Which prop

PabloPicasso

PabloPicasso

Well-Known Member
Joined
12 Feb 2010
Messages
2,901
Visit site
If I were to replace the 2 bladed folding prop on the 110 sail drive which type should I Get. Current one has a hub with three woefully inadequate anodes. I want a folding prop with proper big anodes.
 
PabloPicasso said:
If I were to replace the 2 bladed folding prop on the 110 sail drive which type should I Get. Current one has a hub with three woefully inadequate anodes. I want a folding prop with proper big anodes.
Click to expand...
Not all props need big anodes. My Flexofold does not have any at all also on a saildrive. However the latest ones do have anodes because customers demand them, not because they necessarily need them. As I have said several times the prop you have is well known for galvanic corrosion problems that do not necessarily affect other makes of prop and it is not the size of the anodes but the material used in its construction. Speak to Darglow Engineering for a quote on a Flexofold.
 
PabloPicasso said:
If I were to replace the 2 bladed folding prop on the 110 sail drive which type should I Get. Current one has a hub with three woefully inadequate anodes. I want a folding prop with proper big anodes.
Click to expand...

An alternative is to go for a Kiwi featherer. Cheaper than most, and made out of SS and plastic so no anodes required.
 
Kiwi props autorotate..
If you try and stop them thay slow you down as of you have a fixed prop..
they also give very poor speed.... so what you save on the purchase price will be spent on fuel...:rolleyes:
 
Last edited:
Tomahawk said:
Kiwi props autorotate..
If you try and stop them thay slow youvdown as of yoy have a fixed jo..
they also give very poor speed.... so what you save on tbe purchase price will be spent on fuel...:rolleyes:
Click to expand...

I disagree with this, and would be interested to know on what it is based. With the engine stopped, each Kiwi blade trails behind its pivot point so it is free to adopt the position of minimum drag and, since the blade section is symmetrical, in this position it cannot generate lift in either direction so there is no torque available to make it "autorotate".

The forwards pitch is adjustable so the prop can be matched quite closely to the engine torque curve: arranging it so that WOT gives engine revs for max torque rather than max speed gives better fuel consumption and quieter running. The symmetrical blade shape is less efficient than a conventional propeller, but the difference in fuel efficiency in practice is only a few percent - I have detailed records covering several years with conventional and Kiwi props - same boat - but they're on board and I'm not! More significantly, the reduced drag when sailing means that I can sail in lighter winds than with a conventional prop so more sailing and less motoring is done. I strongly suspect, but can't prove, that the diesel saved thus well outweighs the slight increase in usage when motoring.

To answer PabloPicasso: The Kiwi price has been £850 + VAT for as long as I can remember.
 
Last edited:
Agree with Dave S on Kiwi.

Haven't had a fixed prop on a boat for over 25 years now and will never have one intentially. Current boat had Maxprop but this suffered from stray voltage, maybe mine, maybe the marina, so replaced with a Kiwi for peace of mind. Was intended as a temporary solution to the electrolysis issue but has performed so well - the equal of the max prop when racing and much better when motoring - that it's staying as a fixture.

Nudge
 
Tomahawk said:
Kiwi props autorotate..
If you try and stop them thay slow youvdown as of yoy have a fixed jo..
they also give very poor speed.... so what you save on tbe purchase price will be spent on fuel...:rolleyes:
Click to expand...

Sorry, have to disagree. My Kiwi (since 2006) does not rotate, and pivots each blade to match flow over the blade.

It is slightly slower, do a search for my original findings vs a 2 blade fixed. Around 0.3 knots at 2400rpm. Since then, I have added a ton to the boat, and it still does the job, at 22 degrees pitch, just touches 3650rpm flat out.

However, I get over 0.5kts better speed while sailing.......

Also, I have whacked several things with my prop. It took a chunk out of one corner (zytel nylon blades), and I just faired it off for a season.
Blades take 30 seconds to disassemble from the hub.
Blades are around 50 quid each. I carry a spare, and the retaining pin.
The yearly cost is a cupful of Mobil blue grease, around 2 quid.

The body is now made of stainless, mine is an earlier Nylon66 which has not failed.

At around a grand, still very much cheaper than most 3 bladers.
 
PabloPicasso said:
So 850 +vat that's over £1000. Wow
Click to expand...

The cheapest folding props are around £600 depending on size for a saildrive. Better ones are similar price to the Kiwprop. A new standard aluminium fixed prop is around £300 with a new cone and locking bolt.
 
I have film of them going round and round and round which I managed to film as we were sailing up the French coast.
Only just managed to get it as I didn't have a waterproof camera before.. also the Essex water is so muddy you can't see anything...

IThe film is not very goos as it is very difficult to hold a camera against 8kts of water flow..
 
Last edited:
i had a sort of similar problem...
Engine died for lack of fuel after running in rough seas...
However after a while.... it would condescent to start,,, then stopped again!!

When I separated the fuel lines I heard a rush of air back to the tank.. I opened the fule tank and found globules of black mastic used for sealing the inspection hatch in the bottom of the tqnk... Note not fuel bug... but half a cup lfull of pea sized lumps..

They took a lotmof chasing about to clear all them..,and I had to do it in two goes?..
 
Tomahawk said:
I have film of them going round and round and round which I managed to film as we were sailing up the French coast.
Only just managed to get it as I didn't have a waterproof camera before.. also the Essex water is so muddy you can't see anything...

IThe film is not very goos as it is very difficult to hold a camera against 8kts of water flow..
Click to expand...


Then I am sorry to say you have failed to keep the blades cleaned and lubricated so they are not flapping around, but semi stiff and presenting a blade angle to water. When they are in air, they should just flop under gravity alone.
 
Wen I launched in October both props were good and floppy..
I dived under a couple of weeks ago and cleaned them and checked for fishing line Etc...

Again both looked in good condition... and were nicely floppy...
 
Tranona said:
Speak to Darglow Engineering for a quote on a Flexofold.
Click to expand...

+1 We purchased a 2 blade folding Flexofold from Darglow last autumn. It's been an excellent decision. Expensive...yes, but well worth it in our opinion. It's more powerful motoring than our old fixed 2 blade egg whisk, it goes better astern and has less prop walk! The sailing benefits you will already know about as you are replacing a folding prop. It's been excellent in every department.

Interestingly, I asked both Darglow in the UK and Flexofold in Denmark to quote me for the prop, although Flexofold in Denmark came in about £40 cheaper than Darglow (inc postage), they were going to send me a prop with a 1:10 taper that they said would fit my shaft according to their records for our Westerly. In the end we ordered from Darglow as they match the flexofold to your old prop and locking nut which was worth doing because Flexofold in Denmark would have sent a prop which did not fit the shaft (our shaft was actually a 1:20)!

Great service from Darglow as well.

PS: I inspected the prop when we dried out a couple of weeks ago. No anodes and no corrosion, all working well.
 
You must log in or register to reply here.

Share this page

Top