Airmar thru hull leaking

[SVTatia]

Originally Posted by Buster007

yes but this guy is a flaming retard BS artist

He could be, but the point is sh%$t happens to anyone
Good luck on your fix.

[Buster007]

Originally Posted by 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.

yep i thought the same after i hit send. plus i could do the in water job and find the fitting has a crack and be back to square one.

[Buster007]

So we hauled out and although there was a gasket below the flange nut inside, there was no caulking. and it leaked. It had not for a few years but after a few winters on the hard, stuff happens. outside there was caulking on the threaded part but none on the flange part and outer hull. What was there was dried out and coming apart. The thru hull itself was in good shape. This is a 36 year old boat

sucks that we had to learn this 3 weeks after launch

So I will rebed with lots life seal or 4200 and maybe change to bronze in the off season.

thanks everyones sugestions

[Buster007]

here it is

[Pegu Club]

Originally Posted by Buster007

So we hauled out and although there was a gasket below the flange nut inside, there was no caulking. and it leaked. It had not for a few years but after a few winters on the hard, stuff happens. outside there was caulking on the threaded part but none on the flange part and outer hull. What was there was dried out and coming apart. The thru hull itself was in good shape. This is a 36 year old boat

sucks that we had to learn this 3 weeks after launch

So I will rebed with lots life seal or 4200 and maybe change to bronze in the off season.

thanks everyones sugestions

Good to see you have things well in hand, you’ve done the right thing in hauling out and dealing with this properly, while you’re on the hard have a serious look at all the other thru-hulls, just a thought,

Fair winds,

[capt jgw]

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.

And really, really scary. If I were to try that I'd run the boat aground first, like at a launch ramp or something. Did that once to change a prop, worked well and could just stand there rather than treading water.

[ShineOn]

Originally Posted by 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?

Pull the boat, sort the problem - your bilge pump will not keep up with a failed thru-hull housing if you are not there to help (and maybe even if you are).

Do not shortcut this.

EDIT: realized this was an older post, happy you did the right thing. Safe sailing!

[_m_miles]

I had the same thing happen last fall, so I hauled out a few weeks early. It was a slow leak, but fast enough to let 6” of water into my front berth.

AirMar sells just the housing, and when I cut the old one out I found growth around the 4200 sealant. They recommend regularly cleaning the transducer and also keeping anti-foulant paint on the plastic housing.

Good luck.

[svkatface]

If the leak is small you can try using some 2 part stick epoxy. Stuff is like silly putty and comes in a plastic tube, usually green and gray. Mix together and dive under the boat and stick it down round the edges. I used it when a permanent repair was not available to fix a slow leak between the thru hull flange and hull. Don’t forget to mend it next haul out. Note that if you can’t identify the source of the leak and feel comfortable it is not going to fail then haul out now. Money not important when the water is coming in. Get used to spending it. You have a boat.

[wingssail]

If it was my boat I'd do away with that through hull completely. Most depth transducers will shoot through solid fiberglass with little loss of power. Remove the transducer and fill the hole with solid fiberglass, properly chamfered, and glue the Airmar on the inside of the new exterior skin with epoxy or silicone. Just make sure the glass laminate you build has no air or core material and the glue has no bubbles.

I've done it this way on several boats and my current boat has three transducers glued this way and has had for over 30 years, all still working although the wires are getting brittle.

[AKA-None]

I wonder how well shoot through works with chirp?

[wingssail]

Originally Posted by AKA-None

I wonder how well shoot through works with chirp?

Good question. Isn't chirp just a quick series of different frequencies? I wonder if some frequencies used would be attenuated by the fiberglass? I am shooting 50hz, 196hz and 206hz.

[AKA-None]

It’s a bit more than that as it’s off center also so more like wide rather than simply down, wider cone
No so great in deep water but for shallow it gives a pretty good view sort of 3d like