ORIGINAL: KaP2011
Is there any way to filter out moisture from glow fuel? I've lost a quart from the last 2 gallons of Omega 15% fuel I've used due to moisture. I keep the container sealed between fuelings but it sucks air in when I fuel so I'm still getting moisture. I hate the thought of throwing away a quart of every gallon I use.
Engines tolerate a good amount of moisture in the fuel. The alcohol completely dissolves the water and the alcohol has a lower boiling point than water. So even if you have water in the fuel the droplets are alcohol not water. In fact that is how you distill alcohol to include methanol, by heating the water and alcohol mixture below the water boiling point and above the alcohol boiling point then condense the alcohol.
You will not get much air and moisture in the fuel when the cap is uncovered between fillings. When the fuel is burned much of the hydrogen in the alcohol combines with oxygen to form water. So the muffler pressure tap is pumping water back in your fuel. Still this usually isn't enough moisture in the fuel. Even when you leave it uncapped you often will not get water in the fuel unless the fuel is below the flashpoint of methanol.(52degrees F). That is because the methanol is evaporating and unless a breeze is pushing the vapor out it will prevent the moisture from getting in. Often people complaining about the fuel gaining so much moisture it won't run, the problem is actually that so much methanol has evaporated that there is too much oil and nitro compared to the methanol that the engine will not start.