leaky sterngear - repair sequence advice please.

[smb]

I have a leak around the sterngear of my 38" Trident Voyager. It started following our last lift/launch in the UK, when during the lift I believe the strop was initially caught on the prop. This led to a slightly bent shaft, producing a wobble such that the Volvo shaft seal could not maintain a water tight seal and there was a visible drip - drip whenever the shaft was turning.

Having had the shaft straightened and renewed the seal I found I still had water coming in from elsewhere. Mirrors, contortions, torches and a few 'blind' digital photos revealed dampness around the stern tube where it passes out through the end of the keel.

The cutless bearing is held in a scoop type bearing housing fitted to the end of the keel. As a temporary repair I have applied a fillet of underwater curing epoxy around the perimeter of this housing. This seems to have stopped the leak but on lift-out in September I would like to make a more permanent repair, presumably by removing the bearing housing, cleaning up and repairing any damage to the keel and then re-seating the housing on a bed of Sikaflex.

Is it possible to do this without totally removing the sterntube? Am I right in thinking that if (and thats a big if due to the lower ones location) I can successfully remove the top and bottom bolts from the housing, it will then unscrew from the end of the sterntube? That being so what are the chances of sufficient sealant staying in place when I screw it back on to the tube, or will it all get wiped off on the end of the keel during the final turn or two?

Finally, if I have to move the sterntube to overcome the above, how do I go about it?

All advice will be most welcome as I would like to get back to having a dry(ish) bilge.

Steve

 

[Poignard]

[ QUOTE ]
Am I right in thinking that if (and thats a big if due to the lower ones location) I can successfully remove the top and bottom bolts from the housing, it will then unscrew from the end of the sterntube?

[/ QUOTE ]

That`s right.

As regards sealing it when you put it back together. what I did was to seal the threads on the tube and the screws with Rocol PTFE Sealant X15-72. This keeps the water inside the tube and out of the screw holes. Personally I wouldn't use Sikaflex on threads but some people do.

As you point out, sealing compound applied to the mating faces of the "sternpost"/bearing housing flange will be scraped off by the final turn of the housing. However, if you put a ring of it around the neck of the spigot that goes into the counterbored hole in the sternpost it will keep the water out of there.

This worked for me and now the only time I have to use the bilge pump is to clear water that has come down the chain pipe.

 

[smb]

Many thanks for that. I didn't realise that there was a spigot/counterbore arrangement - should be able to seal around that OK and will take the tip of PTFE for the shaft thread AND screw threads/holes.


Steve