Broken screw for centerboard pivot bracket

papa barry

New Member
I purchased an older Capri 14. One of the mounting screws for the pivot bracket is broken. Does anyone know if these screws fasten to individual embedded nuts or is there an embedded plate with two threaded holes?
 

Chowda

New Member
I broke one of mine as well - sheared the head off and extractor won't back out the screw- I plan on just drilling and screwing a new screw next to it- won't be a machine screw like the other three but hopefully a get enough bite on something
 

caprintx

Member
Just curious - did the screw heads pop off while trying to remove them manually with a screwdriver?

I have a replacement waiting in the garage for my cracked centerboard. Looks like I need to be really careful with those 4 bolts.
 

aquaman

Member
I purchased an older Capri 14. One of the mounting screws for the pivot bracket is broken. Does anyone know if these screws fasten to individual embedded nuts or is there an embedded plate with two threaded holes?
Call Catalina Tech Support @ 916-843-1971. They're a great resource for questions like yours...........
 

speedyox

New Member
Did any of you guys manage to replace your broken centerboard screws?

My bracket got mangled last weekend and the two aft machine screw heads sheared off when I was getting the bracket out.

I've bent the brackets back into shape but can't extract the machine screws. I'm planning to drill new holes near the aft end of the brackets but I'm not sure how to go about getting new screws to hold into the hull. And how to get them sealed.

The existing fasteners are 10-24 x 1.5" and seem to go into grayish threaded holes in the deck. Is this just resin?

Please help me choose one of these options:

1) Use #10 stainless wood screws into new pilot holes next to the old ones? Do I need to seal this with anything? Can I use Butyl tape under the bracket and around the screw heads? This is definately the simpliest solution but I don't have any idea how well it will hold.

2) Drill 1/4" hole 1.25" deep and fill with Marine Tex epoxy. Then drill and tap to 10-24 1" deep. Use 10-24 x 1" machine screws. I've never worked with Marine Tex but will be using it to fix a few chips in the bow caused by the same incident. The internet tells me that there is no reason to tap 1.5" deep for a #10 machine screw and my tap won't go deeper than 1" anyway due to shank diameter. Will this work?

3) Some other idea you brilliant sailors come up with.
 

caprintx

Member
Wish I had some advice but I've just been sailing along with a cracked centerboard because I don't want to snap those screw heads off trying to remove and replace it. Could you cut a slot in the broken screw with a Dremel cutoff wheel then remove with a screwdriver, maybe heat it up with a soldering iron first?
 

speedyox

New Member
I'm still working on fixing mine. I got the broken screws out without destroying the boat but still have some work to do to fix the hole and get everything back together.

The first image shows the 10-24 machine screws broken off in the holes. The second shows what's left of the two screws after using a roll pin to extract them. As you can see the first one came out okay, almost miraculously, after chucking up a 1/4" roll pin and running it in reverse over the broken machine screw. The second one was a lot more frustrating. At first it bit a tiny piece off the screw. Then I couldn't get the roll pin to bite any more so I tried cutting some left handed teeth in the fresh end with an angle grinder. That made it cut better but it still wouldn't bite. I switched to a smaller size roll pin and that took a ton of force to get around the screw and as soon as it bit down it sheared off another tiny piece of the screw rather than turning it out of the hole. This happened with both ends of the smaller roll pin before I went back to the sharp end of the first pin and pushed harder faster and more angrily. After smoking a ton of resin and boiling a lot of my sweat that kept falling on hot metal, the last inch or so of screw came out.

As shown in the third photo, the screws are out but the holes aren't perfect. There is probably 1.25" of good threads on the better hole and 1" on the worse hole. I had to run a tap down the bad hole to clear the threads.

Now I'm trying to decide how I'm going to re install everything. I'm planning on using new 10-24 x 1.5" machine screws and the existing holes.

Option 1: I could just fill all the extra space and the whole recess with butyl tape and trust that 1" of those old threads is good enough (I've read that [in steel at least] tapping more than 2.5 diameters of hole gives no additional pull out strength).

Option 2: Or I could spray the new screws with silicone lube, fill the holes with marine tex. coat the bottom of the brackets with Vaseline and install the center board before the epoxy starts to setup and pray that the bolts and bracket don't end up bonded to the holes.

Option 3: Or I could attempt to cast new threads in the bad holes by spraying the screws with silicone, filling the holes with marine tex and inserting just the new screws (no bracket) and letting that cure before backing the screws out again and putting the bracket on.

I don't like option 3 because if the machine screws seize in the holes, I'm back to where I started (although if I'm lucky, I can back them out with vise grips and avoid shearing them off. Has anyone tried casting machine screws in marine tex?

I don't like option 2 because there's a chance I'd end up epoxying the bracket to the boat.

I don't like option 1 because the centerboard bracket takes a lot of pull out force caused by the long lever arm of the centerboard prying the bracket out of its holes. I'm just not sure if I can believe that 3/4" = 1" of resin or epoxy threads are good enough to resist the board being ripped out of the deck. And if I lose the centerboard downwind of the dock, I'd be screwed making any windward headway.

While I think about that, I can start prepping to fix the chips and scrapes on the bow and the missing chunk of centerboard from this same little incident.
 

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caprintx

Member
Well done and excellent documentation! Thanks for the detailed write-up on your progress. Keep the updates and pics coming.

Just curious Speedyox - how old is your boat and has it seen a lot of use?
 

speedyox

New Member
Mine is an '85 or '86 -- hull number 580-something. I'm not really sure how much use it's seen. I'm the 3rd or 4th owner. All the original rigging is still in servicable shape. I don't think it's spent much time sitting in the water but it has a little blistering on the starboard side and plenty of dings on the centerboard.

This morning I taped off all the scrapes and nicks and sanded and washed the areas I'm going to have to patch with marine tex. Still not 100% sure how I'm going to repair the damaged screw holes but I'm leaning towards option 3.
 

caprintx

Member
Thanks! Mine's about the same vintage and has been well loved with little use. Have you called Catalina to see if it's as simple as drilling new pilot holes near the broken bolts?
 

speedyox

New Member
Well, it's not pretty, but it's fixed.

I ended up soaking a new machine screw in silicone spray then threading it half way into the worst hole. My goal was to keep the bottom half of the hole from being plugged up with epoxy and cast new threads on the top half of the hole. It worked but getting the screw to back out took way more torque than would have been possible with a screw driver. I ended up clamping some medium sized vise grips (~9") onto the screw head horizontally to get it to break free. And even though the screw had been covered in the spray lube, the epoxy has a tight grip on the upper threads and the screw head. I couldn't get it off with a utility knife. I wouldn't trust silicone spray lube to leave a fastener removable after exoxy cures around it. At least not a machine screw-- maybe it would work with a wood screw. The other damaged hole I just left alone since it still had more than an inch of threads.

At the same time, I filled two small, old chips in the cockpit, the leading edge of the centerboard that takes abuse from the trailer, and the new chip on the back of the centerboard and the three fresh wounds on the bow. This was my first time working with Marine Tex and it was a learning experience. I shaped the putty with plastic wrap over it which worked great but I ended up filling the space up to and over my tape which left the repair a little too proud. And since the epoxy is harder than the gel coat, sanding it down without making a small repair into a big one doesn't work very well. In the second photo you can see the tape still under a repair. Getting that out was like peeling a hard boiled egg with a utility blade. The 3rd and 4th images are how I'm leaving it for now. Maybe someday I'll sand the bow down flush and apply new gel coat, but it's good enough to get back on the water already.
 

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