Sealing stern tube into deadwood

[Sniper]

I have removed the stern tube on my wooden Twister for a bit of TLC around the deadwood and will soon have to replace it. I believe white lead paste has been used traditionally to bed it in but I’m wondering if there may be a better method? I’m quite taken with the idea of using CT1 which is an amazing product in many ways but I’m just a bit wary of its adhesive qualities; once it’s stuck its stuck and if I ever needed to remove the tube again I would be faced with a horrendous job.

any views or experiences?

 

[Poignard]

I used a thread-sealing compound on the sterntube threads and something like CT1 on the mating face of the flange of the stern bearing. I also used the thread-sealing compound on the screws securing the stern bearing to the deadwood.

 

[Sniper]

Thanks for that; your experience fits with my intuitive ideas. I guess the best thing is not to get the CT1 too far up the tube from the outer bearing flange so that later removal is still a possibility.

 

[Poignard]

I have looked up the thread sealant I used.

Loctite 572

That was in 2018 and it has been fine since then

 

[Redwing228]

We bedded our tube into the Finesse’s stern post with Sikaflex 291. It was wrapped in PVC tape to form a barrier between the metal and wood.
Write-up of what we did to her is here: Finesse 24 Sailing Yacht
Bill

 

[Sniper]

Thanks for that Information Bill. When you say PVC tape, can you remember exactly what you used?

 

[Redwing228]

Thanks for that Information Bill. When you say PVC tape, can you remember exactly what you used?

We just used PVC electrical insulation tape as I wanted a galvanic barrier between the metal and wood.

 

[tillergirl]

Polysulphide is the right product for that application. CT1 and Sikaflex (I assume you refer to 291) are adhesives that can only be removed mechanically once cured. Why on earth use an adhesive in a service application when at some stage in the future will to be dismantled (e.g. changing the stern bearing). Hardly likely to be frequent but white lead putty was used precisely because the builder's knew at some stage dismantling would be required.

 

[fisherman]

Local 'do it all' boatbuilder/fisherman repaired a stern tube leak. 25ft boat had run into a large mooring rope some one had kicked off the quay, and shaken the deadwood.
He had a grease gun full of white lead putty, and a square headed coach bolt with a hole down the middle, grease nipple in the top. He drilled two holes either side of the front, two at the aft, end into the stern tube housing, from outside, screwed the bolt in, pumped full and plugged the holes. Still fine several years on.

 

[Sniper]

Thanks for all the ideas. I’m starting to think of a plan which will use white lead paste injected into the main void (I think this was used originally) but with CT1 to seal the flanges of the cutlass bearing and stuffing box at each end, using thread sealant on assembly. My thinking is that if ever removal is required in the future, it will be possible to shear or cut the CT1 to allow removal while the bulk of white lead will prevent movement in the tube. I’ll try Fisherman’s idea of injecting through a hollow coach bolt too.

does this sound like a workable plan, mixing old and new technologies?