On Sun, 16 Sep 2007 13:08:32 -0400, a troll wrote:

a "barrel"... is not 42 US gallons, it is 42 US gallons at 60 degrees F at sea
level. :-)


What's the temperature have to do with anything? I know what you're
gonna say. You're gonna say volume decreases with temperature decrease
and vice versa. But does that not also hold true for the measuring
container?
It's the same thought process those dummies who say to loosen the
standing rigging for the winter storage period because the stays and
shrouds shrink with the cold. But, I suppose they think the aluminum
mast doesn't also shrink? Duh!
Ya gotta think outta the box, man.
Wilbur Hubbard

Oh dear,
I am going to regret this: the troll's not only wrong,
but ugly about it too!

Gas expands in volume 950 ppm per deg C
So it's important to sell by mass (which is invariant) or
by volume at a set temperature.

It's not a lot in a tank of gas (so much for filling up in the cold
pre-dawn) but it mounts up if you sell by the million barrels.

Steel and aluminum expand at different rates:
the linear rates are Steel 12 ppm /degC, Aluminum 24 ppm /degC

So the time to ease the stays is when leaving a boat in warming
weather, if at all. A sample 50 ft mast might need two or three
turns easing on each rigging screw for 30 degrees C temp rise. But
more care is needed with plastic rigging.
That can really change with temperature.

Brian Whatcott Altus OK