Recommend a secondary bilge pump please.

FullCircle

FullCircle

Well-Known Member
Joined
19 Nov 2003
Messages
28,223
Visit site
Well,
we had an 'incident' yesterday, and had to remove 9 inches of silty water from the bilges.
The bilge pump routes through the main switch panel, so is switched off. Doh!!
Eventually got bilge pump functioning, but pretty pathetic really.
Took ages to empty and was incorrectly placed in the bilge, so had to liberate the pipe end and use it like a hoover head. Bah.

So, now thinking I want another bilge pump.

What size to go for? Boat is 35ft with a shallow bilge (its a lift keel) so only about 7 1/2 inches depth available, but fairly flat bottom shape.
If its too big it wont hoover up the last 1/2 inch.
Do I go for a remote pump sucking up a pipe then overboard or a bilge mounted pump pushing water out?

How many gallons per hour or minute?

I have a 210Ah battery to hook it to, and will install a bilge monitor on its own feed.


Recommendations please!
 
You need a manual, otherwise when the battery's flat you'll have two useless bilge pumps. In fact, if you're of the paranoid tendency like me, you'll have one electric and two manuals!
 
Re: Secondary bilge pump

Haven't resolved the wiring options: my electric one bypasses the switchboard and has an automatic sensor, so it comes on when there's sufficient water ingress. I s'pose that means something major like prop falling off when I'm not there will flatten battery before ship sinks. Hmm.
The spare MUST be manual as G sez, but accessible in the cockpit without opening anything. He's not the only one to have three . . .
 
Is this additional pump intended to keep the boat afloat when you are not there should a hull fitting fail? If so can you calculate what volume of water 2 or 3 inches in the bilge is (ie to set off a float switch) and then add to that the rate water would come in through your biggest hole in the hull to estimate what rate you need to pump out?

With a fairly flat bilge a little water goes a long way so do you need 1 big or 2 smaller pumps with float switches linked directly to battery so will work as long as you have battery power.

Hope the 'incident' is resolved.
 
Sorry Chaps, I havent explained very well here.
I have the standard Whale Gulper electric which has a float switch which is pretty pathetic.
I have a cockpit mounted manual pump which works well
I have a Whale gusher manual in the cabin.

What I am looking for is a good electric pump to enhance the existing one, also as a fail safe, which I will wire to the same battery as the existing, but not to the same float switch.

The question is, which type, make and/or model is recommended.

A further bit of info.... in cant be more than 190mm high.
 
Bilge pumps should not go through the switch panel, they should be wired so they stay operational when all master switches are off. You need at least one auto one, better with two, if different compartments.

Auto ones are not designed to empty the boat completely, else when it stops, water would come back down the pipe and off it would go again, add infinitum.
 
Just thinking out loud...

Why would you add another electrical pump to supplement the current pathetic one?
Why not just replace the current one? No extra space required and you should be able to use the existing wiring/hoses/pipes.

That's what I would (try to) do.
 
Good point Will, but 2 reasons really.

1. Fail safe if one goes down.
2. Current one is mounted to work on Port tack by ingenious Jeanneau design, now need another which works on Starboard tack.
 
From experience, you cant have enough bilge pumps. I've had some that have only worked for a week or two.

I've also got bilge alarms, fitted at a higher level and a big siren. Experience said. Nothing is to be trusted.
 
Jim,

You dont say if it is sea or sky water you are collecting in the bilges - either way, its clearly important to stop or reduce its ingress.

I happened to hear a couple of chaps talking during the week - one of which had a RIB with a secondary bilge pump operated by a moisture sensor of some sort, rather than a float switch. Cut a long story short, he had worked out that it wasn't switching on when the boat was filling with rainwater - because the moisture sensor only worked on salty water - ions, and all that.

Probably totally irrelevent but just thought I'd mention it while it was on my mind!
 
Particularly with a shallow sump I reckon you need 2 types.
Small automatic 500-1000gph that sits in the lowest place possible and keeps the builges as dry as possible directly wired to batt. This is to keep the builge dry and get rid of any small amounts of water that collect when you are away.
Collision pump (wired to main panel if required) this should be higher than small pump with float and man sw it should be size to cope with at least the flooding from your largest seacock. Put an alarm on it as well because if it kicks in you know you have more water than little pump can handle so it needs urgent attention. I find that a 3" 8000g/h copes comfortably with a 11/2" hole with some leaway for debries reducing capacity. For a collision pump I would not look at anything less than 11/2" 3500gph because the rate of pumping drops off much faster with smaller pumps (the pipe has reletively more surfice area so more friction and the motors anrt big enough to cope with the lift. For 35ft about 7000gph would be my minimum but if you have any 'vunerability' eg large windows/hatches, spade rudder, 'P' bracket & exposed shaft etc then if possible double the capacity. The batt capacity is pretty irrelevent as these pumps only draw 10-20a and run short term (or you run the engine which adds about 10-20% to capacity - more volts). The aim is to make sure the bilge stays dry enough for you to find and fix the leak.
 
Thanks Roly and all.

I am going to have a port and starboard float switch, each attached to a different pump. The starboard side will be covered by the existing standard fit Whale Gusher, the port side will be covered by a 1000GPH Rule unit.
These 2 units will be powered off an auto switch and alarm directly connected to the 210Ah 3rd Domestic battery.

Centrally mounted, but 30mm up will be a 3000GPH Rule, which will only operate on an of shite situation, whih will be connected to the existing pilge pump circuit through the main switch panel. This will also be alarmed very loudly.

Non return valves to be checked out if the flow is not hampered too much with them


Thanks for all your helps
 
You must log in or register to reply here.

Share this page

Top