[Public-List] Stern tube

[David Fay]

Gerard,

Here's a more direct answer to your question.

I don't think you'll have any luck trying to stop the leak on the inside of the boat so you don't have to haul it. That's what I tried to do and it didn't work. The problem is that you're dealing with multiple materials (thiokol, bronze tube, and fiberglass) and finding a sealant that adheres well to all of them will be tough. Second, the pressure of the water from the outside will tend to defeat whatever sealant you use. It's a much better bet to put sealant on the outside of the hull (as I detailed in my previous note) than on the inside. That way the water pressure is working with you not against you. Finally, your stern tube may well be loose now. If it moves, the sealant will have a hard time keeping the water out.

You can try sealing from the inside, and you may get lucky (I tried marine epoxy, boatlife caulk, butyl, and a few others -- nothing worked). But don't be surprised if you have to haul the boat out and make a proper repair.

David

> On May 28, 2020, at 11:32 AM, Gerard Kuperus <gkuperus at hotmail.com> wrote:
> 
> David,
> 
> That is very helpful, although not necessarily good news: it is indeed leaking from the Thiokol. Since I do not plan another haulout right now, what would be my best options to stop the leak for now. Could I use a sealant on it that can be applied to wet surfaces? Some underwater epoxy? 
> As far as I could tell when I replaced the cutlass bearing is that the stern tube is in good shape. I think that because of the movement with removing the bearing a weak point in the Thiokol (at the bottom there is only a thin section, less than a 1/2 inch, at the spot where I saw water, probably a 1/4 of an inch) gave up. Maybe that is wishful thinking, but I hope I can simply fix it, at least for now with an adhesive that works in wet conditions and sticks to fiberglass and Thiokol. I can then again assess at the next haul out. 
> 
> Suggestions?
> 
> Gerard