Water wetter: who is (has been) using it?? - Page 2 - PeachParts Mercedes-Benz Forum

stephenson · #16 01-22-2006, 10:33 AM

Walrus,

Aackk ... you are right, of course, in the convective world - and, that's that where auto radiators are. While I didn't consider it and yapped too quickly (as usual), my comment was more related to radiative transfer. Other form is conductive transfer - it doesn't relate to color, either, right? (Someone who's qualified jump in, please!)

joselu43 · #17 01-22-2006, 01:14 PM

Yes, color matters in radiation (and absorption, that is why the Space Shuttle is black at the bottom and white everywhere else), but the amount of heat radiated by a "radiator" is very small compared to the amount convected away. In that sense we should call the units "convectors" rather than "radiators". The technical name is "heat exchanger".
As far as the water wetter, I know of no mechanism that would allow the WW to improve conduction to the inside walls of the radiator to the point of lowering the overall temperature 10 F. On the other hand, lowering the coolant concentration from 50% to 20% or so, adding distilled water and WW (for its anti corrosion additives etc.) could do it because water is a much better heat transfer agent than coolant (I do not know about WW). Which is what M. B. Doc was saying in his post.

JL

haasman · #18 01-22-2006, 01:34 PM

The old '87 190e 2.3 at one point had a bad (clogged radiator from running the green coolant I believe) I used Water Wetter in it.

It didn't perform miracles but it did lower the running temps about 10 degrees in the summer until I replaced the radiator.

Haasman

Walrus · #19 01-22-2006, 03:28 PM

Quote:

Originally Posted by joselu43

As far as the water wetter, I know of no mechanism that would allow the WW to improve conduction to the inside walls of the radiator to the point of lowering the overall temperature 10 F.
JL

I am not supporting or denying WW 's claims, but I will opine on water conditioners in general. The chief benefit of a water conditioner is to prevent cavitation as the coolant impacts the vibrating, heated combustion chamber surfaces. If coolant is allowed entrained air, as it impacts the hot cylinders walls and other heated engine internals, the air bubbles are allowed to or caused to explode or burst, which can erode the surfaces... Furthermore, the cylinder walls are vibrating similar to an ultrasonic cleaner, which breaks down any entrained air in the coolant fluid, forming micro-bubbles. Conditioners change the surface tension properties to minimize the formation of air bubbles. These bubbles also prevent full conductive heat transfer by acting like a blanket between the fluid and the heated surface.

Of course, all the above could be Bull****, but I believe it to be more or less accurate.

stephenson · #20 01-22-2006, 03:28 PM

haasman,

But, as I understand it, WW directions call for increasing the percentage of water? If so, that is what decreases the coolant maximum temp, right?

So, if one were to increase the percentage of water in their coolant, without adding WW, the max temp (all things being equal) would also decrease?

joselu43 · #21 01-22-2006, 04:56 PM

Walrus, I think I understand your cavitation argument, my problem with it is that air does not dissolve in water in any significant amount, therefore any entrained air (and there should not be much of it if we do a reasonable job of filling the system) will allways be in the form of bubbles. WW cannot affect air bubble formation. At any rate, air cannot contribute to cavitation because it cannot become liquid. On the other hand, water can, and you could argue that WW alters the process in which water in contact with the hot wall evaporates and then away from the wall cools down and cavitates. It is possible and I do not know that there is any data supporting it of contradicting it. There is plenty of data to support what George is asking about:

"So, if one were to increase the percentage of water in their coolant, without adding WW, the max temp (all things being equal) would also decrease?"

Yes. You need the WW for the anticorrosion, lubrication and other stuff only.

JL

Walrus · #22 01-22-2006, 05:13 PM

Quote:

Originally Posted by joselu43

Walrus, I think I understand your cavitation argument, my problem with it is that air does not dissolve in water in any significant amount, therefore any entrained air (and there should not be much of it if we do a reasonable job of filling the system) will allways be in the form of bubbles. JL

Actually, if air did not dissolve into water very well, what would fish do for respirable Oxygen? They do not break down water molecules and release hydrogen, but extract dissolved air from the water.

All this means nothing really... anecdotal evidence exists that conditioners, such as water wetter do work. I agree that lower ratio of glycol additives to water are better, with straight water being a better coolant than water/antifreeze mixture.

joselu43 · #23 01-22-2006, 05:46 PM

Sorry, did not mean to be argumantative. Fish need oxigen, maximum oxigen concentrations in water depend on temperature and salinity. It decreases with both. At zero salinity, 77 F and atmospheric pressure the maximum amount of oxigen is about 0.0089 grams per Kilogram of water. For air the number rises to 0.023 grams per Kilogram. That is what I meant by "any significant amount". As far as wether WW works or not, I have no opinion.

JL