Latest News: Forums Technical Centreboard – Has anyone ever make their own?

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  • #3931
    Shackleton
    Member

    Hi all

    I have a MkII which has an odd “feature”. On certain tacks at certain speeds, the centreboard or (cb housing) emits a low pitch, quite loud vibrational hum. It does not last long, and not all the time, but makes the boat sound like we have an inboard motor! This is bearable when sailing on our home lake, but when in long races or cruising at speed, this gets to be a bit of a pain

    Porters investigated this a couple of years ago and suggested that the CB was slightly warped. Two things that I would like advice on:

    1) Has anyone else ever heard of such a “feature” and if they managed to cure it, was the fault?

    2) Given the cost of a new CB, has anyone ever made their own? I am skilled at joinery, so it’s not the fabrication that concerns me; it’s more that has anyone else tried with success?

    Thanks in advance.

    Tony

    #8192
    Dave Bevan
    Member

    Hi Tony.
    Our old MKII had a similar trait, (low-frequency vibration) but it was only evident if the board was too deep for the point-of-sail (e.g. fully down on a reach). If the boat was properly trimmed, it didn’t do it.

    Good luck with making a new CB, you can get the drawings from the association http://wayfarer.org.uk/index.php?option=com_content&task=view&id=40&Itemid=163

    Dave

    #8193
    Shackleton
    Member

    Dave,

    Thanks for the rapid response. Will try your suggestion re PoS. I have contacted Sarah re the drawings and so may have a go if the trim idea does not work.

    Does anyone have any good recommendations re the best material to use?

    AH

    #8194
    Swiebertje
    Participant

    Best would be a combination of ibashi and ash or cedar planks. Ibachi where it matters (leading edge) and ash or cedar to keep the weight below the maximum defined by the class rules. Use quarter sawn planks and turn them 90 degrees relative to each other to avoid warp. Glue them together to form a board using a strong two pot glue, and take it through a planing machine. Then shape it and add chamfer according to the rules and the drawing. Add a layer of glass fiber and epoxy and finish with UV resistant varnish or two pot paint. Before painting build up a sharp trailing edge with micro balloons and epoxy. Make a big hole for the bolt and fill it with micro balloons and epoxy before drilling the final hole. Or better use a bushing slightly wider then the thickness of the board.

    However, most of us settle for a simple painted plywood board. This must be marine grade ply or it will break on your first trip.

    #8195
    Fantasia
    Member

    There are some great articles on the Wayfarer International site, which is worth a look for all sorts of information. Here is the link to the centreboard section: http://www.wayfarer-international.org/WIT/maint.repair.ref/CB.rudder/CB.rudder_index.html

    Good luck

    #8196
    Anonymous
    Inactive

    Hi, I made myself a new centreboard when my plywood one broke. I used what is sold as mahogany at timber merchants. I was luck enough to get pieces with the grain perpendicular to the face of the board, but made it up out of 3″ planks anyway as that was what I’d ordered. I got the planks ready-planed to the correct thickness. If the grain isn’t perpendicular, i.e. the planks aren’t quarter sawn, you will have to make sure that any tendency to warp in one plank is resisted by the next. I bought an official template to get the shape, though ISTR quite a bit of measuring to get the pivot hole in the right place to get the best allowable angle when the board was fully down. I glued it up and sanded it with a belt sander and varnished it with epoxy varnish. Not sure about the weight, but I reckon that my W’s original board must have been mahogany, 50 years ago.
    To prevent the board rattling in the casing, I glued two thin strips either side of the board near the top.

    #8197
    Shackleton
    Member

    One and all. Thanks for all your advice to date – much appreciated, especially for my first post on the forum.
    Any further advice will be much appreciated. I will be talking to my local friendly wood merchant next week when the official drawings have landed.

    Thanks again.

    Anthony

    #8202
    Anonymous
    Inactive

    I have just dug up a long discussion I had with “Wayfarer 5011” and Kjell Gjaere back in 2005 about the best position for the CB pivot pin hole in a new board. Unfortunately the link to the all-important drawing no longer works. Their e-mail addresses were then hotlane@hotmail.com and kjgj@online.no. You could try them or Swiebertje might be the man to ask about this.

    #8205
    Swiebertje
    Participant

    Kjell’s drawing is now available in English on the WIT site John referred to, a few messages ago.

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