prop cover issues
We covered the prop mostly to keep bird 'stuff 'off them! Of course, we kept the blades horizontal to avoid moisture imbalance, but then our winged friends had a nice perch!
We used the same material as the canopy cover, fuzzy on the inside, waterproof outside, snapped fairly snug over each blade, and tied together so they couldn't slip off.
The bad:
if not taken off frequently, the inside got mouldy.
any movement of the cover caused chafing, wearing thru the varnish on the tips, and moisture gets at the wood anyway!
We ended up leaving it off, and just waxed and re-varnished more frequently.