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Which Centreboard!!!!

Started by James Taylor, 22 Aug 2007, 02:56

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Derek

Not sure of the vintage of your S&T plate but on 3406 I put a captive pin into the hog with a router in order to put the pivot point as low as possible in the boat. This then allows you the shortest possible plate case for a given length of board without going to the trouble of a hatchet system.
Another advantage of this system is that there is no leakage path from the plate case to the inside of the boat - particularly valuable with a double bottem where that means the inside of the tanks.
The plate is slid into position until the notch in the leading edge engages on the pin and the s/s toe-strap plate screwed into place.
This can be done on your back under the trailer without the need to turn the boat on it's side - in fact that is probably the easiest way.

I got Ian Warren to make me a plate for that boat and also one for the boat I intended to have in 1997. It finally went into 3510 this year!

It is possible that your plate is a copy of that idea.
If your Waller foil is delaminating on the trailing edge - I would put money on the S&T being stiffer.
I expect it is likely to be a yellow cedar core and not foam.
Have you checked the comparative thicknesses?

If the S&T foil fits, try fitting the appropriate pin and sealing the plate case.
If you want a gybing board, get the Waller one really dry and seal the trailing edge properly.
This is not just weight / cosmetics - it is a structural consideration.
You risk breaking it when you most need it = when you are standing on it!

Hope this is of some help.

Derek
3510

James Taylor

Forgot to say that the pin is bonded in to the boat when it was converted to a DB Yes I have an AC boat with a double floor and it is lovely and dry !!.

Thanks derek how far back is the pivot point on yours.
Cheers
James

Derek

James,
I cannot answer that readily since the boat is in Exmouth and I am in Toulouse.
If you are building the boat around the plate, it is worth serious attention.
Since you have a boat and a plate, I expect you just want to see if it will go in and retract properly.
This time it is pprobably easier to check it with the mast in (to give you something to hold onto) and the boat rolled on it's side.
If this sounds too much trouble, check the pin to back of case and leading edge notch to plate tip - this should give you a decent idea though it might foul on the trailing edge at the back.
I would recommend you move the pin rather than butcher the plate to fit!
If you move the pin forwards, dont forget to check you've left enough space for the area of plate forward of the pin when retracted.
Position of CLR (centre of lateral resistance) is key to boat balance in conjunction with centre of effort of rig. You can move it without too much reduction in area by raking or over rotating the plate.
If you are going to do this, do mark the plate so you know the setting or you will end up chasing your tail with rake and plate position in search of balance. Mind you, for most of us this pales into insignificance relative to the fact that we seldom sail the thing upright anyway.
Good luck
Derek

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