Water soluable no-clean flux?

[macboy]

I came into some Alpha Cleanline 7000 (click) flux core solder, which claims to be no-clean, leaving behind only a soft, clear, non-conductive, non-corrosive residue. All the active parts of the flux apparently volatilize at soldering temperature. The kicker is: It is also water soluble. The action of the flux is very good; this stuff wets and flows nearly as nicely as Kester 44, my benchmark.

I remember reading wisdom that water-soluble fluxes, while easier to clean, generally MUST be cleaned due to their corrosive and often conductive nature. I've understood that no-clean fluxes are based on chemicals which, when cooled after soldering, turn into a non-corrosive, non-conductive polymer which also entraps the metal oxides which might otherwise cause leakage currents (good old rosin is a prime example). Because of this polymerization, they leave behind a crusty, often ugly residue that is difficult to probe through, and they are harder to clean, requiring solvents. In other words "no clean" is mutually exclusive with "water soluble". Googling "no clean water soluble flux" finds only comparisons between the two worlds.

I have some DMMs with working GOhms ranges, so I tested. Between adjacent Cleanline 7000 joints, there was no measurable conductivity immediately after soldering, nor after adding a blob of distilled water for couple of minutes, nor after cleaning up with water and drying. The claims of "minimal" and "clear, soft" residue are true as well. Could it be true? A no-clean flux that doesn't leave ugly orange-brown residue, and which can be optionally easily cleaned up with water?

[calexanian]

I have always held the same view that water soluble MUST be cleaned. It is really reactive stuff and considering moisture is a fact of life it will always remain a little mobile and active. Now if this is some new product, I don't know. but if it is water soluble why not rinse it? I will stick with my tried and true practice of sticking with whatever Kester recomends for their solder i happen to be using. We have no clean, RA flux, and water clean in the shop depending on what we are doing.