After days of looking I found the leak that has been threatening to flood my new (to me) Beneteau
311. The cause was I imagine to be very substandard plumbing
of the stern tube cooling
fixture. I am wondering if someone could tell me the right (and safe) way for this to be done.
I had originally thought it was the rubber boot/shaft seal. This is a shaft-drive Volvo Penta
MD2020. There is a through-hull behind the engine
with a hose that connects to the stern tube behind the shaft seal
to cool the shaft.
I pumped grease under the shaft seal
but that didn't solve the problem. Every time I ran on the engine
(20 minutes or so on the river here) the leak got worse. Today I arrived to find the bilges flooded and my floor boards floating. Engine fortunately still high enough not to be flooded.
Where the hose connects to the stern tube it looked like someone had sealed the connection with red "wax. "As it turned out the "wax" is some kind of plastic that had been melted on in an attempt to seal a corroded nipple (clamped in the hose) to the stern tube. That plastic weld was all that held the hose in the stern tube. Running on the engine caused the stern tube to warm up and the red plastic (with nipple and hose) came away, causing a fountain of water
about the width of a pencil to spout, flooding the bilges.
Temporary solution - I have a threaded bolt pressing down on the spouting hole, with the weight of some spare conduit pressing down on it to supply pressure. Surprisingly this has completely stopped the leak for now - Joy!
What I am wondering is, how should this fixture have been done in the first place? Where am I likely to get a replacement nipple? Is the nipple supposed to thread into the hole in the stern tube?s there any bonding material that's used? Are the any specific types/materials I should look for/look out for?
Thanks for any replies or thoughts on the proper way this should be done so I can keep the boat dry again.
The previous owner put a considerable time and resources into having engine work done and had the the through hull
that feeds sea water
to the stern tube replace (it had been badly corroded. However I'm very surprised that the actual connection to the stern tube was left this way. If I had put to sea, instead of sailing in the river, this could have turned very serious...