Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 22-08-2015, 02:02   #1
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,060
Images: 3
Incredible Leaking

It took me days to locate an important leaking upsurging out of nowhere..

IT WAS THE ANCILLARY BILGE PUMP ITSELF

1. one-way valve got stuck
2. Sea-cock is on bottom of hull, STUPID!
3. I added a goose neck of 3' high, which was missing at all
You don't ever imagine a bilge pump leaking.... technicians of lifetime experience were quite incredulous either

Did it ever happen to you? Boat is 25yo, I will change all sea-docks into bronze, and change water-pipes next time I go dry
__________________

__________________
TheThunderbird is online now   Reply With Quote
Old 22-08-2015, 02:33   #2
Registered User

Join Date: Apr 2006
Posts: 4,413
re: Incredible Leaking

Bilge pumps should discharge above the static water line.
__________________

__________________
Sandero is offline   Reply With Quote
Old 22-08-2015, 02:54   #3
Senior Cruiser
 
atoll's Avatar

Cruisers Forum Supporter

Join Date: Mar 2010
Location: gettin naughty on the beach in cornwall
Boat: 63 custom alloy sloop,macwester26,prout snowgoose 37 elite catamaran!
Posts: 9,311
Images: 75
re: Incredible Leaking

even with a loop above the water line, bilge pumps that discharge below the water line are liable to siphon
__________________
my catamaran building project updates http://www.cruisersforum.com/forums/...36#post2502136
atoll is offline   Reply With Quote
Old 22-08-2015, 06:15   #4
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,060
Images: 3
re: Incredible Leaking

Quote:
Originally Posted by atoll View Post
even with a loop above the water line, bilge pumps that discharge below the water line are liable to siphon
Absolutely right.

An out-take above the water line is advisable... however it requires a goose-neck and possibly a water-tight plenum box..... not ideal in a cutter much prone to heel

PS boat is a Nauta, basically of Swan-like quality... that was a surprise to me, such a deficiency (great it came out when in harbour... 1/2 gallon/ minute makes a lot of water as you sleep... :-)
__________________
TheThunderbird is online now   Reply With Quote
Old 22-08-2015, 07:37   #5
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 4,019
Re: Incredible Leaking

Check valves in the outlet bilge hose are the bane of the industry. Any design that is 100% dependent on a check valve will eventually flood the boat. This happens a lot. There are many stories here on CF and in magazines about people who can't believe water is coming out of their bilge pump. But it happens all the time.

The "best" system will have the through hull discharge above the "normal" heeled waterline. Put the antisiphon device well above the max heeled waterline. Get rid of the check (aka one-way) valve if possible. Lastly, never route a bilge pump to an outlet below the waterline.
__________________
transmitterdan is offline   Reply With Quote
Old 22-08-2015, 07:56   #6
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,060
Images: 3
Re: Incredible Leaking

Quote:
Originally Posted by atoll View Post
even with a loop above the water line, bilge pumps that discharge below the water line are liable to siphon
Absolutely right.

An out-take above the water line is advisable... however it requires a goose neck and possibly a water-tight plenum box..... not ideal in a cutter much prone to heel


PS boat is a Nauta, basically of Swan-like quality... that was a surprise to me, such deficiency (great it came out when in harbour... 1/2 gallon/ minute makes a lot of water as you sleep... :-)
__________________
TheThunderbird is online now   Reply With Quote
Old 22-08-2015, 08:38   #7
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Incredible Leaking

What is the argument for a discharge below the waterline with a vented loop? There must be one for a "Swan like" boat.
__________________
Guy is offline   Reply With Quote
Old 22-08-2015, 10:06   #8
Registered User
 
Terra Nova's Avatar

Join Date: Apr 2007
Location: Marina del Rey, California
Boat: Freya 39 cutter- Terra Nova
Posts: 3,645
Re: Incredible Leaking

Quote:
Originally Posted by TheThunderbird View Post
...

1. one-way valve got stuck
2. Sea-cock is on bottom of hull, STUPID!...
Both wrong.
Never install a check valve in bilge pump plumbing.
__________________
1st rule of yachting: When a collision is unavoidable, aim for something cheap.
"whatever spare parts you bring, you'll never need"--goboatingnow
"Id rather drown than have computers take over my life."--d design
Terra Nova is offline   Reply With Quote
Old 22-08-2015, 10:24   #9
Registered User
 
MBWhite's Avatar

Join Date: Apr 2012
Location: Illinois
Boat: Hurley Alacrity
Posts: 370
Re: Incredible Leaking

Quote:
Originally Posted by Guy View Post
What is the argument for a discharge below the waterline with a vented loop? There must be one for a "Swan like" boat.
Money? Style?

1) It is prettier and there is no chance of the side of the boat getting stained resulting in extra labor for scrubbing/cleaning.

2) It is often cheaper as the thru hull can be located in any convenient spot instead of the associated labor involved with routing a bilge hose to an above waterline spot.


Personally, I like the outlet to be somewhere it can be seen from the helm so if you do either take on water or develop a leak or have a regular leak that gets worse you can notice it before the water starts creeping above the floorboards.
__________________
MBWhite is offline   Reply With Quote
Old 22-08-2015, 14:12   #10
Registered User

Join Date: Aug 2012
Location: Cruising the Gulf of Mexico.
Boat: 1980 Morgan 415
Posts: 1,439
Re: Incredible Leaking

Foot valves and check valves are the last line of defense for a swamped vessel.

I am a fan.


------------------------------
Looking for another pretty place to work on the boat.
__________________
Working on spending my children's inheritance.
Cap Erict3 is offline   Reply With Quote
Old 22-08-2015, 14:45   #11
Registered User
 
PangurBan's Avatar

Join Date: Jul 2014
Posts: 47
Re: Incredible Leaking

Quote:
Originally Posted by Cap Erict3 View Post
Foot valves and check valves are the last line of defense for a swamped vessel.

I am a fan.


------------------------------
Looking for another pretty place to work on the boat.

What is a foot valve?


Sent from my iPad using Cruisers Sailing Forum
__________________
PangurBan is offline   Reply With Quote
Old 22-08-2015, 14:57   #12
Registered User

Join Date: Aug 2012
Location: Cruising the Gulf of Mexico.
Boat: 1980 Morgan 415
Posts: 1,439
Re: Incredible Leaking

Quote:
Originally Posted by PangurBan View Post
What is a foot valve?


Sent from my iPad using Cruisers Sailing Forum

A check valve below a pump to keep it primed and prevent reverse flow.


------------------------------
Looking for another pretty place to work on the boat.
__________________
Working on spending my children's inheritance.
Cap Erict3 is offline   Reply With Quote
Old 22-08-2015, 16:23   #13
Senior Cruiser
 
nautical62's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: Live Iowa - Sail mostly Bahamas
Boat: Beneteau 32.5
Posts: 2,264
Images: 12
Re: Incredible Leaking

On my first boat, I found out the hard way a previous owner had plumbed a hand pump into a though hull line using that cheap above water corrugated hose. The hose got a leak and nearly sunk the boat. Lesson learned. On later boats I made it point to immediately understand and inspect all plumbing to ensure it's done right. (I switched that one to above water line as well.)

If it were my boat, I'd put the through hull discharge for the bilge pump above water line.
__________________
nautical62 is offline   Reply With Quote
Old 22-08-2015, 18:26   #14
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,060
Images: 3
Re: Incredible Leaking

Quote:
Originally Posted by nautical62 View Post
On my first boat, I found out the hard way a previous owner had plumbed a hand pump into a though hull line using that cheap above water corrugated hose. The hose got a leak and nearly sunk the boat. Lesson learned. On later boats I made it point to immediately understand and inspect all plumbing to ensure it's done right. (I switched that one to above water line as well.)

If it were my boat, I'd put the through hull discharge for the bilge pump above water line.
In principle, I appreciate.

De facto, a 54' has say 12 intakes and 4 out takes
Putting all the out-takes above WL doesn't solve the problem.


Solutions:

Best quality sea cocks (bronze)
Double clamps
Not too old pipes
Control on one-way valves
Vented pipe (siphon)
Routine inspections

When possible, yes, above WL out-takes

Intakes must obviously be well below the WL
__________________
TheThunderbird is online now   Reply With Quote
Old 22-08-2015, 18:42   #15
Registered User

Join Date: Dec 2014
Location: the Med
Boat: Nauta 54' by Scott Kaufman/S&S - 1989
Posts: 1,060
Images: 3
Re: Incredible Leaking

Check valve: you can't live without it when operating the WC
:-)

On other like a, it avoid the reverse flow along the pipe, and is an additional safety measure.

It can't be the only one!!!
__________________

__________________
TheThunderbird is online now   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Incredible New Prop Braking Mechanism! tomperanteau Construction, Maintenance & Refit 16 15-01-2010 10:37
Pearl Harbour Photos - Incredible!!! knottybuoyz Pacific & South China Sea 6 10-11-2006 08:15
Sailing Through Pumice - Incredible!! markpj23 General Sailing Forum 2 09-11-2006 19:31



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 23:40.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.