Flex-O-Fold Propellers vs Kiwi

[allsail68]

I am planning a trip down the ICW, from Annapolis to St Marys, Georgia this August/September. In preparation, among other things, i am considering installing a folding prop. I currently have a 3 blade prop on Universal M35B diesel engine, displacing about 14,000 lbs[C-350], which performs as designed, with all the +'s and -'s of a fixed prop.

Based on price and performance issues, my first choice is a Flex-O-Fold. Recently i have briefly looked at the Kiwi, which appears to be received well.

Although mechanically challenged, the FOF installation seems a little more straight forward to me than the Kiwi? Also less maintenance, with the Kiwi needing greased once a year.

While there appears to be nearly as many opinions on props as anchors, i am still interested in feedback/advice on this issue.

PS... While i do not post much, i do enjoy reading the diverse and knowledgeable information found on this forum.

Thanks.

Al B-

[fstbttms]

I can not speak to the Kiwi prop (never having seen one), but I know from experience that Flex-O-Fold props are fairly easy to install and appear to be very robust pieces of equipment.

[Jentine]

I highly recommend the Flex-O-Fold. I am on my second one and wouldn't consider any other folding prop. You can't beat it for the price, performance or the ease of installation or lack of need form maintenance.

[swagman]

Hi,

We've a Flex-O-Fold and find is OK driving forward, seems to fold Ok when undersail, but is always a worry when trying to bring her to a standstill under motor! The Max Prop feathering prop is much much more effective when put into reverse - we really have to rev the Flow-O-Fold to stop.

I've heard mixed things about the Kiwi prop from pals who've fitted them.

Initially it was all good. Boat sailed faster, motored faster with same revs, great in reverse also. Cheaper too. I was told all these things by more than one user.

But recently I've been told (no personal experiences) that the feathering blades commonly foul against the boss with even minimal marine growth - making it hard for the blades to feather to the correct angle when either under motor or under sail.

Cheers
JOHN

[Kapena]

Never had a flex-o-fold but I did have Martec 2 blade folding props. I now have Kiwi 3 blade feathering props...same boat. The lack of reverse with the martec folding prop sucked! I have a catamaran, twin engine, and could not reverse into a 15 knot wind...full throttle...both engines. The vibration was also very high, but I did not notice this until I changed the props out.

I now have kiwi props. The greasing is easy and takes a few minutes, just when you haul the boat out. They are very effective in forward and reverse. The feathering means you leave the transmission in neutral rather then in gear. The shaft does not rotate. Price is very reasonable. Underway you can't tell the engines are running. No white foam, no noise, no vibration...it's really incredible! It took a little while to get used to the total lack of noise.
Now the bad news....there is no control over the reverse pitch and the result is the motor is overloaded during reverse...My max rpm in reverse is 1100 (nominal max is 2400). Another factor is the blades are carbon fiber and keeping a HARD anti-fouling on it is required...ablative will wear off almost instantly. I would not buy these props again because of the overload on the engines and the shear amount of crud that grows on the props.

[caryocean]

I was thinking of a Kiwi for my 38 footer with a Perkins 4-108. Of course, these props are billed as a real good solution to the drag pitfalls associated with my current fixed three-blade. Anyone who wants to offer advice to me, I will gladly listen. My principal concern is that I will not motor with the same speed. From what I've read, there is not real agreement in the forum regarding the best props for sailboats. I am wrong, again?

[swagman]

Hi Caryocean,
You are probaly right and unlikely to motor as fast with a feathering or folding prop as you might with your fixed bladed item.
But I'd guarantee you'll sail faster!!!!

If its motoring you do most of the time - don't just stick with the fixed prop - consider moving over to a motor yacht.

If you like sailing - change it. Featherings more effective than folding - but usually more expensive also.

Cheers
JOHN

[Moby Dick]

Originally Posted by Kapena

Another factor is the blades are carbon fiber and keeping a HARD anti-fouling on it is required...ablative will wear off almost instantly. I would not buy these props again because of the overload on the engines and the shear amount of crud that grows on the props.

They are not carbon fiber, they are Zytel (fiberglass composite I believe) and what prop would ablative work on anyway? If you want to antifoul a prop, only hard makes sense.

A different, more interesting, question is if Zytel is more susceptable to fouling than a normal prop?

[Alan Wheeler]

The material a blade is made from does not suggest it will hold anti-foul anybetter than any other material. Hard antifoul is the only thing and the fact you are antifouling at all is really only because you can with a composite. You do not antifoul Bronze or alloy props.
As far as Zytel having growth, yep there ain't nothing that doesn't allow stuff to grow.
I don't know what you mean by overlaod on the engine. Why on earth would you want to sustain 2400 RPM in reverse.

[Moby Dick]

Strangely, I note the Kiwiprop manual says you should anitifoul, and use an ablative product- to 'prevent buildup'. I would have thought that would have lasted about a week of use, max.

I want to believe a shiny bronze prop would be a little bit more resistant to fouling because of its copper content. Sadly, I dont think the sea creatures realise it.

[Alan Wheeler]

Maybe you need to stick a small sign on it Moby.
"All sealife please take note: this prop may contain traces of copper and could be detrimental to your health"

[jbinbi]

Just got my kiwi prop in the mail. was looking at max prop and autoprop. could spend what was going to amout to almost 4x for those. plus in this month's practical sailor, ocean going report on kiwi prop is great. FOF is folding, Kiwi is feathering. Kiwi manual does say ablative, btw.

[Stevek]

I just relaunched my boat with a Kiwi prop. With one short trip under my belt, its a big improvement over the old fixed prop. I have concerns over fouling preventing full operation. I will update after a a bit more time with it.

[Michael D]

My short trial with the Kiwi was very positive with none of the reversing problems mentioned. I don't use folding for the same reason as the others mentioned they are useless in reverse. Great however for racing boats but not for cruising that's the province of feathering props. My top three choices were Kiwi, Max and Vari and at the time ran $1250 through $2400 to $2900 in price respectively. Kiwi won out. Time will tell on the rest of it but I saw no big problem with antifouling having used it on my old outboard prop (get the kind that goes on depth gauge thru hull windows or speedo wheels in a small bottle). But then if it wears off I have twin keels so it's easier to re-apply.

HOWEVER you are going down the ICW and I wonder what your draft is at present. My suggestion after having experienced that trip logs, crab pots and all is to keep your old fixed prop in place since you'll be doing a lot of motoring in some very shallow places. Then once arrived at destination change props.

Caveat....make sure you are getting the right prop and it's set up right. Vari-Prop, Max-Prop, and Kiwi Prop will send you a rather extensive questionaire from engine through transmission and shaft to prop. Then they will recommend a set up. I found all three agreed very closely to each other.

Kiwi if not correct though can be reset rather easily. the others I'm not sure of.

Enjoy the trip, buy plenty of DEETs and stop by the North Summit Marina on the Delaware Canal and say hi! Oh and the marina at Oriental as well. Great places.

Cheers

Michael

[fstbttms]

Originally Posted by Michael D

Kiwi if not correct though can be reset rather easily. the others I'm not sure of.

FYI to all and I'm sure I've mentioned this before, but any feathering prop can be serviced in the water by a knowlegable diver. This includes pitch adjustments.