Electric Bilge Pumps.

LoneHort said:
Do what Clark Beek recommends and you will sleep easy. https://www.sailfeed.com/2012/12/all-about-bilge-pumps/
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Better still, for a GRP boat, sort the leaks out and dry the bilges with a cloth. After you've washed them to get rid of the dust and spilled tea.
Then sort out an auto bilge pump that comes on when you have enough water in the bilge to cause a real problem, before the interior gets spoiled.
 
It's a complacent truism that you should never have a leak in a GRP boat - they happen - usually when you've had a cakk-handed alleged marine mechanic on board.
Whilst I've found the raw water system the most common culprit, that's over about 11,000 hrs and 47 years of sailing. Here's a list of the things that have gone wrong, culled from logs since 1978:-
Fractured pipes, leaking waterseals, wet exhausts, anti-siphon valves, flexible pipes leaving their spigots, cracked water-filter cartridges and failed O-rings, leaking cockpit drains, leaking sink-drains, leaking toilet pumps, blocked toilets, fractured freshwater cans, split waterbottles. Now that's taken me from 2017 - 2000.
However leaking hatches, fractured windows, filled cockpits due to pooping and wet recoveree MOBs also have brought water down below, usually in considerable quantities - so in a 31' boat I have 3 diaphragm hand-pumps and 4 large volume centrifugal pumps in addition to two little ones for the shower-tray and engine bilge!!
 
Flica said:
It's a complacent truism that you should never have a leak in a GRP boat - they happen - usually when you've had a cakk-handed alleged marine mechanic on board.
Whilst I've found the raw water system the most common culprit, that's over about 11,000 hrs and 47 years of sailing. Here's a list of the things that have gone wrong, culled from logs since 1978:-
Fractured pipes, leaking waterseals, wet exhausts, anti-siphon valves, flexible pipes leaving their spigots, cracked water-filter cartridges and failed O-rings, leaking cockpit drains, leaking sink-drains, leaking toilet pumps, blocked toilets, fractured freshwater cans, split waterbottles. Now that's taken me from 2017 - 2000.
However leaking hatches, fractured windows, filled cockpits due to pooping and wet recoveree MOBs also have brought water down below, usually in considerable quantities - so in a 31' boat I have 3 diaphragm hand-pumps and 4 large volume centrifugal pumps in addition to two little ones for the shower-tray and engine bilge!!
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All things you need to fix eventually. Some people seem to tolerate long-term rain leaks, prefer to spend their time fitting complex bilge pump systems instead of finding the rain leaks and solving them. Then they get upset when someone says their boat smells.
Yes we get our boat wet sailing it, now and then in quite a big way, with a big wet spinnaker or something. But when we park up, we can just lift a bit of cabin sole and dry what we can't pump out with a j-cloth. We sometimes get a tiny amount of dribble from the stern gland, that is caught by a little bulkhead, so it can be dried before it runs under the engine. We don't pump the engine bilge over the side, particularly in the river.
We have the RORC mandatory manual bilge pumps, plus a bilge alarm, a biggish permantly installed Rule and a 'portable' rule mostly used for emptying rain from the tender, deck washing but also 'just in case'. Plus the shower drain pump, which also deals with anything which gets down the inside of the mast.
One of the manual pumps puts its 32mm hose straight into a little sump, so what that doesn't extract is a few cupfuls (if you pump like a loon to blow the hoses dry so very little is left to seep back past the 20-year old valves). A big syringe is neater for emptying the sump than a sponge or cloth.
If we find water in the bilge, we want to know why, and fix it.
It's a long way from racing old wooden boats where the crew has to pump if it's rough.
 
I have one of these;

Whale Gulper 320 Waste & Bilge Pump (12V / 19LPM / 19mm or 25mm Hose)

Seems to work well with my deep and very narrow sump. No other pump would fit. Pump is out of the bilge. I can only just get a 25mm pipe down the sump. Flow rate is not massive for its size.
 
DJE

I won't install a centrifugal pump to empty the shower sump because they say body hair soon clogs them up. I've tried to use a macerator pump but although it is supposed to self prime it doesn't. I'll be installing a diaphragm pump but it won't be an expensive one: I'll use an el cheapo one from China

Clive Cooper
 
coopec said:
DJE

I won't install a centrifugal pump to empty the shower sump because they say body hair soon clogs them up. I've tried to use a macerator pump but although it is supposed to self prime it doesn't. I'll be installing a diaphragm pump but it won't be an expensive one: I'll use an el cheapo one from China

Clive Cooper
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Shave?
 
skyflyer said:
I would never trust a diaphragm pump as a bilge pump that has to work when the boat is unattended. Strum box or no strum box it is so easy for a tiny bit or crud to get through and lodge under the diaphragm preventing a decent seal. We have diaphragm pumps for the shower sump and the fresh water supply (and you dont get much cleaner than that!) and both have failed in this way before now, despite filters and so on.
I realise impeller pumps can also get damaged or blocked by crud but IMHO its a lower risk.
(But I really would like to fit a secondary pump as a backup using a float switch triggered by a higher level!)
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There are diaphragm pumps designed to deal with small debris in the water. The Whale Gulpers are an example. They differ from diaphragm pumps designed for fresh water in that the latter have three or four small chambers, whereas the ones designed for dirty water generally have only one large chamber and correspondingly larger valves.
 
Diaphragm bilge pumps will deal with a certain amount of muck, but they tend to have issues priming if they dry out with dust or debris in them. The higher the pump is above the water level, the worse they will be. But if they're too close to the water level, you risk the motor getting wet. Once they are wet inside, they tend to work OK.
 
Don't forget to avoid elbows in the discharge pipework from a centrifugal pump to reduce the headloss as far as possible. Likewise, kinks or twists in the pipe can seriously reduce the capacity as do non return valves although the problem of 'cycling' is sometimes difficult to overcome without one. (Cycling is when the discharge pipe contains enough water to lift the float valve when it drains back).
 
+1 on the Gulper 320; poor flow rate relative to size, noise and power consumption, but they do seem to be unstoppable.
 
Graham
I've got a Jabsco off a Caterpillar Dozer which pumps 100 liters per minute (1600 US gallons per hour) which I thought of running off the engine with a mechanical clutch. Would that be worth fitting sometime down the track? What do you think?

Clive
 
Jabsco always the one for bilge/fire/emergency. You might be able to fit an electric clutch, or manual, dedicated to jabsco, off the shelf. When I had a manual clutch it worked on a morse cable.
 
I use a Whale gulper as my primary/daily bilge pump, mated to an auto bilge pump switch with a 30 sec switch off delay to clear as much water from the pipes as possible. Flow rate is not brilliant, but it is better than a centrifugal pump in extracting lower levels of water. I have an Attwood Safari (similar to a Rule) centrifugal pump mounted higher, to deal with unexpected water ingress - better flow rate. Having a keel stepped mast I have not yet been able to stop rainwater ingress down the inside of the mast, but I am working on it!
 
Thanks guys

Thanks for that as I will need a wash down pump too.

Being a Jabsco that should be self priming so that I can have a suction hose which I can shift around the boat if necessary?

To avoid the impeller running dry there is a way I can bleed off some of the outlet and bring it back to the inlet side. Correct?

Clive
 
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coopec said:
Thanks guys

Thanks for that as I will need a wash down pump too.

Being a Jabsco that should be self priming so that I can have a suction hose which I can shift around the boat if necessary?

To avoid the impeller running dry there is a way I can bleed off some of the outlet and bring it back to the inlet side. Correct?

Clive
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If it's belt driven on the engine, is it below W/L? If so it will be wet when using seacock inlet. The norm is to make a valve chest with several ball valves to different bilges/seacock. There are 'run dry' impellers if there is a worry, but I've never bothered, it isn't dry for long because the outlet pipe goes upwards and water sits there, drains back to the pump.
 
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