Bilge pumps

[Alan de Enfield]

Just now, Mickba said:

 

That's what I was looking for.

Do most boats have them?

 

Yes - otherwise how would you pump dispose of the bilge water.

 

Even big ships like aircraft carriers and oil tankers have a bilge pump connected to a 'hole in the side of the boat'

[Mickba]

3 minutes ago, Alan de Enfield said:

 

Yes - otherwise how would you pump dispose of the bilge water.......

 

 

I assume those who do not have the pump in permanent auto mode would switch it on and throw the pipe over the side?

 

I suppose an outlet fitting into the weed hatch would work?

[jonathanA]

50 minutes ago, Mickba said:

 

I assume those who do not have the pump in permanent auto mode would switch it on and throw the pipe over the side?

 

I suppose an outlet fitting into the weed hatch would work?

Nope most people have their bilge pump(s) permanently connected to an skin fitting. Whether the pump has auto mode or just manual is more open to personal choice. Mine is manual only by choice although it does have a float switch for auto operation.

 

I also have a spare one with a few metres of hose and Croc clips for the 12v which I can use as needed or in an emergency. 

[Tony Brooks]

51 minutes ago, Mickba said:

 

I assume those who do not have the pump in permanent auto mode would switch it on and throw the pipe over the side?

 

I suppose an outlet fitting into the weed hatch would work?

 

Unless it was fitted with a tall swan neck, it could beheld to be contrary to the BSS - minimum height between water line and outlet. I would urge you to put that idea out of your head. What do you see wrong with drilling the hull and fitting a skin fitting, all perfectly possible on a DIY basis, using a half decent electric drill a hole saw.

[blackrose]

I always used brass skin fittings as I don't weld. It's fairly basic DIY. If you're drilling from the inside the main thing is measuring and remeasuring from a fixed reference point visible on the outside so you know where the drill is going to come out. That reference point could be the height from the deck or another existing skin fitting, etc. You obviously have you avoid the flange of your skin fitting hitting any rubbing strake, but being just above or below a rubbing strake will help protect the skin fitting from lock walls, etc. 

 

Once you get your pilot drill through it's just a case of keep going with your hole cutter and maybe some cutting fluid or just some WD40. Once you're through deburr the edges with a round file and clean of all the swarf and cutting fluid. Then put some sealant like Stixall around the flange of the skin fitting before putting the nut on the inside and clamping it up. Be careful not to knock the fitting out of the hole and into the water while you're putting the nut on!

 

Ideally your connecting hose will go up higher than the skin fitting before coming back down and connecting to it. That "swan neck" configuration ensures any water entering the skin fitting can't go down the pipe.

Edited September 6 by blackrose

[blackrose]

8 hours ago, Mickba said:

I suppose an outlet fitting into the weed hatch would work?

 

No, that's a bad idea. The weed hatch is under some pressure when the prop is spinning and it's likely to push water from the weed hatch into the pipe, out of the bilge pump and into the boat. It will do the opposite of what you want.

 

If you're installing a skin fitting do it through the side of the boat at least 8" - 10" above the waterline not into the weed hatch.

Edited September 6 by blackrose

[JoeC]

When my boat was built it had five bilge pumps installed - 3 in the bow and 2 in the stern. There are three separate areas in the bow that could collect many litres of water and two in the bilge - one either side of the engine.

 

I am the third owner and bought the boat with just one pump up front and one in the rear. The un-used water outlets have had the pipes removed and tape put over the inside ends of the skin fittings. 

 

There is one bilge switch on my electrical panel (on-off-auto) and I can only see one electrical connection up front that all the three pumps would connect to and one connection at the rear that those two pumps would connect to. My plan is to re-instate the missing pumps.

[David Mack]

A boat with a trad stern, or a cruiser/semi-trad stern with effective deck drainage or a pram hood and a self draining front well deck (with or without a cratch cover) should take on negligible bilge water. So why the need for multiple or automatic bilge pumps?

[blackrose]

Cruiser sterns seldom have effective drainage. I've got 2 automatic bilge pumps in the engine space. I know they can't be relied on completely but hopefully at least one of them will work if required. It might not be water from above. Stern glands have been known to leak. 

 

I've also got a bilge pump at the bow under my bow thruster and one at the rear of the cabin bilge just in case of a water tank leak. My tank holds a maximum of 1,275 litres so it could make quite a mess if it leaked into the boat without being removed.

 

In nearly 20 years none of my bilge pumps have ever actually been used, but they're like lifejackets or insurance policies. One hopes they're never needed but I wouldn't be without them. 

Edited September 6 by blackrose

[alan_fincher]

On 21/06/2024 at 09:40, robtheplod said:

We have a 'Rule' bilge pump.... seems to work ok?

I recently replaced a failed Rule bilge pump with another from the same manufacturer, but very different in appearance.  The new one didn't work, which proved to be because the small plastic impeller was not fixed to the motor shaft - the motor turned, the impeller didn't.

 

From my personal experience I would avoid Rule in future.

[MtB]

22 hours ago, Mickba said:

I assume those who do not have the pump in permanent auto mode would switch it on and throw the pipe over the side?

 

There is a serious risk associated with doing this. 

 

People chucking a 'pipe over the side' tend to make sure the pipe is plenty long enough, meaning the end of it is usually in the canal. If you turn the pump off when the water is all pumped out and fail to bring the pipe back in, the canal will syphon back into the boat. If you got distracted and/or the battery went flat, the same happens.

 

A well known canal personality is rumoured to have actually sunk his boat by this method. 

 

 

[Mickba]

Thanks for the clarification.

I'm surprised that a 25 year old boat doesn't have such a fitting (maybe it does and I can't find it) surprised also that the surveyor said it should be on auto without addressing how it should be connected.

[blackrose]

1 hour ago, Mickba said:

Thanks for the clarification.

I'm surprised that a 25 year old boat doesn't have such a fitting 

 

Plenty of boats don't have skin fittings in the right places because nobody has bothered to fit them. However as we've said, they're not difficult to fit.

[MtB]

4 hours ago, Mickba said:

I'm surprised that a 25 year old boat doesn't have such a fitting 

 

I'm not, as steel boats don't generally take on water. 

 

 

Neither of my boats has a bilge pump and neither has sunk yet. And one was built more than 100 years ago. 

 

Although to be fair Simon replaced the bottom about ten years ago 

 

 

[blackrose]

2 hours ago, MtB said:

I'm not, as steel boats don't generally take on water. 

 

I'm not sure how relevant the hull material is when it comes to the potential for hull penetrations to leak? Plenty of steel boats have leaky stern glands after all and most are designed to drip a bit. That only needs to get worse without being noticed either while the boat is underway or moored up and then a working bilge pump may save a lot of grief.

[blackrose]

21 hours ago, JoeC said:

The un-used water outlets have had the pipes removed and tape put over the inside ends of the skin fittings. 

 

Tape doesn't sound like a very good way of blanking off a redundant skin fitting. I had a 3/4" skin fitting that I no longer used and pushed a plastic wine bottle cork into it with a load of Stixall. I know that's still a bodge but I'm pretty sure it wouldn't leak even if it went underwater and the benefit is I can always hammer the cork out with a socket extension bar or something similar if I ever want to use it again.

Edited September 7 by blackrose

[Tonka]

9 hours ago, MtB said:

 

I'm not, as steel boats don't generally take on water. 

 

 

Neither of my boats has a bilge pump and neither has sunk yet. And one was built more than 100 years ago. 

 

Although to be fair Simon replaced the bottom about ten years ago 

 

 

My narrowboat didn't have any bilge pumps in until it got to 25 years old and I fitted 2. I only fitted them because I am sure that if she did sink and the insurance company found out there were no bilge pumps, they probably wouldn't pay out

[blackrose]

Just now, Tonka said:

I only fitted them because I am sure that if she did sink and the insurance company found out there were no bilge pumps, they probably wouldn't pay out

 

That's another good point.

[Tonka]

58 minutes ago, blackrose said:

 

That's another good point.

Are you saying I have made a good point before ?

[blackrose]

4 hours ago, Tonka said:

Are you saying I have made a good point before ?

 

No sorry, I meant that other good points have been made in this thread regarding bilge pumps.

[cuthound]

14 hours ago, blackrose said:

 

I'm not sure how relevant the hull material is when it comes to the potential for hull penetrations to leak? Plenty of steel boats have leaky stern glands after all and most are designed to drip a bit. That only needs to get worse without being noticed either while the boat is underway or moored up and then a working bilge pump may save a lot of grief.

 

Indeed, when my Vetus Cutlass bearing suddenly failed, it was only the automatic bilge pump kicking in during the early hours that alerted me. If I hadn't have been on board the boat would have sunk.