Airmar thru hull leaking

[Buster007]

Plastic Airmar knotmeter thru hull - I noticed it leaking and I went to insert the plug and tighten. The whole base turns which is no bueno. I tightend as best I could but it still leaks. Is my only alternative a short haul to further investigate?

[Mike OReilly]

If it still leaks when you try the plug, then you've most likely got a thru-hull problem. Hard to solve that in the water.

[tkeithlu]

Yes, it appears that the leak is between the hull and the plastic through hull, not inside the through hull. Pushing sealant into the cack between the two might reduce the flow untilyou can pull the boat. Tightening the ring on the inside of the boat might also help. Sorry - it's one of those little jobs that get really expensive because it involves lifting the boat out of the water.

[Bill O]

^^^^ +1.

If you have some sealant that will work on a wet/leaking joint, apply to surface to slow down the leak. Again a temp fix until you can pull the boat to do the correct fix.

[SVTatia]

I'll treat this as an urgent situation, you don't know if the flange on the outside is good or not, and if the transducer comes off you get a 2 inch hole at the bottom of your boat that could ruin your day. If a haul out is not possible, I would epoxy the thing to the hull until then, rather than just caulk. Better to have a wooden plug nearby just in case.
I watched Sailing Zingaro a few weeks back and he almost lost his boat due to a similar failure, a speed transducer that came undone.

https://www.youtube.com/watch?v=xBWvamrLoe4

[George_SD]

You can use some types of adhesives to fix it temporarily until the next haul out, but you should do it right at the first opportunity.

One way you could without haul-out is to make a water tight dome to put in temporarily above the transducer, then have a diver try to remove the housing from the outside, use generous amount of underwater adhesive, reinstall. Then add a bit of extra adhesive from the inside.

[Buster007]

Originally Posted by Bill O

^^^^ +1.

If you have some sealant that will work on a wet/leaking joint, apply to surface to slow down the leak. Again a temp fix until you can pull the boat to do the correct fix.

can you recommend a sealant
?

[Buster007]

Originally Posted by SVTatia

I'll treat this as an urgent situation, you don't know if the flange on the outside is good or not, and if the transducer comes off you get a 2 inch hole at the bottom of your boat that could ruin your day. If a haul out is not possible, I would epoxy the thing to the hull until then, rather than just caulk. Better to have a wooden plug nearby just in case.
I watched Sailing Zingaro a few weeks back and he almost lost his boat due to a similar failure, a speed transducer that came undone.

yes but this guy is a flaming retard BS artist

[Bill O]

Not sure of your location, but would go for a moisture cure urethane.

They can be expensive, but Gorilla glue makes one that may be available and not too expensive.

[thunderhoof]

I likely problem is that the plastic nut clamping the flange to the hull was over tightened, cracking it. This is a potentially catastrophic situation. Possible short term fix is to use a big bead of 5200 or waterproof epoxy (if it will cure) around the inside joint, nut and hull.
Another possibility is that the face of the thru-hull is not properly seated allowing it to leak even if tight.
I have personally changed a thru-hull in the water with a diver holding a new thru-hull in the water ready when I pushed the old one, nut removed, into the water. Not dry - but it worked.

[CarinaPDX]

Consider buying the optional bronze thru-hull when you do this job. I know the GRP ones are very good but I just don't trust them - over-torquing during install can still cause failures. (So if you do keep the GRP thru-hull do be careful to not tighten too much when you re-install.)

Greg

[Buster007]

Originally Posted by thunderhoof

I likely problem is that the plastic nut clamping the flange to the hull was over tightened, cracking it. This is a potentially catastrophic situation. Possible short term fix is to use a big bead of 5200 or waterproof epoxy (if it will cure) around the inside joint, nut and hull.
Another possibility is that the face of the thru-hull is not properly seated allowing it to leak even if tight.
I have personally changed a thru-hull in the water with a diver holding a new thru-hull in the water ready when I pushed the old one, nut removed, into the water. Not dry - but it worked.

Thanks.

i'm fairly sure the nut is not cracked. i tightened it down but i don't see where the original installer had any caulking or bedding under the nut and against the hull. that's where the annoying slow leak is.
i think if we have a diver remove the thru hull and reset with a bunch of butyl tape or similar on the outside, and same on the underside of the nut/flange on the inside we can pull this off with some bungs at the ready.

otherwise will go for a short haul but all the marinas here want $500 for a short haul.
stupid - the yards are empty now and the equipment is idle.

if they were reasonable they could make $200- $300 for 2-3 hours work.

[Buster007]

good idea.

[Buster007]

really hoping for a mid term solution and change a bunch of thruhulls when hauled for the season in October.

[Madehn]

I live butyl tape and have used it extensively but I don’t think it is rated for underwater hull work. Bite the bullet and do the short haul Better than possible catastrophic failure. Some things you cheap out on and try a quick fix Others like underwater fittings you never take a chance on. Your boat though and your choice.