Stern tube / packing gland hose

[JuanMarcos]

My Beneteau First 38 nearly sank to the bottom of the marina last weekend!!!

After a few hours sailing around Galveston Bay, I pulled into my slip and tied down. When I went below deck to turn on the AC shore power switch, I noticed that water was starting to seep through the soles, and seconds after it started to cover them. I heard the sound of water gushing in from the engine compartment and saw it was coming from where the packing gland hose attached to the stern tube (the bilge pump could not keep up with the rate at which water was coming in). I immediately re attached the hose to the tube and stopped the water from coming in before any serious flooding occurred, and tightened the two hose clamps holding it in place.

I was able to drain the water quickly, dried everything up, and connected a dehumidifier that has kept everything dry.

Here's my question: is it possible that just 2 hose clamps are all that is keeping the hose in place and water from coming into the boat, or is something else wrong with the way that my stuffing box is installed?

After this experience, I will have a hard time relaxing when I take the boat out, so here's my second question: Is there anything I can do to minimize the risk that the hose will ever come off the stern tube ever again?

As always, the generous advice from more experienced boat owners will be immensely appreciated.

 

[JRT]

Wow, sounds like something isn't right on your stuffing box adjustments. Have you adjusted the drip appropriately recently? 2 clamps seem like the correct installation.

 

[heritage]

They are all like yours. Two hose clamps on the stern tube and two hose clamps on the stuffing box. You need to buy the best clamps available and check that there is not any corrosion of the stern tube where the hose attaches.

 

[heritage]

This picture of my old bronze stern shows that the combination of zinc and copper was not quite right. The corrosion occurred under the stern tube hose. I noticed a slow leak, so after a haul out, I pulled the hose back and saw a small amount of corrosion on the bronze. I tapped it lightly with a hammer and chunks of it fell away!

 

[Mechone]

Most Beneteaus do not use the old packing style glands . How old is your boat? Going back to the mid 1980's Beneteau has used Volvo dripless on tubes which use a wide special clamp that comes with it .
with regards to it coming off the clamps must have not been tight or the gland to too tight and drive shaft force worked it off. Remember they are to drip a drop of water very minute or so. The volvo dripless is dripless no water and cannot be driven off by driveshaft . My bilge has dust in it for the last 3 years after replacement, they last about 7 to 10 years and are about 120.00

 

[Tally Ho]

Mine is just like that. Shows the importance of checking the clamps periodically.

I will be checking mine this weekend!

Greg

 

[JuanMarcos]

Thank you all for the valuable advice. I guess I'll just make sure I check and tighten the clamps periodically as necessary (and get an industrial pump to bail water if the worst happens again).

 

[Ralph Johnstone]

I took the hose off the stern tube a few years ago while on the hard for a look see and it was a nightmare to get off. Plenty of heat from a hair dryer before it did surrender after a life and death battle.

Everything looked good and back together it went.

Even if the hose does let go, it's still got to drive the gland up the shaft and that could take a bit of force. Are you sure that everything is copacetic back there. It should have been a life and death battle to get the hose back on the tube. That hose is tough and not forgiving. Are you even sure it is a genuine stern tube hose ? ? ?

 

[NYSail]

A picture always helps let people know what you are speaking about as there are many different set-ups.

I assume you mean the cooling hose as seen in picture. Isn't there a sea-cock to close off the water feed to the stern tube. Make sure the nipple on the stern tube is secure... they have a history of breaking. Regarding what can you do to prevent this..... at the beginning of every season I tighten every clamp on my boat...... and always during the season I do a visual to make sure all is good. All hoses that go to thu hull fittings are the same... two clamps. Vibrations can loosen them.

Good Luck... I'm sure you will be fine.

Greg

 

[Benny17441]

First figure out how come the hose became detached. Is there travel in the shaft? Is the shaft out of balance or motor mounts worn? Is the hose soft and worn? Were the clamps rusted? The reason for having two clamps is redundancy, should one clamp fail the other one will hold, chances of both failing at the same time are nil. Try to eliminate excessive vibration if present, replace clamps, tighten and inspect periodically as well as all the clamps in the other hoses. For the first few outings check it often until you may gain confidence. Some people install 120V powered sump pumps that they can use at the dock to quickly remove water if necessary.

 

[JuanMarcos]

A picture always helps let people know what you are speaking about as there are many different set-ups.

I assume you mean the cooling hose as seen in picture. Isn't there a sea-cock to close off the water feed to the stern tube. Make sure the nipple on the stern tube is secure... they have a history of breaking. Regarding what can you do to prevent this..... at the beginning of every season I tighten every clamp on my boat...... and always during the season I do a visual to make sure all is good. All hoses that go to thu hull fittings are the same... two clamps. Vibrations can loosen them.

Good Luck... I'm sure you will be fine.

Greg

That looks like a dripless system. the hose I'm talking about is the one that goes over the prop shaft and connects the stern tube to the stuffing box.

I will be ckecking the clamps often. When the incident happened, the clamps were loose, so I wonder whether the source of the problem is engine misalignment or some other issue that generates too much vibration. I may end up calling a mechanic for good measure.

Thank you for the reply.

 

[NYSail]

So it sounds like you have the traditional style stuffing box.

Most modern beneteaus Ive seen use the Volvo like in the picture. In any event, the hose on the traditional stuffing box goes through a lot of torque and vibration and must always be checked. Basic vibration will loosen clamps regardless of misalignment or not.

Glad to hear the boat didn't go under!!!!!!

 

[JuanMarcos]

Update: Yesterday I decided to take the boat out and see what's going on with the prop shaft when the engineis on gear. Same thing happened again, but I was able to see the cause. It appears that the stuffing box is seized onto the prop shaft and the whole thing (stuffing box and hose) turn with the shaft, which is why the hose came off the stern tube.
The odd thing is I've been using the boat for 6 months and this is only happening now (even though I have not touched the stuffing box or attempted to tighten the packing).

 

[Mechone]

Update: Yesterday I decided to take the boat out and see what's going on with the prop shaft when the engineis on gear. Same thing happened again, but I was able to see the cause. It appears that the stuffing box is seized onto the prop shaft and the whole thing (stuffing box and hose) turn with the shaft, which is why the hose came off the stern tube.
The odd thing is I've been using the boat for 6 months and this is only happening now (even though I have not touched the stuffing box or attempted to tighten the packing).

Exactly what I said in post #5 it must drip water or it's too tight, do yourself a favour and change it out to Volvo dripless ,I changed out 2 CS 36 boats from packing this past winter

 

[NYSail]

Sounds like someone tighten something and didn't know what they were doing.....

Great time to remove shaft and bring shaft and prop to a shop to have then "trued" up..... At same time figure what type of packing glad you want and get a new one... traditional or drip-less.... have to say the Volvo is great but its like an anchor conversation...... Make your own mind up.

Greg