Stern log installation

[sailoppopotamus]

I seem to have a leak around the stern log. It's not severe, but the boat is out of the water currently so I intend to get this fixed. The stern log in my case is just a brass pipe, glassed into the hull, with various sealants of different colours around it (clearly a previous repair that hasn't stood the test of time). The yard intends to cut the tube out and re-glass it into place. They mentioned using Sikaflex to ensure the repair will be watertight. Is it standard to use sealants in this application? Various things I've read online seem to indicate that people tend to epoxy the tube into the hull without using any sealant at all. If it makes a difference, this is just a brass pipe. It has no cutlass bearing (I have a p-bracket) and no flange.

PS: It's not the lip seal that's leaking. I replaced it and the leak is still there and coming from the perimeter of the tube.

 

[Tranona]

It is probably the end of the brass tube dezincifying. Take the seal off and have a look. The best repair is to take it all out and epoxy a GRP tube in rather than another metal one. lakesterngear.co.uk/catalogue.pdf How to do it was covered in an article in PBO a couple of months ago, but the yard will hopefully know how to do it. Should be no need for sealants.

 

[sailoppopotamus]

The inboard end shows no sign of dezincification, it's got a nice bronze colour to it and no signs of pink. The forum is not letting me upload a photo for some reason.

I like the idea of a GRP stern tube. Vetus make one that seems to match the dimensions of my current tube (44mm OD). That for sure would eliminate the need for Sikaflex. My only concern is that the GRP log might have a thicker wall than the brass one, leaving less space for the shaft to vibrate without hitting the walls. I know it's not supposed to do that, but the 2GM20F I have vibrates quite a lot.