Centaur keel bolt...

jellylegs said:
I have a very slight weeping keel bolt do i just tighten the nut?
Click to expand...

The keel bolts have a donut ring of caulking around the them, then a rectangular steel plate which spreads the load and compresses the caulking when the nut's tightened.

Do make sure it's just a loose nut. Some Centaurs which have been taking the ground regularly have lost keels when the bottom of the stub keel cracks and then falls out.
 
Thankyou for your reply. The stub looks fine. It is the only bolt that has a rust mark around it. She was kept in a marina from new until very recently when she was moved to a drying mooring.

I will have a look and see what happens.
 
I might be inclined to take the nuts off & check the bolt (as much as you can see) is OK. It may well have been withdrawn at some point for a survey & has since bedded in. This will also allow you to check the hull around the hole. If it comes reasonably easily, perhaps unscrew & check the lot & then reseal.

I trust you know to use the two nuts locked together & a spanner on the lower one to unscrew the bolt? Reverse to replace, then tighten the lower nut & finally lock off with upper. Will probably need retightening in a few weeks after the sealant "sets" a little. If pulled for a survey it ust may never have been retightened later.

Centaurs are designed to sit happily on hard ground, it is deep soft mud that can cause problems, with suction causing lateral flexing of the keels as she sinks in & pulls out on each tide.
 
Searush said:
Centaurs are designed to sit happily on hard ground, it is deep soft mud that can cause problems, with suction causing lateral flexing of the keels as she sinks in & pulls out on each tide.
Click to expand...

Unfortunately, drying swing moorings in estuaries can also damage them as we found out in Conwy. By the time the boat just lifted off the bottom, the tide had already gained force and it placed a lot of sideways strain on the keels as the boat bumped through 180 degrees across the uneven ground.

Although some stress cracks can usually be seen on the sides of the stubs, the area which fails is the hidden area between the keel stub and the keel. When the keel falls off, it takes the bottom of the stub with it, the exact shape of the keel. Graham, manager of Dinas Boat Yard (Y Felinheli) bought one which had sunk and rebuilt it.
 
For piece of mind its worth getting a second opinion from someone in the know like a surveyor or a boatyard who have experienced or previously reinforced or repaired Centaur keels.

Hopefully all is ok - we have a number of Centaurs where I moor that dry out and bump around twice a day problem free.
 
Sea Rush, that is a great idea, and thank you. I have sought advice and the view is to do what you say. I hadnt thought about removing the whole boat, but I will bring her up on the hard and have a look.

There are no signs of cracking on the inside, flow coat is all intact.

I plan to have the work done in the winter. Estimated 2k to do both sides. Remove the keel, strengthen the stub, replace the bolts, and re bed.

Ta.
 
jellylegs said:
I plan to have the work done in the winter. Estimated 2k to do both sides. Remove the keel, strengthen the stub, replace the bolts, and re bed. Ta.
Click to expand...

It's well within the scope of a DIYer with the time, I've done it on 2 boats, Job is mainly labour so, leaving out yard time and lifts, I guess it cost me about £50 in materials at the most for each, Centaur & Berwick. As I was selling the Berwick, it cost me an extra £50 for a surveyor to inspect at stages and certify the work.
 
jellylegs said:
How did you lift your boat to drop the keel?
Click to expand...

Got the yard to hoist it high enough to allow the keels to drop when vertical and have space for jacks under them and then blocked the hull - they're very thick so can sit on timber blocks.

That way makes it a bit more difficult as a trolley jack is needed, as well as a couple of scissor or bottle jacks because, as you slacken the keel nuts, the keels swing down to vertical and you must allow them to move slowly as the nuts are slackened in turn. That part (and refitting) is definately a two person job.

The other way is to heel the boat in the slings so the keels are vertical (one at a time) and then lower them. Drawback is cost of yard labour and hoist time for several hours as it has to be repeated to refit.

With the B layout, it's necessary to cut some joinery under the galley area.

As the keel studs, washers and nuts are all stainless, there shouldn't be any need to replace them.
 
Last edited:
You must log in or register to reply here.

Other threads that may be of interest

M
Removing stripped grub screws
2
Replies
39
Views
1K
Humblebee
H

Share this page

Top