I like Rich's idea about putting a vapor trap on the FO vent line, at least
during storage (I notice he said he removed his while cruising).

I went to look for som Silica Gel today and all I could find was Calcium
Chloride which was being sold in 1/2 gallon packs as a moisture absorber.
Any reason not to use that except that it isn't reusable?

I would just run a hose from my sounding tube to the container with just a
pin hole in it for any air pressure changes. Since the boat is on the hard
and the tanks are not being filled or emptied, any air volume changes are
going to be very slow.

--
Roger Long

On Mon, 17 Nov 2008 14:32:46 -0500, "Roger Long"
wrote:

I like Rich's idea about putting a vapor trap on the FO vent line, at least
during storage (I notice he said he removed his while cruising).

I went to look for som Silica Gel today

http://www.agmcontainer.com/

and all I could find was Calcium
Chloride which was being sold in 1/2 gallon packs as a moisture absorber.
Any reason not to use that except that it isn't reusable?


It's crap.

I would just run a hose from my sounding tube to the container with just a
pin hole in it for any air pressure changes. Since the boat is on the hard
and the tanks are not being filled or emptied, any air volume changes are
going to be very slow.

"Roger Long" wrote in
:

Since the boat is on the hard
and the tanks are not being filled or emptied, any air volume changes
are going to be very slow.


Huh?? Air temp rises....tank pressurizes and air flows out.
Air temp drops....tank gets vacuum and breathes in.

Whatever it breathes in that can condense DOES!

simple physics....

"Larry" wrote

Huh?? Air temp rises....tank pressurizes and air flows out.
Air temp drops....tank gets vacuum and breathes in.


This is the simple thinking that vastly overstates the problem.

More accurate rewrite:

Air temp rises. Air volume increases very slightly. A small amount of air
is expelled from tank.
Air temp drops. A small amount of air enters tank.

There is a lot of thermal mass in half a tank of fuel and the tank itself is
protected from the sun and inside a hull. The air volumes are not that
great nor are the temperature swings.

Condensation hysteria.

--
Roger Long

On Mon, 17 Nov 2008 18:27:39 -0500, "Roger Long"
wrote:

"Larry" wrote

Huh?? Air temp rises....tank pressurizes and air flows out.
Air temp drops....tank gets vacuum and breathes in.


This is the simple thinking that vastly overstates the problem.

More accurate rewrite:

Air temp rises. Air volume increases very slightly. A small amount of air
is expelled from tank.
Air temp drops. A small amount of air enters tank.

There is a lot of thermal mass in half a tank of fuel and the tank itself is
protected from the sun and inside a hull. The air volumes are not that
great nor are the temperature swings.

Condensation hysteria.

Everybody's favorite boat expert.
http://www.yachtsurvey.com/myth_of_c...fuel_tanks.htm

--Vic

On 2008-11-17 19:53:02 -0500, Vic Smith said:

Everybody's favorite boat expert.
http://www.yachtsurvey.com/myth_of_c...fuel_tanks.htm

I wouldn't say EVERYone's favorite, but I have yet to fully disagree
with his observations.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

On Mon, 17 Nov 2008 18:53:02 -0600, Vic Smith
wrote:

On Mon, 17 Nov 2008 18:27:39 -0500, "Roger Long"
wrote:

"Larry" wrote

Huh?? Air temp rises....tank pressurizes and air flows out.
Air temp drops....tank gets vacuum and breathes in.


This is the simple thinking that vastly overstates the problem.

More accurate rewrite:

Air temp rises. Air volume increases very slightly. A small amount of air
is expelled from tank.
Air temp drops. A small amount of air enters tank.

There is a lot of thermal mass in half a tank of fuel and the tank itself is
protected from the sun and inside a hull. The air volumes are not that
great nor are the temperature swings.

Condensation hysteria.

Everybody's favorite boat expert.
http://www.yachtsurvey.com/myth_of_c...fuel_tanks.htm

--Vic

I've seen worse cases of arm-waving but who needs advice from
'experts' who cannot do simple arithmetic (*9/5+32) and have not
analysed the situation very well, or done any actual measurements
etc..

Vic Smith wrote:


Everybody's favorite boat expert.
http://www.yachtsurvey.com/myth_of_c...fuel_tanks.htm

The temps c/f are inaccurate. This guy is pretty damn sloppy.

On Mon, 17 Nov 2008 18:27:39 -0500, "Roger Long"
wrote:

"Larry" wrote

Huh?? Air temp rises....tank pressurizes and air flows out.
Air temp drops....tank gets vacuum and breathes in.


This is the simple thinking that vastly overstates the problem.

More accurate rewrite:

Air temp rises. Air volume increases very slightly. A small amount of air
is expelled from tank.
Air temp drops. A small amount of air enters tank.

There is a lot of thermal mass in half a tank of fuel and the tank itself is
protected from the sun and inside a hull. The air volumes are not that
great nor are the temperature swings.

Condensation hysteria.

There are fuel barrels. My farm had two, three hundred gallons, on
stands in the sunlight.

Casady

"Roger Long" wrote in message
...
I like Rich's idea about putting a vapor trap on the FO vent line, at least
during storage (I notice he said he removed his while cruising).

I went to look for som Silica Gel today and all I could find was Calcium
Chloride which was being sold in 1/2 gallon packs as a moisture absorber.
Any reason not to use that except that it isn't reusable?

I would just run a hose from my sounding tube to the container with just a
pin hole in it for any air pressure changes. Since the boat is on the
hard and the tanks are not being filled or emptied, any air volume changes
are going to be very slow.

Silica gel is used by dried flower specialists, and comes in half-kilo jars,
but where from I know not!


Dennis.
Roger Long