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Thread: Bilge Pump discharge on Sail and Oar boat

  1. #1
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    Default Bilge Pump discharge on Sail and Oar boat

    My Campion Apple is coming along pretty well, but visible progress has slowed down now that I'm into many of the little details that just take time. I just finished cutting out and setting up the mount for the bilge pump and I'm trying to settle on a discharge location and I'm finding myself in analysis paralysis. The pump is a bulkhead mounted Whale Gusher Compact 50 and I think it will be adequate for clearing the bilges below the floorboards along with a bucket should I have more water than that.
    There are 3 locations I have in mind, but not sure what would be the best choice.
    1. Discharge aft for a stern discharge as high up as practical. The run would be about 8 feet.
    2. Discharge into the daggerboard trunk. Run would be about 4-6 feet depending on whether I plumb it fore or aft of trunk
    3. Discharge directly over close to pump on port side. Short run, but I'm not sure having a through hull amidships would look very good (call me vain, but I don't like nice lines broken up by equipment).

    What would be the best choice?

    Also, in any of these scenarios, it seems to me that a vented loop to prevent backflow might be difficult; is an inline check valve an appropriate alternative, or would that significantly reduce the discharge capacity?

    Thanks in advance, I've had trouble posting photos in the past but I'll try again. If it works, you should be able to see the bilge pump mount location on the forward part of the port seat tank.

  2. #2
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Your Whale gusher pump already has two, count 'me, two check valves in it. I think you could plumb it into the aft end of the trunk with no problem.

  3. #3
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Looks nice.

    Firstly, what sort of pump? Given the centerboard thought, sounds like you're thinking of the ubiquitous pipe pump, like the Thirsty Mate. Good pumps but hard to operate in a flooded boat. (See third point.) I favor diaphram pumps. They readily self-prime, resist clogging, and have great power.

    Secondly, you want it to be serious. Like the Whale Gusher Titan or Whale Gusher 30. If you dump and need to dewater you do not want to be wasting time with a low capacity pump.

    Thirdly, any location will work for a little water but if you're self-rescueing from a capsize, you'll need to work the pump while stretched out in the boat so that the water is taking your weight and your body is not driving the boat down. So figure where you can lie in the boat and reach a pump handle with some effect. Then find the model that fits.

    I love your air tanks and there is no reason you could not fit the pump inside one with a plate and handle outside. You'd need to seal the plate and seal where the intake and outtake go through the tank but that's not real problem. But you'd also need to make a bigger access hatch. Maybe in the open on the fore end of one of those side tanks or tucked in the bulkhead under the sternsheets.

    The Whale pumps have the power that hose runs whether from strum box to pump or from pump to over are no problem. Plumb anyway you want. But unless you drop the board so it's rear end clears the slot, it won't let enough water pass to keep up with the pump.

    G'luck

  4. #4
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Quote Originally Posted by Ian McColgin View Post
    Looks nice.

    Firstly, what sort of pump? Given the centerboard thought, sounds like you're thinking of the ubiquitous pipe pump, like the Thirsty Mate. Good pumps but hard to operate in a flooded boat. (See third point.) I favor diaphram pumps. They readily self-prime, resist clogging, and have great power.

    Secondly, you want it to be serious. Like the Whale Gusher Titan or Whale Gusher 30. If you dump and need to dewater you do not want to be wasting time with a low capacity pump.

    Thirdly, any location will work for a little water but if you're self-rescueing from a capsize, you'll need to work the pump while stretched out in the boat so that the water is taking your weight and your body is not driving the boat down. So figure where you can lie in the boat and reach a pump handle with some effect. Then find the model that fits.
    G'luck
    Thanks Ian, the Whale Compact 50 is a bulkhead mounted diaphragm pump, it's only a 10 gallon/minute capacity, but my intention for this pump is only to clear the bilges under the floorboards which I've calculated to have a total volume of roughly 21 gallons. In the small boats I've capsized, I've always been faster bailing a flooded boat with a bucket than with a pump. The other reason I chose it was the low profile design allowed me to install it out of the way in one of the seat tanks, otherwise I would have had to have done a surface mount pump somewhere and space is at a premium.

    Quote Originally Posted by Ian McColgin View Post

    I love your air tanks and there is no reason you could not fit the pump inside one with a plate and handle outside. You'd need to seal the plate and seal where the intake and outtake go through the tank but that's not real problem. But you'd also need to make a bigger access hatch. Maybe in the open on the fore end of one of those side tanks or tucked in the bulkhead under the sternsheets.

    The Whale pumps have the power that hose runs whether from strum box to pump or from pump to over are no problem. Plumb anyway you want. But unless you drop the board so it's rear end clears the slot, it won't let enough water pass to keep up with the pump.

    G'luck
    I am fitting the pump in the seat tank, the first photo I posted didn't have the actual pump installed (I removed it to get ready for sanding and paint). Below is a shot of the pump installed with plate, I'm planning on sealing the gasket and the intake and discharge when I figure out where the discharge hose will run.

  5. #5
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Quote Originally Posted by phiil View Post
    Your Whale gusher pump already has two, count 'me, two check valves in it. I think you could plumb it into the aft end of the trunk with no problem.
    I don't have the pump in front of me to check, but the manual specifically says: "It is important to ensure that a vented anti-syphon loop is incorporated in the system" I don't think this model has the check valves, but I will verify when I have the pump in front of me.

  6. #6
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    It has one way valves at each end of the pump - inlet and discharge. As you stroke up creating a suction, the discharge valve is closed by the suction while the inlet side opens. Push the lever down and the pressure opens the discharge side and closes the inlet.

    In most mountings where the inlet and outlet are more or less horizontal, those valves will not reliably act as checks when the pump is not in use. If you mount such that the inlet is below and the outlet above - vertical orientation - then standing water in the hose to the strum box will keep the inlet side closed unless and air bubble gets in the strum box, as is likely, and travels up. At that point if water is coming in the outlet side, that valve might close with the water pressure of the inlet side might close if enough water develops in the pump.

    A check valve down by the strum box is a good idea to keep the water in the hose from backing down when you thought you were done pumping. And it could help prevent any back flow from the ocean to your bilge.

    In big boat applications, if the pump is well above watrline, like in a self-bailing cockpit, and if the outlet through-hull is above the water line, the water will drain out from the pump and outlet hose and the biggish hose (1-1/2" to 2") has too much air to ever get a syphon going. Mostly.

    So no matter how you cut it, a vented loop is at the least a good idea and in a small boat like yours a true necessity. Even with the check valve near the strum box.

  7. #7
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Quote Originally Posted by Ian McColgin View Post

    So no matter how you cut it, a vented loop is at the least a good idea and in a small boat like yours a true necessity. Even with the check valve near the strum box.
    That's what I thought, and have done the vented loop on bigger boats in the past when the discharge is near the waterline and potentially under when healing. I wonder though: is a vented loop essential if the discharge is located above the waterline on or close to the centerline where it shouldn't go under for extended periods (either in daggerboard trunk or aft adjacent rudder)? A siphon could only occur in those locations if they were subjected to below waterline conditions and at that point I would be thinking about my trusty bucket anyway? I don't know...

  8. #8
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    I'll be watching to see how you solve this. I've been wondering about mounted bilge pumps in sail and oar boats, as I'd like to install one in my Ilur, especially if others have had good luck with them. I don't think I'd mind going right through the hull say 6 inches or so below the gunwale, and about half way between the pump and the transom for fore n aft location.

    Very nice looking build. Thanks for posting.

    Mike
    "near it, a small whale-boat, painted red and blue, the delight of the king's old age."

  9. #9
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    In a small boat like this I think a permanently mounted pump is more trouble than it is worth. Nothing moves water faster than a scared sailor with a bucket. Check valves eventually stick, either open or closed. Not a good place to bet the farm. A one gallon bucket does it for me! It also has several other uses.
    Dave

  10. #10
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Dave is correct. Here, I will add that a shallow round galvanized steel scoop called a "Luninberg Dory Bailer" is a better choice than a bucket. it can be used faster than a bucket and is less apt to scar the wood since it is used with a single swing such as operating a cricket bat. If a Whale Gusher pump is to be, permanently, on board, I prefer not to have through hulls in a small boat. I like to have a corrigated discharge hose that can be laid over the rail. If this is a rowing boat then the whale pump is a good, but expensive choice and should be able to be operated from the rowing thwart by the rower or a passenger in the stern sheets. A wood and leather dory bailer can also be easily be made in the home shop and is fun to make as well as being guaranteed not to scar the floor boards.

    https://smallboatsmonthly.com/articl...-scoop-bailer/ Oiled Latigo Red leather is available from Tandy.
    Jay

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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Quote Originally Posted by galleywench View Post
    That's what I thought, and have done the vented loop on bigger boats in the past when the discharge is near the waterline and potentially under when healing. I wonder though: is a vented loop essential if the discharge is located above the waterline on or close to the centerline where it shouldn't go under for extended periods (either in daggerboard trunk or aft adjacent rudder)? A siphon could only occur in those locations if they were subjected to below waterline conditions and at that point I would be thinking about my trusty bucket anyway? I don't know...
    I don't know about smallish boats, but I've seen 3 sailingboats sinkinking on their mooring (one of them an 18 m schooner) only because the wind picked up more than expected, the boats were heeling over more than was normal in the gusts, some water siphoned in, and, with the increasing weight inside the ship, at one point the outlet was not any more above water although the wind had gone down by now. One of these boats even had a vented loop, but it was blocked with debris. If you ever think of leaving your boat in the water without being there yourself, install a vented loop!

  12. #12
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Our boat came with a manual Whale pump installed. It empties through a fitting in the port topsides. It's annoying to use(the handle being down low), won't completely empty the bilge and is in the way underfoot. A portable hand pump with long hose, bailer and sponge is what I use instead. I can get to every bay where water has collected rather than waiting for water to flow through limber holes to the installed pump's strum box.

    I've also installed (in other boats) the type you show a photo of and they are pretty much a pain to use for any length of time. The stroke length of the pumping action is short. MOO and YMMV of course.
    "... and the great shroud of the sea rolled on as it rolled five thousand years ago."

  13. #13
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Good points; all well worth mulling over. I may not have said it earlier, but this is not the pump I will be using if I really need to evacuate water fast. This is mainly a means of clearing the bilge under screwed down floor boards which will amount to ~21 gallons total. I did put some thought into the pump location and it will be accessible both while sailing or rowing. I certainly plan on having a separate bailer/bucket on board at all times; my re-purposed clorox bottle with the bottom cut out has made short work removing a lot of water, but I do like all things 'shippy' and will have to read that Ben Fuller article. Looks like a fun project.

    Jay, I really like the idea of a temporary setup where the discharge can be laid over the side or into the daggerboard trunk and then stowed when not needed. I had never considered that as an option but I'm no fan of putting holes in boats that aren't really needed, so this might be a good plan. I might try this method for the first season to see how it works and evaluate from there.

    I have plenty of bigger things to worry about with the build before I can think about bailing it out so I may run the lines with no thru-hull to start.

    -matt

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    Default Re: Bilge Pump discharge on Sail and Oar boat

    That gives you the advantage of putting the discharge over the lee side too!
    Jay

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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Pump it out the trunk. Like you said, you won't be using it underway. It's just for below floorboard rainwater. Here's what I did on my Hvalsoe 18.





    I looked for a photo in which the floorboards are installed and you can see how the pickup draws water through a hole drilled in the floorboards, but I haven't found that photo.

    You could also skip the whole thing by installing a removable port in the floorboards that allows enough room to use a sponge, especially since the pump you're describing sounds like a wee thing.
    Last edited by Yeadon; 07-14-2017 at 03:49 PM.
    Quote Originally Posted by James McMullen View Post
    Yeadon is right, of course.

  16. #16
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Nice set up!
    Jay

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    Default Re: Bilge Pump discharge on Sail and Oar boat

    I like the discharge into the centreboard slot. No ugly through hulls marring your topsides, and no spray back at you if pumping while sailing with a through hull on the windward side.

  18. #18
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    It would be easy enough to fit a ball valve somewhere near the pump. Much more reliable than a vented loop or a non return valve.

    My sea kayak has a small electric pump and a tiny battery. Seems to me for capsize recovery this would be worth its weight in gold on an open boat.

    Sent from my SM-G930F using Tapatalk

  19. #19
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    I like the CB discharge myself but you need to be sure of the fit. If you have a 1-12" discharge and if you have a very loose fit with a total of 1/8" space (counting both sides) between board and trunk walls and the board is down but not fully clear of the slot, then you need a minimum of 14" fore and aft into the trunk above the lowered board. Of course, it's nigh on to useless if the board is up.

  20. #20
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    I disagree with Snow Pea [#18]. Ball valves only work if both upright and clean. In an inverted boat, a ball valve is just a hole in the boat. And ball valves manage to trap more debris than flappers.

    I am more familiar with larger installations as ball valves are all too common in sailboat cockpit drains. Those are pretty near worthless, especially when draining a really full cockpit, like after a pooping wave where the weight of water overcomes the ball's buoyancy.

  21. #21
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    ^^ hey Ian, I am talking about a seacock type ball valve, not a non return ball valve. To ise the pump open the ball valve first. Of course the best option is to place the outlet well above the heeled or trimed waterline so backflooding is impossible, but if it's a possibility a closed ball valve is often the simplest way.

    Sent from my SM-G930F using Tapatalk

  22. #22
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Quote Originally Posted by Yeadon View Post
    Pump it out the trunk. Like you said, you won't be using it underway. It's just for below floorboard rainwater. Here's what I did on my Hvalsoe 18.





    I looked for a photo in which the floorboards are installed and you can see how the pickup draws water through a hole drilled in the floorboards, but I haven't found that photo.

    You could also skip the whole thing by installing a removable port in the floorboards that allows enough room to use a sponge, especially since the pump you're describing sounds like a wee thing.
    That is slick! i really like that setup, i think i have pump envy...

  23. #23
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    This arrangement works nicely if you have place for it. In the front of the centerboard case of my D18 Myst.


  24. #24
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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Thank you for the clarification Snow Pea. You are quite right.

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    Default Re: Bilge Pump discharge on Sail and Oar boat

    Quote Originally Posted by dktyson View Post
    This arrangement works nicely if you have place for it. In the front of the centerboard case of my D18 Myst.

    We have a winner.

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