Hello,

I have been mulling over the idea of re-routing my water tank vents
from the bilge to an overboard thru-hull vent. I would like to stop
from filling my bilge with water everytime i fill my tanks.

Some people have expressed concern that it opens up the risk of
getting seawater contamination in heavy seas and that the boatbuilder
probably chose to do this on purpose. Since this is a power boat, I
am not worried about creating a siphon from healing over.

I was wondering if anybody has any opinions on why this is a good or
bad idea and any advice on things to consider if I go ahead with this
(such as heights, loops required etc).

Thanks in advance!

Rob

great idear, can't hurt at all.

Rob,

My water tank vent empties into the galley sink. My old boat vent emptied
into the shower stall. I like this arrangement because it does not let in
salt water and we can just watch the sink for an indication as to when the
tank is full.

Cheers

Ansley Sawyer
SV Pacem

My water tank vent empties into the galley sink. My old boat vent emptied
into the shower stall. I like this arrangement because it does not let in
salt water and we can just watch the sink for an indication as to when the
tank is full.

Neither of those locations is the best place for a water tank vent.
They're both full of bacteria and can also become clogged--in a sump by
soap scum, hair etc...in the galley sink by grease, food particles etc.
Plus, if the sump pump fails or the galley drain gets plugged, shower or
galley water can back up into the vent and even the tank.

Out a through-hull is the best place for a water tank vent...into the
bilge a VERY poor second. At least both of those locations allow you to
flush out the vent by overflowing the tank out it each time you fill it.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://69.20.93.241/store/customer/p...40&cat=&page=1

"orbital" wrote in message
m...

Some people have expressed concern that it opens up the risk of
getting seawater contamination in heavy seas and that the boatbuilder
probably chose to do this on purpose.

Do you get sea water into your fuel tanks? They are certainly vented
overboard!

The boats I have owned have all had the vents mounted through the hull. If
you want to assure that you don't get any seawater back in the vent then run
the vent line as high as you can, but a vented loop at the top, then run the
line back down to the hull. There is no way that any significant amount of
spray is going to migrate several feet up a hose.

Rod

"Peggie Hall" wrote in message
...


Out a through-hull is the best place for a water tank vent...into the
bilge a VERY poor second.

Why is the bilge such a poor second? The water goes in the bilge. The
bilge pumps pump it out. What's the problem?


At least both of those locations [bilge or through-hull] allow you to
flush out the vent by overflowing the tank out it each time you fill it.


Aside from the problems with galley-sink and shower that you
mentioned how do these locations disallow you from flushing the
water vent by overflowing the tank as you fill it? You overflow
the tank, it goes into the sink/shower and the vent is flushed, no?

Gary Warner wrote:
"Peggie Hall" wrote in message
...


Out a through-hull is the best place for a water tank vent...into the
bilge a VERY poor second.

Why is the bilge such a poor second? The water goes in the bilge. The
bilge pumps pump it out. What's the problem?

The problem is bilge pumps DON'T pump ALL the water out...which is why
most people do everything possible to keep as much water OUT of the
bilge as possible. 'Cuz the less water that goes into one, the less
there is to turn into a dark smelly swamp.

Aside from the problems with galley-sink and shower that you
mentioned how do these locations disallow you from flushing the
water vent by overflowing the tank as you fill it? You overflow
the tank, it goes into the sink/shower and the vent is flushed, no?

Provided you remember to turn on the sump pump--not too soon, or the
impeller will fry...too late and dirty water in the sump will combine
with the water in the vent and can get back into the tank and
overflow...break out the mop. As often as all of us just stick the hose
in the water fill and and forget it till water running out the vent
reminds us to turn it off, how many of us are that good?

Venting it overboard is the only solution that doesn't create more
problems than it solves.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://69.20.93.241/store/customer/p...40&cat=&page=1

Not sure how grease etc is going to leap out of the galley sink into
the vent. Our tanks are vented into the head sinks via a spout in
each. Easy to see when the tanks are full when filling, no problem
with contamination from salt water or anything else. Works great!

Doug
s/v Callista

"Peggie Hall" wrote in message
...
My water tank vent empties into the galley sink. My old boat vent
emptied
into the shower stall. I like this arrangement because it does not let
in
salt water and we can just watch the sink for an indication as to when
the
tank is full.

Neither of those locations is the best place for a water tank vent.
They're both full of bacteria and can also become clogged--in a sump by
soap scum, hair etc...in the galley sink by grease, food particles etc.
Plus, if the sump pump fails or the galley drain gets plugged, shower or
galley water can back up into the vent and even the tank.

Out a through-hull is the best place for a water tank vent...into the
bilge a VERY poor second. At least both of those locations allow you to
flush out the vent by overflowing the tank out it each time you fill it.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://69.20.93.241/store/customer/p...40&cat=&page=1

Comments below.

Doug
s/v Callista

"Rod McInnis" wrote in message
...

"orbital" wrote in message
m...

Some people have expressed concern that it opens up the risk of
getting seawater contamination in heavy seas and that the boatbuilder
probably chose to do this on purpose.

Do you get sea water into your fuel tanks? They are certainly vented
overboard!

Not necessarily. Current school of thought is to vent them in the cockpit.
No problem with overflow overboard (big fine). No problem with
sal****er infiltration. There was an article about it in the past year or so
in Cruising Worls or PS or ON.

The boats I have owned have all had the vents mounted through the hull.
If
you want to assure that you don't get any seawater back in the vent then
run
the vent line as high as you can, but a vented loop at the top, then run
the
line back down to the hull. There is no way that any significant amount
of
spray is going to migrate several feet up a hose.

Spray isn't the problem. Immersion is the potential problem.

Rod

Doug Dotson wrote:
Not sure how grease etc is going to leap out of the galley sink into
the vent

Prob'ly won't if you never fill the sink to wash dishes or allow any
dirty dishwater to go down the drain.

Our tanks are vented into the head sinks via a spout in
each. Easy to see when the tanks are full when filling...

As long as you're in the head while they're filling... or there's no
plug in the sink if you aren't.

I think the vent should go out the hull. But hey...they're YOUR boats,
so whatever floats 'em for YOU is fine with me.

--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://69.20.93.241/store/customer/p...40&cat=&page=1