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Post by Tom on Oct 27, 2021 13:40:14 GMT
There's a long thread elsewhere that started with a faulty water sensor but has expanded into sources of leaks, types of bilge pumps etc. Thought I'd start a new thread based on our recent challenges with the bilge (i.e. keeping it pumped out). The standard pump had failed (Johnson type, behind the seating in the main salon). This pump is expensive and clearly spec'd and placed so that it will only remove nuisance water. By the time it pulls up the approximately 2 quarts of water that the bilge holds, the switch has turned it off, some water has exited out through the exit side, but some flows back to refill the bilge maybe half way up. I have replaced the pump with a far cheaper SeaFlo unit (3 gpm), and took out the original hose, replacing with 15 mm hose from the bilge to the pump. I have the SeaFlo strainer in place on the inlet side to keep any debris out of the pump. But, clearly this setup will only remove the nuisance water coming from AC units and the fridges. I will be installing a larger traditional bilge pump - but want to have it partially inserted into the bilge. This pump would be for the more than nuisance water - i.e. something bad is happening and we need to find it. Buried in the other thread is a post I'm pasting below - it might have escaped notice but it has some good guidance. Tom, Alchemyst Sep 28, 2021 at 6:22pm NZL50505 said: I'm in the process of overhauling my entire bilge pump setup: 1. New sump pump: to deal with the periodic accumulations that occur from minor leaks / condensation / overflows etc.: www.whalepumps.com/marine/product.aspx?Category_ID=&Product_ID=10014&FriendlyID=Gulper-320This is a small capacity ~19 litres / minute diaphragm pump that means it is self-priming, can deal with minor pollutants that typically clog a centrifugal pump and can pump a combination of fluids inc air / water / oil / diesel / other nasties. But to ensure it doesn't get clogged e.g. with hair, I'm putting a simple strum box (filter) on the front: www.marine-deals.co.nz/livewell-pumps-bait-pumps/whale-sb4222-side-entry-strum-box2. New bilge pump: to deal with worst case scenario of a serious leak that sump pump can't cope with: www.marine-deals.co.nz/bilge-pumps/johnson-l4000-heavy-duty-bilge-pump?gclid=CjwKCAjw-sqKBhBjEiwAVaQ9a_DaUn-ra1TkEG8mbIpdwqVYPX0nn1gJtR0t384gvSHxxQVHKe6TdxoCURgQAvD_BwEThis is a high capacity pump 4000 GPH / ~ 300 litres per minute to help buy time to either fix a serious problem or even prepare to abandon ship. Over the last few weeks on the water I witnessed 2 incidents in quick succession with vessels springing serious leaks and needing emergency assistance from CG / navy. It seemed like a 'message from the sea gods' and when I looked at the 'toys' that come with the standard Jeanneau bilge-pump setup I thought it deserves addressing ASAP!
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Post by Tafika II on Oct 27, 2021 17:57:37 GMT
The upper bilge pump in the sump area is a manual electric and pumps about 300/GPH. It empties through the transom outlet. We added a Whale Supersub Smart Low Profile Automatic Bilge Pumps in the center bilge rated at 1000/GPH that discharges above the waterline via a thru-hull connection. We also added a diverter at the engine intake that could be switched over to use as a bilge pump through the engine (sorry, the photo is not the greatest). I do carry a plug-in non-automatic submersible high volume pump, but I don’t remember the volume. I think it’s 3000/GPH.
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Post by moonshadow on Oct 27, 2021 21:05:15 GMT
By chance have you tested the engine water diverter to see how much water it will move? I was planning on adding a diverter for This and was talked out of it as it “wouldn’t pump a lot of water”. Just curious if you have tried to use it.
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Post by Tafika II on Oct 27, 2021 22:04:21 GMT
Hi Moonshadow! I did "try" the engine diverter but from a gallon bucket rather than the thru-hull fitting. You're correct, it not robust, but in an emergency, it works OK. My guess is about 1 gallons in 2 minutes
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Post by NZL50505 on Oct 28, 2021 9:54:25 GMT
It’s a topic worth highlighting because I think bilge pump systems are often ignored due to being out of sight hence out of mind. When did you last hear a broker or sales agent extolling the virtues of the pump system (unless you were buying an Amel)?.
And unlike other safety systems in our modern lives (such as cars and buildings which are often regulated) the bilge safety systems on our boats are not given anywhere near as much thought from designers as the ‘flow’ of the living space, for example.
But in a dire situation you’ll be wishing someone had given as much thought to the ‘flow’ of water from inside the boat back outside to where it belongs.
Whilst I’m giving my system an upgrade I’m aware it’s still far from best-in-class. My near neighbour on the marina has double my capacity of pumps running off his 12v system plus a standalone portable petrol generator + 220v pump for worst case scenario.
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Post by rxc on Oct 28, 2021 18:06:19 GMT
I think this is an important issue, but not easy to solve. Having several high capacity pumps would be best, but where do you go thru the hull? How are they powered? The shortest distance is to the sides of the boat, but sailboats are prone to burying the rail during normal operation, and dealing with a submerged discharge location creates a number of issues.
I installed a large (4k gal/hr) electric pump in the bilge fwd of my main engine, and it discharges thru the transom, up high. It is a long run of hose, but it is smooth, with only one sharp bend, at the elbow that connects to the thruhull. No check valves or stop valves. It is unlikely that the top of the transom will ever go under unless the boat is already doomed to sink, so I think it will give me some time.
An enormous trash pump powered by a gasoline engine would be best, but where do you stow something like that, and can you set it up when you really need it? And you will have to refill the gas tank, too, so think about all those issues, as well.
Our sailboats are not ships, with large dedicated damage control systems, and trained, dedicated operators ready to operate the equipment. That is why we also have a dinghy, maybe a liferaft, an EPIRB, and life jackets, with handheld waterproof radios.
The small pumps are just service pumps to try keep the bilge dry from things like AC condensation, fridges, and minor leaks. They give you some early warning of a leak, which can be improved with the installation of a simple bilge alarm. They are not damage control equipment. I consider my big pump to just give me additional time to deal with a hose rupture of a fitting failure which I can fix with a plug or a hose wrap or by shutting a seacock.
Probably the best damage control thing you can do is to check your hoses and thruhulls regularly, and KNOW where they all are, and how to get to them. Have suitable sized wood or plastic plugs easily available, as well as tape to wrap a hose, and any tools you might need. Boats have been lost because the crew did not know where ALL of the intentional holes in the hull were located, and could not find the leak. This is something you don't want to have to learn in an emergency.
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Post by NZL50505 on Oct 28, 2021 18:30:04 GMT
I agree with all of that ie:
1. Prevention is better than cure (so replace ageing thru hulls in good time) 2. Know where all the thru hulls are and how to access them in a hurry on a dark chaotic night (make a checklist) 3. Have the basic tools to tackle the most typical causes of leaks readily to hand eg bungs, tape, epoxy and possibly other plugging materials for a non-regular hole
This is great viewing if you want to share the ‘thrill’ of a solo sailor’s sudden emergency leak from the comfort of your keyboard. For anyone who hasn’t already seen it the guy is obviously a bit of an acquired taste with a somewhat unconventional approach to life but he’s actually very bright and I personally find him far more interesting viewing than so many other deathly boring ‘average couples’ sailing vlogs!
This is part 1 of 3 videos showing what happened when a lightening strike blew a hole in his hull when miles away from help…
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Post by NZL50505 on Oct 29, 2021 5:59:25 GMT
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Post by rxc on Oct 29, 2021 16:43:54 GMT
If you get hit by the right lightning bolt, it can make a hole the size of a dinner plate in the hull as it decides to seek a path to the ocean. I don't think any of us can carry a pump to deal with that, especially after the lightning fries the electric equipment. This guy was lucky that it only tore a hole in his shaft seal, and not in the hull. His damage control actions were great, and he was able to stop the leak with equipment and materials at hand. Good Job!
It would not be difficult, and maybe less expensive, to install 2 x 4000 GPH pumps to give the same capacity as the 8000 GPH pump, and it would probably be better because it would be more redundant, especially if you used thruhulls that were well separated. Hoses would be much easier to install, and you would not have a new 3 inch hole in the side of the boat.
The other pump does not look like it is submersible. It looks to me like it is similar to the well pump I used to own, and the motor would need to be permanently mounted out of the water, which would be challenging. In any case, you need power to run all these pumps, so you need to be able to run your engine or genset, because these pumps will quickly suck down your batteries. You need lots of pre-planned, already-installed, tested, robust infrastructure to do serious damage control.
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Post by NZL50505 on Oct 31, 2021 5:01:47 GMT
Main Genset world keep batteries alive for a while and / or portable Genset which you can position higher up could also supply portable 8000 GPH unit.
Hopefully none of this is ever needed of course (a bit like a life raft)..
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Post by bereboot on Oct 31, 2021 8:02:24 GMT
Another possibility is to use the RAW water pump from the engine to bail out the bilges. It has serious capacity.
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Post by Tafika II on Oct 31, 2021 16:08:33 GMT
Please see my post above from Oct 27, 2021 at 10:57am. Is that what you're talking about?
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Post by bereboot on Oct 31, 2021 18:06:59 GMT
Indeed. I remember a vor crew saving their boat this way.
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Post by NZL50505 on Oct 31, 2021 18:17:56 GMT
What’s the flow-rate for a typical 4-cyl Yanmar? I thought it wasn’t that high eg ~1500 lph?
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Post by rxc on Nov 15, 2021 20:11:49 GMT
I just re-read this thread, and thinking about it, the genset could probably do a good job providing power to a large submersible pump. The issue of discharge path would still be there, but with a big enough pump, you could lead the discharge anywhere and not worry about the head losses. Probably a trash pump would be best. Finding a spot to put it would also be a challenge. It would be relatively easy to start the genset as soon as the feet get wet, and flip a simple switch to start the pump. On my 43DS, the genset is on a platform about 1.5 ft above the waterline, so it should take a while to flood out. People who have gensets in their bilge might not benefit very much.
Just a thought.
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