It's close to another that I'd considered......
Wrap the blades with something like cling film, and then fill the hollow thus created with expanding polyurathane foam (the stuff that comes in a can). When it's set, take off the clingfilm and sand the foam to how you want it. Finally, cover the foam with sheets of glass fibre tissue and resin, lapping over the original PVC to make a foam filled, double sided plastic blade.
. "Slowly changing the world, one watt at a time!"[ Parent ]
Covering the cups(?) could lose the low wind and high torque properties I like in PVC blades. Not sure I would put that much effort into it until the hollow type worked out well. G-[ Parent ]
