Unusual(?) Problem

[BuoyOBuoy]

I have a rust spot on the top side of my shaft tube which has cracked open and leaks water. I noticed it a month ago when checking as to why the bilge pump would run periodically but more often than I thought necessary.
When I lifted the floor hatch in the aft cabin I could see it right away. As luck as her own way, this time it was my way. The leak is on the top of the tube and the rust area is about four inches long and the width is about 3/8 to 1/2".
As soon as I spotted it I wrapped it in Flex tape then clamped it with 6 hose clamps. Water ingress stopped.
The boat is now on the hard and I have to get it fixed. Is there a way that I don't know about other than welding? I'm thinking it would be hard to weld the tube in place without solder dropping on the shaft. No ?
Appreciate all suggestions.
Thanks to everyone who has helped on other issues I have had.

 

[mike66]

Marine tex would do it. Or wrap with fiberglass.

 

[Comodave]

My concern would be that if there is rust in one place where else is it rusting? You can do a temporary patch, and it will likely be temporary, but rust never sleeps. Is it possible to replace the whole tube?

 

[SteveK]

Pictures would be nice. What metal is rusting. I mean is it the cracked material or another that was exposed to the leak.

 

[PMF1984]

Is this a stainless shaft log? If so, and as mentioned above, it’s probably shot. Mine lasted 28 years.

 

[PMF1984]

https://www.trawlerforum.com/forums/s6/stern-tube-leak-54288.html

Also known as stern tube.

 

[BuoyOBuoy]

It is the stern tube that is leaking.
I am going back to the boat in a few days and will take a picture of it to post.
My next question will be " What will it entail to replace it ? "
Thanks to everyone for your replies.
This is a great forum for getting help directly or though advice to others.
Appreciated.

 

[PMF1984]

So you might have something like the first two photos.

The boatyard I was at pulled out the existing tube, then fashioned a rig to follow and drill out the existing hole at little bigger. Got a fiberglas tube installed.

 

[Sailor of Fortune]

So you might have something like the first two photos.

The boatyard I was at pulled out the existing tube, then fashioned a rig to follow and drill out the existing hole at little bigger. Got a fiberglas tube installed.

I would go with the FG tube option too.

 

[sbman]

If you end up replacing it, Centek manufactures fiberglass tubing for shaft logs:

https://centekmarine.com/product/category/tubing/

Filter for shaft log there and you can see the sizes available. You can order the proper size from most marine suppliers.