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Topic: Jammed centre board (Read 1792 times)
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graham leighton
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I collected Bayraider 17 No4 a couple of weeks ago & launched her a couple of days later. She is kept on a drying swinging mooring on the River Medway, on England\\\'s East coast. Yesterday I went for my first proper sail only to find the centre board jammed solid, refusing to budge. After unexpected recovery practice my suspicions were confirmed & the casing was full of mud preventing movement.
She had been on the mooring with centre board fully raised & ballast tank empty. The Medway mud is gloopy! no doubt a bit extra is forced into the casing between tides. I\\\'m thinking I should allow a few inches movement in the board so it can drop a bit when the tide is in so the mud washes out & leave the ballast tank full so it doesn\\\'t skit about when on the verge of drying/lifting which may force the mud in.
Has any one else experienced similar?
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Craic
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... the casing was full of mud preventing movement.
She had been on the mooring with centre board fully raised & ballast tank empty. The Medway mud is gloopy! no doubt a bit extra is forced into the casing between tides. I\\\\\\\\\\\\\\\'m thinking I should allow a few inches movement in the board so it can drop a bit when the tide is in so the mud washes out & leave the ballast tank full so it doesn\\\\\\\\\\\\\\\'t skit about when on the verge of drying/lifting which may force the mud in.
Has any one else experienced similar?
Frankly I never had similar, though one of my boats is in a drying out berth. Probably what you have is \\\'the wrong kind of mud\\\'. What you suggest to give the board a few inches slack for movement sounds appropriate. I doubt also leaving the tank full will make much difference, and besides it\\\'s cumbersome to pump it out every before going sailing. I heard some guys use an old fibreglass sail batten for loosening mud and stones in the case so they would not have to careen. |
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Andy Dingle
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Hi Graham. Your problem would certainly spoil your days sailing. In my days of racing dinghy\\\\\\\\\\\\\\\'s and catamarans we would often use a gasket or sealing strip on the centreboard slot as it exited the hull to minimise ingress of water and slowing the boat, we used to use self adhesive strip purposely made for the job. A quick search has come up with: http://www.seamarknunn.com/acatalog/Daggerboard-Slot-Gasket.html?utm_source=comparesailing.co.uk&utm_medium=referral&utm_content=comparesailing&utm_campaign=sailingcpcWhich looks similar to what we used to use. I am sure it would do the same thing on your Bayraider, in this case preventing mud from entering the slot. If the board was raised the gasket would close the slot completely. Just a thought that might help you .. indeed I keep my own BR on a drying mooring too occasionally but I haven\\\\\\\\\\\\\\\'t had this problem yet! Andy Dingle BR12 \\\\\\\\\\\\\\\'Psalter\\\\\\\\\\\\\\\' |
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graham leighton
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Claud & Andy thanks for your replies. My plan B was to come up with some covering for the slot & the tape seems easier than what I had in mind!
I\\\'ll try things & see what works best
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graham leighton
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The answer appears to be just leave the centre board down a bit, which is a quite a relief. Something to bear in mind if any of you intend to dry out on East Coast mud. I suspect that me going aboard when the boat was dry may also have forced mud into the casing.
Anyway had my first proper sail on Sunday; completely delighted.
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gerald turner
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Far be it a voice of doom, be aware that it may cause lateral movement in the centrecase which could cause damage to it if it settled wrong.
I had to repair my \\\\\\\\\\\\\\\'case on the dabber I bought because of this
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Anthony Huggett
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The sealing stip on a racing dinghy is mainly there to miniminise drag caused by turbulence in the centreboard slot. It slows the flow of water into and out of the slot to the point that turbulence is eliminated. However, hydrostatically it has no significant effect - the water will still come just as far up the inside of the slot with or without the gasket when the boat is stationary. There may be some suction effect that lowers the water level when the boat is moving. I\\\'m not sure that a bit of stiff canvas that moves out of the way as you move the board will be that effective at preventing the ingress of mud with the weight of boat on top.
Boats on drying moorings, particularly in nice soft mud, often work themselves a hole to lie in, because as the tide goes out it tends to drag the boat into the same place unless the wind is really strong, so you may find the problem disappears after a little while.
Thanks to Andy for the link to the gasket - I think I\\\'ll try that as I build my BR17.
Regards,
Anthony
P.S. I recall a mate once told me how he sank an Enterprise when a faulty (torn) gasket cause a fountain into the boat! That\\\'s not going to be a problem on the BR because the back of the centreboard case has a top.
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graham leighton
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Gerald, that was my initial concern which made me make sure the centre- board was all the way up to start with. I only leave it down a bit & it appears to be common practice at my club for the few centre boarders without any reports of damage. Bilge keelers dominate. The consensus seems to be that the mud is so soft it gives, but I suppose only time will tell.
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gerald turner
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[quote author=gerald turner
I might add ,I am saving To order a Swallow boat when I have enough money, The Dabber when sold will be a decent enough down payment, in the meantime I am enjoying the Dabber as for what it is,a comfortable boat!
link=topic=396.msg2106#msg2106 date=1303182493]
Far be it a voice of doom, be aware that it may cause lateral movement in the centrecase which could cause damage to it if it settled wrong.
I had to repair my \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'case on the dabber I bought because of this
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graham leighton
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I was a little early declaring that lower the centre-board a bit works! Eventually the lifting line gets caught against the board & slot, so it all jams up again.
I discussed with Matt the idea of slinging something underneath to cover the slot which he thought would work. At my club this quickly developed the name of \\\"nappy.\\\" Matt thought a triangle of boat cover material with eyelets in the corners for lines.
I remembered I had a floor of an old inflatable dinghy in the garage so I made a prototype. I was limited by the length of the floor so it was rectangular with just a slight point towards the bow. I folded over the ends around lengths of hosepipe sticking them down with epoxy, backing up with stitching. I passed a line through the hose & then lines to bow & each stern quarter.
It is successful & much nicer to see water down the centre board slot than mud!
To deploy takes a few minutes. I attach the bow line to the towing eye take the nappy down one side, pass the opposite line around the stern & underneath & then pull it into position with tell tales on the lines marking the right place against the stern fair-leads.
The rectangular shape means it tends to scoop at the bow end so triangular would definitely be better, about 2\\\" at the stern, about 1\\\' wide by the front of the slot and then to the apex perhaps rounding or squaring off when its a few inches wide. I think if too big there would be a drogue effect making deployment harder.
Perhaps all boats should carry a nappy!
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