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- 04/06/2009 at 1:12 pm #3931
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.
Tony04/06/2009 at 3:13 pm #8192Dave BevanMember
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
Dave04/06/2009 at 3:27 pm #8193
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?
AH06/06/2009 at 9:06 am #8194SwiebertjeParticipant
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.06/06/2009 at 9:10 am #8195FantasiaMember
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 luck06/06/2009 at 4:40 pm #8196AnonymousInactive
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.06/06/2009 at 5:51 pm #8197
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.
Anthony07/06/2009 at 7:30 pm #8202AnonymousInactive
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 email@example.com and firstname.lastname@example.org. You could try them or Swiebertje might be the man to ask about this.07/06/2009 at 10:57 pm #8205SwiebertjeParticipant
Kjell’s drawing is now available in English on the WIT site John referred to, a few messages ago.
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