Deep Bilge Pump Ideas???

[Idratherbesailing]

I've got a Gulfstar 37 that has a deep, very narrow, and hard to get to bilge area...by deep, I mean from the sole to the bottom is at least 36". The factory installed a Jabsco diaphram type pump, which works ok for small amounts of water, but would be quickly overwhelmed if any serious water came on board... The bilge area is so restricted in access that you can't even mount a small Rule type pump on an extension and get it to the bottom of the bilge...so I need better solutions...anybody got any ideas that worked for them?How have others solved this sort of problem, either on the Gulfstar or other boats with this sort of bilge shape?

 

[Don S/V ILLusion]

what's your ultimate goal?

We have a similar shaped bilge, approx 40 inches deep, on our boat It's not entirely clear if your purpose is to have a dry bilge or to preclude overwhelming the existing one, or both?Assuming you can mount a larger pump higher on the extension, that would serve preventing overwhelming the existing small pump as you stated.It sounds more like you want to remove all residual water to the bottom of the bilge with a centrifugal pump small enough to sit at the bottom. Both Atwood and Jabsco make such pumps but, not knowing the dimensions of your bilge, might not be physically small enough. Shurewood makes some tiny 12V pumps you might also check the dimensions of.

 

[letterman]

need some more info

Mine is as deep on my 37' Irwin, after I took out some of the ballast. It narrows down, but I could still get a pump down there, using two 45 degree bends so as to not use a 90, which would add pressure and reduce the flow. Are you looking for a manual pump or electric?How wide x long is the area?Is the bilge amidships, nearer to the bow, at the bow? Mine goes from the bow to a foot or so past the bulkhead to the main salon. Then it drops several inches and continues about 3 feet where it again rises 17" to the secondary floor. That floor is below the main salon floor by about 17 inches. I have three electric pumps as I sectioned off my bilge into three sections. And I have one hand pump for one section only. I should think a self priming pump with an extension to reach into the deepest part would work. What I use is a 110 wet dry and just vacuum it out once a week. At sea, I use the 12 volt pumps.

 

[sand sailor]

my problem is the opposit ???

i have a very shallow bilge (not enough room for a bilge pump) so i mounted the pump under the sink and ran a pick up tube to the bilge and epoxied the other end in place with a float switch stays dry and uses the same drain as the sink ( no extra thru hull) just make sure the pump can make the draw

 

[Stillraining]

At the risk of

sounding stupid. This does not sound like a bolt on keel but an encapsulated one. Fill it with concrete.. Would not be the first time this has been done.

 

[Stillraining]

Letterman

I thought you had a swing keel like mine?

 

[RAD]

By accident

I found a small livewell pump on ebay and bought it for 20+ dollars and kept it as a spare in case my standard pump took a crap,well last summer it went and I installed the livewell pump which has a long pick up tube and a screen to get all the way into the bottom of the bilge in the keel area,I had thought that it might not have the power to pump a long way(head pressure)but it works like a charm for the little water I get in the bilge,I also have a Edson manual pump with a hose that gets all the way into my bilge and thats what I've always used to dry out the bilge till I found the livewell pumpI have a link for a larger pump that I think I'll replace the little one with cause I'm concerned about the what if I need to pump a lot of water fast

 

[higgs]

Cement

It would seem to me that cement would hold mositure which would not be good for blister prevention. I am not an expert on this, but I would be interested in hearing more on using cement to fill a bilge. I would also be concerned about what the added weight would do the boat's handling characteristics.

 

[sailaway78]

Bilge Sump

I could not imaging filling the sump with concrete. The advantage of a sump is having a deeper smaller area from which to get water out. My S2 has a fairly deep sump behind the keel, where I have a pump mounted. ( See previous post.) The S37 has no such sump. It is a bolt on keel, and the bilge is almost flat. It is virtually impossible to get all the water out unless you use a shop vac, sponge and some elbow grease. Choices are to either let a little bit of water stand in there, or to do the shopvac, sponge thing every time a little water gets in. Which in my case is every time it rains hard. Use the deeper sump for what it is good for, and don't fill it with anything.

 

[Maine Sail]

Stick with a diaphram..

I'd strongly suggest sticking with a diaphragm type pump. With a bilge this deep you don't want a bilge pump down there but rather a hose you can pull out and clear the end of as and if necessary. If you need to, buy a bigger diaphragm pump, then up size the hose and use smooth walled tubing for less "head pressure" or resistance. Diaphragm pumps are expensive but there is a reason the exist!Let's look at this scenario for a moment? You lose your speed log and now have a hole 2” in diameter, the size of most depth or spped transducers. At 3’ below the waterline the flow rate into the boat would be 136.1 gallons per minute or 7,896 gallons per hour!!!! Even if your boat was equipped with three 2,000 gallon per hour bilge pumps, set up and installed perfectly to achieve their rated capacity of 2000gph (WHICH THEY NEVER ARE), your boat would STILL SINK! Now if the same boat was equipped with a bilge alarm, it would be able to warn you of a problem and give them precious time to find and plug the a hole that may have otherwise gone unnoticed until it was too late.If your concerned about large water ingress there is NO bilge pump configuration that will stop it. Wooden plugs secured to every thru-hull and bilge alarms, I have four on my boat, will do far more for saving your boat than a marginally bigger bilge pump. Again of it were me I use a diaphragm pump in that situation hands down...Bilge pump capacity, especially centrifugals, is very misleading and is usually rated at “open flow rate", which means the figures account for NO, NADA, ZERO vertical lift and NO, NADA, ZERO hose friction or discharge outlet restriction! Actual flow rates under real operating conditions are almost always lower since water must be lifted up and out of the bilge and pushed through lengths of hose, elbows or bends to the discharge point. This resistance is called head. You've already stated that without any hose resistance you have a minimum of three feet just to the turn of the bilge!! At a minimum you're looking at 6 -7 feet, of just lift, without any hose loss. I say six to seven feet because you ALWAYS need a high loop to prevent back siphoning! At this point a 2000 gph centrifugal pump is barely putting out 800gph if that!!Because most centrifugal pumps have large internal tolerances to allow passage of small debris, their flow rate decreases dramatically with increased head pressure. Output of a typical small centrifugal "Rule type" bilge pump will diminish by half with just a few feet of head pressure, and will cease entirely at between 13 and 20 feet, depending on the pump. keep in mind that height or lift is NOT the only factor that adds to head pressure and every curve bend or rib in a hose also adds to this "resistance" or "head loss".Diaphragm pumps are much less affected though not entirely immune to head pressure. A 10.8 GPM diaphragm pump, in many installations, will pump as much per hour, if not more, than a 2000 gph "Rule type" pump...

 

[Napa Ed]

Doomsday Scenario

"Let's look at this scenario for a moment? You lose your speed log"wtf?How about when a rabid narwal rams your hull and the protruding tusk takes out the plotter at your nav station. That's why I always carry an assortment of wooden plugs AND a sextant. Nothing worse than sailing above the arctic circle with a pissed off cetacean attached to the hull and no way to tell which way is home. And if you think that's bad, imagine being in that situation with an Atomic 4.

 

[Maine Sail]

Ed..

I used that as an example because I was trying to make a point about a 2" opening and the amount of water it would let in as the OP was concerned about capacity.Beyond that it happened to my next door neighbors on their Island Packet. When they had the boat spring commissioned the yard guy got side tracked and forgot to tighten the speed log so the only thing holding it in was the resistance of the o-rings. It stayed in there for about three hours then it popped out. Bill managed to get the leak stopped with a wooden plug then found the speed log by pulling the wire. The water was above the floor boards and rising fast and the bilge pump could not compete..I've personally had a through hull crack and begin leaking even though it was not attacked by a Narwhal but rather a spare alternator. If it had snapped all the way off, and I could not have plugged it, my bilge pumps would not have kept up for long.Anything can happen on a boat even strange things that involve human error.I don't really get the WTF sentiment. The OP asked a question myself and others have tried to answer it and you contribute "doomsday conspiracies" Narwhal attacks and WTF's...??