Leak by the Shaft tube

[Stephen Trapani]

I have a pretty good little stream of water coming in just aft and starboard of my dripless shaft stuffing box, where the shaft tube meets the hull, maybe right against the tube, maybe an 1/8 in starboard of it. Two questions:

Is that shaft tube fiberglass? Metal?

Has anyone had a leak there and have any ideas what might be going on?

 

[Ed Schenck]

Yes and yes, I think. From the inside, when removing the stuffing box hose, I find it clamped onto a fiberglass tube. From the original mold I think. But if you look at where the shaft comes out of the boat you can see a metal tube and flange. I assume to strengthen the shaft tube. So I wonder if the H33 is the same way.

I think this link suggests all the Cherubinis were like mine: http://forums.sbo.sailboatowners.com/showthread.php?t=126153

 

[Paul F]

It is likely that the bronze stern tube is broken. Mine broke in the water and almost sunk the boat. You should be able to find them in some marine stores. Here is a link, scroll down the page and you will see them on the bottom self with other underwater gear:
http://www.discountprops.com/machine_shop.htm If it is the stern tube you may have to pull the boat to make the repair.

 

[Stephen Trapani]

How do I tell if it's broken? Could the flange have worked loose a little and water be coming in that way?

 

[Paul F]

Yes, the flange could have developed a leak over time. If you can dive and stuff a thin cloth in around the shaft, you may be able to take off the stuffing box hose and have a look. Don't turn, twist the shaft when you remove the hose. I think, you need to find this leak as it will likely get worse.

 

[gray_penguin]

My 1978 33' had a bronze shaft tube. It was basicly a square plate with 4 bolt holes and the tube part that the shaft seal attached to.

On mine the tube was broken and the 4 bolts were almost rusted through. I searched for a replacement with no luck. I ended up using a 1-1/2" bronze through hull that I modified to fit.

I have this outlined here: Click Here

I am sure to some people this was the ultimate stupid thing to do. Constructive criticism is welcome but please keep your criticism for the sake being critical to yourself

 

[Mark Ferrick]

Gray_Penguin, Very nice solution for the stern tube. I think that I will copy this when I replace my worn one.
Maybe make it permanent in the Owner Modification section for all time?

 

[SamLust]

Very inventive fix. However, based on the pictures in Paul F's link I would think modifying an off the shelf piece would have been easier. I have learned that Buck Algonquin, one of the more prolific, if not larger makers of cast bronze pieces is willing to work with us to make or modify as needed. I'm all about easier. They are the guys that made the stainless packing nut for my rudder tube when Hunter was of no help whatsoever. And just for the record, wherever that is being kept, my stern tube is a 2 bolt. The bolts Hunter used were so un-necessarily long that they were hitting the PSS I installed. Cutting them shorter in place was a REAL piece of work. If you've been in there you know what I mean.

So I give you a "10" for creativity.

 

[H33CRich]

My 1978 33' had a bronze shaft tube. It was basicly a square plate with 4 bolt holes and the tube part that the shaft seal attached to.

On mine the tube was broken and the 4 bolts were almost rusted through. I searched for a replacement with no luck. I ended up using a 1-1/2" bronze through hull that I modified to fit.

A simple solution and very well executed. Nice job.

 

[redhead78]

Steve, I had a similar problem, my shaft log threads onto the stern tube outside, and the stern log is held in wf 2 bolts top and bottom. The bottom bolt came off and allowed water to come in all around the stern tube instead of thru it and I almost sunk. The stern log is designed to let water in thru grooves in the cutlass brg, and small chambers on the side of the stern log, to keep the tube full of water to cool the shaft, and is stopped by the stuffing box. I could not see in this area, did not know till I pulled boat out.Water was pouring in, could not see where it was scary....Red

 

[Stephen Trapani]

Red, So if I understand correctly (if not completely as I surely don't) yours was an easy fix. Rebolt and recaulk, right? Hunter people, do I have any shot at the kind of setup and outcome Red describes here? I am currently in the process of evaluating my haul-out options while a guy a few slips over keeps an eye on the bilge. A boat guy came and looked at it briefly (saw basically what I've already described above) and said I shouldn't even use the motor/shaft and should have the boat towed to wherever I go because it could all bust apart. I'm thinking of renting a little generator and 110 pump instead to carry on board for the trip instead.

 

[sandpiper10471]

Red's setup is different. His cutlass bearing is in the shaft log if I read correctly. Your cutlass bearing is in the strut. I think haulout is most advisable. And do you really need a tow? You have a boat that sails really well. And if there is not wind or you need to enter harbours etc? a dinghy and outboard tied off the the side of the boat can get you a lot of mileage. Pick your weather window well, be patient, and yes, carry that water pump, generator and some good packing rags. Test the pump out while still at the dock. And if memory serves, my 79H33 had a bronze shaft log as does my 37C.

 

[Paul F]

I'll briefly relate what happened when the stern tube failed on the boat. I was single handing a great day sail. Out on a windy day about four hours. In the middle of it somewhere the bilge pump came on and pumped out water. This is not usual but I figured it happens no big deal. I got tired and started the engine about three miles out. It started fine but sounded funny. I opened the lazarette hatch some water was sprinkling out of the hatch. Being thick headed as I am, I gave it no mind. Then when entering the pass the bilge pump really got going and was running all the time. I looked for somewhere to beach the boat so that it would not sink in deep water. Fortunately the Coast Guard was there and came on-board with one of their large pumps and saved the boat. The motor kept on going and we made it into the slip. The Coast Guard stopped the leak with a lot of effort on their part. Really good guys. I called a diver and slept on the boat that night. In the morning the diver came and secured the leak underwater. He had the skills to take the prop shaft off in the water and we repaired the stern tube in the water. He is one of a kind former Navy Diver. You may be able to find a diver like him in Olympia.

If the stern tube blows like mine did expect high water in the engine compartment. Mine was at least half full. Had to replace the starter after everything was over. The small crack under the shower sump is way to small to handle a heavy water flow. I have a second sump pump in the engine compartment now.

The advice given to tow the boat to a pull out is good. As once the stern tube breaks a lot of water will come in.

 

[Stephen Trapani]

So Paul, What exactly broke where? There's a flange with a tube on it that sticks into the hull, right? A rectangular piece of bronze with a tube on it? That broke? How and what did he fix? Not sure which year your boat is and how they differ year to year.

 

[Paul F]

The stern tube application on the 1980 Hunter 33 is exactly the same as gray_penguin shows in his pictures. It is a square bronze base with four bolt holes, one in each corner and a tube in the middle which extends into the boat. This tube is what the stuffing box hose is clamped to. It is the tube that broke from corrosion. The stuffing box hose had nothing to hold onto.

The fix is to replace the stern tube. This is done by removing the prop shaft, then the old stern tube. Replace the stern tube and reinstall everything. We took off the strut so that the prop shaft could slide by the rudder. This is a good time to also replace the cutless bearing if it is bad.

 

[Stephen Trapani]

The stern tube application on the 1980 Hunter 33 is exactly the same as gray_penguin shows in his pictures. It is a square bronze base with four bolt holes, one in each corner and a tube in the middle which extends into the boat. This tube is what the stuffing box hose is clamped to. It is the tube that broke from corrosion. The stuffing box hose had nothing to hold onto.

The fix is to replace the stern tube. This is done by removing the prop shaft, then the old stern tube. Replace the stern tube and reinstall everything. We took off the strut so that the prop shaft could slide by the rudder. This is a good time to also replace the cutless bearing if it is bad.

Okay, so the way I have it figured, either the tube itself is corroded and leaking, or the flange has worked loose and it is letting water in through the hull, outside the flange/tube. The latter is a distinct possibility since the stream of water actually shoots directly forward, parallel to the shaft. Also, the stream has been known to slow way down when the boat sits for a while. From Gray Penguins pictures, that part of the hull is dicey at best. So I can't order a part or do anything until I get it out of the water and see what's actually happening. I'll plan on replacing the cutlass bearing no matter what. Thanks for of all the input, and if anyone has any more ideas please feel free to post. I'll let you know how things turn out in a few weeks when I hopefully have saved up enough money to pull this off.

 

[redhead78]

Steve, correct, my stern log,threads onto the stern tube, then is bolted top and bottom, with a gasket, cutlass brg is in the stern log. SOunds like the guys are on the rite track. boat should come out for this.Sounds like water is getting in around the outside of the stern tube.Hope its an easy fix. Red

 

[klemsaba]

I'm interested in this topic because I think I have the same issue on my S2 8.0... although I wouldn't categorize my leak as streaming. The boat is pulled for the winter and will look at this in the Spring.

 

[Stephen Trapani]

Short version: boat hauled out last weekend. The stern tube/log was corroded and broke into bits when I tried to tap it out. Got the boat out of the water in the nick of time, I guess. So had to take off the shaft (easy just by taking off the strut) and I'm having a new stern tube fabricated out of stainless for $50. It just bolts on to the hull and the dripless packing hose clamps onto it. I'm going for the 5200, permanent fix. Gob the stuff all around it and over it and it should last for forty years. Pictures will follow next weekend when I put it on.

 

[Ed Schenck]

All this discussion about failing stern tubes is making me nervous! Mine, from the outside, looking at the flange seems fine. Inside it can't be seen, it is incased in fiberglass and then the stuffing box hose covers that. Maybe I should unbolt and slide it out the shaft to be sure?