Stern tube fiberglass leak

[Jhubb_99]

We have a Pearson 30' in the water and we have discovered a leak. It is coming from inside, at the elbow of where the shaft log goes through through the stern tube. We didn't see any sign of cracks or thinning on the outside of the hull before she was launched...but then again didn't look at the stern tube area with any special attention at the time. But now on the inside we can see a very small leak (about 8 oz every 2-3 hours)...but is much bigger when we have the engine running and not even engaged (about 2-3 cups in 10 minutes). I've added some pictures. The first is a little zoomed out. The second is zoomed in with some marks to show the outline of the stern tube. And the third is without the marks.

We have slowed the leak temporarily with Life Caulk. After it is dryer in there, we are thinking about trying MarineTex or do a polyester resin/glass mat build-up to get through the season without hauling.

So looking for feed back on both repair methods (to get us through the summer) as well as input on the structural strain on that area. It is not easily accessible and the glass work will not be pretty.....will it be enough you think? Can we cruise for 2 weeks on that temp fix with relative confidence? (I know..that is a loaded question!)

[sailormed]

Difficult to see anything significant on your photos. Instead of putting caulk on the inside against the water pressure, try putting "Stay Afloat" or something similar on the outside. I think you can even find underwater polyester or epoxy for emergency repairs. Good luck.

[Bill Seal]

I had a weeping thru hull, used a West Marine epoxy putty stick and stopped it temporarily while still in the water, it's been a couple of years now, and it's still holding. We're due for a haul-out, maybe I'll fix it then.

[stormalong]

Plumbers epoxy putty, available at any hardware store would be my temporary repair material of choice. It sticks to wet surfaces. Not sure that lifecaulk will stick to wet.

What I saw not too long ago was a boatbuilder replacing an old bronze shaftlog with a fiberglass tube glassed to the hull. Makes sense to me - there is no stress on it and it can be diy'd easily. Centek Makes it and it can be purchased in one foot lengths at fisheries supply.

[ilenart]

I had a leak through the stern tube coming into the yacht which was the result of a botched repair. A shipwright ended up doing a total rebuild, see attached photos. First two photos show the botched repair, then halfway through the repair, then the final result.

Hope this helps, Ilenart

[coopec43]

Well, I have never heard of this before but I'm going to get some before I put my yacht in the water.

[Squanderbucks]

Often times stern tube ( shaft tube) failures are from either the shaft being out of alignment rubbing the inside of the tube or excess vibration causing cracking from fatigue.
Another example of types of issues people often ignore because it’s not too bad. Just vibrates a little or or I just won’t run it very fast. Fix it later

I suggest you get boat hauled and fix it ASAP. Leaks only get worse. Caulk or epoxy putty is only an emergency fix.

[Max Nankervis]

I had a similar leak in the stern tube. A hairline crack in the (stainless, I think) tube just as it enters the boat. Worse when motor was going. Looked a bit unsafe to me as the consequences of a total break.....! The eventual result was a haul-out, and the stern tube cut out with a specially made "keyhole" type saw about 300mm long. (This involved dismantling rudder, etc) Then a fibreglass tube inserted, and parts of shaft area cut away to embed the tube. A difficult job to perfectly align the tube/shaft. And a new dripless seal on shaft. It worked - but somewhat expensive operation. Not a job for the less experienced.