Bilge Pump Discharge - New Thru Hull ??? - SailNet Community
LinkBack Thread Tools
post #1 of 4 Old 04-30-2003 Thread Starter
Junior Member
Join Date: Apr 2003
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Bilge Pump Discharge - New Thru Hull ???

Hi Everyone,
Looking for some advise on installing an electric bilge pump in my sailboat. Do I have to install a new thru hull fitting or is it possible to connect the new bilge pump discharge line (3/4") into a "Y" connection that would be installed in the existing (1 1/2") manual bilge pump discharge line ... aft of the manual pump itself ???
Any advise would greatly be appreciated.

Thank you,
Terry Clarke
CAPTIVA, Port Whitby
Terry Clarke is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #2 of 4 Old 05-01-2003
Senior Member
Join Date: Dec 2002
Posts: 552
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 13
Bilge Pump Discharge - New Thru Hull ???

Expect you''ll get some contrary advice, but:
If your intent is to add an automatic bilge pump, for use when boat untended - your idea has merit.
There''s, obviously a trade-off here. You''ll still only have one pump available (at a time), and would want to ensure that the diverter ("Y") valve is quickly accessable, and preferably c/w mounting feet/flanges (fasten to bulkhead or whatever). Ensure that you don''t "foul" the discharge (vented) loop, and adapt from the .75" pump discharge to the 1.5" overboard discharge as early as possible. NO CHECK VALVES!
GordMay is offline  
Quote Quick Reply Share with Facebook
post #3 of 4 Old 05-01-2003
Senior Nappy Headed Ho
Join Date: Feb 2001
Posts: 734
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Bilge Pump Discharge - New Thru Hull ???

You do not stae the size of the vessel but a 3/4 line for a bilge pump is very small. These are normally 1-1/2 in diameter. Once you run this hose to the aft end of your boat, depending on its size, you will have a lot of water in the hose. I would definitely put a check valve in-line so the pump is not cycling all the time. You could easily have a half to full gallon of water in the line depending on the depth of the bilge. Don''t forget you have to run the discharge hose high enough in the boat to prevent back siphoning when heeled over. Yes to Czech valves! Why cut corners by sharing a through hull? It should be a dedicated line, your life could depend on it!
Denr is offline  
Quote Quick Reply Share with Facebook
post #4 of 4 Old 05-01-2003
Senior Member
Join Date: Jan 2001
Posts: 445
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 15
Bilge Pump Discharge - New Thru Hull ???

Run separate, properly sized hoses for each pump. The single line theory is good until it gets knocked off or screwed up at the end toward the thru hull. Then all pumps on the line are useless. Redundancy, donchaknow. I put a Rule 360gph automatic at the bottom of my 5'' bilge. 8" higher I put a manually switched 1500 gph. There''s also a whale gusher, each on separate lines. Skip the Rule float switches. They seem to go to crap on a regular basis, even the more expensive "waterproof" ones. The 360 auto I have (I don''t know if they make it any more - they might only have the 500) draws very little amperage and has done so since 1994. The float switch problem I''ve noticed more and more after moving to the Caribbean and replacing switch after switch on friend''s boats. Further, hoses and bilge spooge and spooey can lay across the things and keep them from activating. KW
VIEXILE is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Glassing hull GreenEarth General Discussion (sailing related) 18 06-20-2009 12:52 AM
High Tech vs traditional-Comments? Pangaea General Discussion (sailing related) 38 08-07-2007 02:07 AM
hull construction cgha33 Boat Review and Purchase Forum 4 05-23-2003 08:11 PM
Bilge Pump Discharge - New Thru Hull ??? Terry Clarke General Discussion (sailing related) 4 05-10-2003 06:07 PM
bilge pump DQ halyardz Gear & Maintenance 3 06-04-2002 08:36 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome