Bilge pump for hull water?

[jgrace]

I've just had my Valiant on the water for 48 hours for the first time this year, and got quarter of a ton of water in the hull. I'm not sure yet whether it came in through the deck (there was quite a lot of rain during the period) or through an underwater leak (the transom rides slightly lower than it used to because I've just fitted an auxiliary).

Obviously I need to check out how the water's getting in (no I haven't tasted it yet), but I suspect I won't be able to find the source without taking the tubes off, which I don't want to do until the end of the season.

Therefore I've been thinking of getting a bilge pump fitted. So here's a few issues I'd be very grateful for your opinions on.

Do many ribs have bilge pumps for the hull void?

Can one be retrofitted without risk to the structural integrity of the hull?

Might fitting one make matters worse? Presumably the hull air currently pressurises to resist ingress, if there is an air route to topside via the pump, might the rate of water ingress increase?


Jim

[Tim M]

An issue you might want to consider is that if theres a lot of water getting in there over a period of time, a pump is going to drain the battery if its kicking in every hour or so. You might want to run the plump off a seperate battery if you have the space.

[codprawn]

Is the boat kept on a mooring? If not you should have some sort of bung to drain the water out when it's on the trailer.

If it's on a mooring then yes it will fill with water unless you have a cover. The solution is a bilge pump but the battery will run down as has already been said. My battery was flat the other day even though it was a massive 140amp. All the rain we have had does not help.

[jwalker]

Originally Posted by codprawn

...My battery was flat the other day even though it was a massive 140amp...

Solar panel, Cod?

[jgrace]

Originally Posted by Tim M

An issue you might want to consider is that if theres a lot of water getting in there over a period of time, a pump is going to drain the battery if its kicking in every hour or so. You might want to run the plump off a seperate battery if you have the space.

Originally Posted by codprawn

Is the boat kept on a mooring? If not you should have some sort of bung to drain the water out when it's on the trailer.

If it's on a mooring then yes it will fill with water unless you have a cover. The solution is a bilge pump but the battery will run down as has already been said. My battery was flat the other day even though it was a massive 140amp. All the rain we have had does not help.

There are two bungs in Ruby's transom, one for deck water, one for hull water. Launching and retrieving off a trailer for a daytrip is no problem, the water getting into the hull void is not enough to be noticeable during the day and whatever does get in empties out when the bungs are removed on the slip afterwards.

But sometimes during Summer holidays I keep her on a mooring, at a pier or at a pontoon, and in those circumstances I have noticed the hull void is filling with water much more than it used to. But even if the hull filled completely, I reckon the tubes would keep her afloat. So I wasn't thinking of an automatic battery-powered pump, just a manual one to bail her before use, so to speak.

Here's an example of my problem. Yesterday I took her out of Cahirsiveen marina in Kerry, not realising how much hull water was in her, and found I couldn't get her up on the plane with 5 people on board. Worse, because the deck drain was now below sea level and it's not particularly watertight, water started coming in on the deck around our feet and sloshing around making her feel quite unstable. I had bring her back into a slip pronto and haul her out on the trailer to get the water out. Now that I know she's taking water, I just thought that if I had a manual bilge pump I could pump her out before using her.

Which brings me back to the questions I posted at the start of the thread.

Jim

[codprawn]

Originally Posted by jwalker

Solar panel, Cod?

I have one but they don't tend to work when it's raining - prob is the bilge pump DOES work when it's raining......

[Nate]

I fitted a manual bilge pump on my old rib for the very reasons listed above. Only one new hole in the transom was needed for the bilge outlet, and this had a skin fitting and was reinforced so no loss of integrity (fit a non-return valve inline and near the skin fitting to avoid being flooded by following seas...). Also managed to fit it under the deck using a flush deck fitting so it all looked neat. Worked a treat.

As to hull air being pressurised to resist water ingress - doubtful: if water can already get in then air can already get out.

This is what you need: http://www.whale.ltd.uk/marine/product_list/7/108/

[Mark Halliday]

Jim

I put a 500gph auto under the floor in mine.
I cut a hole and fitted a 10" hatch just in front of the well.
3 reasons for this.
1) to fit the pump
2) to get access to the fuel line connection on the tank
3) to put my depth transducer under the deck.

Quite a lot of water enters the hull with the anchor warp, and a lot of plastic bungs leak eventually. Are the O'rings on your bungs sound?

[jgrace]

Thanks for the helpful advice, guys. I'm going to replace the hull drain fitting, socket, bung, the lot and see if that cuts down the water ingress.

If it doesn't I think I'll put a 50mm hole in the deck just inside the transom and fit a flush water tank filler with screw-in stopper. Having had a look at what's on offer in my local chandlers, the manual lever pumps are too big and very expensive. An electric semi-submersible, although much more reasonable pricewise, would require a much bigger hole in the deck to get access to secure it to the bottom. So if I need a pump I think I'll go for the one that looks like a bicycle pump with a pull handle on the top. The suction tube out the bottom should go nicely through the water tank filler hole.

Jim

[Stuart M]

I've got a bilge pump and float switch and it runs off battery no 2. The bilge pipe exists at the top of the transom so no problem with water getting that way.

I guess I'd rather have a flat no 2 battery and no water in the boat. The float switch only activates when there is a few inches of water so hopefully it's not switching on and off all the time.

There is also a grate in the deck so any water coming into the boat drains below the deck. The Rib also has a plastic bung which is removed when the boat is out of the water - also keep a spare on the boat

[jyasaki]

I've got a 1000gph pump in mine. Set up on an manual/off/auto switch (from Rule, I think.) I would advise getting the biggest pump you have room for.

I'm considering mounting a second, as it takes a while to pump out even a modest amount of water, and a backup never hurt anyone. (I get a fair amount of water in through a deck storage hatch from wet divers and dive gear. Not really enough to worry about, but since it does happen, I'm wondering how much would intrude in really rough seas.)

If there is an appreciable amount of water, any pump takes a while to get it out. The head (height the pump has to lift) has a lot to do with that. You want to make sure that the outlet hose is well above the waterline (or any conceivable waterline) as you'll fill the bilge if it goes under.

One other thing about these pumps: The old float type automatic switches are generally crap. They work OK until they're out of warranty, then start hanging up. It's not good when the auto feature doesn't turn on the pump. It's worse when it runs continuously (potential fire hazard, dead batteries.)

Bottom line is that I can't really think of a negative in having a pump, but you still have to be careful of certain scenarios that can occur with one. Having one is certainly better than having to pull the boat anytime you want to drain the bilge.

jky

[codprawn]

I have just discovered a brilliant way to make my bilge pump 20x times more powerful - take out the stainless gauze filter. Makes one hell of a difference. Yes I know the pump will clog but then again so did the gauze. Has also cut battery drain by a massive amount.

[ian parkes]

Got the same problem on my Valiant . Not much gets in a couple of pints or so in a day but if it were on the water for a few days then Iam not sure what may happen .

To test the bung and fittings I filled the hull with some water through the hole and put the bung in quick . Its not the bung leaking .

I suspect the drain valve in the transome as I seem to get more in when there has been a bit of water splashed into the boat by swimmers etc .

I was thinking of an easy cure and my idea was to fit a piece of hosepipe with a plumbing fitting instead of the bung . The hose could then be secured above the water line and a hand pump conected to it daily to empty it .

[Downhilldai]

Ian,
When the boat's on the trailer, have you tried pouring loads of water onto the deck, to see if any passes through the deck into the hull void?

[ian parkes]

yes brad iam pretty sure its getting in topside . the locker in the bow isn't leaking so it has to be the baler fitting through the stern . Gonna have a better test before Scilly this weekend are you coming along . ??

I still fancy a way of pumping the inner hull dry . I wondered if a tube on the drain bung would work like an elephant trunk and draw the water out while on the move ?? problem is its pretty close to the motor .

[jgrace]

Originally Posted by ian parkes

Got the same problem on my Valiant . Not much gets in a couple of pints or so in a day but if it were on the water for a few days then Iam not sure what may happen .

To test the bung and fittings I filled the hull with some water through the hole and put the bung in quick . Its not the bung leaking .

Hi Ian!

Interesting. I'm replacing the lower threaded bung and socket tomorrow in hopes it will help. Sounds like it may not cure it. I'll keep you posted.

OTOH it's possible the pressure of trapped water you put in isn't really equivalent to the pressure of water trying to get in 6" below sealevel. Or 9" below when it's already taken on water. Perhaps it takes on the first inch of water in 24 hours, the 2nd in 12, the 3rd in 6, etc. I've a new auxiliary on the transom this year and I reckon it's possible the extra weight has added enough pressure on the bung to seriously accelerate the rate of leakage.

I suspect the drain valve in the transome as I seem to get more in when there has been a bit of water splashed into the boat by swimmers etc .

It's certainly possible, although water on the deck would push the lower bung deeper also. But if the deck drain is letting water into the hull, it would mean a failure in the joint between the collar and either the inner or outer transom, which sounds unlikely. The transom may even be completely solid at that point. Nevertheless, I'll take a look tomorrow.

I was thinking of an easy cure and my idea was to fit a piece of hosepipe with a plumbing fitting instead of the bung . The hose could then be secured above the water line and a hand pump conected to it daily to empty it .

I'm a bit doubtful about that one
1) won't the hose have to be diverted around the engine bracket making it complicated?
2) if the hose took a knock you'd have a hole in your hull where the bung ought to have been!


Jim

[ian parkes]

would be interested in what you see if you remove the deck drain .

My valiant is a v 490 and has one drain set to one side with a little well. it has a bung in it as well as the one way flap . If I have left the bung in and water had been a inch or so deep in the stern for a while thats when it seems to get the most in .

There is no other access to the inner hull to the inner hull from inside the boat . other than maybe srews that hold the consul down leaking and we havent had that much water in the boat .

Iam pretty sure ill end up treating the symptoms and not a cure

[jgrace]

Originally Posted by ian parkes

would be interested in what you see if you remove the deck drain .

My valiant is a v 490 and has one drain set to one side with a little well. it has a bung in it as well as the one way flap . If I have left the bung in and water had been a inch or so deep in the stern for a while thats when it seems to get the most in .

There is no other access to the inner hull to the inner hull from inside the boat . other than maybe srews that hold the consul down leaking and we havent had that much water in the boat .

Iam pretty sure ill end up treating the symptoms and not a cure

Mine's a V490 too but I suspect it's a different model. 1999?

There's a deck sump at the aft end of the deck with a central hole in it. It doesn't give any access to the hull void, it just leads straight out to the back of the transom.


There's no one way flap. I've got a bung for the hole with lever on it so it can be expanded in the hole. Or at least that's what's supposed to happen, I think the bung has lost its capacity to expand sideways so I'm looking for a new one. Haven't found it yet, it's a larger diameter than the ones in the local chandlery.

I won't be removing the deck drain, just the hull drain at the lowest part of the transom externally.

It may be a bit small to get a photo through it but I'll take a look.

Jim

[ian parkes]

they are similar but I dont have the sump like that its just a recess on the left side as you face the transom . I have the same expanding bung by the sounds of it . the through hull fitting has a flap in it and looks like it may be a replacement .
Its full of water right now being tested so will post again later .

Good luck

[jgrace]

Originally Posted by ian parkes

they are similar but I dont have the sump like that its just a recess on the left side as you face the transom . I have the same expanding bung by the sounds of it . the through hull fitting has a flap in it and looks like it may be a replacement .
Its full of water right now being tested so will post again later .

Good luck

Just took the lower bung and fitting off and still couldn't see through into the hull

But I did notice that the deck drain does indeed have a one-way flap like yours, I had just failed to notice it (obscured by the transom lock inside the boat and part-obscured by the engine bracket outside).

Jim