"J. Severyn" wrote:

You did not provide adequate or even convincing evidence that model
the problem.

If the air in the tank is exchanged 10 times over a few weeks (not
unreasonable due to temperature, barometric pressure changes and local
wind),

"Not unreasonable?" That's what your argument is based on? What is
your criterion for "not unreasonable"?

the amount of water starts adding up. The water droplets on the
inside surface will get caught in the fuel as they drip or slowly flow
into the fuel. They will flow to the bottom of the tank and not
evaporate as they are covered with fuel.

In windy conditions, the air can exchange many more than 10 times.

Do you have any empirical data on which you base this number or did you
just make it up?

Most aircraft have several fuel vents and many high-wingers connect
the top of the tanks to assure fuel delivery. The multiple vents
allow lots of air exchange if the plane is tied down outside with
differences in pressure at the different vents due to placement and
wind.

That is true of my airplane and the three club airplanes with which I am
familiar. All these aircraft are parked outdoors next to a bay on the
Gulf Coast and subjected to continuously damp and frequently windy
conditions. None are routinely topped off after flight--in fact, club
rules proscribe the practice. Persistent presence of water in fuel
samples has not been a problem with any of these aircraft.

So let's use your numbers....times 100 or more. 1.4 Kg of water (or
more) is a significant amount.

Yes, it is. So where is it? Certainly not in the planes I take fuel
samples from.

We have had this discussion before, I believe. I am still waiting for
you to produce any convincing data to make fuel tank
respiration/condensation credible as a serious source of water
contamination in aircraft fuel.

--
Dan
C172RG at BFM