top where there's a bit of air.

There is also air trapped somewhere along the loop.

Say you remove the air at the top of the res. You use a vacuum pump to suck out the gas which is the air.

There's now negative pressure in there.

The water won't go anywhere, it can't, it's not compressible, it will do what mavity told it to and sit at the bottom of the res.

However the bubbles along the loop are compressible because they are gas so when the pressure in the loop dropped due to the vacuum pump they would expand and as they expanded they would be more likely to be flushed out by the flow of water due to the greater surface area.

Interesting thought, but I don't have a reservoir. It could work, I suppose - JonJ678 would probably be able to confirm, but I presume he's away with exams or some such thing?

I find they go away after a few hours, unless your system is sucking air in somewhere

The intake is definitely clear, I've just double-checked it. Nothing going in there. A couple of microbubbles emerge from the CPU block every second or so. A few more from the NB block. And lots from the pump. It all seems to be leak free - if no water's escaping, is it safe to assume no air is entering any of the seals?
I'm inclined to think there's some air in each block tbh, though at a couple a second I'd also have thought they'd have sorted themselves out overnight

 

[miniyazz]

The rad is the last thing in the loop before it drains into my tupperware bowl I'm temporarily using as as res, so I'm not fussed about any air bubbles in there, if bubbles come out they just leave the loop. Besides, there's a fairly large number of bubbles entering it from the pump, so it wouldn't do much good
I've manoeuvred the case (with blocks & pump attached) as best I can, but it's really heavy the case empty is about 14kg, and even without the graphics cards it weighs a ton, when you're trying to move it around without disrupting the tubes entering and leaving it. However I shall now attempt to re-tip the whole system a few times in several directions.

 

[miniyazz]

****
Well got almost all of the air out of the blocks I think. Also got a ridiculous amount of air out of the pump, turning it off then turning it around and turning back on helped a lot. I could tell immediately when the air was out, the pump turned practically silent. 30s later, there's a bit more air in it and it's noised up again

 

[miniyazz]

I just realised why I have bubble issues
Water can hold more 'dissolved' air when cold. So, I've got my sealed loop with 0 air bubbles. Then, I plug it in and crank up the heat. Boom, air bubbles. Looks like I gotta reseal it with hot water!

 

[miniyazz]

Hehe, that's one option. The other thing I was considering is using an iron on one of the waterblocks to heat it up, I feel this would be better for me as the loop can start with cold water. I don't fancy trying to fill it with near boiling water, it's hard enough as it is!

 

[miniyazz]

basically the fast tap flow creates a pressure drop (small vaccum), which then the gasses from the liquid come out to equilibrate.

That is decidedly cunning any idea how long it needs to be left equilibrating?

doesn't anyone use de-ionised anymore?

I thought I was.. how long can it be left in a half-full (once-opened) but sealed container?
Are you saying that deionised water should not have a significant quantity of dissolved gases? 'cause I've just acquired some more and if so, I'll just drain the loop and use that instead.

Tried both deionised with a silver insert to stop forests growing, but got bored and went back to green dyed stuff, much more fun and I can see it when it spills. But its non-conductive supposedly.

Supposedly, all fluids start becoming significantly conductive within a few days of being in your loop because ions from the components become dissolved in it

 

[miniyazz]

I'm a fool

quoted instead of edited

 

[miniyazz]

Tempted by the 'inline res' idea - I don't want a regular res because I move my computer flat-upright way too often so I'd probably create bubbles each time I did that. But with 3+ graphics cards and 7+ HDDs floating around, I really have next to no room for a res at all. Decisions, decisions. Can't do anything at the moment anyway though as my motherboard appears to have died a little and I'm debating whether to sell the RMA replacement and plump for the seemingly promising X58A-UD3R as, tbh, it seems to fulfill all my criteria!

 

[miniyazz]

TBH I think you're right, the T-line is probably the way to go. How's the reduction in flow with that 90ºC bend?

 

[miniyazz]

the air bubs are not from the pump are they? is it not just splitting up a larger air "Cap" put into the loop from the air in your radiator?

Nope, I've checked for that. Even had the loop running for a few hours, no bubbles (not plugged onto CPU etc). Soon as I whacked the iron onto one of the waterblocks and the loop started getting hot, bubbles - within the pump, which is after the waterblocks, and not coming from the radiator