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 Post subject: Centerboard Hinge Replacement
PostPosted: 11 Aug 2022 14:15 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
The forward edge of the stub keel/trunk is where you're going to whack something first. The stainless centerboard hinge is relatively unprotected - right at the interface with hard things and the rest of the hull.

So for $200 (I was mildly surprised) I had my welderator make me a new one. Very precise, elegant work. To me, this is huge. Covering hundreds of miles to wind (or thousands) I'd like the board to work and maybe save a day here and there. Or just port tacking the fleet on start in the BVI Regatta (drives them crazy, but it sometimes works very well).

The old hinge was done, useless threads, banged on something hard at some point and the board was pulling to port in the trunk. I'm HOPING this cures it and I get another couple decades out of the new hinge.

But I'm debating on fasteners. Whether to simply replace the bolts (at least 5 if I can't get that broken one up inside out) or go with Tartan (Chris) recommendation of drilling up in and lagging into (hopefully) the lead in the keel. I lean toward 5 bolts. Burying stainless lags into lead . . . eh. Stainless hates not having 02 around and simply wastes. And getting lags out without breaking them if it is ever needed. Jeeziz. What do YOU think?


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File comment: Old left, new right. Old somewhat mangled.
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File comment: before and after. Look at the threads.
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File comment: Before and after. I buzzed off the weld on the old pin so we could size everything correctly.
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File comment: The old is 2 pieces tacked together. The new is one piece carefully bent. I like the latter.
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 12 Aug 2022 06:20 
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Rail Meat

Joined: 11 Apr 2022 10:25
Posts: 21
I need to replace the same bracket & bolts. I repaired the centerboard and it is ready to reinstall. Machine threads tapped into fiberglass doesn't sound too secure. I went up one size and drilled and tapped and lost one bolt after a while. I was thinking of going up larger and securing the bolt with epoxy sealant after it is drilled and tapped for a next size smaller bolt that would be removable. This gives metal and machine thread in the keel to hold the removable mounting bolts. They make a thread-lock tape that sets up underwater, but is removable.

If the first bolt that provides permanent the threads was an inch longer than the mounting bolt that screws into it, it could be pinned above the drilled / tapped section so it could not move. If this was a 5/8" bolt, it would provide a pretty wide target for drilling for a pin - it would not have to hit the bolt square to secure it. They do make SS thread inserts, but they don't look too beefy.

A better arrangement would be a shaft w/sleeve bushing through the keel to replace the angle brackets - no other parts. The problem would be aligning the jig to drill the hole through the keel so the board movement is centered.


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Sketch of centerboard bolt hole repair.png
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 16 Aug 2022 07:05 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
Yesterday I laid under the centerboard, stared a lot and thought about your thoughts. I don't see pinning as a happening thing.

I'm pretty sure the bolts are into lead. They are solid as a rock. I checked the depth of the holes and my bolts didn't bottom out, so I got bolts 1/4" longer and added flat and lock washers. They feel solid as a rock. One bolt just wouldn't go and I snapped it off again. There were remnants of another bolt in the hole, apparently.

The washers add a tiny bit of height that will need to be faired well with soft West System filler.

BUT! The old hinge was apparently bent just enough to pull the centerboard to port so it wouldn't drop smoothly. The distal tip of the board was binding to port. That's a pretty long lever and sensitive to the distortion in the hinge. The new hinge cured the problem. Balanced and smooth as glass. Besides, the threads in the old hinge were pretty much shot.

I just want the board available for long hauls to wind. Maybe save a lot of time going to SXM and be able to tack less far south than without.

After cleaning out the trunk when I first got the boat so I could drop the board, I think maintenance is key to utility. Drop the board regularly and dig around in the trunk and scrape the board off if you plan on using it. Otherwise it's just an inviting ecosystem cave. This is why I foamed and sealed the skeg. No more cave. Hopefully the Micron 66 does it's thing well enough.


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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 14 Sep 2022 15:48 
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Tactictian

Joined: 06 Aug 2020 09:02
Posts: 142
Just going to mention here that I over-tensioned my CB pin this spring causing the bracket to compress on the board. I didn't realize it until after I had launched the boat and the board didn't go up and down easily. Had to short-haul, remove the board, loosen the bracket a turn, and re-install. Costly mistake. Be sure that your board rotates properly before splashing. If the bracket is too tight you might also have problems aligning the bold holes.


 
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 15 Sep 2022 06:51 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
I twisted mine on before bolting and backed it off a full turn to make sure the bolts lined up. But now I got to look at it before I launch. It seems to go without undue friction, but I think a cascade setup is in our future. She's heavy on the hard. Once up it probably won't come down again until it reaches the Caribbean.


 
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 15 Sep 2022 12:07 
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Rail Meat

Joined: 11 Apr 2022 10:25
Posts: 21
So are the bolts only threaded into the laminate that was drilled and tapped ? Is anything on the thread to keep the bolt in place? Are these 1/2"-13 bolts ? I need a bottom job this winter which would be a good time to put the board back on. I removed it while in the water when I was a bolt gone and one loose.


 
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 15 Sep 2022 13:53 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
I'll have to look as to size. I have the old ones out in the truck . . . they're 3/8" bolts. I'm at the 95% confidence level that they are tapped into lead keel. I spooged them up with 4200 and checked the hole depths, finding I could add 1/2" to the length (which I did). I also added flat and lock washers. The result was a teeny bit proud but it's all faired over now.

I have 1/2" bolts on the pintle plate (4) and the factory install on the centerboard hinge was 3/8" stainless bolts.

When I spoke to . . . Chris at Tartan he said "stainless steel lag bolts into lead." I was polite about it, but I just think that's asking for trouble.

I'd like to know where and how the lead runs in that keel. I know the aft end is just glass about 15" in. But I think I'd do some exploring with a small, long bit and see if I drilt into any of those holes and any obvious lead came out. Then I'd lengthen my bolts and tap into the lead. 1/2" seems rather large. I snapped off one bolt tightening it, but it was already missing where someone had stacked a shorty on a previously snapped off bolt. I just didn't clean the hole out enough.


 
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 16 Sep 2022 08:05 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
Last night I watched Zdunc's youtube (. . . think . . . funonholiday) 6 month ago haul out in Grenada and a few minutes in the slings he's dropping the centerboard. If you watch carefully, he drops two stainless lag bolts on the ground and a single 3/8" threaded bolt as he takes things apart. First time he apparently has had it out but the black bottom paint looked good (except where it was still blue at the hinge). So there appear to be some hinges at least partially lag bolted into the lead.


 
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 16 Sep 2022 08:41 
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Rail Meat

Joined: 11 Apr 2022 10:25
Posts: 21
Thanks for the info. I'd like to try to just drill and tap without doing anything elaborate. I'll check out the Holiday YouTube too. I would assume 4200 would be a good thread lock compound.

Its been years since I had the board installed and boat does make annoying leeway without it. I've won, placed and showed in a few regattas but only where windshifts were most important. I've only got a #2 on the roller furl and below 10k I think a #1 would make a diff too.


 
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 Post subject: Re: Centerboard Hinge Replacement
PostPosted: 16 Sep 2022 13:24 
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Skipper

Joined: 09 Aug 2017 15:35
Posts: 725
Location: Maine/USVI
Start at 2:39. It's a short clip on the centerboard. It looks like, if you watch carefully, he got three 3/8" x 6" or so lag bolts out and two 3/8" x 2" or so threaded bolts. He commented he lost one.
https://www.youtube.com/watch?v=cCDXBkiVPHI


 
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