leaking plumbing through hull fitting

[idealflaw]

hey guys,
I've had a persistent problem of when taking my boat out in the sound, getting standing water in my cabin. This weekend, I found over 3 inches of standing water in my cabin - basically slowly sinking. After MUCH investigation and hunting, I found the culprit - a brass or copper plumbing fixture that is fixed through the hull - it has a large plastic plug with a hole drilled in the plug with a wire coming out of the hole - this is where the knot meter is.

The fixture is leaking at the base (between copper and fiberglass).
I tried using a silicon sealant (3m medium semipermanent because it was ready at hand). I also attempted a putty epoxy but neither were working - mainly because the water was still flowing through the leak and compromising the seal.

Is there any kind of sealant that I can paint/baste/drown over this damned fitting so I can not worry about it, stop the leak and fix it later when I haul the boat out in the winter?
I really don't want to haul the boat out right now and I'm certain there is some magical product out there that will get the job done and keep me dry in the time being.

Please advise.

[sailingdog]

Is the bronze pinkish in color—that means the bronze has been attacked galvanically, and is soon going to fail. If so, you should probably haul the boat and replace the through-hull, since it is in bad shape and you're in danger of sinking. You really should haul the boat and repair this properly.

[idealflaw]

no pinkish color - more of that greenish blue color you see around brass or copper sometimes.

I agree that it'll need to be hauled - it's under the v-birth at the front of the boat - boat movement and waves will only be pounding on this fixture and working it loose.

when I DO haul it, I'm going to totally remove the through hull fitting and just seal the whole thing. It seems kind of pointless to me to have a knot meter when I can only go 8 knots or so and GPS can tell me this just fine. Half the time it's not even accurate due to current.

in the meantime, I'd like to seal it just for peace of mind.

[SteveInMD]

I think you would have to haul out and replace the thru hull fitting with a new one.

[Freesail99]

IF you don't haul the boat and replace the hull fitting, make sure you go to the boat everyday.

[idealflaw]

i may also try tightening the nut with a wrench (need a bigger wrench to do so).

I don't know what the cause of the leak is but I would liken it to something like a failed gasket on a sink...

land or sea, plumbing sucks. it's 2008 and after more than 2000 years of plumbing, it still leaks and fails as much as it always did...

[Freesail99]

i may also try tightening the nut with a wrench (need a bigger wrench to do so).

If that is your plan, be sure to have a wood plug close by, to jam into the hole in the event, it breaks off in your hand. You could sink your boat.

[sailingdog]

Be aware that anything you do to fix the leak now may make repairing it properly more difficult... IMHO, it is just better to fix it properly now, rather than have it as a possible danger to sinking your boat the rest of the season.

[RXBOT]

If you are not going to haul out till end of season you might try. Take a piece of pvc pipe bigger in srea than fitting that is capped of. Remove wires place pipe over fiting and epoxy or glass in place. Your boat, your risk, your call.

[SEMIJim]

I don't know about your area, but in ours we just had a haul-out/spash to replace the prop for $180 ($6/ft). If we had a leak, never mind one so bad we ended-up with standing water in the cabin, that boat would be hauled at my soonest opportunity. I'd take a vacation day to get it done. I think you're being way too cavalier about this.

As far as just yanking the knotmeter transducer: 1. A GPS is not a substitute for a functioning knotmeter, IMO. Sure, a GPS will tell you your SOG, but it can't tell you your speed through the water. 2. A GPS is a wonderful thing, but it's a compex piece of electronics that's dependent on the good graces of others. We rely on ours. But we also have a knotmeter, compass and charts. 3. I bet it will be more difficult to properly patch that hole in your hull than it will be to repair or replace that knotmeter thru-hull.

If you do choose to replace the thru-hull: Do your homework before having the boat hauled. It's probably specific to your knotmeter transducer. You may have to order it somewhere.

I doubt you'll find a sealant that's going to fix your problem on the cheap. But I've been wrong before. Even if I am: This is definitely not the way I'd go. But we love our boat, so we want her to stay afloat and be happy .

Jim