Need a bung ?

winsbury

winsbury

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Our cockpit self drains via a 45mm diameter hole directly to the sea just above the rudder. Although there is a antisurge rubber flap it doesnt completely stop water coming up on deck especially when more than 3 on board as the drain is then below water line.

What I'm looking for is something that has a one way check valve, ball or flap that can mount inside or on top of the hole perhaps with a flange to screw it into postition. It needs to be suited to being in water permanently. Searches on all the websites that I can think of is drawing a blank ... anyone got any good ideas ?
 
Could you fit a dinghy type inspection hatch over it for overload conditions ?

That would have to be removed to have any drain at all of course.

Though the wrong shape a dinghy self bailer or two might suit if you could adapt the drain shape, they have semi-effective one-way flaps but are also closeable, stainless.
 
It might get in the way as a trip hazard, but I was thinking of a short upstand screwed onto a flange around the existing fitting. The advantages would be that the drain would then be above the waterline when fully crewed, so it shoudln't fill the cockpit anymore, but ina swamping, it would still drain down to the level of the upstand. of course, it would be good practice to remove it on the moorings just in case it got blocked.

Rob
 
A dinghy hatch wouldnt work as theres not a lot of space around the hole ( its in a depression to the rear of the cockpit next to the transom, hence why it gets dunked once crew are on board.

I cant quite see how a self bailer would work, all the ones Ive seen are oblong, this is a round hole and given its proximity to the rudder and that it is always wet cutting it to a new shape is impractical without lifting the boat.

upstand is certainly a simple idea but would mean in a swamping the deck wouldnt drain without removing it and since we are likely to be in heavy seas at that point it seems counter-productive.

I really prefer a one way valve of some sort. Ive seen some with ping pong ball type floats that look like they might do the job but cant find anything in the right size.
 
I mentioned self bailers are the wrong shape, I was thinking an adapter plate of a kind might be possible to make up.

I suppose you could make up a ' hit & miss ' style sliding shutter, maybe clamping onto neoprene seals to make it - almost - watertight, I did this on my boat which had a similar problem but as the drains are horizontal into the outboard well it was easy to make, a self bailer in the well plug really shuts off any inflow when closed; can't think of a genuine one way valve though.
 
Back in the mists of time I seem to remember dinghy self-bailers that fitted circular holes with plungers that went down - this was a time when the Elvstrom type were new-fangled. What you do find nowadays though on some RIBS and inflatables are circular self-bailers - see http://polymarineshop.com/cup-self-bailer-and-diaphragm.html - one of these might fit in with a retaining ring, but be removable for full draining if required.
 
Simple solution dad used not perfect but did work. Similar situation with transom hung rudder 2 holes one each side...

He got 2 bouncy balls of slightly larger diameter Hammered through nails to make hooks in the end of to attach to rope/ elastic...

These we fitted very much in the manner of the flaps on the back of enterprises etc.. Get the tension right and the water pressure from cockpit pushes round the ball, and MOST of the incoming water is stopped...

Might be worth a try...

Just if your wife is burning paint off the stern, remember to watch she does not "burn dads balls off"...
 
jwilson said:
Back in the mists of time I seem to remember dinghy self-bailers that fitted circular holes with plungers that went down - this was a time when the Elvstrom type were new-fangled. What you do find nowadays though on some RIBS and inflatables are circular self-bailers - see http://polymarineshop.com/cup-self-bailer-and-diaphragm.html - one of these might fit in with a retaining ring, but be removable for full draining if required.
Click to expand...

That is almost exactly what I originally had in mind and making a collar to make it fit wouldn't be very hard but the water flow is in the wrong direction... I cant fit it from under the boat so it needs to allow water to flow down the tube from the flanged end.
 
Go to a plant hire shop that has water pumps for hire or sale
Daiphragm pumps ( as opposed to centrifugal pumps ) use flap valves or ball valves to control water flow
If the suction hose is fairly long they have 2 valves on the suction side- one at the pump end & one at the suction end
rather like a valve in a strum box on a bilge pump
What you need is the valve of a 2inch or 1.5 inch Pegson pump ( or similar make)
Plumb this into the hose rather than on the end
Other than that get some plumbing fittings & use a "superball" ( remember those as a kid) in line with a bit of plumbing
You could put a 1.5 inch brass nipple ( or a male to male straight connector) inside a straight connector. The ball would sit against the end of the nipple but roll back & foreward within the straight connector. A nipple the other end would stop the ball rolling out & hoses could slip over the nipples & join to cockpit to outlet
You would have to angle it so the ball rolled the right way & you may have to insert reducers on the nipples to allow a bigger straight connector so the water could go around the ball
 
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