After some use I've decided those two bladed folding props are useless in
any rough weather. I'm getting rid of mine and putting on a four bladed prop
with a gear reduction.

Bob Crantz

Some Thing Is missing in your sailing.;---? Why in the hell are you
worrying about a Prop in Bad Weather? You have more than enough Sail
Power and if reefed properly, a hell of a lot smoother ride.

My 2 Blade, Folder would stay open at 200 RPM but cavitation did worry
me. I don't think a 4 Blade fixed is going to help cavitation.




http://community.webtv.net/tassail/ThomPage

The gear reduction reduces the propeller RPM and reduces cavitation.

A nice big 4 blade does the job.

One should worry the most about propellers in bad weather.

BC,

Cavitation is caused be the Prop not having enough water in Choppy Sea.
Reduction Gearing has nothing to do with it.

You're a Pretty Poor sailer if you are depending on a small Aux, Engine
to replace Sails in a Seaway. Even Trawlers hoist a steadying Sail in a
Seaway to improve ride quality




http://community.webtv.net/tassail/ThomPage

Thom Stewart wrote:
BC,

Cavitation is caused be the Prop not having enough water in Choppy Sea.

Cavitation is caused by the prop spinning too fast for the forward
motion of the vessel.

Reduction Gearing has nothing to do with it.

Reduction gearing has EVERYTHING to do with it.

PDW

"Peter" wrote in message
oups.com...


Cavitation is caused by the prop spinning too fast for the forward
motion of the vessel.

Cavitation is caused by water not being able to move fast enough to fill low
pressure spaces created around such things as a propeller. A spinning disc
has no forward speed regardless of RPM yet there is no cavitation. A
propeller is a rotating wing and the low pressure side causes the water to
"boil", hencce the creation of cavitation. Higher RPM gives higher
tangentail blade speeds and greater pressure differential between the faces
of the prop.

Oh Bull **** Pete

You posted; "Reduction gearing has EVERYTHING to do with it."

It seems you've elected to ignore, Prop Pitch, Prop Size, and the Medium
it is operating in. You have also neglected to recognize throttle
control




http://community.webtv.net/tassail/ThomPage