If the drum is full (54 gallons in a 55 gallon drum) then the only air space is the gap at the top.
If the drum is air-tight (factory sealed) then how can water get in?
The only water that could possible be in the drum would be from the mositure in the air when the fuel was put in, and I'm thinking that would only be a fairly small amount.
Sorry but I'm not following this mind set that water can get in a air tight metal drum?
I'd tried to chew him down since it is old fuel, it which will break down over time, though I'm not sure what the life span is on race gasl but it isnt as fresh as it was when it came from the refinery.
JMO< Cp