I have an 81 Hunter 25. It has no bilge pump and I can not see where one has ever been installed. Where is the best place to place one and how do you route the hose from the pump to the outside?
Bilge Pump
- Thread starter nctxia
- Start date
H25 bilge-pump ideas
I replaced the cabin sole in my H25, making it slightly higher, so a proper Rule 1000-GPH series-20 pump fits standing up, right under the ladder. You may, or will, not have this luxury (I have only 4'11-1/2" headroom for my 'luxury').
I also have a manual Whale Gusher 10, mounted up in the cockpit coaming (plenty of room there, and it forms the highest part, so I don't need a vented loop for it), drawing from a Whale strainer dropped into the bilge right over the keel bolts. Neither of these pumps picks up everything; but they do a pretty good job. The electric one left on automatic gets most of it (what little there is at this point) and the one in the 'deeper' section ('deeper' as in by about 3/4") over the keel bolts will get all but about 5/8" of the rest, which then has to be sponged out.
The PO had a Bosworth Gulper 'installed' (this is being kind) under the starboard settee with a mighty big hole cut into the bunk front to lead a 1-1/2" hose, in plain view, into another big hole in the cockpit sole. Just-- no. Fortunately he had let the cabin sole rot to nothing so this whole arrangement is gone for good. I led two 1" hoses aft through limber holes in my new sole joists, going into the athwartships galley locker (beside the step) and then to PVC to make two right-angle turns up into the under-cockpit-seat area.
Originally I installed the manual pump in the face of the cockpit pan, at the aft end of the seat. It worked fine there but caused a problem for those many times I have had to go down that narrow trapezoidal hatch to attend to something. So I removed it, faired over all the holes, and will reinstall it up in the cockpit coaming, forward of the seat-locker lid and just aft of where the traveler goes (this is custom on my boat; see blog). This is a good location which I recommend to anyone because it enables you to man the manual-pump handle whilst sailing singlehanded, should you be taking on storm water or something worse. Gotta think about who's going to have to do this and how it'll have to be done, and most importantly under which worse-case-scenario conditions it's most likely going to need to be done.
I worked on a 1984 H25.5 that had no bilge pump either. I really consider this unconscionable.
In general, work backwards from the discharge line's highest place, which will need a vented loop, locate the pump where it can best be used and maintained, and then extend the hose into the bilge by the shortest way, with the fairest curves, as inconspicuously as you can do it. Remember that no bilge pump ever gets it bone-dry; your main goal in having one is to dewater the boat in the event of some problem. You'll never be done with the sponge (and in this boat, it's vital to keep it dry as there's nowhere for it to slosh except onto the cabin sole).
There is great logic in installing the through-hulls as high as possible in the hull, typically in the side just forward of the transom because it will pour well from there. I led mine out the transom itself, about 2/3 up from the waterline. They are Marelon, fitted with 90-degree elbows immediately inside, with the hoses leading up the inside of the transom to the rail and then forward. When the pumps run the water sort of splashes down into the elbow and comes out in a funny pattern. But despite all the elbows they both work well.
DO NOT use nylon through-hulls for bilge-pump outlets (nor for anything else in the hull). I prefer Marelon for under the water and, these days, stainless-steel ones above. I meant to remove my getting-chalky Marelon ones from the transom and replace them with stainless-steel ones (the Groco are the best), but Jerry and I just painted them over and they look pretty good. Marelon, even just nominally prepped, takes epoxy paint very well.
BTW I also installed a bronze drainplug in the bottom, right in front of the electric bilge pump under the ladder, where the freshwater system's manifold is including its dump valve. Some of the photos on my blog show the cool little G10 fairing/backing block I made for it. (Remember that bronze is the only thing a hull drain should ever be made of-- avoid brass and stainless like they can sink your boat, because they can.) I installed the plug fitting 'upside-down', meaning with the plug accessible from inside. I don't want to think about that plug vibrating loose-- downwards-- from outside when I have no way of putting a wrench on it nor even examining it before it falls out of the boat. Maybe this is under the category of 'worst-case-scenario', but, remember, as I so often say:
If you plan for the best, it'll never happen. If you plan for the worst, it'll never happen.
:dance:
I replaced the cabin sole in my H25, making it slightly higher, so a proper Rule 1000-GPH series-20 pump fits standing up, right under the ladder. You may, or will, not have this luxury (I have only 4'11-1/2" headroom for my 'luxury').
I also have a manual Whale Gusher 10, mounted up in the cockpit coaming (plenty of room there, and it forms the highest part, so I don't need a vented loop for it), drawing from a Whale strainer dropped into the bilge right over the keel bolts. Neither of these pumps picks up everything; but they do a pretty good job. The electric one left on automatic gets most of it (what little there is at this point) and the one in the 'deeper' section ('deeper' as in by about 3/4") over the keel bolts will get all but about 5/8" of the rest, which then has to be sponged out.
The PO had a Bosworth Gulper 'installed' (this is being kind) under the starboard settee with a mighty big hole cut into the bunk front to lead a 1-1/2" hose, in plain view, into another big hole in the cockpit sole. Just-- no. Fortunately he had let the cabin sole rot to nothing so this whole arrangement is gone for good. I led two 1" hoses aft through limber holes in my new sole joists, going into the athwartships galley locker (beside the step) and then to PVC to make two right-angle turns up into the under-cockpit-seat area.
Originally I installed the manual pump in the face of the cockpit pan, at the aft end of the seat. It worked fine there but caused a problem for those many times I have had to go down that narrow trapezoidal hatch to attend to something. So I removed it, faired over all the holes, and will reinstall it up in the cockpit coaming, forward of the seat-locker lid and just aft of where the traveler goes (this is custom on my boat; see blog). This is a good location which I recommend to anyone because it enables you to man the manual-pump handle whilst sailing singlehanded, should you be taking on storm water or something worse. Gotta think about who's going to have to do this and how it'll have to be done, and most importantly under which worse-case-scenario conditions it's most likely going to need to be done.
I worked on a 1984 H25.5 that had no bilge pump either. I really consider this unconscionable.
In general, work backwards from the discharge line's highest place, which will need a vented loop, locate the pump where it can best be used and maintained, and then extend the hose into the bilge by the shortest way, with the fairest curves, as inconspicuously as you can do it. Remember that no bilge pump ever gets it bone-dry; your main goal in having one is to dewater the boat in the event of some problem. You'll never be done with the sponge (and in this boat, it's vital to keep it dry as there's nowhere for it to slosh except onto the cabin sole).
There is great logic in installing the through-hulls as high as possible in the hull, typically in the side just forward of the transom because it will pour well from there. I led mine out the transom itself, about 2/3 up from the waterline. They are Marelon, fitted with 90-degree elbows immediately inside, with the hoses leading up the inside of the transom to the rail and then forward. When the pumps run the water sort of splashes down into the elbow and comes out in a funny pattern. But despite all the elbows they both work well.
DO NOT use nylon through-hulls for bilge-pump outlets (nor for anything else in the hull). I prefer Marelon for under the water and, these days, stainless-steel ones above. I meant to remove my getting-chalky Marelon ones from the transom and replace them with stainless-steel ones (the Groco are the best), but Jerry and I just painted them over and they look pretty good. Marelon, even just nominally prepped, takes epoxy paint very well.
BTW I also installed a bronze drainplug in the bottom, right in front of the electric bilge pump under the ladder, where the freshwater system's manifold is including its dump valve. Some of the photos on my blog show the cool little G10 fairing/backing block I made for it. (Remember that bronze is the only thing a hull drain should ever be made of-- avoid brass and stainless like they can sink your boat, because they can.) I installed the plug fitting 'upside-down', meaning with the plug accessible from inside. I don't want to think about that plug vibrating loose-- downwards-- from outside when I have no way of putting a wrench on it nor even examining it before it falls out of the boat. Maybe this is under the category of 'worst-case-scenario', but, remember, as I so often say:
If you plan for the best, it'll never happen. If you plan for the worst, it'll never happen.
:dance:
Thank you very much for your answer. I had not thought of putting the pump under the ladder. I was thinking of installing the thru-hull on the side of the boat like the sink drain is installed. Does anyone see a problem with doing that?
Through-hulls for bilge pumps are best installed high up on the side of the hull (ideally right below the toe rail), so that they are clear of the water, even when heeled. Reasons: you don't want water coming from the outside-in, and you want to be able to see/hear when the bilge pump is discharging. Also makes installing/serving the through-hull possible while afloat.
NCTXia's question
Re: I was thinking of installing the thru-hull on the side of the boat like the sink drain is installed. Does anyone see a problem with doing that?
1. What Jim said.
2. I removed the through-hull for the galley-sink drain and installed a new one, with seacock (Marelon) in the athwartships locker beside the locker. The bilge-pump hoses pass through here on their way to the transom and I keep the scrubbrushes and other junk here-- but only that much. The lever for the seacock needs to be immediately accessible. My rule is 10 seconds-- from when you know there's a leak to turning the seacock lever over. Let nothing stand in your way.
The old system had no seacock (though by rights it should have had; it was still too low) but it was ugly. I really did a job on the hull trying to 'glass and fair that over. On a good day you can still see a very slight flat in the fairing; but, oh well.
What Jim says about bilge-pump outlets is correct, with the added benefit that, mounted high up in the hull (such as on the transom like mine are), they don't need seacocks. This is more relevant to bronze seacocks than to Marelon ones, which are immune to metallugic corrosion; but the theory is that any metal valves under the waterline (those always wet) can be prone to corrosion fatigue and thus to causing a leak. So, what happens with the bilge pump's outlet is the one causing the leak? You're S.O.L. Even worse, what happens when the boat is so low in the water from the leaking, or necessarily heeled over (hard-pressed to get home fast) and still leaking, that the bilge-pump's outlet has to be now underwater? Again, even more S.O.L.
So your best plan from the start is to make sure the bilge pump hoses are always fresh and clean (replaced regularly), double-clamped, routed smoothly, not prone to airlocks or back-flow siphoning, and never likely to be the source of a leak which would inhibit you from using the pump to pump out its own mess. This means Shields or Trident thick-wall sanitation hose, Marelon through-hulls bonded in with 5200, and a very high exit point that will not find itself underwater till you find yourself underwater first.
To avoid dribbles down the hull you can fashion a thin piece of plastic sheet into a spigot or lip for the through-hull, bent around and sticking out maybe 3/8" beyond the rim of the through-hull's flange. This will help most of the gunky water to fall straight down into the sea rather than to course down the side of your (used-to-be-clean) hull. On smaller-sized through-hulls (and for a bilge pump 1" is absolutely the smallest you should ever use) you might consider stepping up the size a little to accommodate the spigot. This will require adapting maybe the last 4" of hose with something like a 1"-to-1-1/8" adapter. Keeping the adapter mounted very high up (such as immediately inside the through-hull, under the deck) negates most of the worry for the vulnerability for the connection; but it doesn't excuse you from double-clamping it (so now you're using 6 clamps instead of 2), which is a hassle unless you care that much about the finish of your topsides.
As I said before, mine have 90-degree elbows that cause a splash; very little actually dribbles till the very end of the pump cycle (which I guess is the very worst part of it. Oh, well).
Remember what I said about vented loops too!
* * *
Re: I was thinking of installing the thru-hull on the side of the boat like the sink drain is installed. Does anyone see a problem with doing that?
1. What Jim said.
2. I removed the through-hull for the galley-sink drain and installed a new one, with seacock (Marelon) in the athwartships locker beside the locker. The bilge-pump hoses pass through here on their way to the transom and I keep the scrubbrushes and other junk here-- but only that much. The lever for the seacock needs to be immediately accessible. My rule is 10 seconds-- from when you know there's a leak to turning the seacock lever over. Let nothing stand in your way.
The old system had no seacock (though by rights it should have had; it was still too low) but it was ugly. I really did a job on the hull trying to 'glass and fair that over. On a good day you can still see a very slight flat in the fairing; but, oh well.
What Jim says about bilge-pump outlets is correct, with the added benefit that, mounted high up in the hull (such as on the transom like mine are), they don't need seacocks. This is more relevant to bronze seacocks than to Marelon ones, which are immune to metallugic corrosion; but the theory is that any metal valves under the waterline (those always wet) can be prone to corrosion fatigue and thus to causing a leak. So, what happens with the bilge pump's outlet is the one causing the leak? You're S.O.L. Even worse, what happens when the boat is so low in the water from the leaking, or necessarily heeled over (hard-pressed to get home fast) and still leaking, that the bilge-pump's outlet has to be now underwater? Again, even more S.O.L.
So your best plan from the start is to make sure the bilge pump hoses are always fresh and clean (replaced regularly), double-clamped, routed smoothly, not prone to airlocks or back-flow siphoning, and never likely to be the source of a leak which would inhibit you from using the pump to pump out its own mess. This means Shields or Trident thick-wall sanitation hose, Marelon through-hulls bonded in with 5200, and a very high exit point that will not find itself underwater till you find yourself underwater first.
To avoid dribbles down the hull you can fashion a thin piece of plastic sheet into a spigot or lip for the through-hull, bent around and sticking out maybe 3/8" beyond the rim of the through-hull's flange. This will help most of the gunky water to fall straight down into the sea rather than to course down the side of your (used-to-be-clean) hull. On smaller-sized through-hulls (and for a bilge pump 1" is absolutely the smallest you should ever use) you might consider stepping up the size a little to accommodate the spigot. This will require adapting maybe the last 4" of hose with something like a 1"-to-1-1/8" adapter. Keeping the adapter mounted very high up (such as immediately inside the through-hull, under the deck) negates most of the worry for the vulnerability for the connection; but it doesn't excuse you from double-clamping it (so now you're using 6 clamps instead of 2), which is a hassle unless you care that much about the finish of your topsides.
As I said before, mine have 90-degree elbows that cause a splash; very little actually dribbles till the very end of the pump cycle (which I guess is the very worst part of it. Oh, well).
Remember what I said about vented loops too!
* * *
You want the output hose to be as short and direct as possible. The PO of my boat ran the 1 1/2" hose all the way to the transom, and out held maybe two gallons of water. When the pump stopped running, all that water ran back to the bilge which was enough to restart the pump. It ended up pumping the same two gallons of water back and forth forever. I mounted a second small pump with a short 3/4" hose, only holds a few ounces of water, and now the big pump never comes on.
What Capt JGW said
The merit of short bilge-pump hoses cannot be overemphasized. Arguments can be made that smooth-walled hose helps flow measurably; the most important thing to me is sturdiness and durability, which the white sanitation hose excels at.
I neglected to mention in my (verbose) post(s) that I have check-valves in both (electric and manual) pump lines. This is to prevent the mess that Capt JGW refers to. One solution that works is to have the vented loop as far forward as possible, so that the run from there to the exit, like in the transom, will be all downhill-- so that, when the pump stops because it's found insufficient water for the float switch, everything past the vented loop will flow out.
This still leaves the volume of water from the pump itself to the vented loop. The check valve, mounted as close as possible to the pump/strainer, will hold this volume from flowing back into the bilge. On Diana (H25) the check valves are in the athwartships galley locker, about 2 ft of hose from the electric and about 5-6 feet from the manual. They typically hold back a 'head' of water about 3 ft high and maybe 18" long, between the check valves and the vented loops.
It's vital that you do have vented loops and that they be as high as possible (make sure you can inspect and replace the diaphragms). Getting pooped by a following wave (some people report this when under power too) the bilge-pump through-hulls can become inundated and siphon back, past the pumps, into the bilge = not good.
One problem with this system is that this 'head' of water becomes stagnant and, with enough dirt, can eventually contaminate the check-valve seals and make them leak. So it's important to run some (environmentally-responsible) cleaner through the pumps regularly (maybe once or twice a season). But given good use (such as by having a shower that drains into the bilge) they should serve very well for a long time.
The other problem is that when you do have to change out the check valves, disconnecting the hose will release this stinky stagant water into your hands. (Stinky stagnant water is covered in Welcome to Boat Ownership 101.)
To simplify, your bilge pump schematic should look like:
1. Manual pump
2. Electric pump
In both cases hose runs should be led fore-and-aft, not sideways, as much as possible. At least the connections at the through-hull and the vented loop should be double-clamped; once you are forward of the vented loop the rest is not going to flood with seawater (but can still hinder you if a hose falls off and the pump will be recirculating, rather than vacating, the bilge).
Yes; this looks complex. No; you are not better off with just a 36" manual piston Beckson gulper pump for any boat over about 19 ft. :naughty:
The merit of short bilge-pump hoses cannot be overemphasized. Arguments can be made that smooth-walled hose helps flow measurably; the most important thing to me is sturdiness and durability, which the white sanitation hose excels at.
I neglected to mention in my (verbose) post(s) that I have check-valves in both (electric and manual) pump lines. This is to prevent the mess that Capt JGW refers to. One solution that works is to have the vented loop as far forward as possible, so that the run from there to the exit, like in the transom, will be all downhill-- so that, when the pump stops because it's found insufficient water for the float switch, everything past the vented loop will flow out.
This still leaves the volume of water from the pump itself to the vented loop. The check valve, mounted as close as possible to the pump/strainer, will hold this volume from flowing back into the bilge. On Diana (H25) the check valves are in the athwartships galley locker, about 2 ft of hose from the electric and about 5-6 feet from the manual. They typically hold back a 'head' of water about 3 ft high and maybe 18" long, between the check valves and the vented loops.
It's vital that you do have vented loops and that they be as high as possible (make sure you can inspect and replace the diaphragms). Getting pooped by a following wave (some people report this when under power too) the bilge-pump through-hulls can become inundated and siphon back, past the pumps, into the bilge = not good.
One problem with this system is that this 'head' of water becomes stagnant and, with enough dirt, can eventually contaminate the check-valve seals and make them leak. So it's important to run some (environmentally-responsible) cleaner through the pumps regularly (maybe once or twice a season). But given good use (such as by having a shower that drains into the bilge) they should serve very well for a long time.
The other problem is that when you do have to change out the check valves, disconnecting the hose will release this stinky stagant water into your hands. (Stinky stagnant water is covered in Welcome to Boat Ownership 101.)
To simplify, your bilge pump schematic should look like:
1. Manual pump
- pump strainer/pickup -- as low as possible in bilge;
- lift/suction hose -- as short as possible;
- check valve -- in this hose, as close to strainer as possible;
- pump -- as high as possible;
- vented loop -- ditto (ideal: same elevation as pump);
- drainage hose -- to lead aft and downwards for its whole run, no kinks or elbows if possible;
- through-hull fitting -- as high as possible; if below rail area of boat to be fitted with seacock.
2. Electric pump
- pump/strainer -- as low as possible in bilge;
- lift hose -- as short as possible;
- check valve -- in this hose, as close to pump as possible;
- vented loop -- as high as possible;
- drainage hose -- to lead aft and downwards for its whole run, no kinks or elbows if possible;
- through-hull fitting -- as high as possible; if below rail area of boat to be fitted with seacock.
In both cases hose runs should be led fore-and-aft, not sideways, as much as possible. At least the connections at the through-hull and the vented loop should be double-clamped; once you are forward of the vented loop the rest is not going to flood with seawater (but can still hinder you if a hose falls off and the pump will be recirculating, rather than vacating, the bilge).
Yes; this looks complex. No; you are not better off with just a 36" manual piston Beckson gulper pump for any boat over about 19 ft. :naughty:
Caveat on the bilge-pump check valve
I just read this in the SailNet boards:
http://www.sailnet.com/forums/gear-maintenance/93937-bilge-pump-non-return-valve.html
Basically the matter is that small, low-powered bilge pumps (like West Marine's, and cheaper Rule ones) can't handle the weight of water standing atop the check valve. The valves just do not open and the pump won't push against it. My comments referred primarily to the bigger Rule 2000s we used at Cherubini.
I have not run my electric pump as-is with any significant head of water atop the check valve and so have not observed the problem. I would advise, then, that the check valve be situated in a high part of the loop, to allow all water beyond it to flow out. In this way the check valve will stop backflow from the sea; but it will not help to keep the pump from recycling over and over.
One recourse for this is to mount the pickup of the pump high enough that the water between the check valve and the hose always stands in the bilge and doesn't trigger the pump-- which means you'll have to bail it out and that kind of negates the whole idea. Another recourse is to buy more powerful bilge pumps, which, aside from the cost, can never be a bad thing.
I'll experiment more with this and will welcome news of others' experiences as well.
I just read this in the SailNet boards:
http://www.sailnet.com/forums/gear-maintenance/93937-bilge-pump-non-return-valve.html
Basically the matter is that small, low-powered bilge pumps (like West Marine's, and cheaper Rule ones) can't handle the weight of water standing atop the check valve. The valves just do not open and the pump won't push against it. My comments referred primarily to the bigger Rule 2000s we used at Cherubini.
I have not run my electric pump as-is with any significant head of water atop the check valve and so have not observed the problem. I would advise, then, that the check valve be situated in a high part of the loop, to allow all water beyond it to flow out. In this way the check valve will stop backflow from the sea; but it will not help to keep the pump from recycling over and over.
One recourse for this is to mount the pickup of the pump high enough that the water between the check valve and the hose always stands in the bilge and doesn't trigger the pump-- which means you'll have to bail it out and that kind of negates the whole idea. Another recourse is to buy more powerful bilge pumps, which, aside from the cost, can never be a bad thing.
I'll experiment more with this and will welcome news of others' experiences as well.
I don't like check valves on bilge pumps because they restricted water flow. When you really need the pump, you want it to flow as much water as possible. On my boat there's not a good place to put a loop, so I went with the smaller pump with it's hose routed up under the galley counter and out amidships at the gunwhale. I made a pedestal about four inches high and mounted the big pump and it's switch on it, that pump hasn't gotten wet since. The little pump keeps the bilge level down to about half an inch, and if I get a major leak the big pump will come on. The next mod I haven't got to yet is putting an alarm on the big pump.
What Capt JGW said
At Cherubini Boat we devised the concept of 'bilge pumps on a stick'. This was two pumps stacked one atop the other on a board that could be removed, allowing access to pumps necessarily at the bottom of the bilge well (30" down). I have described this in detail elsewhere here; but it's essentially what Capt JGW has done. Note that the alarm always goes on the upper pump-- if that comes on, it's saying that you have a lot of water in the bilge and/or that the lower pump failed.
The problem with bilge pumps isn't necessarily the backflow from the back of the boat. Capt JGW's solution essentially avoids this; there are other ways to do it, like the vented loop. But the universally unavoidable problem is that of the water in the hose, between the pump and the top of the hose run, flowing back into the bilge when the pump cycles off. This water can often be enough to restart the pump, which will continue to try to pump it out, see it flow back, and restart again and again till the battery dies. (It's happened very often.) The check valve is a solution to hold this 'head' of water in the pump, leaving only the very least length of hose between the check valve and the pump to always flow back into the bilge-- hopefully not enough to restart the pump.
What's needed is a pump/switch combination that will deliberately run dry for about 2 minutes after no water is detected in the bilge, with enough oomph to pressurize the hose even with air to get all of that over the highest loop of the hose. Then what falls back into the bilge is just air. I haven't found this set-up yet anywhere. Most cheap bilge pumps are too anemic to be expected to do this, or to push the head of water standing atop a check valve; and this is what we need to figure out how to solve.
At Cherubini Boat we devised the concept of 'bilge pumps on a stick'. This was two pumps stacked one atop the other on a board that could be removed, allowing access to pumps necessarily at the bottom of the bilge well (30" down). I have described this in detail elsewhere here; but it's essentially what Capt JGW has done. Note that the alarm always goes on the upper pump-- if that comes on, it's saying that you have a lot of water in the bilge and/or that the lower pump failed.
The problem with bilge pumps isn't necessarily the backflow from the back of the boat. Capt JGW's solution essentially avoids this; there are other ways to do it, like the vented loop. But the universally unavoidable problem is that of the water in the hose, between the pump and the top of the hose run, flowing back into the bilge when the pump cycles off. This water can often be enough to restart the pump, which will continue to try to pump it out, see it flow back, and restart again and again till the battery dies. (It's happened very often.) The check valve is a solution to hold this 'head' of water in the pump, leaving only the very least length of hose between the check valve and the pump to always flow back into the bilge-- hopefully not enough to restart the pump.
What's needed is a pump/switch combination that will deliberately run dry for about 2 minutes after no water is detected in the bilge, with enough oomph to pressurize the hose even with air to get all of that over the highest loop of the hose. Then what falls back into the bilge is just air. I haven't found this set-up yet anywhere. Most cheap bilge pumps are too anemic to be expected to do this, or to push the head of water standing atop a check valve; and this is what we need to figure out how to solve.