On Sat, 26 Jun 2004 10:03:56 -0400, hanz
wrote:

WHen filling the tanks you better NOT have too
much pressure. Even .5 psi can put a lot of pressure on the tops of
tanks - 2'x 5'lid = 24"x 60" = 1440 sq in x .5= 720 pound of pressure,
enough to cause the lid to buckle and separate.

I was thinking of writing along this line because I had that issue
with my fuel tanks. It's easy to get a lot of pressure. Say a water
tank vent outlet (or filler cap) is 6 feet above the tank. By the time
water comes out the vent or filler cap you have about 1/5 atmosphere
or 3 psi in the tank. Fuel is similar, probably 75% of that pressure.
My tank vents are fairly high up a coaming on a center cockpit and the
fuel tanks are under the sole. There's 7-8 feet of head. My tanks
oozed around some fittings that were not used to pressure and around
an inspection port that wasn't really adequately gasketed.