: Hi Dave and all,
: I've been absent for a while, but I'm back.
: I am not sure the bird mouth is the best way to go.
: Why not stack strips of about 8-10mm wide on both sides of a full
: width strip offsetting them to the outside to get the round and
: then reverse the procedure to get back to a full width strip at
: the top to cap both sides.
: You could do it in two halves. Then sand away the steps on the
: outside and inside and you will have a shaft.
: Just a thought. A lot less fiddling.
: Cheers
: JohnK

I have a set of router bits at various bevel angles so for me the way to go would be as follows:

thickness plane a plank to the width of the staves (for an oval section this would be done in two stages)
route bevel angles on each side, deep enough for one stave
(for an 8 sided mast or paddle I would use the 22.5 deg bit)
part off the stave
repeat for rest of staves
scarf out defects a/r
lay staves bevel up over strips of adhesive tape
glue bevels
roll up the assembly
wrap with cable ties and leave to set

This is a very fast and accurate method. The glue is stronger than the wood so the slightly reduced gluing area compared to the birdsmouth method is not significant.

However, for a twisted paddle I would probably stay with the birdsmouth as it should hold together better when twisting - the masts I made using the above method came out perfectly straight despite some winds and warps in the staves, so it obviously resists any tendency to bend or twist . . .