Grand Banks 35 stern tube

[CharlieO.]

When I had my new fiberglass tube made it had three o-rings to seal it on the stern cutless bearing housing. Prior to replacement water was leaking from a crack in the original stainless-steel tube into the concrete filled keel then coming in through the bilge floor.

 

[Datenight]

Bob and Linda,

We had a shaft tube leak in the green boat about 12 years ago. The bilge was foam filled and glassed like yours. When cutting it out the stench was stomach turning.

I sourced a fiberglass tube from a supplier here in Connecticut and had the yard glass it in (both ends) to ensure proper alignment. The stuffing box was on the inboard side of the tube. New cutlass bearing ( was after the tube) and we were back in business. I did not put the foam back in as we sold the boat shortly after. My plan was to glass a piece of plywood with an access port to pump out on occasion. Never got to it as we sold the boat shortly after but the glassed in tube never leaked.

Rob

 

[Bob and Linda]

Here are pictures you requested. I threw away the black foam because of the odor. The foam in the picture was above the.black stuff. I resurfaced the end of the keel where the housing bolts. I believe that the damage to the FG tube was caused when the cutlass bearing was replaced. It is common practice to saw the bearing lengthwise in oder to remove it. The picture of the tube on a square plate is my connection to the bilge for the vacuum. It is simply hot glued to the FG. I will bolts the housing back to the keel tomorrow.

 

[Frosty]

Your issue is giving me flashbacks to an older boat I had. No problem with the stern tube, but, like in your boat, the deep bilge sump was filled (with softwood and what looked like some cement powder) and then it wasn't exactly fiberglassed over. Nay, instead just plain, unfilled resin was poured in place for a top. No reinforcement. I bet that cracked when the boat was about 6 months old....

This was right under the engine and over the decades fuel/oil/whatever had dripped down onto the resin lid, and seeped through the cracks into the wood below. And sat and fermented for decades. Yep, it reeked. I ended up digging it all out, fairing it, and gaining a deep sump with no "false lid." (Not saying that's what to do in your situation though since you have more going on there.)

Not exactly your situation but close enough to bring back nightmares.

BTW, although sawing lengthwise on a cutless bearing is done, most yards know not to just keep sawing into the boat! Or if they do, they don't just ignore it and move on to the next job. Shame on them!

 

[Xlantic]

Is this the stern tube?

 

[Xlantic]

Looking at this earlier photograph again, I wonder if that cut was inadvertently made when cutting out a previous Cutless bearing or not.

In the diagram, the cutlass bearing abuts the tube, it is not inside it. So if it was cut in the removal of the bearing, whoever did it would have been extraordinarily sloppy.

My theory is that the cut on the FG tube was deliberately cut made to facilitate the tube to slide inside the bronze housing. The cut is very clean.

In any case it looks like the FG tube has slipped a bit from housing, as the surface until the small shoulder is very clean. If so, repairing that cut with fibreglass will impede the tube slipping-in again when you push the housing back into the hull.

Also, I don't see how the FG tube seals against the housing as there is no O ring or sealant. Nor how it seals at the other end of the tube, inside the boat.

Is it not possible to fully remove the housing and the FG tube from the boat to take a look inside? Also from the inside of the boat by removing the inner Cutless bearing?