Bubbles in my system just WONT leave!

[kronchev]

Alright, I have a Spir@l waterblock, Hydro L20 pump, Bonneville heatercore, and now, an Aqua Computers res (see pictures). everything worked great until I put the res in, replacing the T-line with it obviously. There are bubbles in my system that just WONT go away. there are no leaks, or anything like that. from what i can kind of see (after putting a piece of filter foam in the res to stop bubbles, works well) is that the bubbles are being introduced by the pump. but there are NO leaks anywhere, Ive resealed the gasket by hand at least 3 times, and when I try it in my sink, there are no bubbles. anyone have ANY idea? Pics:

[Arcturius]

What are you using for water/additives that makes your hoses so cloudy (or is that all bubles(!))?
When you stop the pump and let some of the bubbles float upward away from the outlet (assuming they're clearly visible in person), and start the pump again, do bubbles immediately form @ the outlet?

[speculation]I don't know anything about that res; *if* it caused an inlet restriction, would the subsequent thrashing of an centrifugal pump cause bubbles? [/speculation]
Somebody else pls lmk if that is in any way accurate; it's a guess, and I'm curious to the real answer.

[kronchev]

Originally Posted by Arcturius

What are you using for water/additives that makes your hoses so cloudy (or is that all bubles(!))?
When you stop the pump and let some of the bubbles float upward away from the outlet (assuming they're clearly visible in person), and start the pump again, do bubbles immediately form @ the outlet?

[speculation]I don't know anything about that res; *if* it caused an inlet restriction, would the subsequent thrashing of an centrifugal pump cause bubbles? [/speculation]
Somebody else pls lmk if that is in any way accurate; it's a guess, and I'm curious to the real answer.

1) I use a capful of waterwetter. the tubing is a bit cloudy but thats mostly bubbles
2) yes
3) You know what, taht might be it. its 12mm OD barbs since its a european system. I didnt think itd really matter that much, but are you saying it might?

[killernoodle]

It is either pump cavitation or the fact that the radiator is on the top of your system placed horizontally. What you will need to do is keep topping off the resevior (possibly put some of that pump filter foam in there) and just let it run for a few weeks. Tilting the case back and forth wouldnt hurt when you lose the froth but just have bubbles left because the radiator will probably have bubbles swirling in it.

[kronchev]

Originally Posted by killernoodle

It is either pump cavitation or the fact that the radiator is on the top of your system placed horizontally. What you will need to do is keep topping off the resevior (possibly put some of that pump filter foam in there) and just let it run for a few weeks. Tilting the case back and forth wouldnt hurt when you lose the froth but just have bubbles left because the radiator will probably have bubbles swirling in it.

thing is the only thing thats changed is the addition of the res. also if i turn off the system the res is already near the top. its been running like this for about 2 months, and i havent seen any change. on the plus side, the cooling isnt affected, but its kidn of annoying.

[Arcturius]

At this point, I'm willing to bet it's pump cavitation. GE link about cavitation (should have read it before my first post ;p)
Does the problem decrease/go away if you slow the velocity of the water by putting a restriction on the outlet (pinch the hose with your fingers quick)?

[Titan151]

Just a thought, but do you still have the same problem if you turn the res sideways. Have you tried switching the inlet and outlet so that the return is coming in the bottom and outlet going out the top. (although this might not work well for your setup). Sounds like since you had it set up in the sink you may have already tried this.

Nice looking res.

[kronchev]

Originally Posted by Titan151

Just a thought, but do you still have the same problem if you turn the res sideways. Have you tried switching the inlet and outlet so that the return is coming in the bottom and outlet going out the top. (although this might not work well for your setup). Sounds like since you had it set up in the sink you may have already tried this.

Nice looking res.

well as you pointed out i really cant change the position of the res, and really its optimal as it is. I'm thinking about (if I get the time) putting a quick connect hose befrore the pump and moving the res so sitting outside, attached to a ledge id put on the removable motherboard tray, just so it could possibly be level, and itd free up a lot of room in the case, since right now i have to almost take it apart to change any of my cards.

[kronchev]

Originally Posted by Arcturius

At this point, I'm willing to bet it's pump cavitation. GE link about cavitation (should have read it before my first post ;p)
Does the problem decrease/go away if you slow the velocity of the water by putting a restriction on the outlet (pinch the hose with your fingers quick)?

link is down but i'll keep at it, thanks. ill try the velocity restriction when I get home. assuming it is that, what are my options to try to stop it?

[bigben2k]

The first thing you ought to check, is your pump inlet connection: it's very likely that it is sucking air into your loop, at that point.

Cavitation would be the second thing to check, but not easy to do: try running the pump in a simpler loop, just as a test (i.e. pump and res only). Then you'll know.

[myv65]

As Ben noted, if there's any air in that reservoir, it's too small to avoid it getting sucked into the pump inlet. Sure, adding a restriction and reducing flow will probably eliminate the problem because the velocity through the reservoir will slow. This is not the same as cavitation, either. Cavitation is lowering the pressure of the fluid so much that some of it vaporizes. These "bubbles" tend to implode as they get to the higher pressure present near the pump outlet. This effect can literally eat away impellers (even the metal ones in industrial pumps). The pressure is lowered at the inlet as a combination of vacuum and fluid velocity. High velocity equals low static pressure (same idea that keeps planes in the air).

[bigben2k]

(Hi Dave! Long time no see!)

Translation: the airtrap becomes ineffective with such small bubbles.

I've replicated this using Jet-Dry in a simple loop, pump and res only. They really don't clear up.

The additive used here, as well as the concentration, may be part of the problem.

[bobkoure]

Originally Posted by myv65

High velocity equals low static pressure

Yeah, OK.

(same idea that keeps planes in the air).

Erm, well... no. Please don't feel badly, it's a common misconception.
Planes don't hang on lower pressure on the tops of their wings but simply blow air downward to stay up. There are two primary effects: simple angle of attack (wing is angled upwards, so air that strikes it is pushed downwards) - and coanda effect (friction / laminar effect from the top surface works like a giant scoop - shape of surface makes the tail end of the "scoop" angle down).
If you're ever in a plane, near another one that's near the top of the clouds you can easily see the air being blown down into the clouds. I'm no aeronautical engineer, but was a (amateur - VFR only) pilot tor a number of years and saw this effect on a number of occasions.

[bigben2k]

Originally Posted by bobkoure

Yeah, OK.

Erm, well... no. Please don't feel badly, it's a common misconception.
Planes don't hang on lower pressure on the tops of their wings but simply blow air downward to stay up. There are two primary effects: simple angle of attack (wing is angled upwards, so air that strikes it is pushed downwards) - and coanda effect (friction / laminar effect from the top surface works like a giant scoop - shape of surface makes the tail end of the "scoop" angle down).
If you're ever in a plane, near another one that's near the top of the clouds you can easily see the air being blown down into the clouds. I'm no aeronautical engineer, but was a (amateur - VFR only) pilot tor a number of years and saw this effect on a number of occasions.

Actually, I believe that both effects are used here: I used to work for an airline, and have seen the turbulence that you speak of, and yes, the flaps do exactly what you describe. Otherwise, the angle of attack is also a factor in keeping a plane up, but it's also combined with this low pressure effect over the wing.

Being on the ground, you can look at any Airbus 330 or 340, and see a visible droop in the wings (span wise). This droop dissapears in flight

[myv65]

OK, should have been more clear, but in a watercooling forum I didn't think anyone would really care. Net lift depends on more than simply making air take a longer (thus faster) path over the upper surface of the wing. Air has mass, so "plowing into it" with the lower surface also results in a lift force.

Would have been easier to simply say the conversion of static to dynamic pressure is V^2/ (2 * g) (ignoring density when using "head" as pressure). What fun is that?

[Titan151]

Originally Posted by myv65

As Ben noted, if there's any air in that reservoir, it's too small to avoid it getting sucked into the pump inlet. Sure, adding a restriction and reducing flow will probably eliminate the problem because the velocity through the reservoir will slow. This is not the same as cavitation, either. Cavitation is lowering the pressure of the fluid so much that some of it vaporizes. These "bubbles" tend to implode as they get to the higher pressure present near the pump outlet. This effect can literally eat away impellers (even the metal ones in industrial pumps). The pressure is lowered at the inlet as a combination of vacuum and fluid velocity. High velocity equals low static pressure (same idea that keeps planes in the air).

Ahhhh, and I almost made it through the whole day without learning something. This is interesting info. I have often heard of the collapse that takes place as being somewhat similar to what happens when a Sonic Boom collapses. Good info to have. I actually have an impeller from the USS Intrepid that was chewed up by cavitation. It now serves as a really sharp cup holder!



OK I know this is a bit off topic, but this is the impeller I was talking about. It was sandblasted and then I painted it with copper paint. I find it interesting as in the original state this thing was a solid plate (no blades). just a flat disk. Whats left is what looks like something that had blades like a prop. Now it is a very heavy throwing star/cup holder!

In short: Cavitation Bad

[Arcturius]

Did any of that testing point to where the problem might be?

[MadHacker]

I had a similar problem... and the bubbles wouldn't go away...
I drained my system then added distilled water...
Then after my machine is running for a day i add my additive (Hydrx Coolant)
No more bubbles...
I think your coolant is acting like soap... ever try getting rid of bubbles in dish water by agitation? Doesn’t happen...

[DrMemory]

I had a very similar problem that was due to the use of water-wetter and some brands of vinyl tubing. While it looked like bubbles and "fogged" up tubing, it turned out to be a coating of some sort on the inside of the tubing. The first brand of vinyl tubing I used did not do this. After I replaced it with another brand (from Home Depot) it clouded over almost immediatly and looked exactly like the picture you've taken. Eventually I removed that tubing (and a water block that I thought was leaking) and replaced it with Clearflex 60. This tubing has stayed clear and "bubble" free for several months.

[Ruiner]

I'll second on the water wetter thing. It coated my cheap vinyl tubing with nasty brown crud. Did the same thing to the overflow tank in my car.