Thanks for sharing these insights into boat building Ross.
Something I'm having trouble with is getting a consistent taper on a small diameter spar perhaps you could share some gems with us.
Now, I could write a very long answer to this, as it goes right back to the marking and cutting process if making a hollow spar, or to the lamination and marking process if building a solid stick. That is something for a proper book, so for the moment, I'll give just a quick run-down on my normal method - this applies to all sorts of spars, and to oars and paddles.
|Here is a hollow mast glued-up. Despite the apparent disarray, the mast has been very carefully straightened and chocked on the bench so that the blank will be straight when the glue cures|
|Marking a square-sectioned, tapered blank for 8-siding using a home-made spar guage (the previous photos were of a 'Bird's Mouth' spar which comes out octagonal anyway - although you do have to plane off a few spurs)|
If you plane carefully to the 32-sided stage, the long-board (flat and/or concave) with give you a beautifully rounded spar in a very short time. Better still, you could leave it octagonal (with edges rounded a bit) - far less labor, and the mast ends up significantly stronger, as the eight corners of the octagon are at the greatest possible distance from the neutral axis of the mast - very efficient, and it looks ok as well!