Shaft Log Leak (Pics)

nk235 · #1 (**permalink**) 04-27-2009

I posted this at the end of the other post about another members shaft log leak but I realized I might be hi-jacking his thread so figured I would just start a new one.

Boat just went in a few weeks ago and just this past weekend as I was playing around with the stuffing box I noticed a small leak coming from the platform the muffler is screwed onto. It only leaks when the engine is in gear and at cruising RPM and it sprays a very small amount of water from a small pin sized hole. The muffler seems to sit on a raised platform of fiberglass ontop the solid fiberglass of the hull so that the screws don't screw into the hole. It is inbetween these two layers that I notice the leak. At first I thought it might be the muffler but I took it out and it is dry. Also it does not leak at all unless this boat is cranking under power so I think it could be the shaft log leaking.

Also as you can see from the 2nd pic, the boat does not have an external shaft strut - the shaft just comes right out of them hull.

Is this something that is a major problem? Should the boat be hauled or is this something that can wait till end of season? Is this type of thing normal?

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Also what is surrounding the shaft log? Meaning in the part of the boat you can't see from the prop to where it enters the cabin near the stuffing box? Is it hollow? is it fiberglass? I'm trying to figure out that if water is getting outside the shaft log, what it might be damaging

Thanks
Nick

erps · #2 (**permalink**) 04-27-2009

Leaks through layers of laminate scare the be-jesus out me. Wonder if it's freeze damage? I think it's going to take a fiberglass guy to look at it. Maybe they can haul it out, drill bazillions of holes into the area, dry it out and then squirt all sorts of epoxy resin into that area and that would just be a patch.

xort · #3 (**permalink**) 04-28-2009

NK

Hard to tell from the pic, where is the water coming from? the shaft log? Or from the fiberglass below? Is the water clear sea water? Or is it oily, sticky?

nk235 · #4 (**permalink**) 04-28-2009

It seamed to be clear but it is such a small amount that I am not sure. Also I took off the muffler which was screwed in with four 1 inch long screws and the whole area seemed to be solid and no water was seen in or around the screw holes. The only reason I am thinking it is the shaft log is because where else would the water be coming from? Also it only happens when the boat is in gear at cruising rpms/speed.

nk235 · #5 (**permalink**) 04-28-2009

Also what do you think is in that raised platform that the muffler is screwed onto and the shaft log enters? Do you think it is hollow? Would it make sense to drill a tiny hole into the front facing triangle to see if water really is getting in there?

KeelHaulin · #6 (**permalink**) 04-28-2009

It could be that this type of installation requires a weep hole to allow water in to the cutless bearing and shaft seal. If there is no way for air to escape then the cutless and shaft seal could get an air pocket trapped in and remain dry which would increase friction and cause heat damage.

capn_dave · #7 (**permalink**) 04-28-2009

the shaft log is leaking? Water cannot run uphill. I really would suspect the muffler. You say it only leaks at crusing rpm and then a fine mist? It also could be water flying off the packing gland when under power.
I would check the muffler again under power.

Fair Winds

Dave

sailingdog · #8 (**permalink**) 04-28-2009

water can run uphill, via capillary action. That's how trees get water from their roots... and it can go a long, long way uphill.

Quote:

Originally Posted by capn_dave

the shaft log is leaking? Water cannot run uphill. I really would suspect the muffler. You say it only leaks at crusing rpm and then a fine mist? It also could be water flying off the packing gland when under power.
I would check the muffler again under power.

Fair Winds

Dave

nk235 · #9 (**permalink**) 04-28-2009

Its def not the muffler or the stuffing box - I am sure of that. Thats why this is confusing me so much because I cannot see what is going on inside of that fiberglass triangle that the muffler is sitting on and the shaft log goes in to.

What is usually surrounding the shaft log? Is it solid fiberglass or is it a hollow area?

sailingdog · #10 (**permalink**) 04-28-2009

I'd hope it was solid fiberglass.

Quote:

Originally Posted by nk235

Its def not the muffler or the stuffing box - I am sure of that. Thats why this is confusing me so much because I cannot see what is going on inside of that fiberglass triangle that the muffler is sitting on and the shaft log goes in to.

What is usually surrounding the shaft log? Is it solid fiberglass or is it a hollow area?