Flooded hull

[NGage]

Hi
I am new to boating and would appreciate some help
I have recently purchased a tohatsu t520 rib which I believe to be a rebadged europa r520.

I have had the boat in the water for a week, having just taken the boat out of the water I noticed how heavy the boat was.
After investigation I found a brass circular disk at the back of the boat that was weeping water, not free flowing in anyway. I could not get the center threaded section to undo so I took the three screws out. An hour later the hull was drained.

Why did it take on so much water , there were no obvious signs of water leaking from anywhere else so assume there is not a breach in the hull

Should I put the plate back on and try and get the threaded section out? Do I add sone sealant and put everything back in place ?

When I put it back in the water do I run with this open or closed ? In or out ?

The deck has a separate bulge pump so no issues with above the hull area

Any help or advice would be gratefully received

[simonl]

Before sealing it up I'd suggest you prod around looking for soft damp wood in the transom. You could try to establish where the water is coming from, starting by establishing if it's from above or below. A hosepipe whilst on a trailer, vs dropping in the water for a few hours on a dry day.

[beamishken]

That sounds like a drain bung id buy a new one and refit it
Its unlikely thats your leak path but without the facility to drain the chamber you will never know if it is leaking

[ShinyShoe]

A similar question was asked last week:

http://www.rib.net/forum/f8/hull-fil...hts-82188.html

Has advice on finding the leak. Even if you consider the 30litres in that post as OP there had, yours sounds worse.

Generally bungs that need unscrewed with screw drivers, spanners, big coins etc are not expected to be opened every time you dunk. Ones that can be undone by hand may be undone each time ashore to check dry, and ones with levers are designed to be routinely opened - usually they are for deck drains etc and really exist to stop the boat filling during launch.

So you either need to free off the bung and put it back, or replace it. It needs bedded on sealant or will leak down the sides. In a week you could easily fill that void through a badly sealed bung. Since water was coming out I'd suspect it as a possibility.

Brass bungs often have an o ring on the thread. If the brass has seized good chance the o ring will be perished too...

[NGage]

Even when the hull was full there were no other water leaks , I was parked on dry tarmac and would have seen a damp patch a mile off. I will try and resell the unit that I took off and give it another try.
I was really concerned at the sheer volume of water that had accumulated, but without releasing the bung it had no where to go with the exception of a small trickle

[ShinyShoe]

No leak means you are probably OK with the jul not leaking. What you are also not sure of is a deck fitting... But since the bung was leaking it's the obvious first place to look... I had similar on a sailing boat ages back. Been dust dry since...

[jeffstevens763@g]

My money on the bung water is under displacement pressure going in through the weeping bung on the trailer it might only be weeping because of debris in the hull stopping flow