Originally Posted by andantesail
John, okay so you got the plastic sleeves from PYI which is where mine came from. Sorry they don't fit your zincs. These have made a huge difference in the way the zincs wear. Previously they wore out at the screws, dumping most of the zinc into the silt below the rudder. Now the zinc actually wears out.
To achieve the same effect I've been doing a little trick that I picked up in one of the sail mags about 10 years ago. The idea is to paint - NOT Bottom Paint - or use fingernail polish around the screw area to slow down the erosion at the zincs weakest points. It helps for cone or shaft zincs.
As for the original theme of this thread I put on an AutoProp on my previous C320 and it was going strong for the 4 yerars until I traded it in for my current boat which came used with an AutoProp. I believe I'm into year 8 with my current AutoProp with no problems. AutoProp seeems to have priced their way out of the mainstream but for me, especially now with a motor sailor, it does exactly what it claims. Although..... I wouldn't even want to think what the replacement cost might be now on my much larger prop