Keel Lock-down Bolt Hole Repair

[heinzir]

Now that Chiquita is out of the water for the season it's time to tackle a few fall projects. The keel lock down bolt hole is no longer a hole; it is a slot almost 4" long on both sides of the centerboard trunk. This happened years ago when the keel cable broke and the top of the 600 lb keel smashed into the bolt, exerting leverage many times its weight. The 1/2" bolt was bent into a "U". I had removed the bolt and caulked the slot to keep water from splashing up into the boat. I have sailed without the keel locked down for a long time and will probably continue to do so because of shallow water issues. But I do want to repair this so that I have the option of locking down the keel if I venture into bigger waters.

I picked up this nifty "multifunction tool" that made short work of cutting thru the hull liner to get at the keel trunk. I will enlarge the new "access port" if necessary when I decide on a course of action. I'll make some sort of wood veneer cover when I'm done.

My idea is to fill the slots with epoxy mixed with chopped fiberglas strands for starters. How do I keep the filler from extending too far into the keel cavity? I can't remove the keel to get access to the inside of the cavity itself.

After the slots are filled, I plan on epoxying 1/4" steel plates, about 4" X 4", over them on each side of the trunk and then covering these with multiple strips of fiberglass and epoxy resin to bond everything in place. I'll build up the fiberglass to about 1/4", tapering down as it extends away from the slot. Then I'll re-drill the bolt hole thru the added fiberglass and steel and thru the puttied original hole.

My question is, does this sound feasible? Any tips on how to keep the initial filler from dripping through into the keel cavity and possibly interfering with the keel motion? Is there a better/easier way to accomplish this repair and maintain the needed strength?

[Bill Reichert]

I think I have the answer. Use a piece of plastic with mold release on it. Two holes in the center for a wire to go through it. Shove the plastic in the hole with wire or zip tie going through hole. Fasten the wire to a stick with a couple spacer blocks at the ends. Once the glass plug has set up, just push on the plastic and it should fall free and clear.
I think a plastic cover for a coffee can should work well. Parafin for canning should also work.
Idea came from suggestion for patching a large hole in drywall except that the backer stays in place. I have some old potato salad containers that are rectangular. They are great fom mixing resin. When they get all gunked up with dry resin, I just flex them and it all cracks and falls out.

[heinzir]

Thanks Bill,

I got started on the project this weekend and did use plastic cut from a food container lid. Instead of using wire I crammed some small pieces of closed cell foam packing material into the cavity between the slots. The foam is wedged in tight enough to hold the plastic in place. I figure the head of the keel will knock the foam out when the keel is lowered.



I used overlapping strips of fiberglass and epoxy resin instead of epoxy putty to fill the slots. I lost track of how many layers I used but it seemed like almost a dozen. The glass in the slots is still not completely flush with the rest of the trunk; there is still a shallow groove on each side. I am waiting til I get the steel plates before I finish the job.



While I'm at it, I think I will insert some foam around the edges of the access openings in the liner, between the liner and the trunk. I'll recess the foam 1/4 to 1/2" back from the edge of the opening and fill the resulting space with fiberglass/epoxy. This will bond the cabin liner to the keel trunk in this area and add some strength. Anyone see a problem with this?

[ChockFullOnuts22]

Henry, that repair looks nice and solid. I think you made a good choice in how you chose to fill the slot. It looks like you've got a good system going there.

As far as a problem with bonding the liner to the hull goes...I don't see it being a problem unless you ever have to remove the liner from the hull, entirely.

[MD Dunaway]

Ahoy!
The only problem I see is in knowing where the hole should go. I think I would have fixed one side, jacked up the boat, lowered the keel to where I would want it to be and drilled the hole. (If that is too difficult then maybe pick a place in the slot about where I thought the hole was before?) Then fixed the other side and drilled the hole on through. If you were to put the boat on blocks and lower the keel you might be able to shine a flashlight from the opposite side and see where the light shines through and drill the hole. I would definitely get the hole placement before I put the steel plates on!

Mike

PS it is very unlikely that you would ever want to take the boat apart. I was watching a video of Nick Hake (of Hake Yachts/Seaward) talking about how they fill the area between the hull and the liner with epoxy and hook up a vacuum pump and basically vacuum pack them together. I would lay on fiberglass until I was sure it would be rock solid.

[THE CUSCUS]

I agree with what Mike saw in the video, as I just dismantled and cut up a M22. With the top deck removed, the liner will not just "lift" out. When it was put together, they had laid rows of epoxy on the inside of the hull and then "stuck" the liner to it as well as using glass mat where it could be gotten to from the interior hatch openings. It would be nearly impossible to remove the liner in any kind of reusable condition.

[heinzir]

I thought about the bolt hole placement issue. To get it perfect I would have to jack the boat up far enough to lower the keel all the way down and I am not inclined to do that. I guess I'm just too lazy. I did have hernia surgery two weeks ago, though.

The bolt hole goes at the very bottom of the slot. It was the upward leverage of the head of the keel that tore the hole into a slot. I also still have the portion of the liner that I had cut away for access. I can tape this back in place and find the center of the 2" original access hole in the liner to locate the proper position to drill. That should get it very close to right on. I guess I'll have to deal with any discrepancies later.

I plan on drilling the holes thru the steel plates before I mount them in place; I might even use a greased bolt through the holes to clamp them in place until the epoxy sets up. I'll also drill a few extra holes in the steel which will, when filled with epoxy, give the plates some extra bite to lock them in place.

The sides of the liner on the centerboard trunk are bulged out slightly, probably as a result of excess pressure from the compression post. The trunk itself is ok. I have spread out the load from the post with a nice oak cap that fits over the entire raised part of the trunk. I'm going to try to squeeze the sides of the liner together a little with some big clamps and then glass/epoxy the inner rim of my new access hole to the trunk.

[ChockFullOnuts22]

The liners are already bonded to the hull? Looks like I fell victim to the trappings of using "hear-say" information. I'll be sure to remember that in the future---thanks for the info.

He should be able to drill the hole in the correct location without much of a problem, since the new fiberglass is translucent and the existing fiberglass is coated. You can still see the "slot" in the trunk through the repair work, so it should just be a matter of drilling your hole at the end of the slot where the lock down bolt hole originally was.

Just make sure you don't paint the repair before you drill your hole, Henry!

[heinzir]

Paint? What's that?

[ChockFullOnuts22]

Haha...well said!

Did you get your steel plates made up yet?

[heinzir]

Haha...well said!

Did you get your steel plates made up yet?

Not yet -- tomorrow maybe.

[MD Dunaway]

Henry. Some like pencil, pastel or paint. I like fiberglass and epoxy. I have the 26 sitting on the patio and have been packing fiberglass into every nook and cranny. Completely filled in the groove under the V-berth making it flat and no doubt stronger (mainly it doesn't trap condensation there anymore) I even toyed around with finding a way to infuse epoxy into the space between the floor and the ballast tank. Those steel side plates will add some serious strength if they are anchored well. Have fun. Just be sure to have good ventillation and not breath too much fumes. Mike

[heinzir]

I epoxied the 1/4" steel plates in place and glassed over them. Probably should have used longer plates but I went with what I had. I filled the space between the edges of the opening in the liner and the trunk with epoxy and glass. It's not the neatest job in the world but it doesn't look too bad with a couple of coats of paint.

[ChockFullOnuts22]

That repair looks great, Henry!

The short plates will be fine as long as you laid enough fiberglass around the edges for a good "anchor." Did you end up adhering the plates to the trunk somehow, or did you just clamp them in place and glass them over?

[heinzir]

Thanks -- I'll probably make a cover for it out of 3/16" luan plywood eventually, stained to match the bulkheads. It will cover the repair as well as the other holes, and I''ll attach it with Velcro dots, like a speaker grill. But I'll probably just leave it open for the first part of the sailing season til I'm sure everything is working properly and nothing leaks.

I clamped the steel plates in place with the (greased) lock down bolt after smearing them with the same epoxy I was using to lay up the glass. I didn't get a lot of laminations over the steel but I did get the edges built up with glass and epoxy pretty well. I had also drilled an extra couple of 1/4" holes in each plate. The epoxy filled the holes and hardened, forming "pillars" or "webs" to lock the steel in place. I don't think they are going anywhere, but then again if the keel cable breaks the keel could come smashing against the bolt with several thousand pounds of leverage.

Henry