Leak at Shaft Log and Hull

[anrimia]

i have a 1973 41' formosa aft cabin center cockpit. i have som e seeping water coming through the aft shaft log where it goes through the hull, this is under the bed right above the keel. i cannot see the pipe actually going through the hull do to alot of fiberglass just drapped over the pipe. My question is does anyone else have the same thing where thr fiberglass is drapped over the pipe and cannot see it or is this something a prior owner did? also what is the part on the outside of the pipe called right before the propeller i call it the cutlass housing. can someone point me to a diagram of the actual housing and how the pipe connectct to it. i used waterweld around the mounting plate and it seemed to stop seeping water after that.

[Hampus]

Hey!
zeehag on this forum also has a yankee clipper but aft cockpt. She had the same broblem you do.
I'll have a look at our boat later and see how it's done there. We have a TW41 CC, same as yours but built by Transworld and not Formosa.

/Hampus

[Laidback]

Anrimia,
The description of the problem is unfortunately not clear enough to understand.
In many boat designs where the gearbox is some distance from the propeller; You will find a pipe which has a larger diameter than the propeller shaft. This pipe is called a log (they used to be made of wood). The pipe may be loose or fixed. The aft end of the pipe, at the point where it exits the hull will contain a cutlass bearing
(about 3 inches long, but it's internal diameter is only a few thousands of an inch bigger than the diameter of the prp shaft) which allows the prop shaft to spin in it and at the same time it allows water to travel the full length of this pipe - right up to the stuffing box which prevent the water traveling any further.
In most modern boats, the shaft log is not really a "log", but a metal casting or machined part that fits over the propeller shaft hole on the inside of the boat. The stuffing box, which is similar to a water pump packing gland, fits around the shaft and clamps to the shaft log.

So, EXACTLY where are you finding water leaking from??
Photo of Cutlass bearing below :-

[Laidback]

Anrimia,
What you may have to plan for is to lift the boat out on to a hard stand to remove the propeller shaft , then remove the shaft log and stuffing box in order to fit a NEW Shaft log.

The reason :- a) the boat is now 37 years old.
b) if the Shaft log is metal - it could have corroded to the extent that the sea water that enters that pipe via the cutlass bearing (as it is meant to do) is now leaking into the boat below the aft cabin bed and above the keel.
c) This intrusion of sea water into hidden places is a serious problem, it may do no damage but it can also cause internal osmotic damage to the hull.

By just sealing a few leaks today may bring bigger problems tomorrow.