Bilge pump outlet location

[Yellow Ballad]

One of the things I have planned for the winter is fitting an electric bilge pump (I've finally succumbed). I'm just thinking ahead of where to put the outlet. I have a manual pump that is fed to the cockpit drains but this backfills the cockpit when used and if the fhit hits the san and I'm using the pump I would rather not share the cockpit drain as it's restricting one of the other from doing it's job. So I need to fit two outlets, one for the manual and one for the electric pump, makes them symmetrical then...

Now do I fit them near the centreline under the stern (behind the cockpit drains) so I can make a high loop and then down or the side of the hull but without a high loop (but I could cross the hoses so high when heeled). My only thought in the center would be in a following sea it could possibly allow water into the hull. Thoughts, suggestions all welcome.. I'm all ears.

Pic for reference

 

[lw395]

A long way above the waterline.
Topsides, just ahead of the transom as high as you can is about the least immersed bit of the hull.
You should still be able to have a slight down slope to the outlet.
Or high on the transom.
Hopefully you're never going to use it, so the issue of bilge water staining the transom is moot.

Following seas and anything low on the transon CAN be an issue.

Anything low on the transom can also allow water to syphon back in, if you are unfortunate to ever seriously need a bilge pump.

 

[Yellow Ballad]

Thanks for the reply, I had come to the conclusion on the side would be better, someone may notice it pumping when I'm not there and raise the alarm.

 

[PetiteFleur]

On the transom high up - I made this mistake when I fitted an electric bilge pump for the engine space - I had a mysterious water 'leak' which regularly appeared. Only solved this year when I had a friend on board - the stern squatted when under power and water slopped down the hose. Solved by making a gooseneck with the outlet hose. In exceptional circumstances water could still enter and the outlet flow is slightly decreased but I'll live with that to get a dry bilge.
I've also fitted a bilge alarm so I know if the bilge is filling.

 

[Yellow Ballad]

Yea I think roughly where my left arrow is and crossed should be ok, probably won't look to aesthetically pleasing but if it works eh!

Out of interest what are the thoughts on using MC4 connectors on the bilge pump? You can get splitters so I can feed a manual live and auto live into the pump and they should keep moisture out? They will also take 6mm2 wire so plenty chunky enough for a 3700 rule pump.

Next is.... auto switches? Go for a rule float jobbie or a water witch? Is there anything else worth looking at?

Cheers

Tom

 

[Graham_Wright]

The higher the outlet is, the more run back there will be. The same is true with a loop. Real pain.

 

[lw395]

The higher the outlet is, the more run back there will be. The same is true with a loop. Real pain.

But it's a plastic yacht where the bilge pump is only for emergencies.
The pain of the run-back might persuade people to sort their deck leaks etc.

 

[Graham_Wright]

But it's a plastic yacht where the bilge pump is only for emergencies.
The pain of the run-back might persuade people to sort their deck leaks, wet sails, rain, oilies run off and waves etc.

 

[Yellow Ballad]

It's a keel stepped mast so I am use to sponging a bit of water out, the pump will hopefully (not) only be for emergencies.

Which actually leads me to ask should I fit the auto switch a bit higher then usual to cope with a bit of rainwater sloshing about.

 

[lw395]

rain, oilies run off and waves etc.

Pop up the hatch in the cabin sole and use a sponge.

I normally take up the whole cabin sole from time to time, give it all a wash.

I thought we were fairly tidy aboard, but there is always hair, dust, crumbs, spilt tea and random detritus just begging to get into a bilge pump and block it.
Our manual pump will pump a mixture of water and air if it's well primed and you go at it vigorously.
Last time I tested it, the run-back took a few moments with a sponge to clear up.

If you seriously want to avoid those issues, an electric diaphragm pump with small bore plumbing will get it most dry. But these are more expensive than the centrifugal pumps chandlers love to sell people.

Another trick on my boat was a big syringe which reached the bottom of the bilge sump.

 

[penberth3]

...My only thought in the center would be in a following sea it could possibly allow water into the hull. Thoughts, suggestions all welcome.. I'm all ears.

Use a non-return valve?

 

[Graham_Wright]

If you seriously want to avoid those issues, an electric diaphragm pump with small bore plumbing will get it most dry.

………and more prone to blockage.

A Jabsco type pump will suck it dry and is inherently non run back.

Non return valves invariably leak back due to dirt.

 

[lw395]

Even diaphragm pumps will tend to run back a little, because with dirty water, the valves rarely seal perfectly (and if they do, they stick). They just take time for the water to trickle back. There may be less water, because they will pump some air/water mix and blow some of the water out.
But often, some runs back as soon as you've packed up.
Sponging a bit of water into a bucket is often just so much simpler.

 

[Yellow Ballad]

Sorry to bump this but I'm getting close to drilling holes in my boat and I really don't want to get it wrong. I was originally thinking about putting it on the side but I'm getting a bit paranoid about healing (although I was going to cross the pipes they will be cross lower then the outlet).

I'm favouring the black outlets but I have a negative transon so I'm not sure how much rainwater I would get down there?!? I could put some "flaps" covering the outlets but that probably be a bit unsightly?

The other option is white (pointing down) but have a high loop before heading below.

Black I think isn't really ideal, even with a loop.

Blue on the side I think would be ok but I don't want to do it and find out it's not...

Thoughts?

Many thanks in advance.

 

[LittleSister]

I vote for black position, with the hose between pump and outlet looped up as high as practicable (i.e near gunwale height), and fitted with siphon break valve at top of that rise (and/or of greater diameter than hose from bilge to pump).

 

[lw395]

Blue, but further aft, with a loop towards the middle of the deck.
Black will collect water in some seas, as will white. You could fit seacocks of course.
Red will leave a stain down the transom.
It's good to see the water coming out as you pump.

Blue might get a bit of water in during a fast spinnaker broach, but not enough to be a concern, at least if the pumps are manual or others with valves.

 

[Graham376]

Our bilge pump outlets are just under the toe rail, alongside the centre cockpit. I would vote for red or blue on your boat, if black submerged there would be increased resistance to pump.

 

[RupertW]

Red for me every time - we find with time spent flushing the bilges clean every now and again there is no stain. If you do get one then I’d look at what might be causing it first.

As it happens we get continuous water in the bilges but it’s fresh from various sources - but that’s another story.

 

[CAPTAIN FANTASTIC]

There is no much difference between red and blue positions, but I would go for blue position as it is less likely to be covered by waves from the stern or from heeling.

 

[Daydream believer]

I have a hoselock fitting in my shower hose line, just before the pump. I can disconnect this & insert a 10ft wandering hose with a quarter inch copper pipe tail on the very end which is a foot long. I have a 7mm hole in the cabin sole( hardly noticeable) & poke it through & can suck up the most shallow of water puddles because the pipe is only 6mm diam. I can also move the hose about the boat & suck up water under the engine etc or areas such as when I spill something or when draining the hot water heater at year end