Does anyone with a Hunter 25.5 have a bilge pump mounted in the recessed area at the keel? If so where do you have the discharge hose running to? I want to mount my bilge pump in this recess since it is obviously the lowest point in the boat. I am thinking about trying to run the discharge to a thru-hull near the outlet for the vanity sink in the head, as high as possible above the waterline. To do this I will have to drill a hole in the inner liner under the sink to get the hose down into the bilge area. Has anyone done this or know of any problems that I might run into when I do this? Any help or tips would be appreciated. Thanks, Dan
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M
Mic Fry
bilge pump
Dan It does take a little more time but I ran my discharge line back to the transom next to the water tank vent line. (hope we never need them)
Dan It does take a little more time but I ran my discharge line back to the transom next to the water tank vent line. (hope we never need them)
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Dan
How long is your discharge hose?
I am trying to make the discharge hose as short as possible. A long hose on the bilge pump severly reduces the actual pumping capacity. I have a bilge pump thru-hull mounted on the Starboard side near the transom but the hose is too long that way for me. I like to keep the bilge water as low as I possibly can. I have also had another boat that had a hole punched in the bottom when I was blown up on an island during a freak storm. The hole was the size of a quarter. The salvage crew had two 3700 gph electric pumps both with really long hoses so they could be held outside of the boat through the cockpit. Even with both of those pumps running they could not keep up with that hole until it was plugged with a towel. That experience taught me about bilge pumps and what long hoses do to them. I also hope we never need to use the pumps for anything other than to drain the icebox but if I ever do need it I want it pumping as much as possible.
I am trying to make the discharge hose as short as possible. A long hose on the bilge pump severly reduces the actual pumping capacity. I have a bilge pump thru-hull mounted on the Starboard side near the transom but the hose is too long that way for me. I like to keep the bilge water as low as I possibly can. I have also had another boat that had a hole punched in the bottom when I was blown up on an island during a freak storm. The hole was the size of a quarter. The salvage crew had two 3700 gph electric pumps both with really long hoses so they could be held outside of the boat through the cockpit. Even with both of those pumps running they could not keep up with that hole until it was plugged with a towel. That experience taught me about bilge pumps and what long hoses do to them. I also hope we never need to use the pumps for anything other than to drain the icebox but if I ever do need it I want it pumping as much as possible.
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Dan
Maybe under galley stove?
I looked closer at trying to get a hose from the bilge to the sink in the head. I don't think it is possible to get a hose through there. I think I might have a better chance at running the output to a thru-hull behind the galley stove. Has anyone done this or run hose through any of the structural webbing under the floors in the bilge? Thanks, Dan
I looked closer at trying to get a hose from the bilge to the sink in the head. I don't think it is possible to get a hose through there. I think I might have a better chance at running the output to a thru-hull behind the galley stove. Has anyone done this or run hose through any of the structural webbing under the floors in the bilge? Thanks, Dan
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Peggie Hall/Head Mistress
Dan, you have to put an arch in the hose...
that's at least a foot above the waterline at maximum heel. If you don't, you can take on water through the bilge pump when you're heeled far enough to put the thru-hull in the water. A long hose shouldn't have anything to do with how much water a pump can move...only with how long it takes the first "pumpful" to get from the pump to the thru-hull. After that, the flow should be constant. It's not surprising that the salvage crew's pumps had a hard time keeping up with the flow of water through a hole in the boat the size of a quarter...a 3/4" garden hose can put more water in a bilge than 3 BIG bilge pumps can remove.
that's at least a foot above the waterline at maximum heel. If you don't, you can take on water through the bilge pump when you're heeled far enough to put the thru-hull in the water. A long hose shouldn't have anything to do with how much water a pump can move...only with how long it takes the first "pumpful" to get from the pump to the thru-hull. After that, the flow should be constant. It's not surprising that the salvage crew's pumps had a hard time keeping up with the flow of water through a hole in the boat the size of a quarter...a 3/4" garden hose can put more water in a bilge than 3 BIG bilge pumps can remove.
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Dan
Loops
You are right about staying above the waterline. I had planned to use check valves to solve that problem since I would not be able to get a loop high enough. I may have to change my plans again and possibly go through the hanging locker behind the head with a thru-hull next to the fuel tank vent. Either that or I will go to the transom and suffer a loss of pump efficiency with the long discharge hose. You cannot add a long hose to a pump and expect it to pump at the same capacity. The pump's rating is most likely stated with 0 ft of hose and no rise in discharge height. The discharge height affects the rating the most but the length of the discharge hose makes a very large difference in how much water the pump is going to move. A ribbed interior wall on the hose will also reduce the gph of the pump versus a smooth hose. You may want to do a little research on this as it could make a big difference in an emergency situation. I hope that none of us will ever have to use them though. Dan
You are right about staying above the waterline. I had planned to use check valves to solve that problem since I would not be able to get a loop high enough. I may have to change my plans again and possibly go through the hanging locker behind the head with a thru-hull next to the fuel tank vent. Either that or I will go to the transom and suffer a loss of pump efficiency with the long discharge hose. You cannot add a long hose to a pump and expect it to pump at the same capacity. The pump's rating is most likely stated with 0 ft of hose and no rise in discharge height. The discharge height affects the rating the most but the length of the discharge hose makes a very large difference in how much water the pump is going to move. A ribbed interior wall on the hose will also reduce the gph of the pump versus a smooth hose. You may want to do a little research on this as it could make a big difference in an emergency situation. I hope that none of us will ever have to use them though. Dan
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Peggie Hall/Head Mistress
Dan, you have to get an arch in the hose...
Check valves can impede the flow of water more than head (rise). They can also fail...an arch can't. Yes, distance CAN make a difference in the rate of flow...the further liquids have to travel, the more momentum they lose. And yes, corrugated hose offers more resistance than smooth-walled hose. But according to the specs for Jabsco bilge pumps (the only ones I happen to have on hand), the difference in volume between hose 3.4' long and hose 6.5 long is less than 15%. Beyond that, it starts to become much more significant. So up to around 7', the issue becomes, not how long the hose should be, but how big a pump to install and whether to use smooth-walled hose or corrugated...the bigger the pump, and the smoother the surface water has to pass through, the more water it will move over ANY distance. Of course, two pumps are better than one, too...and a 25' boat should have at least two.
Check valves can impede the flow of water more than head (rise). They can also fail...an arch can't. Yes, distance CAN make a difference in the rate of flow...the further liquids have to travel, the more momentum they lose. And yes, corrugated hose offers more resistance than smooth-walled hose. But according to the specs for Jabsco bilge pumps (the only ones I happen to have on hand), the difference in volume between hose 3.4' long and hose 6.5 long is less than 15%. Beyond that, it starts to become much more significant. So up to around 7', the issue becomes, not how long the hose should be, but how big a pump to install and whether to use smooth-walled hose or corrugated...the bigger the pump, and the smoother the surface water has to pass through, the more water it will move over ANY distance. Of course, two pumps are better than one, too...and a 25' boat should have at least two.
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