2 Blade vs 3 Blade prop
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The knock on three blade props is that they present more "frontal area" to water flow. The same is said of two blade fixed props to a lesser degree.
Being a basically cheap person, I tend to defend fixed propellers by citing the following points:
1. They cost a lot less.
2. They never fail to "open"
3. They have the absolute minimum parts count.
Absolute performance sailing may dictate a folding or feathering prop, but I take special comfort in my fixed blades when it is dark, foggy or raining and I am in close with the shore.
That said, I have a three blade prop on my powerboat and a two blade one on my 30' sailboat. If properly sized, I don't think you would be able to tell the difference, except that a two blade sailing prop probably yields a little less drag.
Being a basically cheap person, I tend to defend fixed propellers by citing the following points:
1. They cost a lot less.
2. They never fail to "open"
3. They have the absolute minimum parts count.
Absolute performance sailing may dictate a folding or feathering prop, but I take special comfort in my fixed blades when it is dark, foggy or raining and I am in close with the shore.
That said, I have a three blade prop on my powerboat and a two blade one on my 30' sailboat. If properly sized, I don't think you would be able to tell the difference, except that a two blade sailing prop probably yields a little less drag.
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Although some water drag exists when purely sailing with my 22" three-blade prop, when the wind dies and there are places to go, I sure appreciate the thrust it provides when coupled with my turbo 90hp iron genny. Another benefit is increased maneuverabilty in reverse - a godsend when backing down in tight quarters.
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19,484 Posts
Two blades offer less drag, three makes for smoother operation and more thrust.
I've posted this before, but if you're interested in low drag fixed props, check out:
http://www.westbynorth.com/CampbellSailer/
We used a 3 blade version, worked well with much less drag than the conventional "michigan wheel". It replaced a worn out folder.
I've posted this before, but if you're interested in low drag fixed props, check out:
http://www.westbynorth.com/CampbellSailer/
We used a 3 blade version, worked well with much less drag than the conventional "michigan wheel". It replaced a worn out folder.
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Seen the westbynorth site and the campbell sailer props, though wasn't much in the way of prices to go by. Current prop is a 12" 3 blade fixed, and I've had some say just get it refurbished over buying new. Haven't seen much in the way of prices though, except for folding props (way out of my price range, not to mention overkill for my sailing). So any info in the ballpark on prices would be a big help.
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433 Posts
If you have the means to get it refurbished and it has served you well so far then that would be the logical and most affordable option. I took a 4 blade prop from a powerboat engine to be repitched and it only cost me $45.00 and I saw props there waiting to be refurbished that looked way beyond repair but the guy said they were all doable and cheaper than replacement cost.
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4,858 Posts
I had a new blade welded onto one broken off the prop from my old boat, plus the other two blades straightened. A specialty shop in RI did the work 6 years ago and charged me 130.00, far less than replacement value. They ground the welds smooth, computer balanced and polished the entire prop. Looked and performed like brand new when completed.
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90 Posts
Hi,
I have a two bladed folding prop on my O32. It's coming off this winter and going to be replaced by a 3 bladed campbell. The problem with our O32s and folding props is that because we are offset to the side and close to the hull the hydrodynamic forces on the prop cause the blades on a folding prop to move, causing lots of vibration. This is true even of the the geared flex-o-fold prop that I have. It's a great prop, it just doesn't work on my boat. I have toyed with a feathering prop, but as I have already dumped $2K into a folding prop that didn't meet my needs, dropping $4K on something that I can't vouch for doesn't seem like a good idea. I believe the campbell for our size is about $500.
Cheers,
Todd
I have a two bladed folding prop on my O32. It's coming off this winter and going to be replaced by a 3 bladed campbell. The problem with our O32s and folding props is that because we are offset to the side and close to the hull the hydrodynamic forces on the prop cause the blades on a folding prop to move, causing lots of vibration. This is true even of the the geared flex-o-fold prop that I have. It's a great prop, it just doesn't work on my boat. I have toyed with a feathering prop, but as I have already dumped $2K into a folding prop that didn't meet my needs, dropping $4K on something that I can't vouch for doesn't seem like a good idea. I believe the campbell for our size is about $500.
Cheers,
Todd
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993 Posts
Hey PB,
Folks often dissagree with this, but: Buy a three bladed (in my opinion) for reason stated above. Some cruisers go with a folding, but most of the ones I know do not. The barnacles in the warmer waters are killers (especially Florida) Who wants something else to have to worry about?
Besides, PB, with the 454 Chevy block you got in that boat of yours, you will want maximum thrust to outrun those barges!!
Folks often dissagree with this, but: Buy a three bladed (in my opinion) for reason stated above. Some cruisers go with a folding, but most of the ones I know do not. The barnacles in the warmer waters are killers (especially Florida) Who wants something else to have to worry about?
Besides, PB, with the 454 Chevy block you got in that boat of yours, you will want maximum thrust to outrun those barges!!
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454 !!!! Yikes, there's people with bigger outboards on 26 footers than my little 13 horse 2cylinder Yanmar. 3 blade does seem the way to go though. Now it's just a question of (I like what I read about the Campbell's) go new, or refurbish. Probably, just refurbish though. Just makes sense cost wise. Appreciate all the input though, it's been helpful, as my experience with props is limited to outboards.
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2,394 Posts
alrighty...
I'm one cheap SOB, and one one of the tubs, a 30 year old catalina 27 with an A-4....
it had a 2 blade folding prop. 12x7
during one of our fantastic voyages, it ended up in the bottom of the lake.
remember I'm one cheap SOB.
after wandering around ebay for a week or 2, I found a 12x8 fixed 3 blade off of a 1959 Chris-craft inboard, paid 35.00 for it.
I beached the whale, heaved her over using the jib halyard to a concrete pier that was out of the water, changed the prop in an hour and a half, floated the boat.
I now get the same top speed under the iron jenny, 5.5kts, but I do have about 100-150 less RPM. I'm not worried about it.
Drag? I don't care about no drag ferchris-sakes its a 30 year old catalina!
I'm one cheap SOB, and one one of the tubs, a 30 year old catalina 27 with an A-4....
it had a 2 blade folding prop. 12x7
during one of our fantastic voyages, it ended up in the bottom of the lake.
remember I'm one cheap SOB.
after wandering around ebay for a week or 2, I found a 12x8 fixed 3 blade off of a 1959 Chris-craft inboard, paid 35.00 for it.
I beached the whale, heaved her over using the jib halyard to a concrete pier that was out of the water, changed the prop in an hour and a half, floated the boat.
I now get the same top speed under the iron jenny, 5.5kts, but I do have about 100-150 less RPM. I'm not worried about it.
Drag? I don't care about no drag ferchris-sakes its a 30 year old catalina!
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993 Posts
PB,
I will give you one big positive of going new: You will have a spare. If you bought a new one and threw the old one down below (even if not in perfect condition), you would have a spare incase you chewed your new one up on a reef. I cannot guess how much it would cost to get a new prop in the Bahamas, or even worse, down islands??
Tom Neale is a big advocate of carrying a back-up. As for me, er, hmm, well, I never run aground, will never run aground, have never run agroung. I have a wing keel and wings are completely safe from hitting the bottom, right??!!
I will give you one big positive of going new: You will have a spare. If you bought a new one and threw the old one down below (even if not in perfect condition), you would have a spare incase you chewed your new one up on a reef. I cannot guess how much it would cost to get a new prop in the Bahamas, or even worse, down islands??
Tom Neale is a big advocate of carrying a back-up. As for me, er, hmm, well, I never run aground, will never run aground, have never run agroung. I have a wing keel and wings are completely safe from hitting the bottom, right??!!
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Of course they are CD.....just ask SailorMitch. I think he's going to use a wing keel for his tombstone, as a matter of fact!
I'd already thought about having the present one for a spare, but I've put so much in the boat already, I'm getting close to the point of having to w*&% to build up the kitty a bit. That's down right scary. May just go with what I have till I have a little extra bread, then buy a new one and swap 'em out next haulout.
I'd already thought about having the present one for a spare, but I've put so much in the boat already, I'm getting close to the point of having to w*&% to build up the kitty a bit. That's down right scary. May just go with what I have till I have a little extra bread, then buy a new one and swap 'em out next haulout.
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PB...
I think he's going to use a wing keel for his tombstone
What a cool idea...then the kids won't be able to tip over his gravestone! <grin>
I think he's going to use a wing keel for his tombstone
What a cool idea...then the kids won't be able to tip over his gravestone! <grin>
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993 Posts
Better yet, the next time a Sea Ray blows you off the road, might I suggest finding where he slips his boat, a little scuba gear, and a late night swim with a wrench. It might not be the perfect size, but with a little shimming it will work. Plus you will save more money for the cruising kitty and make the waterways a safer place to boat.
I know this might sound extreme to some, but please understand one thing: Sea Rays have two screws and most of their captains would never know it anyway. Plus the entertainment of anchoring on your boat and listening to them scream, "WHY DOES THIS BOAT ONLY GO IN CIRCLES!!??? KNEW I SHOULD HAVE BOUGHT A SAILBOAT!!"
Ahhh (wiping tear from eye), I just love Sea Rays. (SMILE!!)
- CD
I know this might sound extreme to some, but please understand one thing: Sea Rays have two screws and most of their captains would never know it anyway. Plus the entertainment of anchoring on your boat and listening to them scream, "WHY DOES THIS BOAT ONLY GO IN CIRCLES!!??? KNEW I SHOULD HAVE BOUGHT A SAILBOAT!!"
Ahhh (wiping tear from eye), I just love Sea Rays. (SMILE!!)
- CD
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CAM - You are sooo funny. Better than a fin where he really will be stuck in the dirt. No wait, aren't all tombstones basically the design of a fin??
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192 Posts
3 blade vs 2 blade
This past June I replaced the 2 blade prop on our Pacific Seacraft 37 with a 3 blade Campbell sailor prop.Because my prop is in an aperture behind the skeg the 2 blade had a "null" which caused it to loose bite at higher rpm.This caused a wicked vibration in the tiller at full throttle.The 3 blade eliminates the null and thus the vibration.I felt that the Campbell prop was overpriced but I liked the concept so I bit the bullet.One word of caution from an experience engine guy was to double check the pitch as he's seen several Campbells incorrectly pitched.
The 3 blade does bite better which is very noticeable powering into a headsea.
Niftynickers
This past June I replaced the 2 blade prop on our Pacific Seacraft 37 with a 3 blade Campbell sailor prop.Because my prop is in an aperture behind the skeg the 2 blade had a "null" which caused it to loose bite at higher rpm.This caused a wicked vibration in the tiller at full throttle.The 3 blade eliminates the null and thus the vibration.I felt that the Campbell prop was overpriced but I liked the concept so I bit the bullet.One word of caution from an experience engine guy was to double check the pitch as he's seen several Campbells incorrectly pitched.
The 3 blade does bite better which is very noticeable powering into a headsea.
Niftynickers
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Niftynickers, I'm thinking of getting Campbell Sailor -blade for my Hunter 326 (2GM20F) for the same reason you mention, better trust and smoother running. You mentioned seeing several incorrectly piched Campbell prop. Would that be wrong calculation made by WestbyNorth or manufacturing error ?niftynickers said:
WbyN quoted me 14"x9" pitch 3-blade to replace my stock 15"x10" 2-blade.
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