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Yep direct from Marstrom would be about 4k

by the time you take into GST and Import/Shipping costs

the rudder blades+stocks are 1159 euro each!

However i am interested in making up a mould or two for some Stingray Rudders & Centerboards Brian!

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  • 3 weeks later...

ok the plan is to replace my older boyer boards with some newer design high aspect boards.

ive decided on 1500 x 200 x 24 in the Eppler E836 shape. if they end up too long, i can just trim off the bottom with the circular saw :)

the originals were 900 x 350? i think.

does anyone have any reccomendations on type of timber???

duck flat wooden boats in adelaide have suggested Wester Red Cedar..... any thoughts??

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Brian is this for the stingray rudders or the A-Class Centreboards?

Western Red Ceder is good as it stays fairly straight however it is pretty heavy! I think it works well when laminated with a lighter wood like paulownia! It would also help prevent bowing as you can reverse the orientation of the timber in the different lames.

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ok it seems the quoted numbers are 380kg /m3 for cedar and pawlonia is 275kg/m3, and balsa is 170kg/m3, oak is averaging 800kg/m3

so if i made it entirely out of cedar 2.5kg / foil

50% cedar / 50% pawlonia 2.2 kg/foil ( if i can source it)

100% oak 5.3kg/ foil

and if i bought the new nacra carbon foam foil.........4.2- 4.5kg /foil.

i reckon ill just go with 100% WRC, its easy to find and cheap.

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Brian, if you go to the wooden boat section of www.woodworkforums.com there is a bloke there by the name of whitewood and he sells Paulonia from his web site www.paulownia-timber-sales.com.au. Personally I think you made the right decision to go with WRC, in my opinion the paulonia wouldn't have the required strength for that application. Furthermore remember that the glass and epoxy is only there to prevent the wood from becoming waterlogged and to keep it nice and smooooooth, it doesn't add much in the way of strength, unless you are going carbon.

Harry

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G'day Brian

Can I suggest a bit of a rethink on your plan. If your current boards are in OK condition, why not sail the boat for a while, get the feel of it and then decide what might be the next performance boost. IMO the boards you are suggesting are way too much board for the boat. A's are light and once they are moving don't need that much board to generate the lift needed.The straight boards on current designs are around1140x150x16 with about 700 in the water when fully down. This is enough at low speed and at higher wind speed most people raise them a bit. The drag on the boards you are suggesting would be way too much for the lift generated on the A. You would also be adding a lot more weight than is necessary. Typically boards would be 1.2 to 1.5 kgs finished. A good laminating schedule using carbon in the right places and a foam core works. There are plenty of people around with experience in doing high aspect boards which are light and won't break at the hull. A cheaper alternative might be to source a second hand set of McKenzie or Simon Cooke boards from someone who has gone to curved boards.

Cheers

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thanks john, i can get my hands on foam for free, but i havent had enough experience with carbon to know what when and how. if you know of anyone who has boards they want to move on, keep an eye out for me. :) ill measure the boat so i have 700 below bottom of hull, the MK11 of mine is a pretty deep boat compared to the boats nowadays. it would be at least 400- 450 deep in the hull. the boards i have now would be lucky to be 400 below the hull.

thanks for the advice JD.

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