Today I cut the ends of one blank flush and trimmed the corners to get a nice octagonal shape. I used a drum sander to trim the corners - not the quickest way to do it but with my planes in the other shop and cabin fever setting in, I used what I had available. I'll take the second blank to my brother-in-law's shop for turning on a lathe.
I used pieces of a round dowel for plugs, which worked for this experiment but I think I'd want to cut octagonal plugs for the real spars.
Some thoughts and observations from this experiment:
- Use a squeeze bag or caulking gun tubed epoxy to facilitate spreading the thickened epoxy.
- Use enough epoxy for some (but not a lot) squeeze-out to ensure good glue joins. Use enough epoxy around the plugs to ensure filling of the spaces between the plugs and the wall of the spars.
- Assemble the spar in two halves - glue up two sets of four staves and clamp together but do not glue the two halves together. This makes coating the inside surfaces of the spar with epoxy simpler and less messy (if that is possible with epoxy). It also reduces, by two, the sets of mating surfaces to be coated with neat and thickened epoxy.
- Use wax paper or parchment paper underneath the hose clamps.
- Have enough hose clamps on hand.
- Try not to coat the handle of the screwdriver with epoxy (transferred from squeeze-out to glove to screwdriver)…
One other factor to take into account is John Welsford's note on the sail-plan drawing: "taper outside not the inside space." I am not visualizing a straight-forward way to taper and notch the staves prior to assembly. Any suggestions on how to do this?