Leaking hull deck joint

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dahlke
Posts: 111
Joined: Mon Jul 15, 2013 5:20 pm
Location: Randers, Denmark

Leaking hull deck joint

Post by dahlke »

In Ballad #332 there are obvious signs of leaks between deck and hull.
1) visible water damage (foam material and bolts)
2) a lot of paper towel that the PO placed along the joint

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Seeing as all of the interior has already been removed I'm thinking that now would be the time to fix this for good. What are my options if I want a lasting fix? :-)

I'm considering glassing the joint from the inside and resetting all the bolts in whatever caulk is appropriate.
Mads
Ballad #332 (aka. Obelix)
Restoration blog
Boat and restoration pictures
Bob McGovern
Posts: 283
Joined: Fri Oct 26, 2012 3:08 am
Location: Wyoming, USA

Re: Leaking hull deck joint

Post by Bob McGovern »

Are you 100% sure it is your hull-to-deck joint that is leaking? The Ballad did not use the common hard adhesive putty to join the two, but rather a sticky butyl sealant (which no doubt you have encountered. ;) ) If I may modify one of your photos...here is the hull/deck joint proper, with butyl sealant above the hull's turned-in flange:

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Is the water coming in at that interface? Because our sealant is still very much doing its job. Our leaks come from the thru bolts, which compress into the toe rail over time and then drip. Do your carriage bolts have stress cracks around them on top of the toe rail? That may be the cause of the leaks. The corrosion down the length of the bolts suggests that.

Since we have removed the inner skins from the side decks and will need to tape them back on anyhow, we may clean off excess sealant and glass over the whole hull/deck joint anyway. If it is only the bolts that are leaking, those can be popped out (easy, tho tedious) and rebedded. You could use thickened resin under the head, or a flexible epoxy like G*Flex, or polysulfide, or polyurethane (3M 5200), or butyl tape.

Some thug went around our entire outside hull/deck joint with silicone caulk, which will need days of scraping & chemical washing to get off. :( It was the stupid bolts that were leaking, anyhow. Not the joint itself.
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dahlke
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Joined: Mon Jul 15, 2013 5:20 pm
Location: Randers, Denmark

Re: Leaking hull deck joint

Post by dahlke »

Bob, do you read minds? ;) I've been mulling it over ever since I posted and have arrived at the same conclusion. My plan is to do exactly as you described (rebed the bolts) :)

Looking forward to seeing new progress pics :) I'm stuck waiting for plywood. In the meantime I'm trying to dissolve the glue residue (from the foam backed vinyl) on the inside of the hull. I don't know the english term for the stuff I'm using but it might be "potassium soap". Rub on, cover with plastic and leave it for 2 weeks. I did a small test - the glue and small pieces of foam peeled of relatively easy :)
Mads
Ballad #332 (aka. Obelix)
Restoration blog
Boat and restoration pictures
Bob McGovern
Posts: 283
Joined: Fri Oct 26, 2012 3:08 am
Location: Wyoming, USA

Re: Leaking hull deck joint

Post by Bob McGovern »

We have white-painted interior sides -- some other unfortunate did the nasty work of peeling the vinyl liner off and painted the roving. So you can see drip lines on the hull pretty clearly, and they match exactly the bolt locations. It was easy to determine the bolts are the source of ingress. Except for two spots: way aft, we show some laminate damage in the back corners. The Ballad seems to sit off-level on its keel, leaning backwards, so water pools back there and has acid-leached some resin right thru the hull/deck flange.

And port side forward, there was on area of the flange that is clearly leaking and looks different from the factory job. Closer inspection reveals our dear Ballad was T-boned at some time previous! A good sized chunk of the hull, rail, and even part of the deck has clearly been extensively and professionally re-glassed. :shock: You can see the gel-coat mismatch in the right light. But the new gelcoat was sprayed too thick & has cracked, so we are getting leaks there. I'll need to grind it back and epoxy-fair it before we paint.

It's possible the hull-deck joint could leak on these boats, but that butyl is amazing stuff. It never gets brittle or loses its grip. It doesn't add much structural strength, tho, so maybe if the bolts compress & get loose (many of ours are loose), the perimeter seal might fail? Just tightening the bolts should renew the seal. I'm planning 5200 to re-bed ours when the time comes. Countersink the recess to get rid of the cracks, fill flush with epoxy, then bed in polyurethane. I really like the look of bright stainless bolt heads on Peter's Ballad, so we'll wire-brush off the paint.
northerncaller
Posts: 15
Joined: Sun Sep 22, 2013 7:06 am

Re: Leaking hull deck joint

Post by northerncaller »

Hi Guys (dahike and Bob)

I'm really interested in this discussion. My Ballad has a leak on starboard when she's well-heeled over, which I need to find and fix, so the suggestion that it might be the bolts is interesting.

But my main question concerns the interior of the hull. Gancia Girl has what I guess is foam-backed vinyl (not sure that's spelled correctly), which has peeled away and is in pretty poor condition. I've tried sticking ity back temporarily but that hasn't worked and it needs stripping down. I took note of your solution for getting rid of the stuff dahike. Did it work? The post was nearly two years ago so I guess you will know by now! Also, Bob, I noticed that you said you simply painted the inside. Has that worked? What about condensation? What paint did you use and what undercoat? I've counted 22 compartments on the boat, which will all have to be done, so I'm looking for an easy solution! :lol:

Cheers!

Mike
Bob McGovern
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Joined: Fri Oct 26, 2012 3:08 am
Location: Wyoming, USA

Re: Leaking hull deck joint

Post by Bob McGovern »

Mike: I'm still at the 'tabbing and cleanup' phase & have not yet painted the interior. Previous owners used a durable but too-glossy paint on the freeboard parts of the inner hull. They didn't entirely scrape the residual foam stuck to the hull, making for an uneven look. It will all come off & be repainted. Any good quality exterior paint will work just fine. Our boat will be sailed in tropical Mexico, where the air temperature is 32*C and the water is 27*C, so we don't anticipate much condensation. :mrgreen: In Northern climates, renewing the foam or adding carpet like Peter has done would be helpful both in maintaining cabin temperature & holding down condensation.
northerncaller
Posts: 15
Joined: Sun Sep 22, 2013 7:06 am

Re: Leaking hull deck joint

Post by northerncaller »

Thanks Bob. I think I'm going to have to use the foam-backed vinyl again! :?
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