Rob,
I think you have seen this already:
http://www.onesails.com/wingsails.php
My question is would the round section mast be easier/cheaper to build than the normal D section like you have been doing? Notice the diameter is the same all the way up, could you make this by going over a pvc pipe mandrel or such? I think it would be hard to keep the carbon in line though. Maybe an open mold would be better?
Thanks,
Jerry Barth
We are building round and wing section masts, not D's, although there is no reason why we couldn't. Non tapering is more windage when reefed and probably more weight aloft as the wall thickness at the top is at the minimum for both tapered and non tapered.
Male mandrels are lousy unless you have a very good filament winder (ie machine, not hand) as the fibers do not get laid tightly so get out of line when the bag or wrapping is applied. The off axis layers also get crimped as the diameter is reduced under pressure. Building it in 2 pieces in a female half mould and joining them would be a better job, and in one piece, much better. If the mast is more than say 10m long, then either infusing a dry laminate or pressure moulding a wet or prepreg one would be preferred.
rob
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