Keeping a board flat

[dustyyevsky]

I'm going to build a leeboard for a sea kayak currently under construction. I would like to get this very knowledgable group's opinion on the best way to keep it flat once it's been dimensioned. In case your wondering, a leeboard acts like a keel on a boat but hangs off the gunwale and is not supported in any way. The finished dimension will be 1/2'' x 10'' x 44", in a roughly elliptical shape. I'm planning on making it out of a piece of sapele that I have, 4/4 x

6", so I will, at the very least, have one joint down the middle, which is fine. I got to thinking that I might rip it even more to relieve any internal stresses that might be present. I would then plane the pieces close to the finished thickness, glue it up and then plane to final dimension. Am I on the right track here? If so what do you think the minimum number of rips should be? I still want it to look somewhat like a solid board. TIA.

[Mike O.]

Do you have to keep it at 1/2" thick? I've built some dagger boards and rudders but never used anything less than 3/4" in thickness. It seems to me that 1/2" by 44" long is going to have some flex to it. If your not worried about glue failure I think gluing in a few pieces and alternating the grain might help to keep it both flat and straight.

Mike O.

[SonomaProducts.com]

I'm not sure about flatness. I think a water impervious wood would be important even though I suppose this will be covered in glass (maybe not, not yet build boats myself). I'm not sure about sapele but mahogany, teak or white oak are all candidates.

Also, I would use splines to increase the glueup area If you'r only a

1/2" th> I'm going to build a leeboard for a sea kayak currently under