observer wrote in message
...

On Tue, 06 Nov 2007 13:49:51 -0500, Gene Kearns
wrote:


I'm not so sure I'd like to leave a gas tank vented when the boat is
docked and I'm not there because of the fumes and some idiot smoking
nearby.

Hello observer .....

I apologize if you took my comment about keeping the tank full as being a
smart ass comment.
Didn't intend it that way.

I have a old, 13' Whaler and use a couple of the plastic tanks, one 6 gallon
and the other is 3 gallons. Both have a fuel gage (part of the filler cap)
with a small vent in the center.

As far as I know, the only reason to tighten the vent cap is when you are
transporting the tank and don't want spillage. Otherwise, I leave the vent
slightly cracked to equalize the internal pressure as the vapors expand and
contract.

The reason to keep it as full as possible is that it minimizes the amount of
humid air being drawn into the tank. If you are regularly using the boat
and engine, I don't think it's much of a concern.

Eisboch