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