RW Salnick brought forth on stone tablets:
Frogwatch brought forth on stone tablets:

Anybody have experience with these? I am about to replace my fixed 3
bladed prop on my 8.5M S2. This looks like a potentially good
candidate replacement because they have already figured out which prop
works for a given boat and because they say they can put a larger prop
on with their "Extendo" system.
I am a little worried about the plastic of this prop not being able to
take my aggressive barnacle removal method. Is it easy enough to
remove that re-painting it every so-often works?
My old bronze prop has succumbed to corrosion and many impacts with
oyster beds and with a Laser mast in the water.

Now, one of the advantages of a 2 blade prop is that you can align it
with the keel for lower drag. How does one do this? Do you simply
mark the prop shaft inside the boat and then rotate it till your mark
is in the right place? This really seems like a PITA considering the
gawdawful engine installation on most boats. Even on my boat it
requires removing an engine panel and peering down into a dark space.
Is there any other system? Would the prop left in neutral auto-rotate
to the lowest drag position (I have never had a two blade prop so I
dont know) and stay?
Could I attach a magnet to the shaft so that it engages a magnetic
reed switch (non-contact) to tell me when it is in correct position?
Can you get it in correct position by "bumping" the start switch?


If you want the prop to *stay* lined up with the keel, you'll need a
shaft lock.

When you install the shaft lock, set it up so that the prop is properly
lined up with the lock engaged.

see http://www.shaftlok.com/

bob
s/v Eolian
Seattle

(stupidly replying to my own message)

Well, maybe your transmission doesn't freewheel... (I have a Borg
Warner Velvet Drive, which is kind of like an automatic - regardless of
the shift lever position, the output shaft freewheels when the engine is
not running).

If your transmission holds the shaft, then your suggestions seem like
good answers, if the shaft is inaccessible (doh! It's a SAILboat).

Beware of corrosion and salt spray from the stuffing box in whatever you
set up.

bob
s/v Eolian
Seattle