Where to Put Through Hull or Other Alternatives

[rsn48]

Older Catalina 27's don't come with bilge pumps. After entering my boat in the fall and discovering it had 14 inches of water throughout and emptying it, I resolved to add a bilge pump (electric). A chap is installing one for me and is convinced I should have a through the hull, with check valve in the system, above the water line, substantially above it, for the bilge to drain. I keep thinking about a radical heel with water line up to the bottom of the stantions, with the water lapping at this through the hull.

The Catalina 27 is a 75, old dinette style - dinette amidships. Any suggestions where the through the hull can be? Or any comments would be helpful.

[Alan Wheeler]

I'm not quite understanding your line "for the bilge to drai", but.... There are two ways of doing this. Install a non-return valve. These work OK and seldom cause issues. Especially if you have a clean bilge, then the chance of dibree getting into the valve is remote. They are built such that they can take a lot of rubish through them anyway. still, there are one or two that a uneasy using them in case the unit does stick open and allow water to syphon back.
The other way is, you would normally install the hoseing to such an outlet the same way as you would for say a toilet, in that yu have a loop where the hose loops up even higher than the water level will ever get on a heel. An anti-syphon break is installed at the top of the loop. a non return valve can also be fitted to the hose at the pump so as every last bit of water is held in the hose and doesn't run back into the bilge.

You could always pipe a through hull into the cockpit, and use the cockpit drains.

[GordMay]

Bilge Pump Discharges should be located above the maximum heeled waterline, most often near the stern quarter.

A vented loop can be utilized to prevent back-siphoning, but NEVER a check valve.

Pump discharges should be as non-restrictive as possible, which includes:
- Shortest possible length of discharge hose
- Largest possible diameter of discharge hose
- Smooth bore hose
- As few bends as possible
- Largest radius bends as possible

See also:

Manifolding Multiple Bilge Pump Discharges
http://www.cruisersforum.com/forums/...ead.php?t=3817

All About Bilge Pumps ~ by David Pascoe
http://www.yachtsurvey.com/bilge_pumps.htm

Bilgewater Blues ~ by David Pascoe
http://www.docksidereports.com/bilge_water_blues.htm

20 Electric Bilge Pumps Tested (Powerboat Reports/Practical Sailor):
http://www.powerboat-reports.com/sample/bilge.html

Choosing and Installing Bilge Pumps:
http://seagrant.uaf.edu/bookstore/bo...ilge-pumps.pdf

Hysteresis in Your Bilge? ~ by Robert J. Scott
http://www.practical-sailor.com/news...hysteresis.pdf

OYRA - Minimum Offshore Requirements:
http://www.yra.org/charter-associati...nequipment.pdf

Bilge Pumps:First and Last Lines of Defense ~ by Tom Wood
http://www.sailnet.com/collections/c...at=Equipment&C

Installing a Bilge Pump ~ by Don Casey
http://www.boatus.com/boattech/casey/14.htm

[Sunspot Baby]

Wow Gord: What a great list of resources.

I assume Kai Nui is smiling when he suggests running it into the cockpit. I really don't want bilge water on the shiney top side.

Sunspot Baby

[GordMay]

No - I doubt that KAI NUI was kidding - many people drain their bilges to the cockpit, thence out through the scuppers (an indirect drain).
I don’t normally recommend the practice, but it does provide:
- an excellent visual bilge monitoring technique
- eliminates the necessity of another through-hull
- eliminates the likelihood of back-siphoning

BTW: a well maintained bilge isn’t dirty.

[Sunspot Baby]

Unfortunately, in rough conditions some water from my shower sump ends up in the bilge. A recent rupture in an engine oil container drained into the bilge. In fact, any accidental liquid spill ends up in the bilge, something about liquids running down hill.

Among the things I don’t want is that stray 10W40 or soapy water under my feet in the cockpit when I’m busy in boisterous conditions, which is when things tend to go awry.

I agree a well maintained bilge is not dirty, but as the bumper sticker says s**t happens.

I guess anything has plusses and minuses.

Sunspot Baby

[rsn48]

I read the resources you have listed above Gordon: and I also plowed into Casey's Old Boat book. I have decided to take the advice of one your links posted and have multiple pumps. The old Catalina 27 boat with the dinette amidships is really fragmented when it comes to compartments. I have a few electrical panels, switches, etc fairly low in the boat and I know they won't respond well to intrusive water. I have decided to put a pump in every compartment where my electrical items are, plus one in my shallow bilge. This means a total of four pumps (which one of the link authors recommended (a pump for each separate compartment).

This might sound like over kill, but I liked the advice other than worrying about hull and deck integrity, the bilge pump issue and boats flooding should be addressed next over rigging, electronics, etc. This only makes sense. The smaller Rule bilge motors with incorporated floats are cheap, cheaper than replacing some of my electrical panels.

I filled in the transom mount area found on older Catalina 27's. So I have an enclosed transom compartment which houses my gas and propane on platforms. I am going to pump the water into this area which has a through hull drain - which I enlarged over the old small ridiculous hole provided by Catalina which was guaranteed to plug quickly.

The chart recommends 3 pumps for a 27 foot boat, I will be using four.

Here's the link you provided that I think is the best of the lot:

http://www.yachtsurvey.com/bilge_pumps.htm

Gord is correct, I wasn't kidding. True, crud can get into the bilge, and it is certainly not ideal to have that crud in the cockpit, but anything can be cleaned up, and a couple of spurts of oil in the cockpit, and the pump can be shut off untill the problem is handled. The transome is my first choice, but I would certainly consider the cockpit as a viable option.

[rsn48]

On older Catalina's the cockpit drained into the transon storage area. I had this modified so that now the cockpit has its own independent drainage system and through hull in the transom. I now have two through hull drainage spigots (or whatever their called) in the transom. Now virtually now water gets in the storage bin so I think pumping water into it will work.

[S/V Elusive]

It isn't just enough to have an anti-siphon loop - you should also have the anti-siphon fitting at the top of the loop. I thought that I had posted my little story of my bilge pump sucking water back in even though there was a very good anti-siphon loop in it. Apparently there was enough of a head that when the pump shut off, it created enough suction to get flow started.

[Brent Swain]

I just decided to use a different colour of antifouling around my thru hulls to make them easier to find while holding my breath underwater to clear them.Should have figured that out years ago.
Brent

[GordMay]

Originally Posted by Louis Riel

I just decided to use a different colour of antifouling around my thru hulls to make them easier to find while holding my breath underwater to clear them.Should have figured that out years ago.
Brent

Good idea, Brent! Funny how some of the simplest "tricks" can be so effective.
All through-hulls should be "mapped" on a plumbing diagram - but, even when you know where they are, they can be be difficult to find in the shorter time available to a free diver.

[sea yawl]

GordMay,
Back in 2006 you posted links on the topic of bilge pumps. Now 6 years later I am reading through those links. All are very helpful to my bilge pump education, but one has a serious problem:

Hysteresis in Your Bilge? ~ by Robert J. Scott
http://www.practical-sailor.com/news...hysteresis.pdf

The ideas are good but Figure 4 describes a circuit that will not create hysteresis. Instead the pump will operate when switch B is closed, and will not operate when switch B is open. No hysteresis will be created.

To make the circuit create hysteresis,

• the wire connecting the relay contact to the Bilge Pump must be disconnected at the bilge pump, and reconnected to the wire that connects switch B to switch A.
• this will put the relay contact in parallel with switch B.

Connected this way, the relay contact will continue to power the relay, even after switch B opens. When switch A opens, the relay will be depowered, the relay contact will open, and the Bilge Pump will turn off.


Jim Lavery
Hoku Ke'a
Southern Cross 31