Oh Boy,
a lot of double talk, off topic rambling, lord knows what amount of
nonsense theory and yet no explanation of why a 2 blade propeller is
useless.

I don't know why a 4 blade fixed is a better propeller for a sail boat
(S) Guess I never will (g) So, rather than be a PITA, I'll retire from
this discussion.

I'll discuss Middle East Politics with my Dog. At lest we'll stay on
TOPIC (G)

Signing Off




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

Thom Stewart wrote:
Oh Boy,
a lot of double talk, off topic rambling, lord knows what amount of
nonsense theory and yet no explanation of why a 2 blade propeller is
useless.

I have two folding props and for ordinary weekend warrior heavy
weather there is no problem. However, in situations where the boat
can surf down large seas and achieve speeds greatly in excess of the
intended prop range, the water pressure will try to close the props.
However, in these cases you ordinarily would not be relying on the
engines. I've had it happen on two occasions, once when crossing Lake
Ontario with the mast down - it was downwind with 8-10 short chop
behind us and we were surfing up to 13+ knots. The other was also a
following sea - 8-10 foot swells on the beam with with 6 foot chop
from the 25+ wind on the stern. I ran the engines to make it easier
to control while reefing (my crew was quite under the weather at this
point) and again found that surfing would make the props act funny.

In cases where we've had to power against large waves, we don't
achieve the speeds that would cause this problem.



I don't know why a 4 blade fixed is a better propeller for a sail boat
(S) Guess I never will (g)

I thought this was a quiz. Why are you asserting that a 4 blade is
"better"? BC was just trolling with his post - he really has no idea.


So, rather than be a PITA, I'll retire from
this discussion.

You give up too easy.


I'll discuss Middle East Politics with my Dog. At lest we'll stay on
TOPIC (G)

Signing Off




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

"George Orwell" wrote in message ...
| Paladin wrote:
|
|
| "Nomen Nescio" wrote in message ...
| | Undeniably so. If I were you I'd feel cheated.
| |
|
|
| If you were me you'd be four times more intelligent, five times more
| handsome, and ten times richer.
|
| Relative to what? A garden slug?
|
| I couldn't give away that many IQ points on a bad day even if I had
| a case of swill you're on, my dog would commit suicide if I came home
| looking half a butt ugly as the best looking member of your banjo
| strumming inbred family, and I've ****ed away more money at the
| matinee stuffing fivers between your wife's floppy titties than you
| make in a year and a half at the truck stop.
|
| Your limp dick caliber of "wit" doesn't impress me at all sonny. You're
| not my equal in a battle of fact OR flame, and we can all see that. So
| just belly crawl back under whatever dung heap you call home base
| before I make it a 10 minute project to **** really hard in your
| Cheerios instead of givin' you little love spanks across the cheeks
| with it.
|

Whoa! Move over George Carlin...

Paladin

--
Posted via a free Usenet account from http://www.teranews.com

Thom, saturated steam is a vapor. Superheated steam is a gas.
Both have the symbol H2O.
Both are uncondensed liquid if you appreciate that most gases turn to liquid
if you cool them enough.
Humidity is not any substance. It is a measure of the amount of water vapor
in the air.
Relative humidity is the ratio betweeen the amount of water vapor in the air
(at a given temperature) and the amount that would give 100% humidity.
(100% humidity is the maximum the air could hold at that temperature without
producing condensation.)

Re your question about the composition of cavitation bubbles I give a
personal opinion that they are mostly air. Water contains dissolved air
(otherwise fishes could not breathe) and when the action of the propeller
blades reduces the pressure some air has to come out of solution and shows
as bubbles. All that talk about boiling is just BS.
IMO
Edgar

"Thom Stewart" wrote in message
...
Paladin, or Gilly?

I see and awful lot of posting about "Boiling water", "Vapors &
vaporization" and I'm yet to see a mention of "Steam".

What is Steam? Is it a Vapor? Is it a Gas? Is it uncondenced liquid?

What is "Humidity?" Is it a Vapor or a Gas?

The Symbol for Water is H2O; Two parts Hydrogen, one part Oxygen, What
is the Symbol for Water Vapor? What is the Symbol for "Relative
Humidity?"

Relating it to Cavitation and "Useless Propeller" , what is the chemical
composition of those bubbles formed in Cavitation?

A bum ASA member is asking the greater MINDS of this discussion?




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

"Edgar" wrote in message . ..
| Thom, saturated steam is a vapor. Superheated steam is a gas.
| Both have the symbol H2O.
| Both are uncondensed liquid if you appreciate that most gases turn to liquid
| if you cool them enough.
| Humidity is not any substance. It is a measure of the amount of water vapor
| in the air.
| Relative humidity is the ratio betweeen the amount of water vapor in the air
| (at a given temperature) and the amount that would give 100% humidity.
| (100% humidity is the maximum the air could hold at that temperature without
| producing condensation.)
|
| Re your question about the composition of cavitation bubbles I give a
| personal opinion that they are mostly air. Water contains dissolved air
| (otherwise fishes could not breathe) and when the action of the propeller
| blades reduces the pressure some air has to come out of solution and shows
| as bubbles. All that talk about boiling is just BS.
| IMO
| Edgar


B.S. is right. Check it out, folks (DSK, in particular) Edgar represents another informed mind.

Paladin

--
Posted via a free Usenet account from http://www.teranews.com

"Jeff" wrote in message
. ..
Thom Stewart wrote:
Oh Boy,
a lot of double talk, off topic rambling, lord knows what amount of
nonsense theory and yet no explanation of why a 2 blade propeller is
useless.

I have two folding props and for ordinary weekend warrior heavy weather
there is no problem. However, in situations where the boat can surf down
large seas and achieve speeds greatly in excess of the intended prop
range, the water pressure will try to close the props. However, in these
cases you ordinarily would not be relying on the engines. I've had it
happen on two occasions, once when crossing Lake Ontario with the mast
down - it was downwind with 8-10 short chop behind us and we were surfing
up to 13+ knots. The other was also a following sea - 8-10 foot swells on
the beam with with 6 foot chop from the 25+ wind on the stern. I ran the
engines to make it easier to control while reefing (my crew was quite
under the weather at this point) and again found that surfing would make
the props act funny.

In cases where we've had to power against large waves, we don't achieve
the speeds that would cause this problem.



I don't know why a 4 blade fixed is a better propeller for a sail boat
(S) Guess I never will (g)

I thought this was a quiz. Why are you asserting that a 4 blade is
"better"? BC was just trolling with his post - he really has no idea.


Don't four blades have a greater Diameter Area Ratio than 2 or 3 blade
props. Doesn't the greater DAR give greater thrust?

"Borked Pseudo Mailed" wrote in message d.net...
| Paladin wrote:
|
|
| "George Orwell" wrote in message ...
| | Paladin wrote:
| |
| |
| | "Nomen Nescio" wrote in message ...
| | | Undeniably so. If I were you I'd feel cheated.
| | |
| |
| |
| | If you were me you'd be four times more intelligent, five times more
| | handsome, and ten times richer.
| |
| | Relative to what? A garden slug?
| |
| | I couldn't give away that many IQ points on a bad day even if I had
| | a case of swill you're on, my dog would commit suicide if I came home
| | looking half a butt ugly as the best looking member of your banjo
| | strumming inbred family, and I've ****ed away more money at the
| | matinee stuffing fivers between your wife's floppy titties than you
| | make in a year and a half at the truck stop.
| |
| | Your limp dick caliber of "wit" doesn't impress me at all sonny. You're
| | not my equal in a battle of fact OR flame, and we can all see that. So
| | just belly crawl back under whatever dung heap you call home base
| | before I make it a 10 minute project to **** really hard in your
| | Cheerios instead of givin' you little love spanks across the cheeks
| | with it.
| |
|
| Whoa! Move over George Carlin...
|
| All your adolescent chest puffing about being superior and this is the
| very best you could come up with?


Don't confuse best with as much time as it's worth...

Paladin

--
Posted via a free Usenet account from http://www.teranews.com

Gilligan wrote:
"Jeff" wrote in message
I don't know why a 4 blade fixed is a better propeller for a sail boat
(S) Guess I never will (g)
I thought this was a quiz. Why are you asserting that a 4 blade is
"better"? BC was just trolling with his post - he really has no idea.


Don't four blades have a greater Diameter Area Ratio than 2 or 3 blade
props. Doesn't the greater DAR give greater thrust?


I think you mean "Disk Area Ratio." It is certainly easier to have a
larger DAR with a 4-blade prop, and that generally implies more thrust
in a low speed application.

But it does not necessarily follow that this is better for any boat
other than a tugboat.

Jeff,

At surfing speeds or for that matter, any high Hull speeds you shouldn't
be using your engine. If you wanted as a back up, you should have had
the engine running at Idle an in "NEUTRAL" That would have kept the
Prop Blades Folded, eliminating Prop resistance. If you were motoring
without sails and surfing, You could adjusted course to prevent surfing.
I can believe the situation you describe and I bet it was a "Kick-In-the
Ass"! The folding Prop was doing just what it was supposed to do
(Eliminate drag) If you were traveling without a Mast you should have
been "Throttle Jockeying" and when you were going fast enough to effect
the prop blades, you should have been cutting back on the throttle. I'm
sure you were doing just that but even if you weren't the Prop would
have taken care of it self. May be causing a PITA engine cycling but
wouldn't be any worst than a fixed Prop cycle with the change of prop
resistance.

You do bring up a good point though, would you consider it anymore
"Useless" than a fixed Prop under these same condition?




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