"mike regish" wrote in message
. ..
In researching this, I found scuba divers complaining about "hot fills"
where the tank is filled too rapidly and when it cools down they are left
with a less-than-full tank.

I suspect that the water bath approach just results in the skin temperature
of the tank being cooler whereas the gas hasn't really decreased that much
in temperature... Thus, they're still getting "hot fills", they just don't
notice it... The easiest solution to hot fills is to just fill it higher
than normal and when it cools, it's at the target pressure... Or you could
just do it right and slowly fill the tank...