Centaur Keels

dylanwinter

dylanwinter

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www.keepturningleft.co.uk
Can anyone fill me in on Centaur Keels

1/How easy is it to spot as problem

2/how do I know if the keels have been re-inforced

3/is re-enforcing a final solution

4/ I had heard that the real problem comes if the Centaur is allowed to settle into deep mud

is this true?

just the one immersion or repeated immersions?

How deep to create the problem

and while we are on the subject.....

most have now had an engine replacement - are there any installations I should steer clear of.

Are there any other faults I should look out for

I understand that some of them have been hit by the pox

Dylan
 
Dylan,

my father had a late Centaur, no.2187.

Some say the earlier ones were more strongly built; don't know if that's true as I've seen the keel problem on early boats too.

Reinforcing will be obvious if it's sufficient; the 'problem' is only a slight weep from the joints internally, Dad's was on soft mud and I think it would take some time to appear, not a one-off.

Dad glassed in thick ply webs across the keel top voids, very strong stuff, and tightened the bolts with a very long tommy bar; the weep never completely disappeared but was more of an irritation to an engineer than an actual problem.

A chap at my club with an early Centaur did a similar reinforcement, but still whenever the boat was lifted a tiny gap, say 1mm by 6" long, would appear at the keel join leading edge.

Didn't cause any issues, just frustrated the hell out of him !

I reckon the Centaur a very good package, the only thing I ( and Dad ) really disliked was the completely neutral, lilfeless helm; Dad tried all sorts of aircraft inspired tabs, vortex generators etc but never got much of an improvement, definitely a case for an autopilot.
 
so a visible crack and gentle weeping is no problem

Seajet said:
Dylan,

my father had a late Centaur, no.2187.

Some say the earlier ones were more strongly built; don't know if that's true as I've seen the keel problem on early boats too.

Reinforcing will be obvious if it's sufficient; the 'problem' is only a slight weep from the joints internally, Dad's was on soft mud and I think it would take some time to appear, not a one-off.

Dad glassed in thick ply webs across the keel top voids, very strong stuff, and tightened the bolts with a very long tommy bar; the weep never completely disappeared but was more of an irritation to an engineer than an actual problem.

A chap at my club with an early Centaur did a similar reinforcement, but still whenever the boat was lifted a tiny gap, say 1mm by 6" long, would appear at the keel join leading edge.

Didn't cause any issues, just frustrated the hell out of him !

I reckon the Centaur a very good package, the only thing I ( and Dad ) really disliked was the completely neutral, lilfeless helm; Dad tried all sorts of aircraft inspired tabs, vortex generators etc but never got much of an improvement, definitely a case for an autopilot.
Click to expand...


so a visible crack on the outside is no real casue for concern?

and a bit of weeping is fine

good news about the occasional deep mud emmersion

Dylan
 
Keels

Dylan,
Its not just the ply webs across the keel stub, its the weakness of the stub itself. The whole GRB stub flexes when taking to the ground. The signs of this can be seen as longitudinal cracks above the stubs themselves. Obviously the a/f must be removed for them to be seen. A quick rub down with wet/dry paper will confirm that they are cracks and not just scratches.
The solution is too boost up the laminate inside with glass/epoxy and then add extra thick ply /grp webs across inside. I've seen the GRP of the stub so waterlogged that the keel fell off on a swinging mooring.
Don't be put off by what I've said. They just need some TLC. They are great cruising boats. I kept mine for 9 years and covered many miles in her.

PM me if you want any more comments/info
 
dylanwinter said:
4/ I had heard that the real problem comes if the Centaur is allowed to settle into deep mud

is this true?
Click to expand...

Deep mud increases the load on all bilge keels and so does highlight weakness. We have a lot of such mud in the bristol channel with boats going into it on each tide. I have no great knowledge of Centaurs, but I am not aware of people saying " never use a Centaur in the channel". Appreciate thats a bit round about way of saying that it is an issue but not a panic every grounding type one. As far as I know.
 
My Centaur is one of the later ones (2391 of 2444) and has some extra bracing across the keel stubs. I don't have any pics, I'll try to remember to get some @ the W/E.

There seemed to be some water ingress round the keel bolts but since it's stopped I'm thinking the water came from elsewhere. That's entirely possible as the boat had loads of water in when we got her and it's taken some effort to cure leaks (mainy from the fresh water system) and dry her out.

The new Westerly Wiki is getting more usefull as more info is added too:

http://www.westerly-owners.co.uk/westerlywiki/index.php?title=Re_bedding_Keels

There is also a thread in SB thats recently been exhumed!
 
There are two aspects to consider regarding Centeur bilge keels.

Firstly that he hull has been strengthened as previously stated.

Secondly that the keel bolts are tight. The trick we used years ago was to stand between the keels when the boat is up in slings with the keels hanging, grab a keel with each hand. By pushing apart and pulling the keels together you can tell if there is any movement. If there is (the keels will 'rattle') then corrective action is required.

The ideal solution is to drop the keels, rebed in the correct material and refit.
 
I have an earlier one that sits in mud twice a day six months of they year & has done for the last 7 years that I've owned it. The other six, it's on the hard on its keels. Mine's got extra webs glassed in above the keels.

The problem occurs because the keels are splayed out. So when it sits down in mud, they are pushed out. As it rises, they are pulled in. Some other bilge keelers have more parallel keels.

After you've seen a few, you will easily spot the ones that have been beefed up as mine have. Westerly built them heavy anyway but some have extra webs across the keel stubs. When I fitted a new depth sounder, I saw the layup on the bottom is 30mm+

You're right to be careful but if beefed up & looked after, it's not a problem.

A few other things to look for:

1. The older versions suffered from a lower chain plate design flaw as they were placed above the front set of windws. This is a weak spot that over time causes the couch roof to deform up & the windows to leak. The easy fix is to add tie bars inside the boat to tie the chain plates to a point under the windows. The load is then shared between the coachroof & the deck & any movement is limited. Later versions had shorter front windows. I have seen some boats where the lowers have been extended down to deck level instead but this causes an obstruction to walking foreward. I added tie bars a couple of years ago before the windows started to leak. Some people add a nice teak grab handle to the tie bars. Mine are not exactly the same & I made wooden patterns to make sure they fitted exactly.

2. The upper chain plates can over time cause the deck to deform upwards. You can check this easily with a steel rule. I replaced mine a few years ago & fitted a lump of wood under the deck that helps spread the load.

3. Mast step compression is the other thing to look for. The centaur has a compression post inside taking the load from the coachroof to the keel. lay a steel rule on the deack next to the mast step & unless it's been fixed which few have, you will see the coach roof compressed. I haven't done mine yet but may take a look next winter. It certainly shows signs of compression so I'm just keeing an eye on it.

4. The original place for the gas bottle was in the stern locker. Any leakage would go to the bilge which is of course a real fire hazzard. You can get a modification kit to put a locker under one of the cockpit seats. But this takes height form the quarter berth. When I got mine the gas install was a mess. The simple fix for me was a spirit burner. The Origo 3000 is a perfect fit. There may be some who have sealed the stern locker from the bilge & added a drain. IMO, that's better than losing height in the quarter berth.

There are certainly lots of things that can be done to improve the boat. The biggest performance improvement I made was new sails & slab reefing rather than the original boom roller. I just added a track on the boom to take the reefing lines & cleats at the tack end.
 
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Centaur bilge keels, many were recalled by Westerly's to be reinforced but more than a few slipped through the net. look for cracks where web floors are coming away from the hull & bonding coming away from bulkheads, Also leaks.
Im three quarters of the way through a repair on both sides of an early one, she was "professionally" reinforced by a boatyard some years ago & im surprised her keels didnt fall off subsequently. Keel bolts were only done up hand tight and the new grp had been applied straight over the filthy bilge with little to no attempt to grind it clean. No wonder it didnt stick! (danboline, diesel & dirt makes quite a good release agent)
Its worth remembering that to gain proper access with some layouts to get at everything & grind the hull back properly will entail cutting parts of the interior moulding away.
As for mud berths, when a keel sinks into deep mud the wringing strain as the boat comes afloat is huge, in our club two centaurs have come to grief over the years this way, one the hull split vertically at the frd end of the keel & the other pulled its entire keel out by the roots.
 
Mud

I would certainly need to be able to use mud berths

I am heading for one on the Humber

so a mud problem would be a deal breaker for me

just imagine how long the threads would have been had the web been working then

Some-one mentioned no feel on the rudder......

is that right.....

maybe that is a good thing

Dylan
 
Dylan,

either there's a certain amount of scaremongering / bias / urban myth going on, or I've led a more shetered sailing life than I thought.

The comment about Moodys being better built made me wonder; after the October '87 Hurricane there was a yard nearby with a Moody 27 twin keeler, with a keel torn off - not unusual in that carnage.

However I was amazed by how thin the hull at the keel join was, and took a sailing friend who was also an aircraft inspector & designer to see it, with appropriately dropped jaw !

Never heard of cracks in Centaur hulls, and my club has hosted quite a few over the years on soft deep mud, the sort of stuff dangerously futile to try to walk on.

I do wonder if the suggestion that some boats have been bounced on hard sand may be very pertinent here; I once settled my A22 on hard sand, and despite her being a very strong boat and the 'waves' mere ripples, I will never forget the jarring and crashing, it felt like the end of the world !

My Father and the other Centaur owners I knew / know were there for a good few years, and I'd have heard about any dramatic damage or faults.

Another thing, while everyone looks at fin keelers for damage incurred by running aground at speed into something solid, that will seriously disimprove a twin keeler too...
 
My keels seem to be fine. When she was lifted out last autumn I pulled on the keel with the boat in the hoist and the boat swung in the slings with no signs of a 'gap' or stress cracks.

The boat is really dry inside the stubs, not been a drop of water and only slight rust in the immediate area of the bolt. She has been kept on a drying mooring for the past 3 years in my ownership and before me in a mud berth, I believe.

On the topic of the neutral helm, mine is one of the last Centaurs to be built and has the MKII rudder, with a skeg and is 'very' semi-balanced. earlier boats, with the swept back rudder were prone (I am told) to having such huge loads on the rudders on certain points of sail that they were hard to steer.

Engine installations, well it partly depends on who fitted it. Mine has a Nanni 24hp 3 cylinder in her, excellent engine. I wouldnt have chosen it, but came with the boat and I am very pleased with it. Has some prop noticable prop walk, but its not too bad - for what I am doing with the boat.

Generally a great boat, I can keep sailing when newer lighter boats are turning back. The turn of speed is pretty good all things considered.

A good all round package.
 
Lets face it, if the boats were rubbish no-one would buy them.

Yes there are loads for sale but shed loads were built and still giving sterling service.

There was a drawing in the class association mag sometime ago showing how to do the repair.

I'm away from home at the moment but can send a copy by PM if you want?
 
Dunno

capetown said:
Lets face it, if the boats were rubbish no-one would buy them.

Yes there are loads for sale but shed loads were built and still giving sterling service.

There was a drawing in the class association mag sometime ago showing how to do the repair.

I'm away from home at the moment but can send a copy by PM if you want?
Click to expand...

love to see them

dylandotwinteratvirgindotnet
 
Dylan,
The problem will NOT occur from an odd few nights sinking into deep mud, unless already significantly weakened from years of drying out twice a day in deep mud. These boats are, as the slug is, built like brick outhouses.
 
The keel problem is made worse by regular mooring in deep mud: The splayed keel configuration (which improves the sailing qualities) means that as she sinks into mud on a falling tide, huge pressure builds up between the keels as she compresses it and forces the mud away. Later as the tide returns, you get exactly the opposite effect,as the keels act like a giant suction pad, with huge pressure inwards as the hull buoyancy increases. Properly reinforced, this is not a problem, and many hundreds of beefed up Centaurs are quite happily squelching down into their mud berths each tide, engineered to cope with it.
 
Maybe it should be borne in mind that the only real reason for vertical twin keels was to be able to mould encapsulated examples and then be able to get them out of the mould, more production than sailing performance considerations !

It doesn't take Werner Von Braun to work out that splayed keels have the leeward keel vertical-ish when the boat is heeled to give a lateral resistance and the windward one exerting a large righting moment, while watching the vertical-to-hull keeled jobs slide off into the leeward distance.
 
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